diff --git a/src/actions.c b/src/actions.c
index b1886786..296d51da 100644
--- a/src/actions.c
+++ b/src/actions.c
@@ -33,7 +33,7 @@ void here(void)
 void set_modify(int mod)
 {
   static int prev = -1;
-  modified = mod;
+  xctx->modified = mod;
   dbg(1, "set_modify(): %d\n", mod);
   if(mod != prev) {
     prev = mod;
@@ -208,39 +208,39 @@ void resetwin(int create_pixmap, int clear_pixmap, int preview_window)
     }
     /* if(wattr.map_state==IsUnmapped) return; */
 
-    xschem_w=wattr.width;
-    xschem_h=wattr.height;
-    areax2 = xschem_w+2*INT_WIDTH(xctx->lw);
-    areay2 = xschem_h+2*INT_WIDTH(xctx->lw);
-    areax1 = -2*INT_WIDTH(xctx->lw);
-    areay1 = -2*INT_WIDTH(xctx->lw);
-    areaw = areax2-areax1;
-    areah = areay2-areay1;
+    xctx->xschem_w=wattr.width;
+    xctx->xschem_h=wattr.height;
+    xctx->areax2 = xctx->xschem_w+2*INT_WIDTH(xctx->lw);
+    xctx->areay2 = xctx->xschem_h+2*INT_WIDTH(xctx->lw);
+    xctx->areax1 = -2*INT_WIDTH(xctx->lw);
+    xctx->areay1 = -2*INT_WIDTH(xctx->lw);
+    xctx->areaw = xctx->areax2-xctx->areax1;
+    xctx->areah = xctx->areay2-xctx->areay1;
 
     /* if no preview_window or create_pixmap==1  avoid unnecessary work if no resize */
     /* !create_pixmap ensures the XSetTile is executed when done with the preview */
-    if( preview_window || !create_pixmap || xschem_w !=xrect[0].width || xschem_h !=xrect[0].height) {
-      dbg(1, "resetwin(): x=%d y=%d   xschem_w=%d xschem_h=%d\n",
-                       wattr.x, wattr.y, xschem_w,xschem_h);
+    if( preview_window || !create_pixmap || xctx->xschem_w !=xrect[0].width || xctx->xschem_h !=xrect[0].height) {
+      dbg(1, "resetwin(): x=%d y=%d   xctx->xschem_w=%d xctx->xschem_h=%d\n",
+                       wattr.x, wattr.y, xctx->xschem_w,xctx->xschem_h);
       dbg(1, "resetwin(): changing size\n\n");
       xrect[0].x = 0;
       xrect[0].y = 0;
-      xrect[0].width = xschem_w;
-      xrect[0].height = xschem_h;
+      xrect[0].width = xctx->xschem_w;
+      xrect[0].height = xctx->xschem_h;
 
       if(clear_pixmap) XFreePixmap(display,save_pixmap);
 
       /*
       {
         unsigned int w, h;
-        XQueryBestSize(display, TileShape, window,  xschem_w, xschem_h, &w, &h);
+        XQueryBestSize(display, TileShape, window,  xctx->xschem_w, xctx->xschem_h, &w, &h);
         dbg(1, "XQueryBestSize: req: w=%d, h=%d, opt: w=%d h=%d\n",
-                         xschem_w, xschem_h, w, h);
+                         xctx->xschem_w, xctx->xschem_h, w, h);
       }
       */
 
       if(create_pixmap) {
-        save_pixmap = XCreatePixmap(display, window, xschem_w, xschem_h, depth);
+        save_pixmap = XCreatePixmap(display, window, xctx->xschem_w, xctx->xschem_h, depth);
       }
       XSetTile(display,gctiled, save_pixmap);
 #else
@@ -257,27 +257,28 @@ void resetwin(int create_pixmap, int clear_pixmap, int preview_window)
     {
       unsigned int width = rct.right - rct.left;
       unsigned int height = rct.bottom - rct.top;
-      xschem_w = width;
-      xschem_h = height;
-      areax2 = xschem_w + 2 * INT_WIDTH(xctx->lw);
-      areay2 = xschem_h + 2 * INT_WIDTH(xctx->lw);
-      areax1 = -2 * INT_WIDTH(xctx->lw);
-      areay1 = -2 * INT_WIDTH(xctx->lw);
-      areaw = areax2 - areax1;
-      areah = areay2 - areay1;
+      xctx->xschem_w = width;
+      xctx->xschem_h = height;
+      xctx->areax2 = xctx->xschem_w + 2 * INT_WIDTH(xctx->lw);
+      xctx->areay2 = xctx->xschem_h + 2 * INT_WIDTH(xctx->lw);
+      xctx->areax1 = -2 * INT_WIDTH(xctx->lw);
+      xctx->areay1 = -2 * INT_WIDTH(xctx->lw);
+      xctx->areaw = xctx->areax2 - xctx->areax1;
+      xctx->areah = xctx->areay2 - xctx->areay1;
       /* if no preview_window or create_pixmap==1  avoid unnecessary work if no resize */
       /* !create_pixmap ensures the XSetTile is executed when done with the preview */
-      if( preview_window || !create_pixmap || xschem_w !=xrect[0].width || xschem_h !=xrect[0].height) {
-        dbg(1, "resetwin(): x=%d y=%d   xschem_w=%d xschem_h=%d\n",
-          rct.right, rct.bottom, xschem_w, xschem_h);
+      if( preview_window || !create_pixmap || xctx->xschem_w !=xrect[0].width ||
+          xctx->xschem_h !=xrect[0].height) {
+        dbg(1, "resetwin(): x=%d y=%d   xctx->xschem_w=%d xctx->xschem_h=%d\n",
+          rct.right, rct.bottom, xctx->xschem_w, xctx->xschem_h);
         dbg(1, "resetwin(): changing size\n\n");
         xrect[0].x = 0;
         xrect[0].y = 0;
-        xrect[0].width = xschem_w;
-        xrect[0].height = xschem_h;
+        xrect[0].width = xctx->xschem_w;
+        xrect[0].height = xctx->xschem_h;
         if(clear_pixmap) Tk_FreePixmap(display, save_pixmap);
         if(create_pixmap) {
-          save_pixmap = Tk_GetPixmap(display, window, xschem_w, xschem_h, depth);
+          save_pixmap = Tk_GetPixmap(display, window, xctx->xschem_w, xctx->xschem_h, depth);
         }
         XSetTile(display, gctiled, save_pixmap);
       }
@@ -289,13 +290,13 @@ void resetwin(int create_pixmap, int clear_pixmap, int preview_window)
       #if HAS_XRENDER==1
       #if HAS_XCB==1
       save_sfc = cairo_xcb_surface_create_with_xrender_format(xcbconn, screen_xcb, save_pixmap,
-           &format_rgb, xschem_w, xschem_h);
+           &format_rgb, xctx->xschem_w, xctx->xschem_h);
       #else
       save_sfc = cairo_xlib_surface_create_with_xrender_format(display, save_pixmap,
-           DefaultScreenOfDisplay(display), format, xschem_w, xschem_h);
+           DefaultScreenOfDisplay(display), format, xctx->xschem_w, xctx->xschem_h);
       #endif /* HAS_XCB */
       #else
-      save_sfc = cairo_xlib_surface_create(display, save_pixmap, visual, xschem_w, xschem_h);
+      save_sfc = cairo_xlib_surface_create(display, save_pixmap, visual, xctx->xschem_w, xctx->xschem_h);
       #endif /* HAS_XRENDER */
       if(cairo_surface_status(save_sfc)!=CAIRO_STATUS_SUCCESS) {
         fprintf(errfp, "ERROR: invalid cairo xcb surface\n");
@@ -309,9 +310,9 @@ void resetwin(int create_pixmap, int clear_pixmap, int preview_window)
       cairo_set_font_size (cairo_save_ctx, 20);
       /* 20171125 select xlib or xcb :-) */
       #if HAS_XCB==1 && HAS_XRENDER==1
-      cairo_xcb_surface_set_size(sfc, xschem_w, xschem_h);
+      cairo_xcb_surface_set_size(sfc, xctx->xschem_w, xctx->xschem_h);
       #else
-      cairo_xlib_surface_set_size(sfc, xschem_w, xschem_h);
+      cairo_xlib_surface_set_size(sfc, xctx->xschem_w, xctx->xschem_h);
       #endif /* HAS_XCB */
       #endif /* HAS_CAIRO */
 
@@ -405,7 +406,8 @@ void new_window(const char *cell, int symbol)
          exit(0); /* --> child of child will be reparented to init */
        } else if (!pid2) {
          /* child of child */
-         if(!(freopen("/dev/null","w",stdout) && freopen("/dev/null","r",stdin)&& freopen("/dev/null","w",stderr))){
+         if(!(freopen("/dev/null","w",stdout) && freopen("/dev/null","r",stdin) &&
+           freopen("/dev/null","w",stderr))){
            fprintf(errfp, "new_window(): freopen error\n");
            tcleval("exit");
          }
@@ -413,8 +415,6 @@ void new_window(const char *cell, int symbol)
            execl(xschem_executable,xschem_executable,"-r", NULL);
          }
          else if(!symbol) {
-
-
            my_strncpy(f, cell, S(f));
            execl(xschem_executable,xschem_executable,"-r",f, NULL);
          }
@@ -477,7 +477,7 @@ int save(int confirm) /* 20171006 add confirm */
 
      save_ok=0;
      cancel=0;
-     if(modified)
+     if(xctx->modified)
      {
        if(confirm) {
          tcleval("ask_save");
@@ -531,7 +531,7 @@ void ask_new_file(void)
 
     if(!has_x) return;
 
-    if(modified) {
+    if(xctx->modified) {
       if(save(1)) return; /*  user cancels save, so do nothing. */
     }
     tcleval("load_file_dialog {Load Schematic} .sch.sym INITIALLOADDIR");
@@ -759,13 +759,13 @@ void attach_labels_to_inst() /*  offloaded from callback.c 20171005 */
   /* printf("indirect=%d\n", indirect); */
 
   rebuild_selected_array();
-  k = lastselected;
+  k = xctx->lastsel;
   first_call=1; /*  20171214 for place_symbol--> new_prop_string */
   prepare_netlist_structs(0);
-  for(j=0;j<k;j++) if(selectedgroup[j].type==ELEMENT) {
+  for(j=0;j<k;j++) if(xctx->sel_array[j].type==ELEMENT) {
 
     found=1;
-    my_strdup(5, &prop, xctx->inst[selectedgroup[j].n].instname);
+    my_strdup(5, &prop, xctx->inst[xctx->sel_array[j].n].instname);
     my_strcat(6, &prop, "_");
     tclsetvar("custom_label_prefix",prop);
 
@@ -783,7 +783,7 @@ void attach_labels_to_inst() /*  offloaded from callback.c 20171005 */
     rot_txt = tclgetvar("rotated_text");
     if(strcmp(rot_txt,"")) rotated_text=atoi(rot_txt);
 
-    my_strdup(7, &type,(xctx->inst[selectedgroup[j].n].ptr+ xctx->sym)->type);
+    my_strdup(7, &type,(xctx->inst[xctx->sel_array[j].n].ptr+ xctx->sym)->type);
     if( type && IS_LABEL_OR_PIN(type) ) {
       continue;
     }
@@ -791,16 +791,16 @@ void attach_labels_to_inst() /*  offloaded from callback.c 20171005 */
     if(!do_all_inst && !strcmp(tclgetvar("do_all_inst"),"1")) do_all_inst=1;
 
     dbg(1, "attach_labels_to_inst(): 1--> %s %.16g %.16g   %s\n",
-        xctx->inst[selectedgroup[j].n].name,
-        xctx->inst[selectedgroup[j].n].x0,
-        xctx->inst[selectedgroup[j].n].y0,
-        xctx->sym[xctx->inst[selectedgroup[j].n].ptr].name);
+        xctx->inst[xctx->sel_array[j].n].name,
+        xctx->inst[xctx->sel_array[j].n].x0,
+        xctx->inst[xctx->sel_array[j].n].y0,
+        xctx->sym[xctx->inst[xctx->sel_array[j].n].ptr].name);
 
-    x0 = xctx->inst[selectedgroup[j].n].x0;
-    y0 = xctx->inst[selectedgroup[j].n].y0;
-    rot = xctx->inst[selectedgroup[j].n].rot;
-    flip = xctx->inst[selectedgroup[j].n].flip;
-    symbol = xctx->sym + xctx->inst[selectedgroup[j].n].ptr;
+    x0 = xctx->inst[xctx->sel_array[j].n].x0;
+    y0 = xctx->inst[xctx->sel_array[j].n].y0;
+    rot = xctx->inst[xctx->sel_array[j].n].rot;
+    flip = xctx->inst[xctx->sel_array[j].n].flip;
+    symbol = xctx->sym + xctx->inst[xctx->sel_array[j].n].ptr;
     npin = symbol->rects[PINLAYER];
     rct=symbol->rect[PINLAYER];
 
@@ -829,7 +829,7 @@ void attach_labels_to_inst() /*  offloaded from callback.c 20171005 */
        skip=0;
        while(iptr) {
          ii = iptr->n;
-         if(ii == selectedgroup[j].n) {
+         if(ii == xctx->sel_array[j].n) {
            iptr = iptr->next;
            continue;
          }
@@ -895,9 +895,9 @@ void delete_files(void)
 {
   char str[PATH_MAX + 100];
   rebuild_selected_array();
-  if(lastselected && selectedgroup[0].type==ELEMENT) {
+  if(xctx->lastsel && xctx->sel_array[0].type==ELEMENT) {
     my_snprintf(str, S(str), "delete_files {%s}",
-         abs_sym_path(xctx->inst[selectedgroup[0].n].name, ""));
+         abs_sym_path(xctx->inst[xctx->sel_array[0].n].name, ""));
   } else {
     my_snprintf(str, S(str), "delete_files {%s}",
          abs_sym_path(xctx->sch[xctx->currsch], ""));
@@ -910,19 +910,19 @@ void place_net_label(int type)
   struct stat buf;
   if(type == 1) {
     if(!stat(abs_sym_path("lab_pin.sym", ""), &buf)) {
-      place_symbol(-1, "lab_pin.sym", mousex_snap, mousey_snap, 0, 0, NULL, 4, 1);
+      place_symbol(-1, "lab_pin.sym", xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL, 4, 1);
     } else if(!stat(abs_sym_path("devices/lab_pin.sym", ""), &buf)) {
-      place_symbol(-1, "devices/lab_pin.sym", mousex_snap, mousey_snap, 0, 0, NULL, 4, 1);
+      place_symbol(-1, "devices/lab_pin.sym", xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL, 4, 1);
     }
   } else {
     if(!stat(abs_sym_path("lab_wire.sym", ""), &buf)) {
-      place_symbol(-1, "lab_wire.sym", mousex_snap, mousey_snap, 0, 0, NULL, 4, 1);
+      place_symbol(-1, "lab_wire.sym", xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL, 4, 1);
     } else if(!stat(abs_sym_path("devices/lab_wire.sym", ""), &buf)) {
-      place_symbol(-1, "devices/lab_wire.sym", mousex_snap, mousey_snap, 0, 0, NULL, 4, 1);
+      place_symbol(-1, "devices/lab_wire.sym", xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL, 4, 1);
     }
   }
   move_objects(START,0,0,0);
-  ui_state |= START_SYMPIN;
+  xctx->ui_state |= START_SYMPIN;
 }
 
 /*  draw_sym==4 select element after placing */
@@ -960,7 +960,7 @@ int place_symbol(int pos, const char *symbol_name, double x, double y, int rot,
   if(pos==-1 || pos > xctx->instances) n=xctx->instances;
   else
   {
-   prepared_hash_instances = 0; /* instances moved so need to rebuild hash */
+   xctx->prep_hash_inst = 0; /* instances moved so need to rebuild hash */
    for(j=xctx->instances;j>pos;j--)
    {
     xctx->inst[j]=xctx->inst[j-1];
@@ -975,8 +975,8 @@ int place_symbol(int pos, const char *symbol_name, double x, double y, int rot,
   dbg(1, "place_symbol(): entering my_strdup: name=%s\n",name);  /*  03-02-2000 */
   my_strdup(12, &xctx->inst[n].name ,name);
   dbg(1, "place_symbol(): done my_strdup: name=%s\n",name);  /*  03-02-2000 */
-  /*  xctx->inst[n].x0=symbol_name ? x : mousex_snap; */
-  /*  xctx->inst[n].y0=symbol_name ? y : mousey_snap; */
+  /*  xctx->inst[n].x0=symbol_name ? x : xctx->mousex_snap; */
+  /*  xctx->inst[n].y0=symbol_name ? y : xctx->mousey_snap; */
   xctx->inst[n].x0= x ; /*  20070228 x and y given in callback */
   xctx->inst[n].y0= y ;
   xctx->inst[n].rot=symbol_name ? rot : 0;
@@ -1008,14 +1008,14 @@ int place_symbol(int pos, const char *symbol_name, double x, double y, int rot,
   xctx->instances++; /* must be updated before calling symbol_bbox() */
 
 
-  if(prepared_hash_instances) hash_inst(XINSERT, n); /* no need to rehash, add item */
-  /* prepared_hash_instances=0; */
+  if(xctx->prep_hash_inst) hash_inst(XINSERT, n); /* no need to rehash, add item */
+  /* xctx->prep_hash_inst=0; */
 
 
   /* force these vars to 0 to trigger a prepare_netlist_structs(0) needed by symbol_bbox->translate
    * to translate @#n:net_name texts */
-  prepared_netlist_structs=0;
-  prepared_hilight_structs=0;
+  xctx->prep_net_structs=0;
+  xctx->prep_hi_structs=0;
   symbol_bbox(n, &xctx->inst[n].x1, &xctx->inst[n].y1,
                     &xctx->inst[n].x2, &xctx->inst[n].y2);
   if(draw_sym & 3) bbox(ADD, xctx->inst[n].x1, xctx->inst[n].y1, xctx->inst[n].x2, xctx->inst[n].y2);
@@ -1029,11 +1029,11 @@ int place_symbol(int pos, const char *symbol_name, double x, double y, int rot,
 
   if(draw_sym & 4 ) {
     select_element(n, SELECTED,0, 0);
-    ui_state |= SELECTION;
+    xctx->ui_state |= SELECTION;
     drawtemparc(gc[SELLAYER], END, 0.0, 0.0, 0.0, 0.0, 0.0);
     drawtemprect(gc[SELLAYER], END, 0.0, 0.0, 0.0, 0.0);
     drawtempline(gc[SELLAYER], END, 0.0, 0.0, 0.0, 0.0);
-    need_rebuild_selected_array = 1;
+    xctx->need_reb_sel_arr = 1;
     rebuild_selected_array();
   }
 
@@ -1044,13 +1044,13 @@ int place_symbol(int pos, const char *symbol_name, double x, double y, int rot,
 void symbol_in_new_window(void)
 {
  rebuild_selected_array();
- if(lastselected !=1 || selectedgroup[0].type!=ELEMENT)
+ if(xctx->lastsel !=1 || xctx->sel_array[0].type!=ELEMENT)
  {
   new_window(xctx->sch[xctx->currsch],1);
  }
  else
  {
-  new_window(abs_sym_path(xctx->inst[selectedgroup[0].n].name, ""),1);
+  new_window(abs_sym_path(xctx->inst[xctx->sel_array[0].n].name, ""),1);
  }
 
 }
@@ -1060,7 +1060,7 @@ void schematic_in_new_window(void)
 {
  char filename[PATH_MAX];
  rebuild_selected_array();
- if(lastselected !=1 || selectedgroup[0].type!=ELEMENT)
+ if(xctx->lastsel !=1 || xctx->sel_array[0].type!=ELEMENT)
  {
   /*  new_window("", 0); */
   new_window(xctx->sch[xctx->currsch], 0); /*  20111007 duplicate current schematic if no inst selected */
@@ -1069,22 +1069,22 @@ void schematic_in_new_window(void)
  else
  {
   if(                   /*  do not descend if not subcircuit */
-     (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type &&
+     (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type &&
      strcmp(
-        (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type,
+        (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type,
          "subcircuit"
      ) &&
      strcmp(
-        (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type,
+        (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type,
          "primitive"
      )
   ) return;
 
   my_strncpy(filename, abs_sym_path(get_tok_value(
-    (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->prop_ptr, "schematic",0 ), "")
+    (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->prop_ptr, "schematic",0 ), "")
     , S(filename));
   if(!filename[0]) {
-    my_strncpy(filename, add_ext(abs_sym_path(xctx->inst[selectedgroup[0].n].name, ""), ".sch"), S(filename));
+    my_strncpy(filename, add_ext(abs_sym_path(xctx->inst[xctx->sel_array[0].n].name, ""), ".sch"), S(filename));
   }
 
   new_window(filename, 0);
@@ -1097,13 +1097,13 @@ void launcher(void)
   char program[PATH_MAX];
   int n;
   rebuild_selected_array();
-  if(lastselected ==1 && selectedgroup[0].type==ELEMENT)
+  if(xctx->lastsel ==1 && xctx->sel_array[0].type==ELEMENT)
   {
-    double mx=mousex, my=mousey;
+    double mx=xctx->mousex, my=xctx->mousey;
     select_object(mx,my,SELECTED, 0);
     tcleval("update; after 300");
     select_object(mx,my,0, 0);
-    n=selectedgroup[0].n;
+    n=xctx->sel_array[0].n;
     my_strncpy(program, get_tok_value(xctx->inst[n].prop_ptr,"program",0), S(program)); /* handle backslashes */
     str = get_tok_value(xctx->inst[n].prop_ptr,"url",0); /* handle backslashes */
     dbg(1, "launcher(): str=%s\n", str);
@@ -1132,14 +1132,14 @@ void descend_schematic(int instnumber)
  int save_ok = 0;
 
  rebuild_selected_array();
- if(lastselected !=1 || selectedgroup[0].type!=ELEMENT)
+ if(xctx->lastsel !=1 || xctx->sel_array[0].type!=ELEMENT)
  {
   dbg(1, "descend_schematic(): wrong selection\n");
   return;
  }
  else
  {
-  dbg(1, "descend_schematic(): selected:%s\n", xctx->inst[selectedgroup[0].n].name);
+  dbg(1, "descend_schematic(): selected:%s\n", xctx->inst[xctx->sel_array[0].n].name);
   /* no name set for current schematic: save it before descending*/
   if(!strcmp(xctx->sch[xctx->currsch],""))
   {
@@ -1157,25 +1157,25 @@ void descend_schematic(int instnumber)
     if(save_ok==-1) return;
   }
 
-  dbg(1, "descend_schematic(): type of instance: %s\n", (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type);
+  dbg(1, "descend_schematic(): type of instance: %s\n", (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type);
 
   if(                   /*  do not descend if not subcircuit */
-     (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type &&
-     strcmp( (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type, "subcircuit") &&
-     strcmp( (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type, "primitive")
+     (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type &&
+     strcmp( (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type, "subcircuit") &&
+     strcmp( (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type, "primitive")
   ) return;
 
-  if(modified)
+  if(xctx->modified)
   {
     if(save(1)) return;
   }
 
   /*  build up current hierarchy path */
-  dbg(1, "descend_schematic(): selected instname=%s\n", xctx->inst[selectedgroup[0].n].instname);
+  dbg(1, "descend_schematic(): selected instname=%s\n", xctx->inst[xctx->sel_array[0].n].instname);
 
 
-  if(xctx->inst[selectedgroup[0].n].instname && xctx->inst[selectedgroup[0].n].instname[0]) {
-    str=expandlabel(xctx->inst[selectedgroup[0].n].instname, &inst_mult);
+  if(xctx->inst[xctx->sel_array[0].n].instname && xctx->inst[xctx->sel_array[0].n].instname[0]) {
+    str=expandlabel(xctx->inst[xctx->sel_array[0].n].instname, &inst_mult);
   } else {
     str = "";
     inst_mult = 1;
@@ -1213,7 +1213,7 @@ void descend_schematic(int instnumber)
   dbg(1, "descend_schematic(): current path: %s\n", xctx->sch_path[xctx->currsch+1]);
   dbg(1, "descend_schematic(): inst_number=%d\n", inst_number);
 
-  xctx->previous_instance[xctx->currsch]=selectedgroup[0].n;
+  xctx->previous_instance[xctx->currsch]=xctx->sel_array[0].n;
   xctx->zoom_array[xctx->currsch].x=xctx->xorigin;
   xctx->zoom_array[xctx->currsch].y=xctx->yorigin;
   xctx->zoom_array[xctx->currsch].zoom=xctx->zoom;
@@ -1221,7 +1221,7 @@ void descend_schematic(int instnumber)
   hilight_child_pins();
 
   my_strncpy(filename, abs_sym_path(get_tok_value(
-     (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->prop_ptr, "schematic",0 ), "")
+     (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->prop_ptr, "schematic",0 ), "")
      , S(filename));
 
   unselect_all();
@@ -1229,7 +1229,7 @@ void descend_schematic(int instnumber)
   if(filename[0]) {
     load_schematic(1,filename, 1);
   } else {
-    my_strncpy(filename, add_ext(abs_sym_path(xctx->inst[selectedgroup[0].n].name, ""), ".sch"), S(filename));
+    my_strncpy(filename, add_ext(abs_sym_path(xctx->inst[xctx->sel_array[0].n].name, ""), ".sch"), S(filename));
     load_schematic(1, filename, 1);
   }
   if(hilight_nets)
@@ -1237,7 +1237,7 @@ void descend_schematic(int instnumber)
     prepare_netlist_structs(0);
     if(enable_drill) drill_hilight();
   }
-  dbg(1, "descend_schematic(): before zoom(): prepared_hash_instances=%d\n", prepared_hash_instances);
+  dbg(1, "descend_schematic(): before zoom(): xctx->prep_hash_inst=%d\n", xctx->prep_hash_inst);
   zoom_full(1, 0);
  }
 }
@@ -1253,7 +1253,7 @@ void go_back(int confirm) /*  20171006 add confirm */
  if(xctx->currsch>0)
  {
   /* if current sym/schematic is changed ask save before going up */
-  if(modified)
+  if(xctx->modified)
   {
     if(confirm) {
       tcleval("ask_save");
@@ -1276,12 +1276,12 @@ void go_back(int confirm) /*  20171006 add confirm */
   }
   my_strncpy(xctx->sch[xctx->currsch] , "", S(xctx->sch[xctx->currsch]));
   xctx->currsch--;
-  save_modified = modified; /* we propagate modified flag (cleared by load_schematic */
+  save_modified = xctx->modified; /* we propagate xctx->modified flag (cleared by load_schematic */
                             /* by default) to parent schematic if going back from embedded symbol */
 
   my_strncpy(filename, xctx->sch[xctx->currsch], S(filename));
   load_schematic(1, filename, 1);
-  if(from_embedded_sym) modified=save_modified; /* to force ask save embedded sym in parent schematic */
+  if(from_embedded_sym) xctx->modified=save_modified; /* to force ask save embedded sym in parent schematic */
 
   hilight_parent_pins();
   if(enable_drill) drill_hilight();
@@ -1321,12 +1321,12 @@ void change_linewidth(double w)
     }
     XSetLineAttributes (display, gctiled, INT_WIDTH(xctx->lw), LineSolid, CapRound , JoinRound);
   }
-  areax1 = -2*INT_WIDTH(xctx->lw);
-  areay1 = -2*INT_WIDTH(xctx->lw);
-  areax2 = xrect[0].width+2*INT_WIDTH(xctx->lw);
-  areay2 = xrect[0].height+2*INT_WIDTH(xctx->lw);
-  areaw = areax2-areax1;
-  areah = areay2 - areay1;
+  xctx->areax1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areay1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areax2 = xrect[0].width+2*INT_WIDTH(xctx->lw);
+  xctx->areay2 = xrect[0].height+2*INT_WIDTH(xctx->lw);
+  xctx->areaw = xctx->areax2-xctx->areax1;
+  xctx->areah = xctx->areay2 - xctx->areay1;
 }
 
 void calc_drawing_bbox(xRect *boundbox, int selected)
@@ -1452,8 +1452,9 @@ void calc_drawing_bbox(xRect *boundbox, int selected)
     int j, rects, found, hilight_conn_inst;
     type = (xctx->inst[i].ptr+ xctx->sym)->type;
     found = 0;
-    hilight_conn_inst = !strcmp(get_tok_value((xctx->inst[i].ptr+ xctx->sym)->prop_ptr, "highlight", 0), "true") ||
-                             !strcmp(get_tok_value(xctx->inst[i].prop_ptr, "highlight", 0), "true");
+    hilight_conn_inst = !strcmp(
+     get_tok_value((xctx->inst[i].ptr+ xctx->sym)->prop_ptr, "highlight", 0), "true") ||
+     !strcmp(get_tok_value(xctx->inst[i].prop_ptr, "highlight", 0), "true");
     if( hilight_conn_inst && (rects = (xctx->inst[i].ptr+ xctx->sym)->rects[PINLAYER]) > 0 ) {
       prepare_netlist_structs(0);
       for(j=0;j<rects;j++) {
@@ -1499,22 +1500,23 @@ void zoom_full(int dr, int sel)
   if(change_lw) {
     xctx->lw = 1.;
   }
-  areax1 = -2*INT_WIDTH(xctx->lw);
-  areay1 = -2*INT_WIDTH(xctx->lw);
-  areax2 = xrect[0].width+2*INT_WIDTH(xctx->lw);
-  areay2 = xrect[0].height+2*INT_WIDTH(xctx->lw);
-  areaw = areax2-areax1;
-  areah = areay2 - areay1;
+  xctx->areax1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areay1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areax2 = xrect[0].width+2*INT_WIDTH(xctx->lw);
+  xctx->areay2 = xrect[0].height+2*INT_WIDTH(xctx->lw);
+  xctx->areaw = xctx->areax2-xctx->areax1;
+  xctx->areah = xctx->areay2 - xctx->areay1;
 
   calc_drawing_bbox(&boundbox, sel);
-  xctx->zoom=(boundbox.x2-boundbox.x1)/(areaw-4*INT_WIDTH(xctx->lw));
-  yy1=(boundbox.y2-boundbox.y1)/(areah-4*INT_WIDTH(xctx->lw));
+  xctx->zoom=(boundbox.x2-boundbox.x1)/(xctx->areaw-4*INT_WIDTH(xctx->lw));
+  yy1=(boundbox.y2-boundbox.y1)/(xctx->areah-4*INT_WIDTH(xctx->lw));
   if(yy1>xctx->zoom) xctx->zoom=yy1;
   xctx->zoom*=1.05;
   xctx->mooz=1/xctx->zoom;
-  xctx->xorigin=-boundbox.x1+(areaw-4*INT_WIDTH(xctx->lw))/40*xctx->zoom;
-  xctx->yorigin=(areah-4*INT_WIDTH(xctx->lw))*xctx->zoom-boundbox.y2 - (areah-4*INT_WIDTH(xctx->lw))/40*xctx->zoom;
-  dbg(1, "zoom_full(): areaw=%d, areah=%d\n", areaw, areah);
+  xctx->xorigin=-boundbox.x1+(xctx->areaw-4*INT_WIDTH(xctx->lw))/40*xctx->zoom;
+  xctx->yorigin=(xctx->areah-4*INT_WIDTH(xctx->lw))*xctx->zoom-boundbox.y2 -
+                (xctx->areah-4*INT_WIDTH(xctx->lw))/40*xctx->zoom;
+  dbg(1, "zoom_full(): xctx->areaw=%d, xctx->areah=%d\n", xctx->areaw, xctx->areah);
 
   change_linewidth(-1.);
   if(dr)
@@ -1533,8 +1535,8 @@ void view_zoom(double z)
     if(xctx->zoom<CADMINZOOM) return;
     xctx->zoom/= factor;
     xctx->mooz=1/xctx->zoom;
-    xctx->xorigin=-mousex_snap+(mousex_snap+xctx->xorigin)/factor;
-    xctx->yorigin=-mousey_snap+(mousey_snap+xctx->yorigin)/factor;
+    xctx->xorigin=-xctx->mousex_snap+(xctx->mousex_snap+xctx->xorigin)/factor;
+    xctx->yorigin=-xctx->mousey_snap+(xctx->mousey_snap+xctx->yorigin)/factor;
     change_linewidth(-1.);
     draw();
 }
@@ -1550,11 +1552,11 @@ void view_unzoom(double z)
   /* 20181022 make unzoom and zoom symmetric  */
   /* keeping the mouse pointer as the origin */
   if(unzoom_nodrift) {
-    xctx->xorigin=-mousex_snap+(mousex_snap+xctx->xorigin)*factor;
-    xctx->yorigin=-mousey_snap+(mousey_snap+xctx->yorigin)*factor;
+    xctx->xorigin=-xctx->mousex_snap+(xctx->mousex_snap+xctx->xorigin)*factor;
+    xctx->yorigin=-xctx->mousey_snap+(xctx->mousey_snap+xctx->yorigin)*factor;
   } else {
-    xctx->xorigin=xctx->xorigin+areaw*xctx->zoom*(1-1/factor)/2;
-    xctx->yorigin=xctx->yorigin+areah*xctx->zoom*(1-1/factor)/2;
+    xctx->xorigin=xctx->xorigin+xctx->areaw*xctx->zoom*(1-1/factor)/2;
+    xctx->yorigin=xctx->yorigin+xctx->areah*xctx->zoom*(1-1/factor)/2;
   }
   change_linewidth(-1.);
   draw();
@@ -1567,29 +1569,30 @@ void zoom_box(int what)
 
   if( (what & START) )
   {
-    x1=x2=mousex_snap;y1=y2=mousey_snap;
-    ui_state |= STARTZOOM;
+    x1=x2=xctx->mousex_snap;y1=y2=xctx->mousey_snap;
+    xctx->ui_state |= STARTZOOM;
   }
   if( what & END)
   {
-    ui_state &= ~STARTZOOM;
+    xctx->ui_state &= ~STARTZOOM;
     RECTORDER(x1,y1,x2,y2);
     drawtemprect(gctiled, NOW, xx1,yy1,xx2,yy2);
     xctx->xorigin=-x1;xctx->yorigin=-y1;
-    xctx->zoom=(x2-x1)/(areaw-4*INT_WIDTH(xctx->lw));
-    yy1=(y2-y1)/(areah-4*INT_WIDTH(xctx->lw));
+    xctx->zoom=(x2-x1)/(xctx->areaw-4*INT_WIDTH(xctx->lw));
+    yy1=(y2-y1)/(xctx->areah-4*INT_WIDTH(xctx->lw));
     if(yy1>xctx->zoom) xctx->zoom=yy1;
     xctx->mooz=1/xctx->zoom;
     change_linewidth(-1.);
     draw();
-    dbg(1, "zoom_box(): coord: %.16g %.16g %.16g %.16g zoom=%.16g\n",x1,y1,mousex_snap, mousey_snap,xctx->zoom);
+    dbg(1, "zoom_box(): coord: %.16g %.16g %.16g %.16g zoom=%.16g\n",
+      x1,y1,xctx->mousex_snap, xctx->mousey_snap,xctx->zoom);
   }
   if(what & RUBBER)
   {
     xx1=x1;yy1=y1;xx2=x2;yy2=y2;
     RECTORDER(xx1,yy1,xx2,yy2);
     drawtemprect(gctiled,NOW, xx1,yy1,xx2,yy2);
-    x2=mousex_snap;y2=mousey_snap;
+    x2=xctx->mousex_snap;y2=xctx->mousey_snap;
 
 
     /*  20171211 update selected objects while dragging */
@@ -1621,10 +1624,10 @@ void draw_stuff(void)
    #endif
      for(i = 0; i < n; i++)
       {
-       w=(float)(areaw*xctx->zoom/800) * rand() / (RAND_MAX+1.0);
-       h=(float)(areah*xctx->zoom/80) * rand() / (RAND_MAX+1.0);
-       x1=(float)(areaw*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->xorigin;
-       y1=(float)(areah*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->yorigin;
+       w=(float)(xctx->areaw*xctx->zoom/800) * rand() / (RAND_MAX+1.0);
+       h=(float)(xctx->areah*xctx->zoom/80) * rand() / (RAND_MAX+1.0);
+       x1=(float)(xctx->areaw*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->xorigin;
+       y1=(float)(xctx->areah*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->yorigin;
        x2=x1+w;
        y2=y1+h;
        ORDER(x1,y1,x2,y2);
@@ -1638,10 +1641,10 @@ void draw_stuff(void)
   
      for(i = 0; i < n; i++)
       {
-       w=(float)(areaw*xctx->zoom/80) * rand() / (RAND_MAX+1.0);
-       h=(float)(areah*xctx->zoom/800) * rand() / (RAND_MAX+1.0);
-       x1=(float)(areaw*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->xorigin;
-       y1=(float)(areah*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->yorigin;
+       w=(float)(xctx->areaw*xctx->zoom/80) * rand() / (RAND_MAX+1.0);
+       h=(float)(xctx->areah*xctx->zoom/800) * rand() / (RAND_MAX+1.0);
+       x1=(float)(xctx->areaw*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->xorigin;
+       y1=(float)(xctx->areah*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->yorigin;
        x2=x1+w;
        y2=y1+h;
        ORDER(x1,y1,x2,y2);
@@ -1657,8 +1660,8 @@ void draw_stuff(void)
      {
        w=(float)xctx->zoom * rand() / (RAND_MAX+1.0);
        h=w;
-       x1=(float)(areaw*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->xorigin;
-       y1=(float)(areah*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->yorigin;
+       x1=(float)(xctx->areaw*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->xorigin;
+       y1=(float)(xctx->areah*xctx->zoom) * rand() / (RAND_MAX+1.0)-xctx->yorigin;
        x2=x1+w;
        y2=y1+h;
        RECTORDER(x1,y1,x2,y2);
@@ -1683,7 +1686,7 @@ void restore_selection(double x1, double y1, double x2, double y2)
   xx1 = x1; yy1 = y1; xx2 = x2; yy2 = y2;
   RECTORDER(xx1,yy1,xx2,yy2);
   rebuild_selected_array();
-  if(!lastselected) return;
+  if(!xctx->lastsel) return;
   bbox(START,0.0, 0.0, 0.0, 0.0);
   bbox(ADD, xx1, yy1, xx2, yy2);
   bbox(SET,0.0, 0.0, 0.0, 0.0);
@@ -1697,7 +1700,7 @@ void new_wire(int what, double mx_snap, double my_snap)
  static double xx1,yy1,xx2,yy2;
 
    if( (what & PLACE) ) {
-     if( (ui_state & STARTWIRE) && (x1!=x2 || y1!=y2) ) {
+     if( (xctx->ui_state & STARTWIRE) && (x1!=x2 || y1!=y2) ) {
        push_undo();
        if(manhattan_lines==1) {
          if(xx2!=xx1) {
@@ -1732,8 +1735,8 @@ void new_wire(int what, double mx_snap, double my_snap)
          drawline(WIRELAYER,NOW, xx1,yy1,xx2,yy2, 0);
        }
        hash_wire(XINSERT, xctx->wires-1, 1);
-       /* prepared_hash_wires = 0; */
-       prepared_hilight_structs = 0;
+       /* xctx->prep_hash_wires = 0; */
+       xctx->prep_hi_structs = 0;
 
        update_conn_cues(1,1);
        if(show_pin_net_names) {
@@ -1750,12 +1753,12 @@ void new_wire(int what, double mx_snap, double my_snap)
      if(! (what &END)) {
        x1=mx_snap;
        y1=my_snap;
-       x2=mousex_snap;
-       y2=mousey_snap;
+       x2=xctx->mousex_snap;
+       y2=xctx->mousey_snap;
        xx1=x1;
        yy1=y1;
-       xx2=mousex_snap;
-       yy2=mousey_snap;
+       xx2=xctx->mousex_snap;
+       yy2=xctx->mousey_snap;
        if(manhattan_lines==1) {
          x2 = mx_snap; y2 = my_snap;
          xx1 = x1; yy1 = y1; xx2 = x2; yy2 = y2;
@@ -1779,10 +1782,10 @@ void new_wire(int what, double mx_snap, double my_snap)
          drawtempline(gc[WIRELAYER], NOW, xx1,yy1,xx2,yy2);
        }
      }
-     ui_state |= STARTWIRE;
+     xctx->ui_state |= STARTWIRE;
    }
    if( what & END) {
-     ui_state &= ~STARTWIRE;
+     xctx->ui_state &= ~STARTWIRE;
    }
    if( (what & RUBBER)  ) {
      if(manhattan_lines==1) {
@@ -1840,12 +1843,12 @@ void change_layer()
   double x1,y1,x2,y2, a, b, r;
 
 
-   if(lastselected) push_undo();
-   for(k=0;k<lastselected;k++)
+   if(xctx->lastsel) push_undo();
+   for(k=0;k<xctx->lastsel;k++)
    {
-     n=selectedgroup[k].n;
-     type=selectedgroup[k].type;
-     c=selectedgroup[k].col;
+     n=xctx->sel_array[k].n;
+     type=xctx->sel_array[k].type;
+     c=xctx->sel_array[k].col;
      if(type==LINE && xctx->line[c][n].sel==SELECTED) {
        x1 = xctx->line[c][n].x1;
        y1 = xctx->line[c][n].y1;
@@ -1873,7 +1876,7 @@ void change_layer()
        storeobject(-1, x1,y1,x2,y2,xRECT,rectcolor, 0, xctx->rect[c][n].prop_ptr);
      }
    }
-   if(lastselected) delete_only_rect_line_arc_poly();
+   if(xctx->lastsel) delete_only_rect_line_arc_poly();
    unselect_all();
 }
 
@@ -1888,19 +1891,19 @@ void new_arc(int what, double sweep)
     state=0;
     r = -1.;
     sweep_angle=sweep;
-    xx1 = xx2 = x1 = x2 = x3 = mousex_snap;
-    yy1 = yy2 = y1 = y2 = y3 = mousey_snap;
-    ui_state |= STARTARC;
+    xx1 = xx2 = x1 = x2 = x3 = xctx->mousex_snap;
+    yy1 = yy2 = y1 = y2 = y3 = xctx->mousey_snap;
+    xctx->ui_state |= STARTARC;
   }
   if(what & SET) {
     if(state==0) {
-      x2 = mousex_snap;
-      y2 = mousey_snap;
+      x2 = xctx->mousex_snap;
+      y2 = xctx->mousey_snap;
       drawtempline(gctiled, NOW, xx1,yy1,xx2,yy2);
       state=1;
     } else if(state==1) {
-      x3 = mousex_snap;
-      y3 = mousey_snap;
+      x3 = xctx->mousex_snap;
+      y3 = xctx->mousey_snap;
       arc_3_points(x1, y1, x2, y2, x3, y3, &x, &y, &r, &a, &b);
       if(sweep_angle==360.) b=360.;
       if(r>0.) {
@@ -1908,22 +1911,22 @@ void new_arc(int what, double sweep)
         drawarc(rectcolor, NOW, x, y, r, a, b, 0, 0);
         store_arc(-1, x, y, r, a, b, rectcolor, 0, NULL);
       }
-      ui_state &= ~STARTARC;
+      xctx->ui_state &= ~STARTARC;
       state=0;
     }
   }
   if(what & RUBBER) {
     if(state==0) {
       drawtempline(gctiled, NOW, xx1,yy1,xx2,yy2);
-      xx2 = mousex_snap;
-      yy2 = mousey_snap;
+      xx2 = xctx->mousex_snap;
+      yy2 = xctx->mousey_snap;
       xx1 = x1;yy1 = y1;
       ORDER(xx1,yy1,xx2,yy2);
       drawtempline(gc[SELLAYER], NOW, xx1,yy1,xx2,yy2);
     }
     else if(state==1) {
-      x3 = mousex_snap;
-      y3 = mousey_snap;
+      x3 = xctx->mousex_snap;
+      y3 = xctx->mousey_snap;
       if(r>0.) drawtemparc(gctiled, NOW, x, y, r, a, b);
       arc_3_points(x1, y1, x2, y2, x3, y3, &x, &y, &r, &a, &b);
       if(sweep_angle==360.) b=360.;
@@ -1938,7 +1941,7 @@ void new_line(int what)
 
    if( (what & PLACE) )
    {
-     if( (x1!=x2 || y1!=y2) && (ui_state & STARTLINE) )
+     if( (x1!=x2 || y1!=y2) && (xctx->ui_state & STARTLINE) )
      {
        push_undo();
        if(manhattan_lines==1) {
@@ -1974,12 +1977,12 @@ void new_line(int what)
          drawline(rectcolor,NOW, xx1,yy1,xx2,yy2, 0);
        }
      }
-     x1=x2=mousex_snap;y1=y2=mousey_snap;
-     ui_state |= STARTLINE;
+     x1=x2=xctx->mousex_snap;y1=y2=xctx->mousey_snap;
+     xctx->ui_state |= STARTLINE;
    }
    if( what & END)
    {
-     ui_state &= ~STARTLINE;
+     xctx->ui_state &= ~STARTLINE;
    }
 
    if(what & RUBBER)
@@ -1992,7 +1995,7 @@ void new_line(int what)
        ORDER(xx2,yy1,xx2,yy2);
        drawtempline(gctiled, NOW, xx2,yy1,xx2,yy2);
        restore_selection(x1, y1, x2, y2);
-       x2 = mousex_snap; y2 = mousey_snap;
+       x2 = xctx->mousex_snap; y2 = xctx->mousey_snap;
        if(!(what & CLEAR)) {
          xx1 = x1; yy1 = y1; xx2 = x2; yy2 = y2;
          ORDER(xx1,yy1,xx2,yy1);
@@ -2009,7 +2012,7 @@ void new_line(int what)
        ORDER(xx1,yy2,xx2,yy2);
        drawtempline(gctiled, NOW, xx1,yy2,xx2,yy2);
        restore_selection(x1, y1, x2, y2);
-       x2 = mousex_snap; y2 = mousey_snap;
+       x2 = xctx->mousex_snap; y2 = xctx->mousey_snap;
        if(!(what & CLEAR)) {
          xx1 = x1; yy1 = y1; xx2 = x2; yy2 = y2;
          ORDER(xx1,yy1,xx1,yy2);
@@ -2023,7 +2026,7 @@ void new_line(int what)
        ORDER(xx1,yy1,xx2,yy2);
        drawtempline(gctiled, NOW, xx1,yy1,xx2,yy2);
        restore_selection(x1, y1, x2, y2);
-       x2 = mousex_snap; y2 = mousey_snap;
+       x2 = xctx->mousex_snap; y2 = xctx->mousey_snap;
        if(!(what & CLEAR)) {
          xx1 = x1; yy1 = y1; xx2 = x2; yy2 = y2;
          ORDER(xx1,yy1,xx2,yy2);
@@ -2040,7 +2043,7 @@ void new_rect(int what)
 
    if( (what & PLACE) )
    {
-    if( (x1!=x2 || y1!=y2) && (ui_state & STARTRECT) )
+    if( (x1!=x2 || y1!=y2) && (xctx->ui_state & STARTRECT) )
     {
      int save_draw;
      RECTORDER(x1,y1,x2,y2);
@@ -2052,19 +2055,19 @@ void new_rect(int what)
      draw_window = save_draw;
      storeobject(-1, x1,y1,x2,y2,xRECT,rectcolor, 0, NULL);
     }
-    x1=x2=mousex_snap;y1=y2=mousey_snap;
-    ui_state |= STARTRECT;
+    x1=x2=xctx->mousex_snap;y1=y2=xctx->mousey_snap;
+    xctx->ui_state |= STARTRECT;
    }
    if( what & END)
    {
-    ui_state &= ~STARTRECT;
+    xctx->ui_state &= ~STARTRECT;
    }
    if(what & RUBBER)
    {
     xx1=x1;yy1=y1;xx2=x2;yy2=y2;
     RECTORDER(xx1,yy1,xx2,yy2);
     drawtemprect(gctiled,NOW, xx1,yy1,xx2,yy2);
-    x2=mousex_snap;y2=mousey_snap;
+    x2=xctx->mousex_snap;y2=xctx->mousey_snap;
     xx1=x1;yy1=y1;xx2=x2;yy2=y2;
     RECTORDER(xx1,yy1,xx2,yy2);
     drawtemprect(gc[rectcolor], NOW, xx1,yy1,xx2,yy2);
@@ -2088,13 +2091,13 @@ void new_polygon(int what)
    if( what & PLACE )
    {
      /* fprintf(errfp, "new_poly: PLACE, points=%d\n", points); */
-     y[points]=mousey_snap;
-     x[points]=mousex_snap;
+     y[points]=xctx->mousey_snap;
+     x[points]=xctx->mousex_snap;
      points++;
      x[points]=x[points-1]; /* prepare next point for rubber */
      y[points] = y[points-1];
      /* fprintf(errfp, "added point: %.16g %.16g\n", x[points-1], y[points-1]); */
-     ui_state |= STARTPOLYGON;
+     xctx->ui_state |= STARTPOLYGON;
    }
    if( what & ADD)
    {
@@ -2106,8 +2109,8 @@ void new_polygon(int what)
        y[points] = y[0];
      /* add point */
      } else if(x[points] != x[points-1] || y[points] != y[points-1]) {
-       x[points] = mousex_snap;
-       y[points] = mousey_snap;
+       x[points] = xctx->mousex_snap;
+       y[points] = xctx->mousey_snap;
      } else {
        return;
      }
@@ -2124,7 +2127,7 @@ void new_polygon(int what)
      store_poly(-1, x, y, points, rectcolor, 0, NULL);
      /* fprintf(errfp, "new_poly: finish: points=%d\n", points); */
      drawtemppolygon(gc[rectcolor], NOW, x, y, points);
-     ui_state &= ~STARTPOLYGON;
+     xctx->ui_state &= ~STARTPOLYGON;
      drawpolygon(rectcolor, NOW, x, y, points, 0, 0);
      my_free(711, &x);
      my_free(712, &y);
@@ -2134,8 +2137,8 @@ void new_polygon(int what)
    {
      /* fprintf(errfp, "new_poly: RUBBER\n"); */
      drawtemppolygon(gctiled, NOW, x, y, points+1);
-     y[points] = mousey_snap;
-     x[points] = mousex_snap;
+     y[points] = xctx->mousey_snap;
+     x[points] = xctx->mousex_snap;
      drawtemppolygon(gc[rectcolor], NOW, x, y, points+1);
    }
 }
@@ -2412,20 +2415,20 @@ void pan(int what)
     xx1=xpan;yy1=ypan;xx2=xpan2;yy2=ypan2;
     ORDER(xx1,yy1,xx2,yy2);
     drawtempline(gctiled, NOW, xx1,yy1,xx2,yy2);
-    xpan2=mousex_snap;ypan2=mousey_snap;
+    xpan2=xctx->mousex_snap;ypan2=xctx->mousey_snap;
     xx1=xpan;yy1=ypan;xx2=xpan2;yy2=ypan2;
     ORDER(xx1,yy1,xx2,yy2);
     drawtempline(gc[SELLAYER], NOW, xx1,yy1,xx2,yy2);
  }
  if(what & START)
  {
-    ui_state |= STARTPAN;
-    xpan=mousex_snap;ypan=mousey_snap;xpan2=xpan;ypan2=ypan;
+    xctx->ui_state |= STARTPAN;
+    xpan=xctx->mousex_snap;ypan=xctx->mousey_snap;xpan2=xpan;ypan2=ypan;
  }
  if(what & END)
  {
-    ui_state &= ~STARTPAN;
-    xctx->xorigin+=-xpan+mousex_snap;xctx->yorigin+=-ypan+mousey_snap;
+    xctx->ui_state &= ~STARTPAN;
+    xctx->xorigin+=-xpan+xctx->mousex_snap;xctx->yorigin+=-ypan+xctx->mousey_snap;
     draw();
  }
 }
@@ -2447,7 +2450,7 @@ void select_rect(int what, int select)
     xx1=xr;xx2=xr2;yy1=yr;yy2=yr2;
     RECTORDER(xx1,yy1,xx2,yy2);
     drawtemprect(gctiled,NOW, xx1,yy1,xx2,yy2);
-    xr2=mousex_snap;yr2=mousey_snap;
+    xr2=xctx->mousex_snap;yr2=xctx->mousey_snap;
 
     /*  20171026 update unselected objects while dragging */
     rebuild_selected_array();
@@ -2470,16 +2473,16 @@ void select_rect(int what, int select)
      * }
      */
     sel = select;
-    ui_state |= STARTSELECT;
+    xctx->ui_state |= STARTSELECT;
 
     /*  use m[xy]_double_save instead of mouse[xy]_snap */
     /*  to avoid delays in setting the start point of a */
     /*  selection rectangle, this is noticeable and annoying on */
     /*  networked / slow X servers. 20171218 */
-    /* xr=xr2=mousex_snap; */
-    /* yr=yr2=mousey_snap; */
-    xr=xr2=mx_double_save;
-    yr=yr2=my_double_save;
+    /* xr=xr2=xctx->mousex_snap; */
+    /* yr=yr2=xctx->mousey_snap; */
+    xr=xr2=xctx->mx_double_save;
+    yr=yr2=xctx->my_double_save;
     sem=1;
  }
  else if(what & END)
@@ -2497,7 +2500,7 @@ void select_rect(int what, int select)
     bbox(END,0.0, 0.0, 0.0, 0.0);
     /*  /20171219 */
 
-    ui_state &= ~STARTSELECT;
+    xctx->ui_state &= ~STARTSELECT;
     sem=0;
  }
 }
diff --git a/src/callback.c b/src/callback.c
index 77ed1ab4..3af6ce9f 100644
--- a/src/callback.c
+++ b/src/callback.c
@@ -27,21 +27,21 @@ static int last_command=0;
 void start_line(double mx, double my)
 {
     last_command = STARTLINE;
-    if(ui_state & STARTLINE) {
+    if(xctx->ui_state & STARTLINE) {
       if(!vertical_move) {
         mx_save = mx;
-        mx_double_save=mousex_snap;
+        xctx->mx_double_save=xctx->mousex_snap;
       }
       if(!horizontal_move) {
         my_save = my;
-        my_double_save=mousey_snap;
+        xctx->my_double_save=xctx->mousey_snap;
       }
-      if(horizontal_move) mousey_snap = my_double_save;
-      if(vertical_move) mousex_snap = mx_double_save;
+      if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+      if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
     } else {
       mx_save = mx; my_save = my;
-      mx_double_save=mousex_snap;
-      my_double_save=mousey_snap;
+      xctx->mx_double_save=xctx->mousex_snap;
+      xctx->my_double_save=xctx->mousey_snap;
     }
     new_line(PLACE);
 }
@@ -49,23 +49,23 @@ void start_line(double mx, double my)
 void start_wire(double mx, double my)
 {
      last_command = STARTWIRE;
-     if(ui_state & STARTWIRE) {
+     if(xctx->ui_state & STARTWIRE) {
        if(!vertical_move) {
          mx_save = mx;
-         mx_double_save=mousex_snap;
+         xctx->mx_double_save=xctx->mousex_snap;
        }
        if(!horizontal_move) {
          my_save = my;
-         my_double_save=mousey_snap;
+         xctx->my_double_save=xctx->mousey_snap;
        }
-       if(horizontal_move) mousey_snap = my_double_save;
-       if(vertical_move) mousex_snap = mx_double_save;
+       if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+       if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
      } else {
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
      }
-     new_wire(PLACE,mousex_snap, mousey_snap);
+     new_wire(PLACE,xctx->mousex_snap, xctx->mousey_snap);
 
 }
 /* main window callback */
@@ -136,12 +136,12 @@ int callback(int event, int mx, int my, KeySym key,
    /* return 0; */
  }
  semaphore++;           /* used to debug Tcl-Tk frontend */
- mousex=X_TO_XSCHEM(mx);
- mousey=Y_TO_XSCHEM(my);
- mousex_snap=ROUND(mousex / cadsnap) * cadsnap;
- mousey_snap=ROUND(mousey / cadsnap) * cadsnap;
+ xctx->mousex=X_TO_XSCHEM(mx);
+ xctx->mousey=Y_TO_XSCHEM(my);
+ xctx->mousex_snap=ROUND(xctx->mousex / cadsnap) * cadsnap;
+ xctx->mousey_snap=ROUND(xctx->mousey / cadsnap) * cadsnap;
  my_snprintf(str, S(str), "mouse = %.16g %.16g - selected: %d path: %s",
-   mousex_snap, mousey_snap, lastselected, xctx->sch_path[xctx->currsch] );
+   xctx->mousex_snap, xctx->mousey_snap, xctx->lastsel, xctx->sch_path[xctx->currsch] );
  statusmsg(str,1);
  switch(event)
  {
@@ -151,17 +151,17 @@ int callback(int event, int mx, int my, KeySym key,
     /* xschem window *sending* selected objects
        when the pointer comes back in abort copy operation since it has been done
        in another xschem window; STARTCOPY set and selection file does not exist any more */
-    if( stat(sel_or_clip, &buf)  && (ui_state & STARTCOPY) )
+    if( stat(sel_or_clip, &buf)  && (xctx->ui_state & STARTCOPY) )
     {
       copy_objects(ABORT); /* also unlinks sel_or_flip file */
       unselect_all();
     }
     /* xschem window *receiving* selected objects */
     /* no selected objects and selection file exists */
-    if(lastselected == 0  && !stat(sel_or_clip, &buf)) {
+    if(xctx->lastsel == 0  && !stat(sel_or_clip, &buf)) {
       dbg(2, "callback(): Enter event\n");
-      mousex_snap = 490;
-      mousey_snap = -340;
+      xctx->mousex_snap = 490;
+      xctx->mousey_snap = -340;
       merge_file(1, ".sch");
       xunlink(sel_or_clip);
     }
@@ -191,74 +191,77 @@ int callback(int event, int mx, int my, KeySym key,
   case MotionNotify:
     if(semaphore >= 2) break;
 #ifndef __unix__
-    if ((ui_state & STARTWIRE) || (ui_state & STARTARC) || (ui_state & STARTLINE) || (ui_state & STARTMOVE) ||
-      (ui_state & STARTCOPY) || (ui_state & STARTRECT) || (ui_state & STARTPOLYGON) ||
-      (ui_state & STARTPAN2) || (ui_state & STARTPAN) || (ui_state & STARTSELECT)) {
+    if ((xctx->ui_state & STARTWIRE) || (xctx->ui_state & STARTARC) ||
+        (xctx->ui_state & STARTLINE) || (xctx->ui_state & STARTMOVE) ||
+        (xctx->ui_state & STARTCOPY) || (xctx->ui_state & STARTRECT) ||i
+        (xctx->ui_state & STARTPOLYGON) || (xctx->ui_state & STARTPAN2) ||
+        (xctx->ui_state & STARTPAN) || (xctx->ui_state & STARTSELECT)) {
       XCopyArea(display, save_pixmap, window, gctiled, xrect[0].x, xrect[0].y,
         xrect[0].width, xrect[0].height, xrect[0].x, xrect[0].y);
     }
 #endif
-    if(ui_state & STARTPAN2)   pan2(RUBBER, mx, my); /* 20121123 -  20160425 moved up */
-    if(ui_state) {
+    if(xctx->ui_state & STARTPAN2)   pan2(RUBBER, mx, my); /* 20121123 -  20160425 moved up */
+    if(xctx->ui_state) {
       #ifdef TURBOX_FIX
       /* fix Exceed TurboX bugs when drawing with pixmap tiled fill pattern */
       /* *NOT* a solution but at least makes the program useable. 20171130 */
       XSetClipRectangles(display, gctiled, 0,0, xrect, 1, Unsorted);
       #endif
       my_snprintf(str, S(str), "mouse = %.16g %.16g - selected: %d w=%.16g h=%.16g",
-        mousex_snap, mousey_snap,
-        lastselected ,
-        mousex_snap-mx_double_save, mousey_snap-my_double_save
+        xctx->mousex_snap, xctx->mousey_snap,
+        xctx->lastsel ,
+        xctx->mousex_snap-xctx->mx_double_save, xctx->mousey_snap-xctx->my_double_save
       );
       statusmsg(str,1);
     }
-    if(ui_state & STARTPAN)    pan(RUBBER);
-    if(ui_state & STARTZOOM)   zoom_box(RUBBER);
-    if(ui_state & STARTSELECT && !(ui_state & PLACE_SYMBOL) && !(ui_state & STARTPAN2)) {
+    if(xctx->ui_state & STARTPAN)    pan(RUBBER);
+    if(xctx->ui_state & STARTZOOM)   zoom_box(RUBBER);
+    if(xctx->ui_state & STARTSELECT && !(xctx->ui_state & PLACE_SYMBOL) && !(xctx->ui_state & STARTPAN2)) {
       if( (state & Button1Mask)  && (state & Mod1Mask)) { /* 20171026 added unselect by area  */
           select_rect(RUBBER,0);
       } else if(state & Button1Mask) {
           select_rect(RUBBER,1);
       }
     }
-    if(ui_state & STARTWIRE) {
-      if(horizontal_move) mousey_snap = my_double_save;
-      if(vertical_move) mousex_snap = mx_double_save;
-      new_wire(RUBBER, mousex_snap, mousey_snap);
+    if(xctx->ui_state & STARTWIRE) {
+      if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+      if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
+      new_wire(RUBBER, xctx->mousex_snap, xctx->mousey_snap);
     }
-    if(ui_state & STARTARC) {
-      if(horizontal_move) mousey_snap = my_double_save;
-      if(vertical_move) mousex_snap = mx_double_save;
+    if(xctx->ui_state & STARTARC) {
+      if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+      if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
       new_arc(RUBBER, 0);
     }
-    if(ui_state & STARTLINE) {
-      if(horizontal_move) mousey_snap = my_double_save;
-      if(vertical_move) mousex_snap = mx_double_save;
+    if(xctx->ui_state & STARTLINE) {
+      if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+      if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
       new_line(RUBBER);
     }
-    if(ui_state & STARTMOVE) {
-      if(horizontal_move) mousey_snap = my_double_save;
-      if(vertical_move) mousex_snap = mx_double_save;
+    if(xctx->ui_state & STARTMOVE) {
+      if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+      if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
       move_objects(RUBBER,0,0,0);
     }
-    if(ui_state & STARTCOPY) {
-      if(horizontal_move) mousey_snap = my_double_save;
-      if(vertical_move) mousex_snap = mx_double_save;
+    if(xctx->ui_state & STARTCOPY) {
+      if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+      if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
       copy_objects(RUBBER);
     }
-    if(ui_state & STARTRECT) new_rect(RUBBER);
-    if(ui_state & STARTPOLYGON) {
-      if(horizontal_move) mousey_snap = my_double_save;
-      if(vertical_move) mousex_snap = mx_double_save;
+    if(xctx->ui_state & STARTRECT) new_rect(RUBBER);
+    if(xctx->ui_state & STARTPOLYGON) {
+      if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+      if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
       new_polygon(RUBBER);
     }
     /* start of a mouse area select */
-    if(!(ui_state & STARTPOLYGON) && (state&Button1Mask) && !(ui_state & STARTWIRE) && 
-       !(ui_state & STARTPAN2) && !(state & Mod1Mask) && !(state & ShiftMask) && !(ui_state & PLACE_SYMBOL))
+    if(!(xctx->ui_state & STARTPOLYGON) && (state&Button1Mask) && !(xctx->ui_state & STARTWIRE) && 
+       !(xctx->ui_state & STARTPAN2) && !(state & Mod1Mask) &&
+       !(state & ShiftMask) && !(xctx->ui_state & PLACE_SYMBOL))
     {
       static int onetime=0;
       if(mx != mx_save || my != my_save) {
-        if( !(ui_state & STARTSELECT)) {
+        if( !(xctx->ui_state & STARTSELECT)) {
           select_rect(START,1);
           onetime=1;
         }
@@ -267,20 +270,20 @@ int callback(int event, int mx, int my, KeySym key,
             unselect_all(); /* 20171026 avoid multiple calls of unselect_all() */
             onetime=0;
           }
-          ui_state|=STARTSELECT; /* set it again cause unselect_all() clears it... 20121123 */
+          xctx->ui_state|=STARTSELECT; /* set it again cause unselect_all() clears it... 20121123 */
         }
       }
     }
     if((state & Button1Mask)  && (state & Mod1Mask) && !(state & ShiftMask) &&
-       !(ui_state & STARTPAN2) && !(ui_state & PLACE_SYMBOL)) { /* 20150927 unselect area */
-      if( !(ui_state & STARTSELECT)) {
+       !(xctx->ui_state & STARTPAN2) && !(xctx->ui_state & PLACE_SYMBOL)) { /* 20150927 unselect area */
+      if( !(xctx->ui_state & STARTSELECT)) {
         select_rect(START,0);
       }
     }
-    else if((state&Button1Mask) && (state & ShiftMask) && !(ui_state & PLACE_SYMBOL) &&
-             !(ui_state & STARTPAN2) ) {
+    else if((state&Button1Mask) && (state & ShiftMask) && !(xctx->ui_state & PLACE_SYMBOL) &&
+             !(xctx->ui_state & STARTPAN2) ) {
       if(mx != mx_save || my != my_save) {
-        if( !(ui_state & STARTSELECT)) {
+        if( !(xctx->ui_state & STARTSELECT)) {
           select_rect(START,1);
         }
         if(abs(mx-mx_save) > 8 || abs(my-my_save) > 8 ) {  /* set some reasonable threshold before unselecting */
@@ -294,13 +297,13 @@ int callback(int event, int mx, int my, KeySym key,
     break;
   case KeyPress:
    if(key==' ') {
-     if(ui_state & STARTWIRE) { /*  & instead of == 20190409 */
-       new_wire(RUBBER|CLEAR, mousex_snap, mousey_snap);
+     if(xctx->ui_state & STARTWIRE) { /*  & instead of == 20190409 */
+       new_wire(RUBBER|CLEAR, xctx->mousex_snap, xctx->mousey_snap);
        manhattan_lines++;
        manhattan_lines %=3;
-       new_wire(RUBBER, mousex_snap, mousey_snap);
+       new_wire(RUBBER, xctx->mousex_snap, xctx->mousey_snap);
 
-     } else if(ui_state==STARTLINE) {
+     } else if(xctx->ui_state==STARTLINE) {
        new_line(RUBBER|CLEAR);
        manhattan_lines++;
        manhattan_lines %=3;
@@ -308,10 +311,10 @@ int callback(int event, int mx, int my, KeySym key,
      } else {
        if(semaphore<2) {
          rebuild_selected_array();
-         if(lastselected==0) ui_state &=~SELECTION;
+         if(xctx->lastsel==0) xctx->ui_state &=~SELECTION;
        }
        pan2(START, mx, my);
-       ui_state |= STARTPAN2;
+       xctx->ui_state |= STARTPAN2;
      }
      break;
    }
@@ -376,13 +379,13 @@ int callback(int event, int mx, int my, KeySym key,
      print_hilight_net(4);
      break;
    }
-   if(key == 'J'  && state==(Mod1Mask | ShiftMask) )    /* create labels with i prefix from hilight nets 20120913 */
+   if(key == 'J'  && state==(Mod1Mask | ShiftMask) ) /* create labels with i prefix from hilight nets */
    {
      if(semaphore >= 2) break;
      print_hilight_net(2);
      break;
    }
-   if(key == 'h'  && state==ControlMask )       /* 20161102 go to http link */
+   if(key == 'h'  && state==ControlMask )       /* go to http link */
    {
      launcher();
      break;
@@ -400,14 +403,14 @@ int callback(int event, int mx, int my, KeySym key,
        tcleval("set horizontal_move 1" );
        tcleval("xschem set horizontal_move");
      }
-     if(ui_state & STARTWIRE) {
-       if(horizontal_move) mousey_snap = my_double_save;
-       if(vertical_move) mousex_snap = mx_double_save;
-       new_wire(RUBBER, mousex_snap, mousey_snap);
+     if(xctx->ui_state & STARTWIRE) {
+       if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+       if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
+       new_wire(RUBBER, xctx->mousex_snap, xctx->mousey_snap);
      }
-     if(ui_state & STARTLINE) {
-       if(horizontal_move) mousey_snap = my_double_save;
-       if(vertical_move) mousex_snap = mx_double_save;
+     if(xctx->ui_state & STARTLINE) {
+       if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+       if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
        new_line(RUBBER);
      }
      break;
@@ -424,14 +427,14 @@ int callback(int event, int mx, int my, KeySym key,
        tcleval("set vertical_move 1" );
        tcleval("xschem set vertical_move");
      }
-     if(ui_state & STARTWIRE) {
-       if(horizontal_move) mousey_snap = my_double_save;
-       if(vertical_move) mousex_snap = mx_double_save;
-       new_wire(RUBBER, mousex_snap, mousey_snap);
+     if(xctx->ui_state & STARTWIRE) {
+       if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+       if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
+       new_wire(RUBBER, xctx->mousex_snap, xctx->mousey_snap);
      }
-     if(ui_state & STARTLINE) {
-       if(horizontal_move) mousey_snap = my_double_save;
-       if(vertical_move) mousex_snap = mx_double_save;
+     if(xctx->ui_state & STARTLINE) {
+       if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+       if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
        new_line(RUBBER);
      }
      break;
@@ -515,17 +518,17 @@ int callback(int event, int mx, int my, KeySym key,
      double x, y;
      int xx, yy;
      if(semaphore >= 2) break;
-     if(!(ui_state & STARTWIRE)){
-       find_closest_net_or_symbol_pin(mousex, mousey, &x, &y);
+     if(!(xctx->ui_state & STARTWIRE)){
+       find_closest_net_or_symbol_pin(xctx->mousex, xctx->mousey, &x, &y);
        xx = X_TO_SCREEN(x);
        yy = Y_TO_SCREEN(y);
        mx_save = xx; my_save = yy;
-       mx_double_save = ROUND(x / cadsnap) * cadsnap;
-       my_double_save = ROUND(y / cadsnap) * cadsnap;
+       xctx->mx_double_save = ROUND(x / cadsnap) * cadsnap;
+       xctx->my_double_save = ROUND(y / cadsnap) * cadsnap;
        new_wire(PLACE, x, y);
      }
      else {
-       find_closest_net_or_symbol_pin(mousex, mousey, &x, &y);
+       find_closest_net_or_symbol_pin(xctx->mousex, xctx->mousey, &x, &y);
        new_wire(RUBBER, x, y);
        new_wire(PLACE|END, x, y);
        horizontal_move = vertical_move=0;
@@ -539,7 +542,7 @@ int callback(int event, int mx, int my, KeySym key,
      start_wire(mx, my);
      break;
    }
-   if(key == XK_Return && (state == 0 ) && ui_state & STARTPOLYGON) { /* close polygon */
+   if(key == XK_Return && (state == 0 ) && xctx->ui_state & STARTPOLYGON) { /* close polygon */
     new_polygon(ADD|END);
     break;
    }
@@ -551,27 +554,27 @@ int callback(int event, int mx, int my, KeySym key,
     last_command=0;
     manhattan_lines = 0;
     horizontal_move = vertical_move = 0;
-    dbg(1, "callback(): Escape: ui_state=%ld\n", ui_state);
-    if(ui_state & STARTMOVE)
+    dbg(1, "callback(): Escape: xctx->ui_state=%ld\n", xctx->ui_state);
+    if(xctx->ui_state & STARTMOVE)
     {
      move_objects(ABORT,0,0,0);
-     if(ui_state & START_SYMPIN) {
+     if(xctx->ui_state & START_SYMPIN) {
        delete();
-       ui_state &= ~START_SYMPIN;
+       xctx->ui_state &= ~START_SYMPIN;
      }
      break;
     }
-    if(ui_state & STARTCOPY)
+    if(xctx->ui_state & STARTCOPY)
     {
      copy_objects(ABORT);
      break;
     }
-    if(ui_state & STARTMERGE) {
+    if(xctx->ui_state & STARTMERGE) {
       delete();
       set_modify(0); /* aborted merge: no change, so reset modify flag set by delete() */
     }
 
-    ui_state = 0;
+    xctx->ui_state = 0;
     unselect_all();
     draw();
     break;
@@ -588,21 +591,21 @@ int callback(int event, int mx, int my, KeySym key,
    if(key=='p' && state == Mod1Mask)                           /* add symbol pin */
    {
     unselect_all();
-    storeobject(-1, mousex_snap-2.5, mousey_snap-2.5, mousex_snap+2.5, mousey_snap+2.5,
+    storeobject(-1, xctx->mousex_snap-2.5, xctx->mousey_snap-2.5, xctx->mousex_snap+2.5, xctx->mousey_snap+2.5,
                 xRECT, PINLAYER, SELECTED, "name=XXX\ndir=inout");
-    need_rebuild_selected_array=1;
+    xctx->need_reb_sel_arr=1;
     rebuild_selected_array();
     move_objects(START,0,0,0);
-    ui_state |= START_SYMPIN;
+    xctx->ui_state |= START_SYMPIN;
     break;
    }
-   if(key=='w' && !ui_state && state==ControlMask)              /* start polygon, 20171115 */
+   if(key=='w' && !xctx->ui_state && state==ControlMask)              /* start polygon, 20171115 */
    {
      if(semaphore >= 2) break;
      dbg(1, "callback(): start polygon\n");
      mx_save = mx; my_save = my;
-     mx_double_save=mousex_snap;
-     my_double_save=mousey_snap;
+     xctx->mx_double_save=xctx->mousex_snap;
+     xctx->my_double_save=xctx->mousey_snap;
      last_command = 0;
      new_polygon(PLACE);
      break;
@@ -613,7 +616,8 @@ int callback(int event, int mx, int my, KeySym key,
    }
    if(key=='P' && state == ShiftMask)                   /* pan, other way to. */
    {
-    xctx->xorigin=-mousex_snap+areaw*xctx->zoom/2.0;xctx->yorigin=-mousey_snap+areah*xctx->zoom/2.0;
+    xctx->xorigin=-xctx->mousex_snap+xctx->areaw*xctx->zoom/2.0;
+    xctx->yorigin=-xctx->mousey_snap+xctx->areah*xctx->zoom/2.0;
     draw();
     break;
    }
@@ -630,7 +634,7 @@ int callback(int event, int mx, int my, KeySym key,
     dbg(1, "callback(): new color: %d\n",color_index[rectcolor]);
     break;
    }
-   if(key==XK_Delete && (ui_state & SELECTION) )        /* delete objects */
+   if(key==XK_Delete && (xctx->ui_state & SELECTION) )        /* delete objects */
    {
      if(semaphore >= 2) break;
      delete();break;
@@ -662,7 +666,7 @@ int callback(int event, int mx, int my, KeySym key,
    if(key=='q' && state == ControlMask) /* exit */
    {
      if(semaphore >= 2) break;
-     if(modified) {
+     if(xctx->modified) {
        tcleval("tk_messageBox -type okcancel -message {UNSAVED data: want to exit?}");
        if(strcmp(tclresult(),"ok")==0) {
          tcleval( "exit");
@@ -677,15 +681,15 @@ int callback(int event, int mx, int my, KeySym key,
    {
      if(semaphore >= 2) break;
      last_command = 0;
-     place_text(1, mousex_snap, mousey_snap); /* 1 = draw text 24122002 */
+     place_text(1, xctx->mousex_snap, xctx->mousey_snap); /* 1 = draw text 24122002 */
      break;
    }
-   if(key=='r' && !ui_state && state==0)              /* start rect */
+   if(key=='r' && !xctx->ui_state && state==0)              /* start rect */
    {
     dbg(1, "callback(): start rect\n");
     mx_save = mx; my_save = my;
-    mx_double_save=mousex_snap;
-    my_double_save=mousey_snap;
+    xctx->mx_double_save=xctx->mousex_snap;
+    xctx->my_double_save=xctx->mousey_snap;
     last_command = 0;
     new_rect(PLACE);
     break;
@@ -794,7 +798,7 @@ int callback(int event, int mx, int my, KeySym key,
    {
     if(semaphore >= 2) break;
     rebuild_selected_array();
-    if(lastselected) {  /* 20071203 check if something selected */
+    if(xctx->lastsel) {  /* 20071203 check if something selected */
       save_selection(2);
       delete();
     }
@@ -804,7 +808,7 @@ int callback(int event, int mx, int my, KeySym key,
    {
      if(semaphore >= 2) break;
      rebuild_selected_array();
-     if(lastselected) {  /* 20071203 check if something selected */
+     if(xctx->lastsel) {  /* 20071203 check if something selected */
        save_selection(2);
      }
     break;
@@ -813,8 +817,8 @@ int callback(int event, int mx, int my, KeySym key,
    {
      if(semaphore >= 2) break;
      mx_save = mx; my_save = my;
-     mx_double_save=mousex_snap;
-     my_double_save=mousey_snap;
+     xctx->mx_double_save=xctx->mousex_snap;
+     xctx->my_double_save=xctx->mousey_snap;
      last_command = 0;
      new_arc(PLACE, 180.);
      break;
@@ -823,8 +827,8 @@ int callback(int event, int mx, int my, KeySym key,
    {
      if(semaphore >= 2) break;
      mx_save = mx; my_save = my;
-     mx_double_save=mousex_snap;
-     my_double_save=mousey_snap;
+     xctx->mx_double_save=xctx->mousex_snap;
+     xctx->my_double_save=xctx->mousey_snap;
      last_command = 0;
      new_arc(PLACE, 360.);
      break;
@@ -858,13 +862,13 @@ int callback(int event, int mx, int my, KeySym key,
    {
     if(semaphore >= 2) break;
     rebuild_selected_array();
-    if(lastselected==0 ) {
+    if(xctx->lastsel==0 ) {
       my_snprintf(str, S(str), "edit_file {%s}", abs_sym_path(xctx->sch[xctx->currsch], ""));
       tcleval(str);
     }
-    else if(selectedgroup[0].type==ELEMENT) {
+    else if(xctx->sel_array[0].type==ELEMENT) {
       my_snprintf(str, S(str), "edit_file {%s}",
-         abs_sym_path(xctx->inst[selectedgroup[0].n].name, ""));
+         abs_sym_path(xctx->inst[xctx->sel_array[0].n].name, ""));
       tcleval(str);
 
     }
@@ -886,15 +890,15 @@ int callback(int event, int mx, int my, KeySym key,
     last_command = 0;
     unselect_all();
 
-    /* place_symbol(-1,NULL,mousex_snap, mousey_snap, 0, 0, NULL,3, 1);*/
+    /* place_symbol(-1,NULL,xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL,3, 1);*/
     mx_save = mx; my_save = my;
-    mx_double_save = mousex_snap;
-    my_double_save = mousey_snap;
-    if(place_symbol(-1,NULL,mousex_snap, mousey_snap, 0, 0, NULL, 4, 1) ) {
-      mousey_snap = my_double_save;
-      mousex_snap = mx_double_save;
+    xctx->mx_double_save = xctx->mousex_snap;
+    xctx->my_double_save = xctx->mousey_snap;
+    if(place_symbol(-1,NULL,xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL, 4, 1) ) {
+      xctx->mousey_snap = xctx->my_double_save;
+      xctx->mousex_snap = xctx->mx_double_save;
       move_objects(START,0,0,0);
-      ui_state |= PLACE_SYMBOL;
+      xctx->ui_state |= PLACE_SYMBOL;
     }
     break;
    }
@@ -1034,10 +1038,10 @@ int callback(int event, int mx, int my, KeySym key,
     push_undo();
     round_schematic_to_grid(cadsnap);
     set_modify(1);
-    prepared_hash_instances=0;
-    prepared_hash_wires=0;
-    prepared_netlist_structs=0;
-    prepared_hilight_structs=0;
+    xctx->prep_hash_inst=0;
+    xctx->prep_hash_wires=0;
+    xctx->prep_net_structs=0;
+    xctx->prep_hi_structs=0;
 
     draw();
     break;
@@ -1101,15 +1105,15 @@ int callback(int event, int mx, int my, KeySym key,
    }
    if(key=='F' && state==ShiftMask)                     /* Flip */
    {
-    if(ui_state & STARTMOVE) move_objects(FLIP,0,0,0);
-    else if(ui_state & STARTCOPY) copy_objects(FLIP);
+    if(xctx->ui_state & STARTMOVE) move_objects(FLIP,0,0,0);
+    else if(xctx->ui_state & STARTCOPY) copy_objects(FLIP);
     else {
       rebuild_selected_array();
       mx_save = mx; my_save = my;
-      mx_double_save=mousex_snap;
-      my_double_save=mousey_snap;
+      xctx->mx_double_save=xctx->mousex_snap;
+      xctx->my_double_save=xctx->mousey_snap;
       move_objects(START,0,0,0);
-      if(lastselected>1) move_objects(FLIP,0,0,0);
+      if(xctx->lastsel>1) move_objects(FLIP,0,0,0);
       else               move_objects(FLIP|ROTATELOCAL,0,0,0);
       move_objects(END,0,0,0);
     }
@@ -1123,13 +1127,13 @@ int callback(int event, int mx, int my, KeySym key,
    }
    if(key=='f' && state==Mod1Mask)              /* flip objects around their anchor points 20171208 */
    {
-    if(ui_state & STARTMOVE) move_objects(FLIP|ROTATELOCAL,0,0,0);
-    else if(ui_state & STARTCOPY) copy_objects(FLIP|ROTATELOCAL);
+    if(xctx->ui_state & STARTMOVE) move_objects(FLIP|ROTATELOCAL,0,0,0);
+    else if(xctx->ui_state & STARTCOPY) copy_objects(FLIP|ROTATELOCAL);
     else {
       rebuild_selected_array();
       mx_save = mx; my_save = my;
-      mx_double_save=mousex_snap;
-      my_double_save=mousey_snap;
+      xctx->mx_double_save=xctx->mousex_snap;
+      xctx->my_double_save=xctx->mousey_snap;
       move_objects(START,0,0,0);
       move_objects(FLIP|ROTATELOCAL,0,0,0);
       move_objects(END,0,0,0);
@@ -1138,15 +1142,15 @@ int callback(int event, int mx, int my, KeySym key,
    }
    if(key=='R' && state==ShiftMask)             /* Rotate */
    {
-    if(ui_state & STARTMOVE) move_objects(ROTATE,0,0,0);
-    else if(ui_state & STARTCOPY) copy_objects(ROTATE);
+    if(xctx->ui_state & STARTMOVE) move_objects(ROTATE,0,0,0);
+    else if(xctx->ui_state & STARTCOPY) copy_objects(ROTATE);
     else {
       rebuild_selected_array();
       mx_save = mx; my_save = my;
-      mx_double_save=mousex_snap;
-      my_double_save=mousey_snap;
+      xctx->mx_double_save=xctx->mousex_snap;
+      xctx->my_double_save=xctx->mousey_snap;
       move_objects(START,0,0,0);
-      if(lastselected>1) move_objects(ROTATE,0,0,0);
+      if(xctx->lastsel>1) move_objects(ROTATE,0,0,0);
       else               move_objects(ROTATE|ROTATELOCAL,0,0,0);
       move_objects(END,0,0,0);
     }
@@ -1155,35 +1159,35 @@ int callback(int event, int mx, int my, KeySym key,
    }
    if(key=='r' && state==Mod1Mask)              /* Rotate objects around their anchor points 20171208 */
    {
-    if(ui_state & STARTMOVE) move_objects(ROTATE|ROTATELOCAL,0,0,0);
-    else if(ui_state & STARTCOPY) copy_objects(ROTATE|ROTATELOCAL);
+    if(xctx->ui_state & STARTMOVE) move_objects(ROTATE|ROTATELOCAL,0,0,0);
+    else if(xctx->ui_state & STARTCOPY) copy_objects(ROTATE|ROTATELOCAL);
     else {
       rebuild_selected_array();
       mx_save = mx; my_save = my;
-      mx_double_save=mousex_snap;
-      my_double_save=mousey_snap;
+      xctx->mx_double_save=xctx->mousex_snap;
+      xctx->my_double_save=xctx->mousey_snap;
       move_objects(START,0,0,0);
       move_objects(ROTATE|ROTATELOCAL,0,0,0);
       move_objects(END,0,0,0);
     }
     break;
    }
-   if(key=='m' && state==0 && !(ui_state & (STARTMOVE | STARTCOPY)))/* move selected obj. */
+   if(key=='m' && state==0 && !(xctx->ui_state & (STARTMOVE | STARTCOPY)))/* move selected obj. */
    {
     mx_save = mx; my_save = my;
-    mx_double_save=mousex_snap;
-    my_double_save=mousey_snap;
+    xctx->mx_double_save=xctx->mousex_snap;
+    xctx->my_double_save=xctx->mousey_snap;
     move_objects(START,0,0,0);
     break;
    }
 
    if(key=='c' && state==0 &&           /* copy selected obj.  */
-     !(ui_state & (STARTMOVE | STARTCOPY)))
+     !(xctx->ui_state & (STARTMOVE | STARTCOPY)))
    {
     if(semaphore >= 2) break;
     mx_save = mx; my_save = my;
-    mx_double_save=mousex_snap;
-    my_double_save=mousey_snap;
+    xctx->mx_double_save=xctx->mousex_snap;
+    xctx->my_double_save=xctx->mousey_snap;
     copy_objects(START);
     break;
    }
@@ -1353,9 +1357,9 @@ int callback(int event, int mx, int my, KeySym key,
       ORDER(x1, y1, x2, y2);
       storeobject(-1, x1, y1, x2, y2, WIRE,0,0,NULL);
     }
-    prepared_netlist_structs = 0;
-    prepared_hilight_structs = 0;
-    prepared_hash_wires = 0;
+    xctx->prep_net_structs = 0;
+    xctx->prep_hi_structs = 0;
+    xctx->prep_hash_wires = 0;
     zoom_full(1, 0);
     break;
    }
@@ -1385,21 +1389,21 @@ int callback(int event, int mx, int my, KeySym key,
    break;
 
   case ButtonPress:                     /* end operation */
-   dbg(1, "callback(): ButtonPress  ui_state=%ld state=%d\n",ui_state,state);
-   if(ui_state & STARTPAN2) {
-     ui_state &=~STARTPAN2;
+   dbg(1, "callback(): ButtonPress  xctx->ui_state=%ld state=%d\n",xctx->ui_state,state);
+   if(xctx->ui_state & STARTPAN2) {
+     xctx->ui_state &=~STARTPAN2;
      mx_save = mx; my_save = my;
-     mx_double_save=mousex_snap;
-     my_double_save=mousey_snap;
+     xctx->mx_double_save=xctx->mousex_snap;
+     xctx->my_double_save=xctx->mousey_snap;
 
      break;
    }
    if(button==Button5 && state == 0 ) view_unzoom(CADZOOMSTEP);
    else if(button == Button3 && semaphore <2) {
-     if(!(ui_state & STARTPOLYGON) && !(state & Mod1Mask) ) {
+     if(!(xctx->ui_state & STARTPOLYGON) && !(state & Mod1Mask) ) {
        last_command = 0;
        unselect_all();
-       select_object(mousex,mousey,SELECTED, 1);
+       select_object(xctx->mousex,xctx->mousey,SELECTED, 1);
        rebuild_selected_array();
        if(state & ShiftMask) {
          edit_property(1);
@@ -1430,29 +1434,29 @@ int callback(int event, int mx, int my, KeySym key,
    else if(button==Button1 && (state & Mod1Mask) ) {
      last_command = 0;
      mx_save = mx; my_save = my;
-     mx_double_save=mousex_snap;
-     my_double_save=mousey_snap;
+     xctx->mx_double_save=xctx->mousex_snap;
+     xctx->my_double_save=xctx->mousey_snap;
 
      /* useless code ? 20200905 */
      /* if(semaphore<2) {
        rebuild_selected_array();
-       if(lastselected==0) ui_state &=~SELECTION;
+       if(xctx->lastsel==0) xctx->ui_state &=~SELECTION;
      } */
 
-     select_object(mousex, mousey, 0, 0);
+     select_object(xctx->mousex, xctx->mousey, 0, 0);
      rebuild_selected_array();
-     if(lastselected==0) ui_state &=~SELECTION;
+     if(xctx->lastsel==0) xctx->ui_state &=~SELECTION;
    }
    else if(button==Button2 && (state == 0)) {
      pan2(START, mx, my);
-     ui_state |= STARTPAN2;
+     xctx->ui_state |= STARTPAN2;
      break;
    }
    else if(semaphore >= 2) { /* button1 click to select another instance while edit prop dialog open */
      if(button==Button1 && state==0 && tclgetvar("edit_symbol_prop_new_sel")[0]) {
        tcleval("set edit_symbol_prop_new_sel 1; .dialog.f1.b1 invoke"); /* invoke 'OK' of edit prop dialog */
      } else if(button==Button1 && (state & ShiftMask) && tclgetvar("edit_symbol_prop_new_sel")[0]) {
-       select_object(mousex, mousey, SELECTED, 0);
+       select_object(xctx->mousex, xctx->mousey, SELECTED, 0);
        rebuild_selected_array();
      }
      break;
@@ -1464,160 +1468,160 @@ int callback(int event, int mx, int my, KeySym key,
        if(last_command == STARTWIRE)  start_wire(mx, my);
        break;
      }
-     if(!(ui_state & STARTPOLYGON) && !(ui_state & STARTWIRE) && !(ui_state & STARTLINE) ) {
+     if(!(xctx->ui_state & STARTPOLYGON) && !(xctx->ui_state & STARTWIRE) && !(xctx->ui_state & STARTLINE) ) {
        horizontal_move = vertical_move=0;
        tcleval("set vertical_move 0; set horizontal_move 0" );
      }
-     if(ui_state & MENUSTARTTEXT) {
-       place_text(1, mousex_snap, mousey_snap);
-       ui_state &=~MENUSTARTTEXT;
+     if(xctx->ui_state & MENUSTARTTEXT) {
+       place_text(1, xctx->mousex_snap, xctx->mousey_snap);
+       xctx->ui_state &=~MENUSTARTTEXT;
        break;
      }
-     if(ui_state & MENUSTARTWIRE) {
+     if(xctx->ui_state & MENUSTARTWIRE) {
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
-       new_wire(PLACE, mousex_snap, mousey_snap);
-       ui_state &=~MENUSTARTWIRE;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
+       new_wire(PLACE, xctx->mousex_snap, xctx->mousey_snap);
+       xctx->ui_state &=~MENUSTARTWIRE;
        break;
      }
-     if(ui_state & MENUSTARTSNAPWIRE) {
+     if(xctx->ui_state & MENUSTARTSNAPWIRE) {
        double x, y;
        int xx, yy;
 
-       find_closest_net_or_symbol_pin(mousex, mousey, &x, &y);
+       find_closest_net_or_symbol_pin(xctx->mousex, xctx->mousey, &x, &y);
        xx = X_TO_SCREEN(x);
        yy = Y_TO_SCREEN(y);
        mx_save = xx; my_save = yy;
-       mx_double_save = ROUND(x / cadsnap) * cadsnap;
-       my_double_save = ROUND(y / cadsnap) * cadsnap;
+       xctx->mx_double_save = ROUND(x / cadsnap) * cadsnap;
+       xctx->my_double_save = ROUND(y / cadsnap) * cadsnap;
 
        new_wire(PLACE, x, y);
-       ui_state &=~MENUSTARTSNAPWIRE;
+       xctx->ui_state &=~MENUSTARTSNAPWIRE;
        break;
      }
-     if(ui_state & MENUSTARTLINE) {
+     if(xctx->ui_state & MENUSTARTLINE) {
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
        new_line(PLACE);
-       ui_state &=~MENUSTARTLINE;
+       xctx->ui_state &=~MENUSTARTLINE;
        break;
      }
-     if(ui_state & MENUSTARTRECT) {
+     if(xctx->ui_state & MENUSTARTRECT) {
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
        new_rect(PLACE);
-       ui_state &=~MENUSTARTRECT;
+       xctx->ui_state &=~MENUSTARTRECT;
        break;
      }
-     if(ui_state & MENUSTARTPOLYGON) {
+     if(xctx->ui_state & MENUSTARTPOLYGON) {
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
        new_polygon(PLACE);
-       ui_state &=~MENUSTARTPOLYGON;
+       xctx->ui_state &=~MENUSTARTPOLYGON;
        break;
      }
-     if(ui_state & MENUSTARTARC) {
+     if(xctx->ui_state & MENUSTARTARC) {
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
        new_arc(PLACE, 180.);
-       ui_state &=~MENUSTARTARC;
+       xctx->ui_state &=~MENUSTARTARC;
        break;
      }
-     if(ui_state & MENUSTARTCIRCLE) {
+     if(xctx->ui_state & MENUSTARTCIRCLE) {
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
        new_arc(PLACE, 360.);
-       ui_state &=~MENUSTARTCIRCLE;
+       xctx->ui_state &=~MENUSTARTCIRCLE;
        break;
      }
-     if(ui_state & MENUSTARTZOOM) {
+     if(xctx->ui_state & MENUSTARTZOOM) {
        zoom_box(START);
-       ui_state &=~MENUSTARTZOOM;
+       xctx->ui_state &=~MENUSTARTZOOM;
        break;
      }
-     if(ui_state & STARTPAN) {
+     if(xctx->ui_state & STARTPAN) {
        pan(END);
        break;
      }
-     if(ui_state & STARTZOOM) {
+     if(xctx->ui_state & STARTZOOM) {
        zoom_box(END);
        break;
      }
-     if(ui_state & STARTWIRE) {
+     if(xctx->ui_state & STARTWIRE) {
        if(persistent_command) {
          if(!vertical_move) {
            mx_save = mx;
-           mx_double_save=mousex_snap;
+           xctx->mx_double_save=xctx->mousex_snap;
          }
          if(!horizontal_move) {
            my_save = my;
-           my_double_save=mousey_snap;
+           xctx->my_double_save=xctx->mousey_snap;
          }
-         if(horizontal_move) mousey_snap = my_double_save;
-         if(vertical_move) mousex_snap = mx_double_save;
-         new_wire(PLACE, mousex_snap, mousey_snap);
+         if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+         if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
+         new_wire(PLACE, xctx->mousex_snap, xctx->mousey_snap);
 
        } else {
-         new_wire(PLACE|END, mousex_snap, mousey_snap);
+         new_wire(PLACE|END, xctx->mousex_snap, xctx->mousey_snap);
        }
        break;
      }
-     if(ui_state & STARTARC) {
+     if(xctx->ui_state & STARTARC) {
        new_arc(SET, 0);
        break;
      }
-     if(ui_state & STARTLINE) {
+     if(xctx->ui_state & STARTLINE) {
        if(persistent_command) {
          if(!vertical_move) {
            mx_save = mx;
-           mx_double_save=mousex_snap;
+           xctx->mx_double_save=xctx->mousex_snap;
          }
          if(!horizontal_move) {
            my_save = my;
-           my_double_save=mousey_snap;
+           xctx->my_double_save=xctx->mousey_snap;
          }
-         if(horizontal_move) mousey_snap = my_double_save;
-         if(vertical_move) mousex_snap = mx_double_save;
+         if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+         if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
          new_line(PLACE);
        } else {
          new_line(PLACE|END);
        }
        break;
      }
-     if(ui_state & STARTRECT) {
+     if(xctx->ui_state & STARTRECT) {
        new_rect(PLACE|END);
        break;
      }
-     if(ui_state & STARTPOLYGON) {
-       if(horizontal_move) mousey_snap = my_double_save;
-       if(vertical_move) mousex_snap = mx_double_save;
+     if(xctx->ui_state & STARTPOLYGON) {
+       if(horizontal_move) xctx->mousey_snap = xctx->my_double_save;
+       if(vertical_move) xctx->mousex_snap = xctx->mx_double_save;
        new_polygon(ADD);
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
        horizontal_move = vertical_move=0;
        tcleval("set vertical_move 0; set horizontal_move 0" );
        break;
      }
-     if(ui_state & STARTMOVE) {
+     if(xctx->ui_state & STARTMOVE) {
        move_objects(END,0,0,0);
-       ui_state &=~START_SYMPIN;
+       xctx->ui_state &=~START_SYMPIN;
        break;
      }
-     if(ui_state & STARTCOPY) {
+     if(xctx->ui_state & STARTCOPY) {
        copy_objects(END);
        break;
      }
-     if( !(ui_state & STARTSELECT) && !(ui_state & STARTWIRE) && !(ui_state & STARTLINE)  ) {
-       int prev_last_sel = lastselected;
+     if( !(xctx->ui_state & STARTSELECT) && !(xctx->ui_state & STARTWIRE) && !(xctx->ui_state & STARTLINE)  ) {
+       int prev_last_sel = xctx->lastsel;
        mx_save = mx; my_save = my;
-       mx_double_save=mousex_snap;
-       my_double_save=mousey_snap;
+       xctx->mx_double_save=xctx->mousex_snap;
+       xctx->my_double_save=xctx->mousey_snap;
        if( !(state & ShiftMask) && !(state & Mod1Mask) ) {
          unselect_all();
 #ifndef __unix__
@@ -1625,7 +1629,7 @@ int callback(int event, int mx, int my, KeySym key,
            xrect[0].width, xrect[0].height, xrect[0].x, xrect[0].y);
 #endif
        }
-       sel = select_object(mousex, mousey, SELECTED, 0);
+       sel = select_object(xctx->mousex, xctx->mousey, SELECTED, 0);
        rebuild_selected_array();
 #ifndef __unix__
        draw_selection(gc[SELLAYER], 0); /* 20181009 moved outside of cadlayers loop */
@@ -1653,7 +1657,7 @@ int callback(int event, int mx, int my, KeySym key,
        }
        if(auto_hilight) {
          hilight_net(0);
-         if(lastselected) {
+         if(xctx->lastsel) {
            redraw_hilights();
            /* draw_hilight_net(1); */
          }
@@ -1663,17 +1667,17 @@ int callback(int event, int mx, int my, KeySym key,
    } /* button==Button1 */
    break;
   case ButtonRelease:
-   if(ui_state & STARTPAN2) {
-     ui_state &=~STARTPAN2;
+   if(xctx->ui_state & STARTPAN2) {
+     xctx->ui_state &=~STARTPAN2;
      mx_save = mx; my_save = my;
-     mx_double_save=mousex_snap;
-     my_double_save=mousey_snap;
+     xctx->mx_double_save=xctx->mousex_snap;
+     xctx->my_double_save=xctx->mousey_snap;
 
      break;
    }
-   dbg(1, "callback(): ButtonRelease  ui_state=%ld state=%d\n",ui_state,state);
+   dbg(1, "callback(): ButtonRelease  xctx->ui_state=%ld state=%d\n",xctx->ui_state,state);
    if(semaphore >= 2) break;
-   if(ui_state & STARTSELECT) {
+   if(xctx->ui_state & STARTSELECT) {
      if(state & ControlMask) {
        enable_stretch=1;
        select_rect(END,-1);
@@ -1685,22 +1689,22 @@ int callback(int event, int mx, int my, KeySym key,
      }
      rebuild_selected_array();
      my_snprintf(str, S(str), "mouse = %.16g %.16g - selected: %d path: %s",
-       mousex_snap, mousey_snap, lastselected, xctx->sch_path[xctx->currsch] );
+       xctx->mousex_snap, xctx->mousey_snap, xctx->lastsel, xctx->sch_path[xctx->currsch] );
      statusmsg(str,1);
 
    }
    break;
   case -3:  /* double click  : edit prop */
    if(semaphore >= 2) break;
-   dbg(1, "callback(): DoubleClick  ui_state=%ld state=%d\n",ui_state,state);
+   dbg(1, "callback(): DoubleClick  xctx->ui_state=%ld state=%d\n",xctx->ui_state,state);
    if(button==Button1) {
-     if(ui_state == STARTWIRE) {
-       ui_state &= ~STARTWIRE;
+     if(xctx->ui_state == STARTWIRE) {
+       xctx->ui_state &= ~STARTWIRE;
      }
-     if(ui_state == STARTLINE) {
-       ui_state &= ~STARTLINE;
+     if(xctx->ui_state == STARTLINE) {
+       xctx->ui_state &= ~STARTLINE;
      }
-     if( (ui_state & STARTPOLYGON) && (state ==0 ) ) {
+     if( (xctx->ui_state & STARTPOLYGON) && (state ==0 ) ) {
        new_polygon(SET);
      }
    }
diff --git a/src/check.c b/src/check.c
index 4d1725f1..c2e7bb9b 100644
--- a/src/check.c
+++ b/src/check.c
@@ -56,10 +56,10 @@ void update_conn_cues(int draw_cues, int dr_win)
   if(!xctx->wires) return;
   if(!draw_dots) return;
   if(cadhalfdotsize*xctx->mooz<0.7) return;
-  x1 = X_TO_XSCHEM(areax1);
-  y1 = Y_TO_XSCHEM(areay1);
-  x2 = X_TO_XSCHEM(areax2);
-  y2 = Y_TO_XSCHEM(areay2);
+  x1 = X_TO_XSCHEM(xctx->areax1);
+  y1 = Y_TO_XSCHEM(xctx->areay1);
+  x2 = X_TO_XSCHEM(xctx->areax2);
+  y2 = Y_TO_XSCHEM(xctx->areay2);
   for(init_wire_iterator(x1, y1, x2, y2); ( wireptr = wire_iterator_next() ) ;) {
     k=wireptr->n;
     /* optimization when editing small areas (detailed zoom)  of a huge schematic */
@@ -142,7 +142,7 @@ void trim_wires(void)
   static unsigned short *wireflag=NULL;
 
   doloops = 0;
-  prepared_hash_wires = 0;
+  xctx->prep_hash_wires = 0;
   timer(0);
   do {
     dbg(1, "trim_wires(): start: %g\n", timer(1));
@@ -264,7 +264,7 @@ void trim_wires(void)
     }
     xctx->wires -= j;
     if(j) {
-      prepared_hash_wires=0;
+      xctx->prep_hash_wires=0;
       changed = 1;
     }
     dbg(1, "trim_wires(): delete_1: %g\n", timer(1));
@@ -359,15 +359,15 @@ void trim_wires(void)
     }
     xctx->wires -= j;
     if(j) {
-      prepared_hash_wires=0; /* after wire deletions full rehash is needed */
+      xctx->prep_hash_wires=0; /* after wire deletions full rehash is needed */
       changed = 1;
     }
     dbg(1, "trim_wires(): delete_2: %g\n", timer(1));
 
     if(changed) {
-      need_rebuild_selected_array = 1;
-      prepared_netlist_structs=0;
-      prepared_hilight_structs=0;
+      xctx->need_reb_sel_arr = 1;
+      xctx->prep_net_structs=0;
+      xctx->prep_hi_structs=0;
       set_modify(1);
     }
   } while(changed);
@@ -384,12 +384,12 @@ void break_wires_at_pins(void)
   int changed=0;
 
   hash_wires();
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
   rebuild_selected_array();
 
   /* for(k=0;k<xctx->instances;k++) */
-  for(j=0;j<lastselected;j++) if(selectedgroup[j].type==ELEMENT) {
-    k = selectedgroup[j].n;
+  for(j=0;j<xctx->lastsel;j++) if(xctx->sel_array[j].type==ELEMENT) {
+    k = xctx->sel_array[j].n;
     if( (rects = (xctx->inst[k].ptr+ xctx->sym)->rects[PINLAYER]) > 0 )
     {
       for(r=0;r<rects;r++)
@@ -426,7 +426,7 @@ void break_wires_at_pins(void)
               xctx->wire[xctx->wires].node=NULL;
               hash_wire(XINSERT, xctx->wires, 0);  /* insertion happens at beginning of list */
               my_strdup(32, &xctx->wire[xctx->wires].node, xctx->wire[i].node);
-              need_rebuild_selected_array=1;
+              xctx->need_reb_sel_arr=1;
               xctx->wires++;
               xctx->wire[i].x1 = x0;
               xctx->wire[i].y1 = y0;
@@ -436,14 +436,14 @@ void break_wires_at_pins(void)
       }
     }
   }
-  /* prepared_hash_wires=0; */
+  /* xctx->prep_hash_wires=0; */
   /* hash_wires(); */
   rebuild_selected_array();
-  for(j=0;j<lastselected;j++) if(selectedgroup[j].type==WIRE) {
+  for(j=0;j<xctx->lastsel;j++) if(xctx->sel_array[j].type==WIRE) {
   /* for(k=0; k < xctx->wires; k++) { */
     int l;
 
-    k = selectedgroup[j].n;
+    k = xctx->sel_array[j].n;
     for(l=0;l<2;l++) {
       if(l==0 ) {
         x0 = xctx->wire[k].x1;
@@ -481,7 +481,7 @@ void break_wires_at_pins(void)
               xctx->wire[xctx->wires].bus=0;
             xctx->wire[xctx->wires].node=NULL;
             hash_wire(XINSERT, xctx->wires, 0);  /* insertion happens at beginning of list */
-            need_rebuild_selected_array=1;
+            xctx->need_reb_sel_arr=1;
             xctx->wires++;
             xctx->wire[i].x1 = x0;
             xctx->wire[i].y1 = y0;
@@ -491,9 +491,9 @@ void break_wires_at_pins(void)
     }
   }
   set_modify(1);
-  prepared_netlist_structs=0;
-  prepared_hilight_structs=0;
-  prepared_hash_wires=0;
+  xctx->prep_net_structs=0;
+  xctx->prep_hi_structs=0;
+  xctx->prep_hash_wires=0;
   /*update_conn_cues(0, 0); */
 
 }
diff --git a/src/clip.c b/src/clip.c
index ac8c1777..a6e364f0 100644
--- a/src/clip.c
+++ b/src/clip.c
@@ -31,9 +31,9 @@
 static int outcode(double x,double y)
 {
  register int code=0;
- if(y > xschem_h) code = UP;
+ if(y > xctx->xschem_h) code = UP;
  else if(y < 0) code = DOWN;
- if(x > xschem_w) code |= RIGHT;
+ if(x > xctx->xschem_w) code |= RIGHT;
  else if(x < 0) code |= LEFT;
  return code;
 }
@@ -53,11 +53,11 @@ int clip( double *xa,double *ya,double *xb,double *yb)
   {
    outpoint=outa? outa:outb;
    if(UP & outpoint)
-     {x= *xa + (*xb-*xa) * (xschem_h - *ya) / (*yb - *ya); y = xschem_h;}
+     {x= *xa + (*xb-*xa) * (xctx->xschem_h - *ya) / (*yb - *ya); y = xctx->xschem_h;}
    else if(DOWN & outpoint)
      {x= *xa + (*xb-*xa) * (0 - *ya) / (*yb - *ya); y = 0;}
    else if(RIGHT & outpoint)
-     {y= *ya + (*yb-*ya) * (xschem_w - *xa) / (*xb - *xa); x = xschem_w;}
+     {y= *ya + (*yb-*ya) * (xctx->xschem_w - *xa) / (*xb - *xa); x = xctx->xschem_w;}
    /* else if(LEFT & outpoint) */
    else
      {y= *ya + (*yb-*ya) * (0 - *xa) / (*xb - *xa); x = 0;}
@@ -98,7 +98,7 @@ double dist_from_rect(double mx, double my, double x1, double y1, double x2, dou
  if(tmp < dist) dist=tmp;
 
  dbg(1, "dist_from_rect(): x1,y1,x2,y2=%.16g,%.16g,%.16g,%.16g\n",x1,y1,x2,y2);
- dbg(1, "dist_from_rect(): mx,my==%.16g,%.16g\n",mousex,mousey);
+ dbg(1, "dist_from_rect(): mx,my==%.16g,%.16g\n",xctx->mousex,xctx->mousey);
  dbg(1, "dist_from_rect(): dist=%.16g\n",dist);
  return dist*dist;
 }
diff --git a/src/draw.c b/src/draw.c
index bfe8c323..db37bd4d 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -59,15 +59,15 @@ void print_image()
   if(!has_x) return ;
 
   changed_size = 0;
-  w = ww = xschem_w;
-  h = hh = xschem_h;
+  w = ww = xctx->xschem_w;
+  h = hh = xctx->xschem_h;
   if(!plotfile[0]) {
-    my_snprintf(cmd, S(cmd), "input_line {Enter image size} {} {%dx%d}", xschem_w, xschem_h);
+    my_snprintf(cmd, S(cmd), "input_line {Enter image size} {} {%dx%d}", xctx->xschem_w, xctx->xschem_h);
     tcleval(cmd);
     if(sscanf(tclresult(), "%dx%d", &w, &h) != 2) {
-      w = xschem_w; h = xschem_h;
+      w = xctx->xschem_w; h = xctx->xschem_h;
     } else {
-     if(w != xschem_w || h != xschem_h) changed_size = 1;
+     if(w != xctx->xschem_w || h != xctx->xschem_h) changed_size = 1;
     }
     my_strdup(60, &tmpstring, "tk_getSaveFile -title {Select destination file} -initialdir [pwd]");
     tcleval(tmpstring);
@@ -77,7 +77,7 @@ void print_image()
     else return;
   }
 
-  modified_save=modified; /* 20161121 save state */
+  modified_save=xctx->modified; /* 20161121 save state */
   push_undo();
   trim_wires();    /* 20161121 add connection boxes on wires but undo at end */
 
@@ -85,20 +85,20 @@ void print_image()
 
   xrect[0].x = 0;
   xrect[0].y = 0;
-  xschem_w = xrect[0].width = w;
-  xschem_h = xrect[0].height = h;
-  areax2 = w+2*INT_WIDTH(xctx->lw);
-  areay2 = h+2*INT_WIDTH(xctx->lw);
-  areax1 = -2*INT_WIDTH(xctx->lw);
-  areay1 = -2*INT_WIDTH(xctx->lw);
-  areaw = areax2-areax1;
-  areah = areay2-areay1;
+  xctx->xschem_w = xrect[0].width = w;
+  xctx->xschem_h = xrect[0].height = h;
+  xctx->areax2 = w+2*INT_WIDTH(xctx->lw);
+  xctx->areay2 = h+2*INT_WIDTH(xctx->lw);
+  xctx->areax1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areay1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areaw = xctx->areax2-xctx->areax1;
+  xctx->areah = xctx->areay2-xctx->areay1;
   saveorx = xctx->xorigin;
   saveory = xctx->yorigin;
   savezoom = xctx->zoom;
 #ifdef __unix__
   XFreePixmap(display,save_pixmap);
-  /* save_pixmap = XCreatePixmap(display,window,areaw,areah,depth); */
+  /* save_pixmap = XCreatePixmap(display,window,xctx->areaw,xctx->areah,depth); */
   save_pixmap = XCreatePixmap(display,window,w,h,depth); /* 20161119 pixmap should be exact size of  */
                                                          /* cliprectangle to avoid random borders */
 #else
@@ -156,29 +156,29 @@ void print_image()
   } else tcleval( "convert_to_png plot.xpm plot.png");
   my_strncpy(plotfile,"", S(plotfile));
   pop_undo(0); /* 20161121 restore state */
-  modified=modified_save;
+  xctx->modified=modified_save;
 
   w=ww;h=hh;
   xrect[0].x = 0;
   xrect[0].y = 0;
-  xschem_w = xrect[0].width = w;
-  xschem_h = xrect[0].height = h;
-  areax2 = w+2*INT_WIDTH(xctx->lw);
-  areay2 = h+2*INT_WIDTH(xctx->lw);
-  areax1 = -2*INT_WIDTH(xctx->lw);
-  areay1 = -2*INT_WIDTH(xctx->lw);
-  areaw = areax2-areax1;
-  areah = areay2-areay1;
+  xctx->xschem_w = xrect[0].width = w;
+  xctx->xschem_h = xrect[0].height = h;
+  xctx->areax2 = w+2*INT_WIDTH(xctx->lw);
+  xctx->areay2 = h+2*INT_WIDTH(xctx->lw);
+  xctx->areax1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areay1 = -2*INT_WIDTH(xctx->lw);
+  xctx->areaw = xctx->areax2-xctx->areax1;
+  xctx->areah = xctx->areay2-xctx->areay1;
   xctx->zoom = savezoom;
   xctx->mooz = 1/xctx->zoom;
   xctx->xorigin = saveorx;
   xctx->yorigin = saveory;
 #ifdef __unix__
   XFreePixmap(display,save_pixmap);
-  save_pixmap = XCreatePixmap(display,window,areaw,areah,depth);
+  save_pixmap = XCreatePixmap(display,window,xctx->areaw,xctx->areah,depth);
 #else
   Tk_FreePixmap(display, save_pixmap);
-  save_pixmap = Tk_GetPixmap(display, window, areaw, areah, depth);
+  save_pixmap = Tk_GetPixmap(display, window, xctx->areaw, xctx->areah, depth);
 #endif
   XSetTile(display, gctiled, save_pixmap);
 
@@ -329,7 +329,7 @@ void draw_string(int layer, int what, const char *str, int rot, int flip, int hc
   if(size*xctx->mooz>1600) return; /* too big */
 
   text_bbox(str, xscale, yscale, rot, flip, hcenter, vcenter, x,y, &textx1,&texty1,&textx2,&texty2);
-  if(!textclip(areax1,areay1,areax2,areay2,textx1,texty1,textx2,texty2)) {
+  if(!textclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,textx1,texty1,textx2,texty2)) {
     return;
   }
   
@@ -410,7 +410,7 @@ void draw_string(int layer, int what, const char *str, int rot, int flip, int hc
   text_bbox(str, xscale, yscale, rot, flip, hcenter, vcenter, x1,y1, &textx1,&texty1,&textx2,&texty2);
   xscale*=nocairo_font_xscale;
   yscale*=nocairo_font_yscale;
-  if(!textclip(areax1,areay1,areax2,areay2,textx1,texty1,textx2,texty2)) return;
+  if(!textclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,textx1,texty1,textx2,texty2)) return;
   x1=textx1;y1=texty1;
   if(rot&1) {y1=texty2;rot=3;}
   else rot=0;
@@ -499,7 +499,7 @@ void draw_symbol(int what,int c, int n,int layer,int tmp_flip, int rot,
       xctx->inst[n].flags|=1;
       return;
     }
-    else if(OUTSIDE(x1,y1,x2,y2,areax1,areay1,areax2,areay2))
+    else if(OUTSIDE(x1,y1,x2,y2,xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2))
     {
      xctx->inst[n].flags|=1;
      return;
@@ -659,7 +659,7 @@ void draw_temp_symbol(int what, GC gc, int n,int layer,int tmp_flip, int rot,
    x2=X_TO_SCREEN(xctx->inst[n].x2+xoffset);
    y1=Y_TO_SCREEN(xctx->inst[n].y1+yoffset);
    y2=Y_TO_SCREEN (xctx->inst[n].y2+yoffset);
-   if(OUTSIDE(x1,y1,x2,y2,areax1,areay1,areax2,areay2))
+   if(OUTSIDE(x1,y1,x2,y2,xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2))
    {
     xctx->inst[n].flags|=1;
     return;
@@ -761,22 +761,22 @@ void drawgrid()
  delta=cadgrid*xctx->mooz;
  while(delta<CADGRIDTHRESHOLD) delta*=CADGRIDMULTIPLY;  /* <-- to be improved,but works */
  x = xctx->xorigin*xctx->mooz;y = xctx->yorigin*xctx->mooz;
- if(y>areay1 && y<areay2)
+ if(y>xctx->areay1 && y<xctx->areay2)
  {
-  if(draw_window) XDrawLine(display, window, gc[GRIDLAYER],areax1+1,(int)y, areax2-1, (int)y);
+  if(draw_window) XDrawLine(display, window, gc[GRIDLAYER],xctx->areax1+1,(int)y, xctx->areax2-1, (int)y);
   if(draw_pixmap)
-    XDrawLine(display, save_pixmap, gc[GRIDLAYER],areax1+1,(int)y, areax2-1, (int)y);
+    XDrawLine(display, save_pixmap, gc[GRIDLAYER],xctx->areax1+1,(int)y, xctx->areax2-1, (int)y);
  }
- if(x>areax1 && x<areax2)
+ if(x>xctx->areax1 && x<xctx->areax2)
  {
-  if(draw_window) XDrawLine(display, window, gc[GRIDLAYER],(int)x,areay1+1, (int)x, areay2-1);
+  if(draw_window) XDrawLine(display, window, gc[GRIDLAYER],(int)x,xctx->areay1+1, (int)x, xctx->areay2-1);
   if(draw_pixmap)
-    XDrawLine(display, save_pixmap, gc[GRIDLAYER],(int)x,areay1+1, (int)x, areay2-1);
+    XDrawLine(display, save_pixmap, gc[GRIDLAYER],(int)x,xctx->areay1+1, (int)x, xctx->areay2-1);
  }
- tmp = floor((areay1+1)/delta)*delta-fmod(-xctx->yorigin*xctx->mooz,delta);
- for(x=floor((areax1+1)/delta)*delta-fmod(-xctx->xorigin*xctx->mooz,delta);x<areax2;x+=delta)
+ tmp = floor((xctx->areay1+1)/delta)*delta-fmod(-xctx->yorigin*xctx->mooz,delta);
+ for(x=floor((xctx->areax1+1)/delta)*delta-fmod(-xctx->xorigin*xctx->mooz,delta);x<xctx->areax2;x+=delta)
  {
-  for(y=tmp;y<areay2;y+=delta)
+  for(y=tmp;y<xctx->areay2;y+=delta)
   {
    if(i>=CADMAXGRIDPOINTS)
    {
@@ -1006,7 +1006,7 @@ void drawtemparc(GC gc, int what, double x, double y, double r, double a, double
   y1=Y_TO_SCREEN(y1);
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    xarc[i].x=(short)xx1;
    xarc[i].y=(short)yy1;
@@ -1028,7 +1028,7 @@ void drawtemparc(GC gc, int what, double x, double y, double r, double a, double
   y1=Y_TO_SCREEN(y1);
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    XDrawArc(display, window, gc, xx1, yy1, xx2-xx1, yy2-yy1, a*64, b*64);
   }
@@ -1101,7 +1101,7 @@ void filledarc(int c, int what, double x, double y, double r, double a, double b
   y1=Y_TO_SCREEN(y1);
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    xarc[i].x=(short)xx1;
    xarc[i].y=(short)yy1;
@@ -1123,7 +1123,7 @@ void filledarc(int c, int what, double x, double y, double r, double a, double b
   y1=Y_TO_SCREEN(y1);
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    if(draw_window) XFillArc(display, window, gc[c], xx1, yy1, xx2-xx1, yy2-yy1, a*64, b*64);
    if(draw_pixmap) XFillArc(display, save_pixmap, gc[c], xx1, yy1, xx2-xx1, yy2-yy1, a*64, b*64);
@@ -1166,7 +1166,7 @@ void drawarc(int c, int what, double x, double y, double r, double a, double b,
   y1=Y_TO_SCREEN(y1);
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    xarc[i].x=(short)xx1;
    xarc[i].y=(short)yy1;
@@ -1191,7 +1191,7 @@ void drawarc(int c, int what, double x, double y, double r, double a, double b,
   y1=Y_TO_SCREEN(y1);
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    if(dash) {
      char dash_arr[2];
@@ -1245,7 +1245,7 @@ void filledrect(int c, int what, double rectx1,double recty1,double rectx2,doubl
   x2=X_TO_SCREEN(rectx2);
   y2=Y_TO_SCREEN(recty2);
   if(!only_probes && (x2-x1)< 2 && (y2-y1)< 2) return;
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    if(draw_window) XFillRectangle(display, window, gcstipple[c], (int)x1, (int)y1,
     (unsigned int)x2 - (unsigned int)x1,
@@ -1271,7 +1271,7 @@ void filledrect(int c, int what, double rectx1,double recty1,double rectx2,doubl
   x2=X_TO_SCREEN(rectx2);
   y2=Y_TO_SCREEN(recty2);
   if(!only_probes && (x2-x1)< 2 && (y2-y1)< 2) return;
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    r[i].x=(short)x1;
    r[i].y=(short)y1;
@@ -1370,7 +1370,7 @@ void drawpolygon(int c, int what, double *x, double *y, int points, int poly_fil
   y1=Y_TO_SCREEN(y1);
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
-  if( !rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) ) {
+  if( !rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) ) {
     return;
   }
   if( !only_probes && (x2-x1)<0.3 && (y2-y1)<0.3) return;
@@ -1415,7 +1415,7 @@ void drawtemppolygon(GC g, int what, double *x, double *y, int points)
   x2=X_TO_SCREEN(x2);
   y2=Y_TO_SCREEN(y2);
   p = my_malloc(39, sizeof(XPoint) * points);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) ) {
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) ) {
     for(i=0;i<points; i++) {
       p[i].x = X_TO_SCREEN(x[i]);
       p[i].y = Y_TO_SCREEN(y[i]);
@@ -1441,7 +1441,7 @@ void drawrect(int c, int what, double rectx1,double recty1,double rectx2,double
   x2=X_TO_SCREEN(rectx2);
   y2=Y_TO_SCREEN(recty2);
   if(!only_probes && (x2-x1)< 0.3 && (y2-y1)< 0.3) return;
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    if(dash) {
      dash_arr[0] = dash_arr[1] = dash;
@@ -1477,7 +1477,7 @@ void drawrect(int c, int what, double rectx1,double recty1,double rectx2,double
   x2=X_TO_SCREEN(rectx2);
   y2=Y_TO_SCREEN(recty2);
   if(!only_probes && (x2-x1)< 0.3 && (y2-y1)< 0.3) return;
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    r[i].x=(short)x1;
    r[i].y=(short)y1;
@@ -1508,7 +1508,7 @@ void drawtemprect(GC gc, int what, double rectx1,double recty1,double rectx2,dou
   x2=X_TO_SCREEN(rectx2);
   y2=Y_TO_SCREEN(recty2);
   if( (x2-x1)< 0.3 && (y2-y1)< 0.3) return;
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    XDrawRectangle(display, window, gc, (int)x1, (int)y1,
     (unsigned int)x2 - (unsigned int)x1,
@@ -1528,7 +1528,7 @@ void drawtemprect(GC gc, int what, double rectx1,double recty1,double rectx2,dou
   x2=X_TO_SCREEN(rectx2);
   y2=Y_TO_SCREEN(recty2);
   if( (x2-x1)< 0.3 && (y2-y1)< 0.3) return;
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    r[i].x=(short)x1;
    r[i].y=(short)y1;
@@ -1565,14 +1565,15 @@ void draw(void)
  rebuild_selected_array();
  if(has_x) {
     if(draw_pixmap)
-      XFillRectangle(display, save_pixmap, gc[BACKLAYER], areax1, areay1, areaw, areah);
-    if(draw_window) XFillRectangle(display, window, gc[BACKLAYER], areax1, areay1, areaw, areah);
-    dbg(2, "draw(): window: %d %d %d %d\n",areax1, areay1, areax2, areay2);
+      XFillRectangle(display, save_pixmap, gc[BACKLAYER], xctx->areax1, xctx->areay1, xctx->areaw, xctx->areah);
+    if(draw_window) 
+      XFillRectangle(display, window, gc[BACKLAYER], xctx->areax1, xctx->areay1, xctx->areaw, xctx->areah);
+    dbg(2, "draw(): window: %d %d %d %d\n",xctx->areax1, xctx->areay1, xctx->areax2, xctx->areay2);
     drawgrid();
-    x1 = X_TO_XSCHEM(areax1);
-    y1 = Y_TO_XSCHEM(areay1);
-    x2 = X_TO_XSCHEM(areax2);
-    y2 = Y_TO_XSCHEM(areay2);
+    x1 = X_TO_XSCHEM(xctx->areax1);
+    y1 = Y_TO_XSCHEM(xctx->areay1);
+    x2 = X_TO_XSCHEM(xctx->areax2);
+    y2 = Y_TO_XSCHEM(xctx->areay2);
     use_hash =  (xctx->wires> 2000 || xctx->instances > 2000 ) &&  (x2 - x1  < ITERATOR_THRESHOLD);
 
     if(use_hash) {
diff --git a/src/editprop.c b/src/editprop.c
index fec71316..ba2084ab 100644
--- a/src/editprop.c
+++ b/src/editprop.c
@@ -401,8 +401,8 @@ void edit_rect_property(void)
   const char *dash;
   int preserve;
   char *oldprop=NULL;
-  if(xctx->rect[selectedgroup[0].col][selectedgroup[0].n].prop_ptr!=NULL) {
-    my_strdup(67, &oldprop, xctx->rect[selectedgroup[0].col][selectedgroup[0].n].prop_ptr);
+  if(xctx->rect[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr!=NULL) {
+    my_strdup(67, &oldprop, xctx->rect[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr);
     tclsetvar("retval",oldprop);
   } else {
     tclsetvar("retval","");
@@ -414,10 +414,10 @@ void edit_rect_property(void)
   {
     push_undo();
     set_modify(1);
-    for(i=0; i<lastselected; i++) {
-      if(selectedgroup[i].type != xRECT) continue;
-      c = selectedgroup[i].col;
-      n = selectedgroup[i].n;
+    for(i=0; i<xctx->lastsel; i++) {
+      if(xctx->sel_array[i].type != xRECT) continue;
+      c = xctx->sel_array[i].col;
+      n = xctx->sel_array[i].n;
       if(preserve == 1) {
         set_different_token(&xctx->rect[c][n].prop_ptr,
                (char *) tclgetvar("retval"), oldprop, 0, 0);
@@ -456,8 +456,8 @@ void edit_line_property(void)
   const char *dash;
   int preserve;
   char *oldprop=NULL;
-  if(xctx->line[selectedgroup[0].col][selectedgroup[0].n].prop_ptr!=NULL) {
-    my_strdup(46, &oldprop, xctx->line[selectedgroup[0].col][selectedgroup[0].n].prop_ptr);
+  if(xctx->line[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr!=NULL) {
+    my_strdup(46, &oldprop, xctx->line[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr);
     tclsetvar("retval", oldprop);
   } else {
     tclsetvar("retval","");
@@ -470,10 +470,10 @@ void edit_line_property(void)
     push_undo();
     set_modify(1);
     bbox(START, 0.0 , 0.0 , 0.0 , 0.0);
-    for(i=0; i<lastselected; i++) {
-      if(selectedgroup[i].type != LINE) continue;
-      c = selectedgroup[i].col;
-      n = selectedgroup[i].n;
+    for(i=0; i<xctx->lastsel; i++) {
+      if(xctx->sel_array[i].type != LINE) continue;
+      c = xctx->sel_array[i].col;
+      n = xctx->sel_array[i].n;
       if(preserve == 1) {
         set_different_token(&xctx->line[c][n].prop_ptr,
                (char *) tclgetvar("retval"), oldprop, 0, 0);
@@ -510,8 +510,8 @@ void edit_wire_property(void)
   char *oldprop=NULL;
   const char *bus_ptr;
 
-  if(xctx->wire[selectedgroup[0].n].prop_ptr!=NULL) {
-    my_strdup(47, &oldprop, xctx->wire[selectedgroup[0].n].prop_ptr);
+  if(xctx->wire[xctx->sel_array[0].n].prop_ptr!=NULL) {
+    my_strdup(47, &oldprop, xctx->wire[xctx->sel_array[0].n].prop_ptr);
     tclsetvar("retval", oldprop);
   } else {
     tclsetvar("retval","");
@@ -523,14 +523,14 @@ void edit_wire_property(void)
     push_undo();
     set_modify(1);
     bbox(START, 0.0 , 0.0 , 0.0 , 0.0);
-    for(i=0; i<lastselected; i++) {
+    for(i=0; i<xctx->lastsel; i++) {
       int oldbus=0;
-      int k = selectedgroup[i].n;
-      if(selectedgroup[i].type != WIRE) continue;
+      int k = xctx->sel_array[i].n;
+      if(xctx->sel_array[i].type != WIRE) continue;
       /* does not seem to be necessary */
-     /*  prepared_hash_wires=0;
-      *  prepared_netlist_structs=0;
-      *  prepared_hilight_structs=0; */
+     /*  xctx->prep_hash_wires=0;
+      *  xctx->prep_net_structs=0;
+      *  xctx->prep_hi_structs=0; */
       oldbus = xctx->wire[k].bus;
       if(preserve == 1) {
         set_different_token(&xctx->wire[k].prop_ptr,
@@ -573,8 +573,8 @@ void edit_arc_property(void)
   const char *dash;
   int preserve;
 
-  if(xctx->arc[selectedgroup[0].col][selectedgroup[0].n].prop_ptr!=NULL) {
-    my_strdup(98, &oldprop, xctx->arc[selectedgroup[0].col][selectedgroup[0].n].prop_ptr);
+  if(xctx->arc[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr!=NULL) {
+    my_strdup(98, &oldprop, xctx->arc[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr);
     tclsetvar("retval", oldprop);
   } else {
     tclsetvar("retval","");
@@ -585,11 +585,11 @@ void edit_arc_property(void)
   {
 
    set_modify(1); push_undo();
-   for(ii=0; ii<lastselected; ii++) {
-     if(selectedgroup[ii].type != ARC) continue;
+   for(ii=0; ii<xctx->lastsel; ii++) {
+     if(xctx->sel_array[ii].type != ARC) continue;
 
-     i = selectedgroup[ii].n;
-     c = selectedgroup[ii].col;
+     i = xctx->sel_array[ii].n;
+     c = xctx->sel_array[ii].col;
 
      if(preserve == 1) {
         set_different_token(&xctx->arc[c][i].prop_ptr, (char *) tclgetvar("retval"), oldprop, 0, 0);
@@ -640,8 +640,8 @@ void edit_polygon_property(void)
   int preserve;
 
   dbg(1, "edit_property(): input property:\n");
-  if(xctx->poly[selectedgroup[0].col][selectedgroup[0].n].prop_ptr!=NULL) {
-    my_strdup(112, &oldprop, xctx->poly[selectedgroup[0].col][selectedgroup[0].n].prop_ptr);
+  if(xctx->poly[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr!=NULL) {
+    my_strdup(112, &oldprop, xctx->poly[xctx->sel_array[0].col][xctx->sel_array[0].n].prop_ptr);
     tclsetvar("retval", oldprop);
   } else {
     tclsetvar("retval","");
@@ -652,11 +652,11 @@ void edit_polygon_property(void)
   {
 
    set_modify(1); push_undo();
-   for(ii=0; ii<lastselected; ii++) {
-     if(selectedgroup[ii].type != POLYGON) continue;
+   for(ii=0; ii<xctx->lastsel; ii++) {
+     if(xctx->sel_array[ii].type != POLYGON) continue;
 
-     i = selectedgroup[ii].n;
-     c = selectedgroup[ii].col;
+     i = xctx->sel_array[ii].n;
+     c = xctx->sel_array[ii].col;
 
      if(preserve == 1) {
         set_different_token(&xctx->poly[c][i].prop_ptr, (char *) tclgetvar("retval"), oldprop, 0, 0);
@@ -714,7 +714,7 @@ void edit_text_property(int x)
    char *oldprop = NULL;
 
    dbg(1, "edit_text_property(): entering\n");
-   sel = selectedgroup[0].n;
+   sel = xctx->sel_array[0].n;
    my_strdup(656, &oldprop, xctx->text[sel].prop_ptr);
    if(xctx->text[sel].prop_ptr !=NULL)
       tclsetvar("props",xctx->text[sel].prop_ptr);
@@ -749,10 +749,10 @@ void edit_text_property(int x)
      dbg(1, "edit_text_property(): rcode !=\"\"\n");
      set_modify(1); push_undo();
      bbox(START,0.0,0.0,0.0,0.0);
-     for(k=0;k<lastselected;k++)
+     for(k=0;k<xctx->lastsel;k++)
      {
-       if(selectedgroup[k].type!=xTEXT) continue;
-       sel=selectedgroup[k].n;
+       if(xctx->sel_array[k].type!=xTEXT) continue;
+       sel=xctx->sel_array[k].n;
 
        rot = xctx->text[sel].rot;      /* calculate bbox, some cleanup needed here */
        flip = xctx->text[sel].flip;
@@ -871,7 +871,7 @@ void edit_symbol_property(int x)
 {
    char *result=NULL;
 
-   i=selectedgroup[0].n;
+   i=xctx->sel_array[0].n;
    netlist_commands = 0;
    if ((xctx->inst[i].ptr + xctx->sym)->type!=NULL)
      netlist_commands =  !strcmp( (xctx->inst[i].ptr+ xctx->sym)->type, "netlist_commands");
@@ -902,10 +902,10 @@ void edit_symbol_property(int x)
      else if(x==2)    tcleval("viewdata $::retval");
      my_strdup(78, &result, tclresult());
    }
-   dbg(1, "edit_symbol_property(): before update_symbol, modified=%d\n", modified);
+   dbg(1, "edit_symbol_property(): before update_symbol, xctx->modified=%d\n", xctx->modified);
    update_symbol(result, x);
    my_free(728, &result);
-   dbg(1, "edit_symbol_property(): done update_symbol, modified=%d\n", modified);
+   dbg(1, "edit_symbol_property(): done update_symbol, xctx->modified=%d\n", xctx->modified);
    i=-1;
 }
 
@@ -924,7 +924,7 @@ void update_symbol(const char *result, int x)
   int pushed=0;
 
   dbg(1, "update_symbol(): entering\n");
-  i=selectedgroup[0].n;
+  i=xctx->sel_array[0].n;
   if(!result) {
    dbg(1, "update_symbol(): edit symbol prop aborted\n");
    return;
@@ -975,19 +975,19 @@ void update_symbol(const char *result, int x)
   sym_number = -1;
   if(strcmp(symbol, xctx->inst[i].name)) {
     set_modify(1);
-    prepared_hash_instances=0;
-    prepared_netlist_structs=0;
-    prepared_hilight_structs=0;
+    xctx->prep_hash_inst=0;
+    xctx->prep_net_structs=0;
+    xctx->prep_hi_structs=0;
     sym_number=match_symbol(symbol); /* check if exist */
     if(sym_number>=0) {
       prefix=(get_tok_value((xctx->sym+sym_number)->templ, "name",0))[0]; /* get new symbol prefix  */
     }
   }
 
-  for(k=0;k<lastselected;k++) {
+  for(k=0;k<xctx->lastsel;k++) {
     dbg(1, "update_symbol(): for k loop: k=%d\n", k);
-    if(selectedgroup[k].type!=ELEMENT) continue;
-    i=selectedgroup[k].n;
+    if(xctx->sel_array[k].type!=ELEMENT) continue;
+    i=xctx->sel_array[k].n;
 
     /* 20171220 calculate bbox before changes to correctly redraw areas */
     /* must be recalculated as cairo text extents vary with zoom factor. */
@@ -1015,9 +1015,9 @@ void update_symbol(const char *result, int x)
           if(!pushed) { push_undo(); pushed=1;}
           my_strdup(111, &xctx->inst[i].prop_ptr, ss);
           set_modify(1);
-          prepared_hash_instances=0;
-          prepared_netlist_structs=0;
-          prepared_hilight_structs=0;
+          xctx->prep_hash_inst=0;
+          xctx->prep_net_structs=0;
+          xctx->prep_hi_structs=0;
         }
         my_free(729, &ss);
       }
@@ -1028,17 +1028,17 @@ void update_symbol(const char *result, int x)
             if(!pushed) { push_undo(); pushed=1;}
             my_strdup(84, &xctx->inst[i].prop_ptr, new_prop);
             set_modify(1);
-            prepared_hash_instances=0;
-            prepared_netlist_structs=0;
-            prepared_hilight_structs=0;
+            xctx->prep_hash_inst=0;
+            xctx->prep_net_structs=0;
+            xctx->prep_hi_structs=0;
           }
         }  else {
           if(!pushed) { push_undo(); pushed=1;}
           my_strdup(86, &xctx->inst[i].prop_ptr, "");
           set_modify(1);
-          prepared_hash_instances=0;
-          prepared_netlist_structs=0;
-          prepared_hilight_structs=0;
+          xctx->prep_hash_inst=0;
+          xctx->prep_net_structs=0;
+          xctx->prep_hi_structs=0;
         }
       }
     }
@@ -1064,16 +1064,16 @@ void update_symbol(const char *result, int x)
       else xctx->inst[i].flags &=~2;
     }
     my_strdup2(90, &xctx->inst[i].instname, get_tok_value(xctx->inst[i].prop_ptr, "name",0));
-  }  /* end for(k=0;k<lastselected;k++) */
+  }  /* end for(k=0;k<xctx->lastsel;k++) */
 
    /* new symbol bbox after prop changes (may change due to text length) */
-  if(modified) {
-    prepared_hash_instances=0;
-    prepared_netlist_structs=0;
-    prepared_hilight_structs=0;
-    for(k=0;k<lastselected;k++) {
-      if(selectedgroup[k].type!=ELEMENT) continue;
-      i=selectedgroup[k].n;
+  if(xctx->modified) {
+    xctx->prep_hash_inst=0;
+    xctx->prep_net_structs=0;
+    xctx->prep_hi_structs=0;
+    for(k=0;k<xctx->lastsel;k++) {
+      if(xctx->sel_array[k].type!=ELEMENT) continue;
+      i=xctx->sel_array[k].n;
       symbol_bbox(i, &xctx->inst[i].x1, &xctx->inst[i].y1, &xctx->inst[i].x2, &xctx->inst[i].y2);
       bbox(ADD, xctx->inst[i].x1, xctx->inst[i].y1, xctx->inst[i].x2, xctx->inst[i].y2);
     }
@@ -1114,47 +1114,47 @@ void change_elem_order(void)
    int c, new_n;
 
     rebuild_selected_array();
-    if(lastselected==1)
+    if(xctx->lastsel==1)
     {
-     my_snprintf(tmp_txt, S(tmp_txt), "%d",selectedgroup[0].n);
+     my_snprintf(tmp_txt, S(tmp_txt), "%d",xctx->sel_array[0].n);
      tclsetvar("retval",tmp_txt);
      tcleval("text_line {Object Sequence number} 0");
      if(strcmp(tclgetvar("rcode"),"") )
      {
       push_undo();
       set_modify(1);
-      prepared_hash_instances=0;
-      prepared_netlist_structs=0;
-      prepared_hilight_structs=0;
+      xctx->prep_hash_inst=0;
+      xctx->prep_net_structs=0;
+      xctx->prep_hi_structs=0;
      }
      sscanf(tclgetvar("retval"), "%d",&new_n);
 
-     if(selectedgroup[0].type==ELEMENT)
+     if(xctx->sel_array[0].type==ELEMENT)
      {
       if(new_n>=xctx->instances) new_n=xctx->instances-1;
       tmpinst=xctx->inst[new_n];
-      xctx->inst[new_n]=xctx->inst[selectedgroup[0].n];
-      xctx->inst[selectedgroup[0].n]=tmpinst;
-      dbg(1, "change_elem_order(): selected element %d\n", selectedgroup[0].n);
+      xctx->inst[new_n]=xctx->inst[xctx->sel_array[0].n];
+      xctx->inst[xctx->sel_array[0].n]=tmpinst;
+      dbg(1, "change_elem_order(): selected element %d\n", xctx->sel_array[0].n);
      }
-     else if(selectedgroup[0].type==xRECT)
+     else if(xctx->sel_array[0].type==xRECT)
      {
-      c=selectedgroup[0].col;
+      c=xctx->sel_array[0].col;
       if(new_n>=xctx->rects[c]) new_n=xctx->rects[c]-1;
       tmpbox=xctx->rect[c][new_n];
-      xctx->rect[c][new_n]=xctx->rect[c][selectedgroup[0].n];
-      xctx->rect[c][selectedgroup[0].n]=tmpbox;
-      dbg(1, "change_elem_order(): selected element %d\n", selectedgroup[0].n);
+      xctx->rect[c][new_n]=xctx->rect[c][xctx->sel_array[0].n];
+      xctx->rect[c][xctx->sel_array[0].n]=tmpbox;
+      dbg(1, "change_elem_order(): selected element %d\n", xctx->sel_array[0].n);
      }
-     else if(selectedgroup[0].type==WIRE)
+     else if(xctx->sel_array[0].type==WIRE)
      {
       if(new_n>=xctx->wires) new_n=xctx->wires-1;
       tmpwire=xctx->wire[new_n];
-      xctx->wire[new_n]=xctx->wire[selectedgroup[0].n];
-      xctx->wire[selectedgroup[0].n]=tmpwire;
-      dbg(1, "change_elem_order(): selected element %d\n", selectedgroup[0].n);
+      xctx->wire[new_n]=xctx->wire[xctx->sel_array[0].n];
+      xctx->wire[xctx->sel_array[0].n]=tmpwire;
+      dbg(1, "change_elem_order(): selected element %d\n", xctx->sel_array[0].n);
      }
-     need_rebuild_selected_array = 1;
+     xctx->need_reb_sel_arr = 1;
     }
 }
 
@@ -1165,7 +1165,7 @@ void edit_property(int x)
 
  if(!has_x) return;
  rebuild_selected_array(); /* from the .sel field in objects build */
- if(lastselected==0 )      /* the array of selected objs */
+ if(xctx->lastsel==0 )      /* the array of selected objs */
  {
    char *old_prop = NULL;
    char *new_prop = NULL;
@@ -1262,15 +1262,15 @@ void edit_property(int x)
    return;
  }
 
- switch(selectedgroup[0].type)
+ switch(xctx->sel_array[0].type)
  {
   case ELEMENT:
    edit_symbol_property(x);
    while( x == 0 && tclgetvar("edit_symbol_prop_new_sel")[0] == '1' ) {
      unselect_all();
-     select_object(mousex, mousey, SELECTED, 0);
+     select_object(xctx->mousex, xctx->mousey, SELECTED, 0);
      rebuild_selected_array();
-     if(lastselected && selectedgroup[0].type ==ELEMENT) {
+     if(xctx->lastsel && xctx->sel_array[0].type ==ELEMENT) {
        edit_symbol_property(0);
      } else {
        break;
diff --git a/src/font.c b/src/font.c
index a0568253..48ebeba0 100644
--- a/src/font.c
+++ b/src/font.c
@@ -38,19 +38,19 @@ void compile_font(void)
   select_inside(code*FONTOFFSET-1,-FONTHEIGHT-1,
                  code*FONTOFFSET+FONTWIDTH+1,FONTWHITESPACE + FONTDESCENT+1, 1);
   rebuild_selected_array();
-  character[code] = my_calloc(134, lastselected*4+1, sizeof(double));
-  character[code][0] = (double)lastselected;
+  character[code] = my_calloc(134, xctx->lastsel*4+1, sizeof(double));
+  character[code][0] = (double)xctx->lastsel;
   dbg(2, "compile_font(): character[%d][]={%.16g",code,character[code][0]);
-  for(i=0;i<lastselected;i++)
+  for(i=0;i<xctx->lastsel;i++)
   {
    character[code][i*4+1] =
-      xctx->line[selectedgroup[i].col][selectedgroup[i].n].x1-code*FONTOFFSET;
+      xctx->line[xctx->sel_array[i].col][xctx->sel_array[i].n].x1-code*FONTOFFSET;
    character[code][i*4+2] =
-      xctx->line[selectedgroup[i].col][selectedgroup[i].n].y1+FONTHEIGHT;
+      xctx->line[xctx->sel_array[i].col][xctx->sel_array[i].n].y1+FONTHEIGHT;
    character[code][i*4+3] =
-      xctx->line[selectedgroup[i].col][selectedgroup[i].n].x2-code*FONTOFFSET;
+      xctx->line[xctx->sel_array[i].col][xctx->sel_array[i].n].x2-code*FONTOFFSET;
    character[code][i*4+4] =
-      xctx->line[selectedgroup[i].col][selectedgroup[i].n].y2+FONTHEIGHT;
+      xctx->line[xctx->sel_array[i].col][xctx->sel_array[i].n].y2+FONTHEIGHT;
    dbg(2, ",\n%.16g,%.16g,%.16g,%.16g",
     character[code][i*4+1],character[code][i*4+2],
     character[code][i*4+3],character[code][i*4+4]);
diff --git a/src/globals.c b/src/globals.c
index 91e76a40..81a87108 100644
--- a/src/globals.c
+++ b/src/globals.c
@@ -163,8 +163,6 @@ int incr_hilight=1;
 int auto_hilight=0;
 unsigned int color_index[256]; /* layer color lookup table */
 unsigned int rectcolor ; /* this is the currently used layer */
-unsigned long ui_state = 0; /* this signals that we are doing a net place,panning etc. */
-                          /* used to prevent nesting of some commands */
 char *undo_dirname = NULL;
 int cur_undo_ptr=0;
 int tail_undo_ptr=0;
@@ -179,21 +177,12 @@ int cadlayers=0;
 int *enable_layer;
 int n_active_layers=0;
 int *active_layer;
-int need_rebuild_selected_array=1;
 int depth;
 int *fill_type; /*20171117 for every layer: 0: no fill, 1, solid fill, 2: stipple fill */
 char **color_array;
-int areax1,areay1,areax2,areay2,areaw,areah; /* window corners / size */
-int xschem_h, xschem_w; /* 20171130 window size */
-double mousex,mousey; /* mouse coord. */
-double mousex_snap,mousey_snap; /* mouse coord. snapped to grid */
-double mx_double_save, my_double_save;
 char *xschem_executable=NULL;
 double cadsnap = CADSNAP;
 double *character[256]; /* array or per-char coordinates of xschem internal vector font */
-int lastselected = 0;
-int max_selected;
-Selected *selectedgroup;     /*  array of selected objects to be */
 Tcl_Interp *interp;
 int do_netlist=0;  /* set by process_options if user wants netllist from cmdline */
 int do_simulation=0;
@@ -206,20 +195,14 @@ int netlist_show=0;
 int flat_netlist=0;
 int netlist_type=-1;
 char bus_replacement_char[3] = {0, 0, 0};
-int prepared_netlist_structs=0;
-int prepared_hilight_structs=0;
-int prepared_hash_instances=0;
-int prepared_hash_wires=0;
 int horizontal_move=0;
 int vertical_move=0;
-int modified = 0;
 int color_ps=-1;
 int only_probes=0;
 int hilight_color=0;
 int pending_fullzoom=0;
 int split_files=0; /* split netlist files 20081202 */
 char *netlist_dir=NULL; /* user set netlist directory via cmd-option or menu or xschemrc */
-char user_top_netl_name[PATH_MAX] = ""; /* user set netlist name via cmd option -N <name> */
 int dark_colorscheme=1;
 double color_dim=0.0;
 int no_undo=0;
diff --git a/src/hilight.c b/src/hilight.c
index c9d6fac8..dde9ba4e 100644
--- a/src/hilight.c
+++ b/src/hilight.c
@@ -314,9 +314,9 @@ void hilight_net_pin_mismatches(void)
 
   rebuild_selected_array();
   prepare_netlist_structs(0);
-  for(k=0; k<lastselected; k++) {
-    if(selectedgroup[k].type!=ELEMENT) continue;
-    j = selectedgroup[k].n ;
+  for(k=0; k<xctx->lastsel; k++) {
+    if(xctx->sel_array[k].type!=ELEMENT) continue;
+    j = xctx->sel_array[k].n ;
     my_strdup(23, &type,(xctx->inst[j].ptr+ xctx->sym)->type);
     if( type && IS_LABEL_SH_OR_PIN(type)) break;
     symbol = xctx->sym + xctx->inst[j].ptr;
@@ -534,7 +534,7 @@ int search(const char *tok, const char *val, int sub, int sel, int what)
           }
           if(sel==1) {
             select_element(i, SELECTED, 1, 0);
-            ui_state|=SELECTION;
+            xctx->ui_state|=SELECTION;
           }
 
           if(sel==-1) { /* 20171211 unselect */
@@ -577,7 +577,7 @@ int search(const char *tok, const char *val, int sub, int sel, int what)
             }
             if(sel==1) {
               select_wire(i,SELECTED, 1);
-              ui_state|=SELECTION;
+              xctx->ui_state|=SELECTION;
             }
             if(sel==-1) {
               select_wire(i,0, 1);
@@ -601,7 +601,7 @@ int search(const char *tok, const char *val, int sub, int sel, int what)
         {
             if(sel==1) {
               select_line(c, i,SELECTED, 1);
-              ui_state|=SELECTION;
+              xctx->ui_state|=SELECTION;
             }
             if(sel==-1) {
               select_line(c, i,0, 1);
@@ -626,7 +626,7 @@ int search(const char *tok, const char *val, int sub, int sel, int what)
         {
             if(sel==1) {
               select_box(c, i,SELECTED, 1);
-              ui_state|=SELECTION;
+              xctx->ui_state|=SELECTION;
             }
             if(sel==-1) {
               select_box(c, i,0, 1);
@@ -814,10 +814,10 @@ void hilight_net(int to_waveform)
   rebuild_selected_array();
   tcleval("sim_is_xyce");
   sim_is_xyce = atoi( tclresult() );
-  for(i=0;i<lastselected;i++)
+  for(i=0;i<xctx->lastsel;i++)
   {
-   n = selectedgroup[i].n;
-   switch(selectedgroup[i].type)
+   n = xctx->sel_array[i].n;
+   switch(xctx->sel_array[i].type)
    {
     case WIRE:
       hilight_nets=1;
@@ -863,10 +863,10 @@ void unhilight_net(void)
   prepare_netlist_structs(0);
   dbg(1, "unhilight_net(): entering\n");
   rebuild_selected_array();
-  for(i=0;i<lastselected;i++)
+  for(i=0;i<xctx->lastsel;i++)
   {
-   n = selectedgroup[i].n;
-   switch(selectedgroup[i].type)
+   n = xctx->sel_array[i].n;
+   switch(xctx->sel_array[i].type)
    {
     case WIRE:
       bus_hilight_lookup(xctx->wire[n].node, hilight_color, XDELETE);
@@ -946,7 +946,7 @@ void select_hilight_net(void)
    if(entry) xctx->inst[i].sel = SELECTED;
   }
  }
- need_rebuild_selected_array = 1;
+ xctx->need_reb_sel_arr = 1;
  rebuild_selected_array();
  redraw_hilights();
  
@@ -969,10 +969,10 @@ void draw_hilight_net(int on_window)
  prepare_netlist_structs(0);
  save_draw = draw_window;
  draw_window = on_window;
- x1 = X_TO_XSCHEM(areax1);
- y1 = Y_TO_XSCHEM(areay1);
- x2 = X_TO_XSCHEM(areax2);
- y2 = Y_TO_XSCHEM(areay2);
+ x1 = X_TO_XSCHEM(xctx->areax1);
+ y1 = Y_TO_XSCHEM(xctx->areay1);
+ x2 = X_TO_XSCHEM(xctx->areax2);
+ y2 = Y_TO_XSCHEM(xctx->areay2);
  use_hash = (xctx->wires> 2000 || xctx->instances > 2000 ) &&  (x2 - x1  < ITERATOR_THRESHOLD);
  if(use_hash) {
    hash_wires();
@@ -1024,7 +1024,7 @@ void draw_hilight_net(int on_window)
    y1=Y_TO_SCREEN(xctx->inst[i].y1);
    y2=Y_TO_SCREEN(xctx->inst[i].y2);
    inst_color[i]=0;
-   if(OUTSIDE(x1,y1,x2,y2,areax1,areay1,areax2,areay2)) continue;
+   if(OUTSIDE(x1,y1,x2,y2,xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2)) continue;
    /* /20150409 */
 
   type = (xctx->inst[i].ptr+ xctx->sym)->type;
@@ -1069,7 +1069,7 @@ void draw_hilight_net(int on_window)
       x2=X_TO_SCREEN(xctx->inst[i].x2);
       y1=Y_TO_SCREEN(xctx->inst[i].y1);
       y2=Y_TO_SCREEN(xctx->inst[i].y2);
-      if(OUTSIDE(x1,y1,x2,y2,areax1,areay1,areax2,areay2)) continue;
+      if(OUTSIDE(x1,y1,x2,y2,xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2)) continue;
       dbg(1, "draw_hilight_net(): instance:%d\n",i);
       /* 20160414 from draw() */
       symptr = (xctx->inst[i].ptr+ xctx->sym);
@@ -1228,8 +1228,8 @@ void print_hilight_net(int show)
 
  /* 20170323 this delete_netlist_structs is necessary, without it segfaults when going back (ctrl-e)  */
  /* from a schematic after placing pins (ctrl-j) and changing some pin direction (ipin -->iopin) */
- prepared_hilight_structs=0;
- prepared_netlist_structs=0;
+ xctx->prep_hi_structs=0;
+ xctx->prep_net_structs=0;
 
  /* delete_netlist_structs(); */
  my_free(781, &filetmp1);
diff --git a/src/in_memory_undo.c b/src/in_memory_undo.c
index 24e7f79a..843efddc 100644
--- a/src/in_memory_undo.c
+++ b/src/in_memory_undo.c
@@ -423,10 +423,10 @@ void pop_undo(int redo)
 
   link_symbols_to_instances();
   set_modify(1);
-  prepared_hash_instances=0;
-  prepared_hash_wires=0;
-  prepared_netlist_structs=0;
-  prepared_hilight_structs=0;
+  xctx->prep_hash_inst=0;
+  xctx->prep_hash_wires=0;
+  xctx->prep_net_structs=0;
+  xctx->prep_hi_structs=0;
   update_conn_cues(0, 0);
 }
 
diff --git a/src/move.c b/src/move.c
index da9a0004..39419d05 100644
--- a/src/move.c
+++ b/src/move.c
@@ -31,36 +31,36 @@ static int rotatelocal=0;
 
 
 void rebuild_selected_array() /* can be used only if new selected set is lower */
-                              /* that is, selectedgroup[] size can not increase */
+                              /* that is, xctx->sel_array[] size can not increase */
 {
  int i,c;
 
  dbg(1, "rebuild selected array\n");
- if(!need_rebuild_selected_array) return;
- lastselected=0;
+ if(!xctx->need_reb_sel_arr) return;
+ xctx->lastsel=0;
  for(i=0;i<xctx->texts;i++)
   if(xctx->text[i].sel)
   {
    check_selected_storage();
-   selectedgroup[lastselected].type = xTEXT;
-   selectedgroup[lastselected].n = i;
-   selectedgroup[lastselected++].col = TEXTLAYER;
+   xctx->sel_array[xctx->lastsel].type = xTEXT;
+   xctx->sel_array[xctx->lastsel].n = i;
+   xctx->sel_array[xctx->lastsel++].col = TEXTLAYER;
   }
  for(i=0;i<xctx->instances;i++)
   if(xctx->inst[i].sel)
   {
    check_selected_storage();
-   selectedgroup[lastselected].type = ELEMENT;
-   selectedgroup[lastselected].n = i;
-   selectedgroup[lastselected++].col = WIRELAYER;
+   xctx->sel_array[xctx->lastsel].type = ELEMENT;
+   xctx->sel_array[xctx->lastsel].n = i;
+   xctx->sel_array[xctx->lastsel++].col = WIRELAYER;
   }
  for(i=0;i<xctx->wires;i++)
   if(xctx->wire[i].sel)
   {
    check_selected_storage();
-   selectedgroup[lastselected].type = WIRE;
-   selectedgroup[lastselected].n = i;
-   selectedgroup[lastselected++].col = WIRELAYER;
+   xctx->sel_array[xctx->lastsel].type = WIRE;
+   xctx->sel_array[xctx->lastsel].n = i;
+   xctx->sel_array[xctx->lastsel++].col = WIRELAYER;
   }
  for(c=0;c<cadlayers;c++)
  {
@@ -68,36 +68,36 @@ void rebuild_selected_array() /* can be used only if new selected set is lower *
    if(xctx->arc[c][i].sel)
    {
     check_selected_storage();
-    selectedgroup[lastselected].type = ARC;
-    selectedgroup[lastselected].n = i;
-    selectedgroup[lastselected++].col = c;
+    xctx->sel_array[xctx->lastsel].type = ARC;
+    xctx->sel_array[xctx->lastsel].n = i;
+    xctx->sel_array[xctx->lastsel++].col = c;
    }
   for(i=0;i<xctx->rects[c];i++)
    if(xctx->rect[c][i].sel)
    {
     check_selected_storage();
-    selectedgroup[lastselected].type = xRECT;
-    selectedgroup[lastselected].n = i;
-    selectedgroup[lastselected++].col = c;
+    xctx->sel_array[xctx->lastsel].type = xRECT;
+    xctx->sel_array[xctx->lastsel].n = i;
+    xctx->sel_array[xctx->lastsel++].col = c;
    }
   for(i=0;i<xctx->lines[c];i++)
    if(xctx->line[c][i].sel)
    {
     check_selected_storage();
-    selectedgroup[lastselected].type = LINE;
-    selectedgroup[lastselected].n = i;
-    selectedgroup[lastselected++].col = c;
+    xctx->sel_array[xctx->lastsel].type = LINE;
+    xctx->sel_array[xctx->lastsel].n = i;
+    xctx->sel_array[xctx->lastsel++].col = c;
    }
   for(i=0;i<xctx->polygons[c];i++)
    if(xctx->poly[c][i].sel)
    {
     check_selected_storage();
-    selectedgroup[lastselected].type = POLYGON;
-    selectedgroup[lastselected].n = i;
-    selectedgroup[lastselected++].col = c;
+    xctx->sel_array[xctx->lastsel].type = POLYGON;
+    xctx->sel_array[xctx->lastsel].n = i;
+    xctx->sel_array[xctx->lastsel++].col = c;
    }
  }
- need_rebuild_selected_array=0;
+ xctx->need_reb_sel_arr=0;
 }
 
 void check_collapsing_objects()
@@ -164,7 +164,7 @@ void check_collapsing_objects()
    }
 
   if(found) {
-    need_rebuild_selected_array=1;
+    xctx->need_reb_sel_arr=1;
     rebuild_selected_array();
   }
 }
@@ -175,10 +175,10 @@ void update_symbol_bboxes(int rot, int flip)
 
   for(i=0;i<lastsel;i++)
   {
-    n = selectedgroup[i].n;
+    n = xctx->sel_array[i].n;
     dbg(1, "update_symbol_bboxes(): i=%d, lastsel=%d, n=%d\n", i, lastsel, n);
     dbg(1, "update_symbol_bboxes(): symbol flip=%d, rot=%d\n",  xctx->inst[n].flip, xctx->inst[n].rot);
-    if(selectedgroup[i].type == ELEMENT) {
+    if(xctx->sel_array[i].type == ELEMENT) {
       save_flip = xctx->inst[n].flip;
       save_rot = xctx->inst[n].rot;
       xctx->inst[n].flip = flip ^ xctx->inst[n].flip;
@@ -197,11 +197,11 @@ void draw_selection(GC g, int interruptable)
   int customfont;
   #endif
 
-  if(g == gc[SELLAYER]) lastsel = lastselected;
+  if(g == gc[SELLAYER]) lastsel = xctx->lastsel;
   for(i=0;i<lastsel;i++)
   {
-   c = selectedgroup[i].col;n = selectedgroup[i].n;
-   switch(selectedgroup[i].type)
+   c = xctx->sel_array[i].col;n = xctx->sel_array[i].n;
+   switch(xctx->sel_array[i].type)
    {
     case xTEXT:
      if(rotatelocal) {
@@ -523,17 +523,17 @@ void copy_objects(int what)
   rebuild_selected_array();
   save_selection(1);
   deltax = deltay = 0.0;
-  lastsel = lastselected;
-  x1=mousex_snap;y_1=mousey_snap;
+  lastsel = xctx->lastsel;
+  x1=xctx->mousex_snap;y_1=xctx->mousey_snap;
    move_flip = 0;move_rot = 0;
-  ui_state|=STARTCOPY;
+  xctx->ui_state|=STARTCOPY;
  }
  if(what & ABORT)                               /* draw objects while moving */
  {
   char *str = NULL; /* 20161122 overflow safe */
   draw_selection(gctiled,0);
   move_rot=move_flip=deltax=deltay=0;
-  ui_state&=~STARTCOPY;
+  xctx->ui_state&=~STARTCOPY;
   my_strdup(225, &str, user_conf_dir);
   my_strcat(226, &str, "/.selection.sch");
   xunlink(str);
@@ -542,7 +542,7 @@ void copy_objects(int what)
  }
  if(what & RUBBER)                              /* draw objects while moving */
  {
-  x2=mousex_snap;y_2=mousey_snap;
+  x2=xctx->mousex_snap;y_2=xctx->mousey_snap;
   draw_selection(gctiled,0);
   deltax = x2-x1; deltay = y_2 - y_1;
   draw_selection(gc[SELLAYER],1);
@@ -575,13 +575,13 @@ void copy_objects(int what)
   newpropcnt=0;
   set_modify(1); push_undo(); /* 20150327 push_undo */
   firstw = firsti = 1;
-  for(i=0;i<lastselected;i++)
+  for(i=0;i<xctx->lastsel;i++)
   {
-   n = selectedgroup[i].n;
-   if(selectedgroup[i].type == WIRE)
+   n = xctx->sel_array[i].n;
+   if(xctx->sel_array[i].type == WIRE)
    {
        if(firstw) {
-         prepared_hash_wires=0;
+         xctx->prep_hash_wires=0;
          firstw = 0;
        }
        check_wire_storage();
@@ -627,7 +627,7 @@ void copy_objects(int what)
         if(xctx->wire[n].sel == SELECTED1) xctx->wire[n].sel = SELECTED2;
         else if(xctx->wire[n].sel == SELECTED2) xctx->wire[n].sel = SELECTED1;
        }
-       selectedgroup[i].n=xctx->wires;
+       xctx->sel_array[i].n=xctx->wires;
        storeobject(-1, rx1,ry1,rx2,ry2,WIRE,0,xctx->wire[n].sel,xctx->wire[n].prop_ptr);
        xctx->wire[n].sel=0;
        if(xctx->wire[n].bus)
@@ -641,10 +641,10 @@ void copy_objects(int what)
 
   for(k=0;k<cadlayers;k++)
   {
-   for(i=0;i<lastselected;i++)
+   for(i=0;i<xctx->lastsel;i++)
    {
-    c = selectedgroup[i].col;n = selectedgroup[i].n;
-    switch(selectedgroup[i].type)
+    c = xctx->sel_array[i].col;n = xctx->sel_array[i].n;
+    switch(xctx->sel_array[i].type)
     {
      case LINE:
       if(c!=k) break;
@@ -680,7 +680,7 @@ void copy_objects(int what)
         drawline(k, THICK, rx1,ry1,rx2,ry2, xctx->line[c][n].dash);
       else
         drawline(k, ADD, rx1,ry1,rx2,ry2, xctx->line[c][n].dash);
-      selectedgroup[i].n=xctx->lines[c];
+      xctx->sel_array[i].n=xctx->lines[c];
       storeobject(-1, rx1, ry1, rx2, ry2, LINE, c, xctx->line[c][n].sel, xctx->line[c][n].prop_ptr);
       xctx->line[c][n].sel=0;
       break;
@@ -715,7 +715,7 @@ void copy_objects(int what)
         }
         /* bbox(ADD, bx1, by1, bx2, by2); */
         drawpolygon(k,  NOW, x, y, p->points, p->fill, p->dash); /* 20180914 added fill */
-        selectedgroup[i].n=xctx->polygons[c];
+        xctx->sel_array[i].n=xctx->polygons[c];
         store_poly(-1, x, y, p->points, c, p->sel, p->prop_ptr);
         p->sel=0;
         my_free(819, &x);
@@ -750,7 +750,7 @@ void copy_objects(int what)
       xctx->arc[c][n].sel=0;
       drawarc(k, ADD, rx1+deltax, ry1+deltay, 
                  xctx->arc[c][n].r, angle, xctx->arc[c][n].b, xctx->arc[c][n].fill, xctx->arc[c][n].dash);
-      selectedgroup[i].n=xctx->arcs[c];
+      xctx->sel_array[i].n=xctx->arcs[c];
       store_arc(-1, rx1+deltax, ry1+deltay,
                  xctx->arc[c][n].r, angle, xctx->arc[c][n].b, c, SELECTED, xctx->arc[c][n].prop_ptr);
       break;
@@ -771,7 +771,7 @@ void copy_objects(int what)
       xctx->rect[c][n].sel=0;
       drawrect(k, ADD, rx1+deltax, ry1+deltay, rx2+deltax, ry2+deltay, xctx->rect[c][n].dash);
       filledrect(k, ADD, rx1+deltax, ry1+deltay, rx2+deltax, ry2+deltay);
-      selectedgroup[i].n=xctx->rects[c];
+      xctx->sel_array[i].n=xctx->rects[c];
       storeobject(-1, rx1+deltax, ry1+deltay,
                  rx2+deltax, ry2+deltay,xRECT, c, SELECTED, xctx->rect[c][n].prop_ptr);
       break;
@@ -869,14 +869,14 @@ void copy_objects(int what)
         cairo_restore(cairo_save_ctx);
       }
       #endif
-      selectedgroup[i].n=xctx->texts;
+      xctx->sel_array[i].n=xctx->texts;
       xctx->texts++;
        dbg(2, "copy_objects(): done copy string\n");
       break;
      case ELEMENT:
       if(k==0) {
        if(firsti) {
-         prepared_hash_instances = 0;
+         xctx->prep_hash_inst = 0;
          firsti = 0;
        }
        check_inst_storage();
@@ -909,34 +909,34 @@ void copy_objects(int what)
        new_prop_string(xctx->instances, xctx->inst[n].prop_ptr,newpropcnt++, dis_uniq_names);
        my_strdup2(235, &xctx->inst[xctx->instances].instname,
                    get_tok_value(xctx->inst[xctx->instances].prop_ptr, "name", 0));
-       n=selectedgroup[i].n=xctx->instances;
+       n=xctx->sel_array[i].n=xctx->instances;
 
        xctx->instances++;
       }
       break;
-    } /* end switch(selectedgroup[i].type) */
-   } /* end for(i=0;i<lastselected;i++) */
+    } /* end switch(xctx->sel_array[i].type) */
+   } /* end for(i=0;i<xctx->lastsel;i++) */
 
 
 
    if(k == 0 ) {
      /* force these vars to 0 to trigger a prepare_netlist_structs(0) needed by symbol_bbox->translate
       * to translate @#n:net_name texts */
-     need_rebuild_selected_array=1;
+     xctx->need_reb_sel_arr=1;
      rebuild_selected_array();
      if(!firsti || !firstw) {
-       prepared_netlist_structs=0;
-       prepared_hilight_structs=0;
+       xctx->prep_net_structs=0;
+       xctx->prep_hi_structs=0;
      }
      if(show_pin_net_names) {
        prepare_netlist_structs(0);
      }
    }
 
-   for(i = 0; i < lastselected; i++) {
-     n = selectedgroup[i].n;
+   for(i = 0; i < xctx->lastsel; i++) {
+     n = xctx->sel_array[i].n;
      if(k == 0) {
-       if(selectedgroup[i].type == ELEMENT) {
+       if(xctx->sel_array[i].type == ELEMENT) {
          int p;
          symbol_bbox(n, &xctx->inst[n].x1, &xctx->inst[n].y1, &xctx->inst[n].x2, &xctx->inst[n].y2 );
          bbox(ADD, xctx->inst[n].x1, xctx->inst[n].y1, xctx->inst[n].x2, xctx->inst[n].y2 );
@@ -946,7 +946,7 @@ void copy_objects(int what)
            }
          }
        }
-       if(show_pin_net_names && selectedgroup[i].type == WIRE) {
+       if(show_pin_net_names && xctx->sel_array[i].type == WIRE) {
          find_inst_to_be_redrawn(xctx->wire[n].node);
        }
      }
@@ -960,7 +960,7 @@ void copy_objects(int what)
   } /* end for(k=0;k<cadlayers;k++) */
   check_collapsing_objects();
   update_conn_cues(1, 1);
-  ui_state &= ~STARTCOPY;
+  xctx->ui_state &= ~STARTCOPY;
   x1=y_1=x2=y_2=move_rot=move_flip=deltax=deltay=0;
   bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
   draw();
@@ -996,26 +996,26 @@ void move_objects(int what, int merge, double dx, double dy)
   rotatelocal=0;
   deltax = deltay = 0.0;
   rebuild_selected_array();
-  lastsel = lastselected;
-  if(lastselected==1 && selectedgroup[0].type==ARC &&
-          xctx->arc[c=selectedgroup[0].col][n=selectedgroup[0].n].sel!=SELECTED) {
+  lastsel = xctx->lastsel;
+  if(xctx->lastsel==1 && xctx->sel_array[0].type==ARC &&
+          xctx->arc[c=xctx->sel_array[0].col][n=xctx->sel_array[0].n].sel!=SELECTED) {
     x1 = xctx->arc[c][n].x;
     y_1 = xctx->arc[c][n].y;
-  } else {x1=mousex_snap;y_1=mousey_snap;}
+  } else {x1=xctx->mousex_snap;y_1=xctx->mousey_snap;}
   move_flip = 0;move_rot = 0;
-  ui_state|=STARTMOVE;
+  xctx->ui_state|=STARTMOVE;
  }
  if(what & ABORT)                               /* draw objects while moving */
  {
   draw_selection(gctiled,0);
   move_rot=move_flip=deltax=deltay=0;
-  ui_state &= ~STARTMOVE;
-  ui_state &= ~PLACE_SYMBOL;
+  xctx->ui_state &= ~STARTMOVE;
+  xctx->ui_state &= ~PLACE_SYMBOL;
   update_symbol_bboxes(0, 0);
  }
  if(what & RUBBER)                              /* abort operation */
  {
-  x2=mousex_snap;y_2=mousey_snap;
+  x2=xctx->mousex_snap;y_2=xctx->mousey_snap;
   draw_selection(gctiled,0);
   deltax = x2-x1; deltay = y_2 - y_1;
   draw_selection(gc[SELLAYER],1);
@@ -1044,11 +1044,11 @@ void move_objects(int what, int merge, double dx, double dy)
   draw_selection(gctiled,0);
   bbox(START, 0.0 , 0.0 , 0.0 , 0.0);
   set_modify(1);
-  if( !(ui_state & (STARTMERGE | PLACE_SYMBOL)) ) {
+  if( !(xctx->ui_state & (STARTMERGE | PLACE_SYMBOL)) ) {
     dbg(1, "move_objects(): push undo state\n");
     push_undo(); /* 20150327 push_undo */
   }
-  ui_state &= ~PLACE_SYMBOL;
+  xctx->ui_state &= ~PLACE_SYMBOL;
   if(dx!=0.0 || dy!=0.0) {
     deltax = dx;
     deltay = dy;
@@ -1056,10 +1056,10 @@ void move_objects(int what, int merge, double dx, double dy)
 
   /* calculate moving symbols bboxes before actually doing the move */
   firsti = firstw = 1;
-  for(i=0;i<lastselected;i++)
+  for(i=0;i<xctx->lastsel;i++)
   {
-    n = selectedgroup[i].n;
-    if( selectedgroup[i].type == ELEMENT) {
+    n = xctx->sel_array[i].n;
+    if( xctx->sel_array[i].type == ELEMENT) {
        int p;
        symbol_bbox(n, &inst[n].x1, &inst[n].y1, &inst[n].x2, &inst[n].y2 );
        bbox(ADD, inst[n].x1, inst[n].y1, inst[n].x2, inst[n].y2 );
@@ -1069,21 +1069,21 @@ void move_objects(int what, int merge, double dx, double dy)
          }
        }
     }
-    if(show_pin_net_names && selectedgroup[i].type == WIRE) {
+    if(show_pin_net_names && xctx->sel_array[i].type == WIRE) {
       find_inst_to_be_redrawn(wire[n].node);
     }
   }
   if(show_pin_net_names) find_inst_hash_clear();
   for(k=0;k<cadlayers;k++)
   {
-   for(i=0;i<lastselected;i++)
+   for(i=0;i<xctx->lastsel;i++)
    {
-    c = selectedgroup[i].col;n = selectedgroup[i].n;
-    switch(selectedgroup[i].type)
+    c = xctx->sel_array[i].col;n = xctx->sel_array[i].n;
+    switch(xctx->sel_array[i].type)
     {
      case WIRE:
       if(firstw) {
-        prepared_hash_wires=0;
+        xctx->prep_hash_wires=0;
         firstw = 0;
       }
       if(k == 0) {
@@ -1407,7 +1407,7 @@ void move_objects(int what, int merge, double dx, double dy)
      case ELEMENT:
       if(k==0) {
        if(firsti) {
-         prepared_hash_instances=0;
+         xctx->prep_hash_inst=0;
          firsti = 0;
        }
        if(rotatelocal) {
@@ -1423,24 +1423,24 @@ void move_objects(int what, int merge, double dx, double dy)
 
       }
       break;
-    } /* end switch(selectedgroup[i].type) */
-   } /* end for(i=0;i<lastselected;i++) */
+    } /* end switch(xctx->sel_array[i].type) */
+   } /* end for(i=0;i<xctx->lastsel;i++) */
 
    if(k == 0 ) {
      /* force these vars to 0 to trigger a prepare_netlist_structs(0) needed by symbol_bbox->translate
       * to translate @#n:net_name texts */
      if(!firsti || !firstw) {
-       prepared_netlist_structs=0;
-       prepared_hilight_structs=0;
+       xctx->prep_net_structs=0;
+       xctx->prep_hi_structs=0;
      }
      if(show_pin_net_names) {
        prepare_netlist_structs(0);
      }
    }
-   for(i = 0; i < lastselected; i++) {
-     n = selectedgroup[i].n;
+   for(i = 0; i < xctx->lastsel; i++) {
+     n = xctx->sel_array[i].n;
      if(k == 0) {
-       if(selectedgroup[i].type == ELEMENT) {
+       if(xctx->sel_array[i].type == ELEMENT) {
          int p;
          symbol_bbox(n, &inst[n].x1, &inst[n].y1, &inst[n].x2, &inst[n].y2 );
          bbox(ADD, inst[n].x1, inst[n].y1, inst[n].x2, inst[n].y2 );
@@ -1450,7 +1450,7 @@ void move_objects(int what, int merge, double dx, double dy)
            }
          }
        }
-       if(show_pin_net_names && selectedgroup[i].type == WIRE) {
+       if(show_pin_net_names && xctx->sel_array[i].type == WIRE) {
          find_inst_to_be_redrawn(wire[n].node);
        }
      }
@@ -1465,11 +1465,11 @@ void move_objects(int what, int merge, double dx, double dy)
   } /*end for(k=0;k<cadlayers;k++) */
   check_collapsing_objects();
   update_conn_cues(1, 1);
-  ui_state &= ~STARTMOVE;
-  ui_state &= ~STARTMERGE;
+  xctx->ui_state &= ~STARTMOVE;
+  xctx->ui_state &= ~STARTMERGE;
   x1=y_1=x2=y_2=move_rot=move_flip=deltax=deltay=0;
   bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
-  dbg(2, "move_objects(): bbox= %d %d %d %d\n", areax1, areay1, areaw, areah);
+  dbg(2, "move_objects(): bbox= %d %d %d %d\n", xctx->areax1, xctx->areay1, xctx->areaw, xctx->areah);
   draw();
   bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
   rotatelocal=0;
diff --git a/src/netlist.c b/src/netlist.c
index 1148305f..658cd588 100644
--- a/src/netlist.c
+++ b/src/netlist.c
@@ -62,7 +62,7 @@ void del_inst_table(void)
   for(i=0;i<NBOXES;i++)
     for(j=0;j<NBOXES;j++)
       insttable[i][j] = delinstentry(insttable[i][j]);
-  prepared_hash_instances=0;
+  xctx->prep_hash_inst=0;
   dbg(1, "del_inst_table(): cleared object hash table\n");
 }
 
@@ -114,12 +114,12 @@ void hash_instances(void) /* 20171203 insert object bbox in spatial hash table *
 {
  int n;
 
- if(prepared_hash_instances) return;
+ if(xctx->prep_hash_inst) return;
  del_inst_table();
  for(n=0; n<xctx->instances; n++) {
    hash_inst(XINSERT, n);
  }
- prepared_hash_instances=1;
+ xctx->prep_hash_inst=1;
 }
 
 static void instpindelete(int n,int pin, int x, int y)
@@ -221,7 +221,7 @@ void del_wire_table(void)
  for(i=0;i<NBOXES;i++)
   for(j=0;j<NBOXES;j++)
    wiretable[i][j] = delwireentry(wiretable[i][j]);
- prepared_hash_wires=0;
+ xctx->prep_hash_wires=0;
 }
 
 void get_square(double x, double y, int *xx, int *yy)
@@ -349,11 +349,11 @@ void hash_wires(void)
 {
  int n;
 
- if(prepared_hash_wires) return;
+ if(xctx->prep_hash_wires) return;
  del_wire_table();
 
  for(n=0; n<xctx->wires; n++) hash_wire(XINSERT, n, 0);
- prepared_hash_wires=1;
+ xctx->prep_hash_wires=1;
 }
 
 /* return 0 if library path of s matches any lib name in tcl variable $xschem_libs */
@@ -630,8 +630,8 @@ void prepare_netlist_structs(int for_netlist)
   xInstance * const inst = xctx->inst;
   int const instances = xctx->instances;
 
-  if (for_netlist>0 && prepared_netlist_structs) return;
-  else if (!for_netlist && prepared_hilight_structs) return;
+  if (for_netlist>0 && xctx->prep_net_structs) return;
+  else if (!for_netlist && xctx->prep_hi_structs) return;
   /* delete instance pins spatial hash, wires spatial hash, node_hash, wires and inst nodes.*/
   else delete_netlist_structs();
   if(netlist_count == 0 ) startlevel = xctx->currsch;
@@ -803,7 +803,8 @@ void prepare_netlist_structs(int for_netlist)
       my_strdup(265, &xctx->wire[i].node , tmp_str);
       my_strdup(266, &xctx->wire[i].prop_ptr,
       subst_token(xctx->wire[i].prop_ptr, "lab", xctx->wire[i].node));
-      bus_hash_lookup(xctx->wire[i].node,"", XINSERT, 0,"","","","");   /* insert unnamed wire name in hash table */
+      /* insert unnamed wire name in hash table */
+      bus_hash_lookup(xctx->wire[i].node,"", XINSERT, 0,"","","","");
       wirecheck(i);
     }
   }
@@ -1014,9 +1015,9 @@ void prepare_netlist_structs(int for_netlist)
   /*---------------------- */
   rebuild_selected_array();
   if (for_netlist>0) {
-    prepared_netlist_structs=1;
-    prepared_hilight_structs=1;
-  } else prepared_hilight_structs=1;
+    xctx->prep_net_structs=1;
+    xctx->prep_hi_structs=1;
+  } else xctx->prep_hi_structs=1;
 
   my_free(835, &dir);
   my_free(836, &type);
@@ -1132,7 +1133,8 @@ int sym_vs_sch_pins()
               }
 
               if(fscanf(fd, "%lf %lf %d %d", &tmpd, &tmpd, &tmpi, &tmpi) < 4) {
-                fprintf(errfp,"sym_vs_sch_pins() WARNING: missing fields for INST object, filename=%s\n", filename);
+                fprintf(errfp,"sym_vs_sch_pins() WARNING: missing fields for INST object, filename=%s\n",
+                  filename);
                 read_line(fd, 0);
                 break;
               }
@@ -1304,6 +1306,6 @@ void delete_netlist_structs(void)
   del_inst_pin_table();
   free_node_hash();
   dbg(1, "delete_netlist_structs(): end erasing\n");
-  prepared_netlist_structs=0;
-  prepared_hilight_structs=0;
+  xctx->prep_net_structs=0;
+  xctx->prep_hi_structs=0;
 }
diff --git a/src/options.c b/src/options.c
index 45bcfb05..98ca5b6c 100644
--- a/src/options.c
+++ b/src/options.c
@@ -110,7 +110,7 @@ void check_opt(char *opt, char *optval, int type)
 
     } else if( (type == SHORT && *opt == 'N') || (type == LONG && !strcmp("netlist_filename", opt)) ) {
         dbg(1, "process_options(): set netlist name to %s\n", optval);
-        if(optval) my_strncpy(user_top_netl_name, optval, S(user_top_netl_name));
+        if(optval) my_strncpy(xctx->netlist_name, optval, S(xctx->netlist_name));
 
     } else if( (type == SHORT && *opt == 's') || (type == LONG && !strcmp("spice", opt)) ) {
         dbg(1, "process_options(): set netlist type to spice\n");
diff --git a/src/paste.c b/src/paste.c
index e9cc2704..79fd769e 100644
--- a/src/paste.c
+++ b/src/paste.c
@@ -317,10 +317,10 @@ void merge_file(int selection_load, const char ext[])
       my_snprintf(name, S(name), "%s/.clipboard.sch", user_conf_dir);
     }
     if( (fd=fopen(name,"r"))!= NULL) {
-     prepared_hilight_structs=0;
-     prepared_netlist_structs=0;
-     prepared_hash_instances=0;
-     prepared_hash_wires=0;
+     xctx->prep_hi_structs=0;
+     xctx->prep_net_structs=0;
+     xctx->prep_hash_inst=0;
+     xctx->prep_hash_wires=0;
      got_mouse = 0;
      push_undo();
      unselect_all();
@@ -349,9 +349,9 @@ void merge_file(int selection_load, const char ext[])
         load_ascii_string(&aux_ptr, fd);
         if(selection_load)
         {
-          mx_double_save = mousex_snap;
-          my_double_save = mousey_snap;
-          sscanf( aux_ptr, "%lf %lf", &mousex_snap, &mousey_snap);
+          xctx->mx_double_save = xctx->mousex_snap;
+          xctx->my_double_save = xctx->mousey_snap;
+          sscanf( aux_ptr, "%lf %lf", &xctx->mousex_snap, &xctx->mousey_snap);
           got_mouse = 1;
         }
         break;
@@ -384,20 +384,20 @@ void merge_file(int selection_load, const char ext[])
       read_line(fd, 0); /* discard any remaining characters till (but not including) newline */
      }
      if(!got_mouse) {
-       mx_double_save = mousex_snap;
-       my_double_save = mousey_snap;
-       mousex_snap = 0.;
-       mousey_snap = 0.;
+       xctx->mx_double_save = xctx->mousex_snap;
+       xctx->my_double_save = xctx->mousey_snap;
+       xctx->mousex_snap = 0.;
+       xctx->mousey_snap = 0.;
      }
      my_free(875, &aux_ptr);
      match_merged_inst(old);
      fclose(fd);
-     ui_state |= STARTMERGE;
-     dbg(1, "merge_file(): loaded file:wire=%d inst=%d ui_state=%ld\n",
-             xctx->wires , xctx->instances, ui_state);
+     xctx->ui_state |= STARTMERGE;
+     dbg(1, "merge_file(): loaded file:wire=%d inst=%d xctx->ui_state=%ld\n",
+             xctx->wires , xctx->instances, xctx->ui_state);
      move_objects(START,0,0,0);
-     mousex_snap = mx_double_save;
-     mousey_snap = my_double_save;
+     xctx->mousex_snap = xctx->mx_double_save;
+     xctx->mousey_snap = xctx->my_double_save;
      move_objects(RUBBER,0,0,0);
     } else {
       dbg(0, "merge_file(): can not open %s\n", name);
diff --git a/src/psprint.c b/src/psprint.c
index 1bdebde8..45a4f636 100644
--- a/src/psprint.c
+++ b/src/psprint.c
@@ -98,7 +98,7 @@ static void ps_drawpolygon(int c, int what, double *x, double *y, int points, in
   y1=Y_TO_PS(y1);
   x2=X_TO_PS(x2);
   y2=Y_TO_PS(y2);
-  if( !rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) ) {
+  if( !rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) ) {
     return;
   }
 
@@ -136,7 +136,7 @@ static void ps_filledrect(int gc, double rectx1,double recty1,double rectx2,doub
   y1=Y_TO_PS(recty1);
   x2=X_TO_PS(rectx2);
   y2=Y_TO_PS(recty2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
     psdash = dash / xctx->zoom;
     if(dash) {
@@ -164,7 +164,7 @@ static void ps_drawarc(int gc, int fillarc, double x,double y,double r,double a,
   x2=X_TO_PS(x2);
   y2=Y_TO_PS(y2);
 
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
     psdash = dash / xctx->zoom;
     if(dash) {
@@ -219,7 +219,7 @@ static void ps_draw_string(int gctext,  const char *str,
  xscale*=nocairo_font_xscale;
  yscale*=nocairo_font_yscale;
 
- if(!textclip(areax1,areay1,areax2,areay2,rx1,ry1,rx2,ry2)) return;
+ if(!textclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,rx1,ry1,rx2,ry2)) return;
  set_ps_colors(gctext);
  x1=rx1;y1=ry1;
  if(rot&1) {y1=ry2;rot=3;}
@@ -262,19 +262,19 @@ static void ps_drawgrid()
  while(delta<CADGRIDTHRESHOLD) delta*=CADGRIDMULTIPLY;  /* <-- to be improved,but works */
  x = xctx->xorigin* xctx->mooz;y = xctx->yorigin* xctx->mooz;
  set_ps_colors(GRIDLAYER);
- if(y>areay1 && y<areay2)
+ if(y>xctx->areay1 && y<xctx->areay2)
  {
-  ps_xdrawline(GRIDLAYER,areax1+1,(int)y, areax2-1, (int)y);
+  ps_xdrawline(GRIDLAYER,xctx->areax1+1,(int)y, xctx->areax2-1, (int)y);
  }
- if(x>areax1 && x<areax2)
+ if(x>xctx->areax1 && x<xctx->areax2)
  {
-  ps_xdrawline(GRIDLAYER,(int)x,areay1+1, (int)x, areay2-1);
+  ps_xdrawline(GRIDLAYER,(int)x,xctx->areay1+1, (int)x, xctx->areay2-1);
  }
  set_ps_colors(GRIDLAYER);
- tmp = floor((areay1+1)/delta)*delta-fmod(-xctx->yorigin* xctx->mooz,delta);
- for(x=floor((areax1+1)/delta)*delta-fmod(-xctx->xorigin* xctx->mooz,delta);x<areax2;x+=delta)
+ tmp = floor((xctx->areay1+1)/delta)*delta-fmod(-xctx->yorigin* xctx->mooz,delta);
+ for(x=floor((xctx->areax1+1)/delta)*delta-fmod(-xctx->xorigin* xctx->mooz,delta);x<xctx->areax2;x+=delta)
  {
-  for(y=tmp;y<areay2;y+=delta)
+  for(y=tmp;y<xctx->areay2;y+=delta)
   {
    ps_xdrawpoint(GRIDLAYER,(int)(x), (int)(y));
   }
@@ -304,7 +304,7 @@ static void ps_draw_symbol(int n,int layer,int tmp_flip, int rot,
    x2=X_TO_PS(xctx->inst[n].x2);
    y1=Y_TO_PS(xctx->inst[n].y1);
    y2=Y_TO_PS(xctx->inst[n].y2);
-   if(OUTSIDE(x1,y1,x2,y2,areax1,areay1,areax2,areay2))
+   if(OUTSIDE(x1,y1,x2,y2,xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2))
    {
     xctx->inst[n].flags|=1;
     return;
@@ -441,7 +441,7 @@ void ps_draw(void)
      return;
    }
  }
- modified_save=modified;
+ modified_save=xctx->modified;
  push_undo();
  trim_wires();    /* 20161121 add connection boxes on wires but undo at end */
  ps_colors=my_calloc(311, cadlayers, sizeof(Ps_color));
@@ -453,8 +453,8 @@ void ps_draw(void)
  old_grid=draw_grid;
  draw_grid=0;
 
- dx=areax2-areax1;
- dy=areay2-areay1;
+ dx=xctx->areax2-xctx->areax1;
+ dy=xctx->areay2-xctx->areay1;
  dbg(1, "ps_draw(): dx=%.16g  dy=%.16g\n", dx, dy);
 
  fd=fopen("plot.ps", "w");
@@ -563,10 +563,10 @@ void ps_draw(void)
    int i;
    update_conn_cues(0, 0);
    /* draw connecting dots */
-   x1 = X_TO_XSCHEM(areax1);
-   y1 = Y_TO_XSCHEM(areay1);
-   x2 = X_TO_XSCHEM(areax2);
-   y2 = Y_TO_XSCHEM(areay2);
+   x1 = X_TO_XSCHEM(xctx->areax1);
+   y1 = Y_TO_XSCHEM(xctx->areay1);
+   x2 = X_TO_XSCHEM(xctx->areax2);
+   y2 = Y_TO_XSCHEM(xctx->areay2);
    for(init_wire_iterator(x1, y1, x2, y2); ( wireptr = wire_iterator_next() ) ;) {
      i = wireptr->n;
      if( xctx->wire[i].end1 >1 ) { /* 20150331 draw_dots */
@@ -599,6 +599,6 @@ void ps_draw(void)
  tcleval( tmp);
  my_free(880, &tmp);
  pop_undo(0);
- modified=modified_save;
+ xctx->modified=modified_save;
 }
 
diff --git a/src/save.c b/src/save.c
index 32ec1817..1b175167 100644
--- a/src/save.c
+++ b/src/save.c
@@ -934,10 +934,10 @@ int save_schematic(const char *schname) /* 20171020 added return value */
   fclose(fd);
   my_strncpy(xctx->current_name, rel_sym_path(name), S(xctx->current_name));
   /* <<<<< >>>> why clear all these? */
-  prepared_hilight_structs=0;
-  prepared_netlist_structs=0;
-  prepared_hash_instances=0;
-  prepared_hash_wires=0;
+  xctx->prep_hi_structs=0;
+  xctx->prep_net_structs=0;
+  xctx->prep_hash_inst=0;
+  xctx->prep_hash_wires=0;
   if(!strstr(xctx->sch[xctx->currsch], ".xschem_embedded_")) {
      set_modify(0);
   }
@@ -978,10 +978,10 @@ void load_schematic(int load_symbols, const char *filename, int reset_undo) /* 2
   static int save_netlist_type = 0;
   static int loaded_symbol = 0;
 
-  prepared_hilight_structs=0;
-  prepared_netlist_structs=0;
-  prepared_hash_instances=0;
-  prepared_hash_wires=0;
+  xctx->prep_hi_structs=0;
+  xctx->prep_net_structs=0;
+  xctx->prep_hash_inst=0;
+  xctx->prep_hash_wires=0;
   if(reset_undo) clear_undo();
   if(filename && filename[0]) {
     my_strncpy(name, filename, S(name));
@@ -1041,7 +1041,7 @@ void load_schematic(int load_symbols, const char *filename, int reset_undo) /* 2
   }
   if(has_x) { /* 20161207 moved after if( (fd=..))  */
     if(reset_undo) {
-      tcleval( "wm title . \"xschem - [file tail [xschem get schname]]\""); /* 20150417 set window and icon title */
+      tcleval( "wm title . \"xschem - [file tail [xschem get schname]]\""); /* set window and icon title */
       tcleval( "wm iconname . \"xschem - [file tail [xschem get schname]]\"");
     }
   }
@@ -1227,10 +1227,10 @@ void pop_undo(int redo)
   dbg(2, "pop_undo(): loaded file:wire=%d inst=%d\n",xctx->wires , xctx->instances);
   link_symbols_to_instances();
   set_modify(1);
-  prepared_hash_instances=0;
-  prepared_hash_wires=0;
-  prepared_netlist_structs=0;
-  prepared_hilight_structs=0;
+  xctx->prep_hash_inst=0;
+  xctx->prep_hash_wires=0;
+  xctx->prep_net_structs=0;
+  xctx->prep_hi_structs=0;
   update_conn_cues(0, 0);
 
   dbg(2, "pop_undo(): returning\n");
@@ -1378,7 +1378,7 @@ void align_sch_pins_with_sym(const char *name, int pos)
 }
 
 /* replace i/o/iopin instances of LCC schematics with symbol pins (boxes on PINLAYER layer) */
-void add_pinlayer_boxes(int *lastr, xRect **bb, const char *symtype, char *prop_ptr, double inst_x0, double inst_y0)
+void add_pinlayer_boxes(int *lastr, xRect **bb, const char *symtype, char *prop_ptr, double i_x0, double i_y0)
 {
   int i, save;
   const char *label;
@@ -1386,8 +1386,8 @@ void add_pinlayer_boxes(int *lastr, xRect **bb, const char *symtype, char *prop_
 
   i = lastr[PINLAYER];
   my_realloc(652, &bb[PINLAYER], (i + 1) * sizeof(xRect));
-  bb[PINLAYER][i].x1 = inst_x0 - 2.5; bb[PINLAYER][i].x2 = inst_x0 + 2.5;
-  bb[PINLAYER][i].y1 = inst_y0 - 2.5; bb[PINLAYER][i].y2 = inst_y0 + 2.5;
+  bb[PINLAYER][i].x1 = i_x0 - 2.5; bb[PINLAYER][i].x2 = i_x0 + 2.5;
+  bb[PINLAYER][i].y1 = i_y0 - 2.5; bb[PINLAYER][i].y2 = i_y0 + 2.5;
   RECTORDER(bb[PINLAYER][i].x1, bb[PINLAYER][i].y1, bb[PINLAYER][i].x2, bb[PINLAYER][i].y2);
   bb[PINLAYER][i].prop_ptr = NULL;
   label = get_tok_value(prop_ptr, "lab", 0);
@@ -1822,7 +1822,8 @@ int load_sym_def(const char *name, FILE *embed_fd)
        if (tmp) my_strdup(651, &tt[i].txt_ptr, tmp);
        ROTATION(rot, flip, 0.0, 0.0, tt[i].x0, tt[i].y0, rx1, ry1);
        tt[i].x0 = lcc[level].x0 + rx1;  tt[i].y0 = lcc[level].y0 + ry1;
-       tt[i].rot = (tt[i].rot + ((lcc[level].flip && (tt[i].rot & 1)) ? lcc[level].rot + 2 : lcc[level].rot)) & 0x3;
+       tt[i].rot = (tt[i].rot + ((lcc[level].flip && (tt[i].rot & 1)) ?
+                   lcc[level].rot + 2 : lcc[level].rot)) & 0x3;
        tt[i].flip = lcc[level].flip ^ tt[i].flip;
      }
      tt[i].prop_ptr=NULL;
@@ -2094,14 +2095,14 @@ void create_sch_from_sym(void)
   /* printf("indirect=%d\n", indirect); */
 
   rebuild_selected_array();
-  if(lastselected > 1)  return;
-  if(lastselected==1 && selectedgroup[0].type==ELEMENT)
+  if(xctx->lastsel > 1)  return;
+  if(xctx->lastsel==1 && xctx->sel_array[0].type==ELEMENT)
   {
     my_strncpy(schname, abs_sym_path(get_tok_value(
-      (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->prop_ptr, "schematic",0 ), "")
+      (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->prop_ptr, "schematic",0 ), "")
       , S(schname));
     if(!schname[0]) {
-      my_strncpy(schname, add_ext(abs_sym_path(xctx->inst[selectedgroup[0].n].name, ""), ".sch"), S(schname));
+      my_strncpy(schname, add_ext(abs_sym_path(xctx->inst[xctx->sel_array[0].n].name, ""), ".sch"), S(schname));
     }
     if( !stat(schname, &buf) ) {
       my_strdup(353, &savecmd, "ask_save \" create schematic file: ");
@@ -2129,7 +2130,7 @@ void create_sch_from_sym(void)
     fputc('\n', fd);
     fprintf(fd, "S {}");
     fputc('\n', fd);
-    ptr = xctx->inst[selectedgroup[0].n].ptr+xctx->sym;
+    ptr = xctx->inst[xctx->sel_array[0].n].ptr+xctx->sym;
     npin = ptr->rects[GENERICLAYER];
     rct = ptr->rect[GENERICLAYER];
     ypos=0;
@@ -2179,7 +2180,7 @@ void create_sch_from_sym(void)
       } /* for(i) */
     }  /* for(j) */
     fclose(fd);
-  } /* if(lastselected...) */
+  } /* if(xctx->lastsel...) */
   my_free(916, &dir);
   my_free(917, &prop);
   my_free(918, &savecmd);
@@ -2194,39 +2195,39 @@ void descend_symbol(void)
   char name[PATH_MAX];
   char name_embedded[PATH_MAX];
   rebuild_selected_array();
-  if(lastselected > 1)  return;
-  if(lastselected==1 && selectedgroup[0].type==ELEMENT) {
-    if(modified) {
+  if(xctx->lastsel > 1)  return;
+  if(xctx->lastsel==1 && xctx->sel_array[0].type==ELEMENT) {
+    if(xctx->modified) {
       if(save(1)) return;
     }
-    my_snprintf(name, S(name), "%s", xctx->inst[selectedgroup[0].n].name);
+    my_snprintf(name, S(name), "%s", xctx->inst[xctx->sel_array[0].n].name);
     /* dont allow descend in the default missing symbol */
-    if((xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type &&
-       !strcmp( (xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->type,"missing")) return;
+    if((xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type &&
+       !strcmp( (xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->type,"missing")) return;
   }
   else return;
 
   /* build up current hierarchy path */
-  my_strdup(363,  &str, xctx->inst[selectedgroup[0].n].instname);
+  my_strdup(363,  &str, xctx->inst[xctx->sel_array[0].n].instname);
   my_strdup(364, &xctx->sch_path[xctx->currsch+1], xctx->sch_path[xctx->currsch]);
   my_strcat(365, &xctx->sch_path[xctx->currsch+1], str);
   my_strcat(366, &xctx->sch_path[xctx->currsch+1], ".");
   xctx->sch_inst_number[xctx->currsch+1] = 1;
   my_free(921, &str);
-  xctx->previous_instance[xctx->currsch]=selectedgroup[0].n;
+  xctx->previous_instance[xctx->currsch]=xctx->sel_array[0].n;
   xctx->zoom_array[xctx->currsch].x=xctx->xorigin;
   xctx->zoom_array[xctx->currsch].y=xctx->yorigin;
   xctx->zoom_array[xctx->currsch].zoom=xctx->zoom;
   ++xctx->currsch;
-  if((xctx->inst[selectedgroup[0].n].ptr+ xctx->sym)->flags & EMBEDDED ||
-    !strcmp(get_tok_value(xctx->inst[selectedgroup[0].n].prop_ptr,"embed", 0), "true")) {
+  if((xctx->inst[xctx->sel_array[0].n].ptr+ xctx->sym)->flags & EMBEDDED ||
+    !strcmp(get_tok_value(xctx->inst[xctx->sel_array[0].n].prop_ptr,"embed", 0), "true")) {
     /* save embedded symbol into a temporary file */
     my_snprintf(name_embedded, S(name_embedded),
       "%s/.xschem_embedded_%d_%s", tclgetvar("XSCHEM_TMP_DIR"), getpid(), get_cell_w_ext(name, 0));
     if(!(fd = fopen(name_embedded, "w")) ) {
       fprintf(errfp, "descend_symbol(): problems opening file %s \n", name_embedded);
     }
-    save_embedded_symbol(xctx->inst[selectedgroup[0].n].ptr+xctx->sym, fd);
+    save_embedded_symbol(xctx->inst[xctx->sel_array[0].n].ptr+xctx->sym, fd);
     fclose(fd);
     unselect_all();
     remove_symbols(); /* must follow save (if) embedded */
@@ -2247,10 +2248,10 @@ void round_schematic_to_grid(double cadsnap)
 {
  int i, c, n, p;
  rebuild_selected_array();
- for(i=0;i<lastselected;i++)
+ for(i=0;i<xctx->lastsel;i++)
  {
-   c = selectedgroup[i].col; n = selectedgroup[i].n;
-   switch(selectedgroup[i].type)
+   c = xctx->sel_array[i].col; n = xctx->sel_array[i].n;
+   switch(xctx->sel_array[i].type)
    {
      case xTEXT:
        SNAP_TO_GRID(xctx->text[n].x0);
@@ -2340,11 +2341,11 @@ void save_selection(int what)
     return;
  }
  fprintf(fd, "v {xschem version=%s file_version=%s}\n", XSCHEM_VERSION, XSCHEM_FILE_VERSION);
- fprintf(fd, "G { %.16g %.16g }\n", mousex_snap, mousey_snap);
- for(i=0;i<lastselected;i++)
+ fprintf(fd, "G { %.16g %.16g }\n", xctx->mousex_snap, xctx->mousey_snap);
+ for(i=0;i<xctx->lastsel;i++)
  {
-   c = selectedgroup[i].col;n = selectedgroup[i].n;
-   switch(selectedgroup[i].type)
+   c = xctx->sel_array[i].col;n = xctx->sel_array[i].n;
+   switch(xctx->sel_array[i].type)
    {
      case xTEXT:
       fprintf(fd, "T ");
@@ -2357,7 +2358,8 @@ void save_selection(int what)
      break;
 
      case ARC:
-      fprintf(fd, "A %d %.16g %.16g %.16g %.16g %.16g ", c, xctx->arc[c][n].x, xctx->arc[c][n].y, xctx->arc[c][n].r,
+      fprintf(fd, "A %d %.16g %.16g %.16g %.16g %.16g ",
+        c, xctx->arc[c][n].x, xctx->arc[c][n].y, xctx->arc[c][n].r,
        xctx->arc[c][n].a, xctx->arc[c][n].b);
       save_ascii_string(xctx->arc[c][n].prop_ptr,fd);
       fputc('\n' ,fd);
diff --git a/src/scheduler.c b/src/scheduler.c
index 8c2e302d..08369ce2 100644
--- a/src/scheduler.c
+++ b/src/scheduler.c
@@ -205,12 +205,12 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
  }
  else if(!strcmp(argv[1],"add_symbol_pin")) {
     unselect_all();
-    storeobject(-1, mousex_snap-2.5, mousey_snap-2.5, mousex_snap+2.5, mousey_snap+2.5,
+    storeobject(-1, xctx->mousex_snap-2.5, xctx->mousey_snap-2.5, xctx->mousex_snap+2.5, xctx->mousey_snap+2.5,
                 xRECT, PINLAYER, SELECTED, "name=XXX\ndir=inout");
-    need_rebuild_selected_array=1;
+    xctx->need_reb_sel_arr=1;
     rebuild_selected_array();
     move_objects(START,0,0,0);
-    ui_state |= START_SYMPIN;
+    xctx->ui_state |= START_SYMPIN;
     Tcl_ResetResult(interp);
  }
  else if(!strcmp(argv[1],"make_symbol"))
@@ -278,19 +278,19 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      if(factor == 0.) factor = 1.;
      RECTORDER(x1,y1,x2,y2);
      xctx->xorigin=-x1;xctx->yorigin=-y1;
-     xctx->zoom=(x2-x1)/(areaw-4*INT_WIDTH(xctx->lw));
-     yy1=(y2-y1)/(areah-4*INT_WIDTH(xctx->lw));
+     xctx->zoom=(x2-x1)/(xctx->areaw-4*INT_WIDTH(xctx->lw));
+     yy1=(y2-y1)/(xctx->areah-4*INT_WIDTH(xctx->lw));
      if(yy1>xctx->zoom) xctx->zoom=yy1;
      xctx->mooz=1/xctx->zoom;
-     xctx->xorigin=xctx->xorigin+areaw*xctx->zoom*(1-1/factor)/2;
-     xctx->yorigin=xctx->yorigin+areah*xctx->zoom*(1-1/factor)/2;
+     xctx->xorigin=xctx->xorigin+xctx->areaw*xctx->zoom*(1-1/factor)/2;
+     xctx->yorigin=xctx->yorigin+xctx->areah*xctx->zoom*(1-1/factor)/2;
      xctx->zoom*= factor;
      xctx->mooz=1/xctx->zoom;
      change_linewidth(-1.);
      draw();
    }
    else {
-     ui_state |=MENUSTARTZOOM;
+     xctx->ui_state |=MENUSTARTZOOM;
    }
    Tcl_ResetResult(interp);
  }
@@ -312,21 +312,21 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
  {
    int ret;
    semaphore++;
-   mx_double_save = mousex_snap;
-   my_double_save = mousey_snap;
+   xctx->mx_double_save = xctx->mousex_snap;
+   xctx->my_double_save = xctx->mousey_snap;
    if(argc == 4) {
-     ret = place_symbol(-1,argv[2],mousex_snap, mousey_snap, 0, 0, argv[3], 4, 1);
+     ret = place_symbol(-1,argv[2],xctx->mousex_snap, xctx->mousey_snap, 0, 0, argv[3], 4, 1);
    } else if(argc == 3) {
-     ret = place_symbol(-1,argv[2],mousex_snap, mousey_snap, 0, 0, NULL, 4, 1);
+     ret = place_symbol(-1,argv[2],xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL, 4, 1);
    } else {
-     ret = place_symbol(-1,NULL,mousex_snap, mousey_snap, 0, 0, NULL, 4, 1);
+     ret = place_symbol(-1,NULL,xctx->mousex_snap, xctx->mousey_snap, 0, 0, NULL, 4, 1);
    }
 
    if(ret) {
-     mousey_snap = my_double_save;
-     mousex_snap = mx_double_save;
+     xctx->mousey_snap = xctx->my_double_save;
+     xctx->mousex_snap = xctx->mx_double_save;
      move_objects(START,0,0,0);
-     ui_state |= PLACE_SYMBOL;
+     xctx->ui_state |= PLACE_SYMBOL;
    }
    semaphore--;
    Tcl_ResetResult(interp);
@@ -334,8 +334,8 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
 
  else if(!strcmp(argv[1],"place_text"))
  {
-   ui_state |= MENUSTARTTEXT;
-   /* place_text(0,mousex_snap, mousey_snap); */
+   xctx->ui_state |= MENUSTARTTEXT;
+   /* place_text(0,xctx->mousex_snap, xctx->mousey_snap); */
    /* move_objects(START,0,0,0); */
    Tcl_ResetResult(interp);
  }
@@ -390,7 +390,7 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
 
  else if(!strcmp(argv[1],"exit"))
  {
-   if(modified && has_x) {
+   if(xctx->modified && has_x) {
      tcleval("tk_messageBox -type okcancel -message {UNSAVED data: want to exit?}");
      if(strcmp(tclresult(),"ok")==0) tcleval( "exit");
    }
@@ -398,10 +398,10 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
    Tcl_ResetResult(interp);
  }
  else if(!strcmp(argv[1], "rebuild_connectivity")) {
-   prepared_hash_instances=0;
-   prepared_hash_wires=0;
-   prepared_netlist_structs=0;
-   prepared_hilight_structs=0;
+   xctx->prep_hash_inst=0;
+   xctx->prep_hash_wires=0;
+   xctx->prep_net_structs=0;
+   xctx->prep_hi_structs=0;
    prepare_netlist_structs(0);
    Tcl_ResetResult(interp);
  }
@@ -442,10 +442,10 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      }
      draw();
      set_modify(0);
-     prepared_hash_instances=0;
-     prepared_hash_wires=0;
-     prepared_netlist_structs=0;
-     prepared_hilight_structs=0;
+     xctx->prep_hash_inst=0;
+     xctx->prep_hash_wires=0;
+     xctx->prep_net_structs=0;
+     xctx->prep_hi_structs=0;
      if(has_x) {
        tcleval( "wm title . \"xschem - [file tail [xschem get schname]]\""); /* set window and icon title */
        tcleval( "wm iconname . \"xschem - [file tail [xschem get schname]]\"");
@@ -529,9 +529,9 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
        push_undo();
      }
      set_modify(1);
-     prepared_hash_instances=0;
-     prepared_netlist_structs=0;
-     prepared_hilight_structs=0;
+     xctx->prep_hash_inst=0;
+     xctx->prep_net_structs=0;
+     xctx->prep_hi_structs=0;
      if(!strcmp(argv[3], "name")) hash_all_names(inst);
      if(argc >= 5) {
        new_prop_string(inst, subst_token(xctx->inst[inst].prop_ptr, argv[3], argv[4]),fast, dis_uniq_names);
@@ -581,9 +581,9 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      push_undo();
      set_modify(1);
      if(!fast) {
-       prepared_hash_instances=0;
-       prepared_netlist_structs=0;
-       prepared_hilight_structs=0;
+       xctx->prep_hash_inst=0;
+       xctx->prep_net_structs=0;
+       xctx->prep_hi_structs=0;
      }
      sym_number=match_symbol(symbol);
      if(sym_number>=0)
@@ -791,13 +791,13 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
    int n, i;
    char *res = NULL;
    rebuild_selected_array();
-   for(n=0; n < lastselected; n++) {
-     if(selectedgroup[n].type == ELEMENT) {
-       i = selectedgroup[n].n;
+   for(n=0; n < xctx->lastsel; n++) {
+     if(xctx->sel_array[n].type == ELEMENT) {
+       i = xctx->sel_array[n].n;
        my_strcat(1191, &res, "{");
        my_strcat(1192, &res, xctx->inst[i].instname);
        my_strcat(645, &res, "}");
-       if(n < lastselected-1) my_strcat(646, &res, " ");
+       if(n < xctx->lastsel-1) my_strcat(646, &res, " ");
      }
    }
    Tcl_AppendResult(interp, res, NULL);
@@ -806,11 +806,11 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
    int n, i;
    char *res = NULL;
    rebuild_selected_array();
-   for(n=0; n < lastselected; n++) {
-     if(selectedgroup[n].type == WIRE) {
-       i = selectedgroup[n].n;
+   for(n=0; n < xctx->lastsel; n++) {
+     if(xctx->sel_array[n].type == WIRE) {
+       i = xctx->sel_array[n].n;
        my_strcat(434, &res, get_tok_value(xctx->wire[i].prop_ptr,"lab",0));
-       if(n < lastselected-1) my_strcat(442, &res, " ");
+       if(n < xctx->lastsel-1) my_strcat(442, &res, " ");
      }
    }
    Tcl_AppendResult(interp, res, NULL);
@@ -852,11 +852,11 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      place_symbol(-1, argv[2], atof(argv[3]), atof(argv[4]), atoi(argv[5]), atoi(argv[6]), argv[7], 0, x);
    }
  } else if(!strcmp(argv[1],"arc")) {
-   ui_state |= MENUSTARTARC;
+   xctx->ui_state |= MENUSTARTARC;
  } else if(!strcmp(argv[1],"circle")) {
-   ui_state |= MENUSTARTCIRCLE;
+   xctx->ui_state |= MENUSTARTCIRCLE;
  } else if(!strcmp(argv[1],"snap_wire")) {
-   ui_state |= MENUSTARTSNAPWIRE;
+   xctx->ui_state |= MENUSTARTSNAPWIRE;
  } else if(!strcmp(argv[1],"wire")) {
    double x1,y1,x2,y2;
    int pos, save;
@@ -873,15 +873,15 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      else prop = NULL;
      push_undo();
      storeobject(pos, x1,y1,x2,y2,WIRE,0,0,prop);
-     prepared_hilight_structs=0;
-     prepared_netlist_structs=0;
-     prepared_hash_wires=0;
+     xctx->prep_hi_structs=0;
+     xctx->prep_net_structs=0;
+     xctx->prep_hash_wires=0;
 
      save = draw_window; draw_window = 1;
      drawline(WIRELAYER,NOW, x1,y1,x2,y2, 0);
      draw_window = save;
    }
-   else ui_state |= MENUSTARTWIRE;
+   else xctx->ui_state |= MENUSTARTWIRE;
  } else if(!strcmp(argv[1],"line")) {
    double x1,y1,x2,y2;
    int pos, save;
@@ -898,7 +898,7 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      drawline(rectcolor,NOW, x1,y1,x2,y2, 0);
      draw_window = save;
    }
-   else ui_state |= MENUSTARTLINE;
+   else xctx->ui_state |= MENUSTARTLINE;
  } else if(!strcmp(argv[1],"rect")) {
    double x1,y1,x2,y2;
    int pos, save;
@@ -915,17 +915,17 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      drawrect(rectcolor,NOW, x1,y1,x2,y2, 0);
      draw_window = save;
    }
-   else ui_state |= MENUSTARTRECT;
+   else xctx->ui_state |= MENUSTARTRECT;
  } else if(!strcmp(argv[1],"polygon")) {
-   ui_state |= MENUSTARTPOLYGON;
+   xctx->ui_state |= MENUSTARTPOLYGON;
  } else if(!strcmp(argv[1],"align")) {
     push_undo();
     round_schematic_to_grid(cadsnap);
     set_modify(1);
-    prepared_hash_instances=0;
-    prepared_hash_wires=0;
-    prepared_netlist_structs=0;
-    prepared_hilight_structs=0;
+    xctx->prep_hash_inst=0;
+    xctx->prep_hash_wires=0;
+    xctx->prep_net_structs=0;
+    xctx->prep_hi_structs=0;
     draw();
  } else if(!strcmp(argv[1],"saveas")) {
    if(argc == 4) {
@@ -958,12 +958,12 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
   printf("wires=%d\n", xctx->wires);
   printf("instances=%d\n", xctx->instances);
   printf("symbols=%d\n", xctx->symbols);
-  printf("lastselected=%d\n", lastselected);
+  printf("xctx->lastsel=%d\n", xctx->lastsel);
   printf("texts=%d\n", xctx->texts);
   printf("maxt=%d\n", xctx->maxt);
   printf("maxw=%d\n", xctx->maxw);
   printf("maxi=%d\n", xctx->maxi);
-  printf("max_selected=%d\n", max_selected);
+  printf("xctx->maxsel=%d\n", xctx->maxsel);
   printf("zoom=%.16g\n", xctx->zoom);
   printf("xorigin=%.16g\n", xctx->xorigin);
   printf("yorigin=%.16g\n", xctx->yorigin);
@@ -982,16 +982,16 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
     printf("sch_path[%d]=%s\n",i,xctx->sch_path[i]? xctx->sch_path[i]:"<NULL>");
     printf("sch[%d]=%s\n",i,xctx->sch[i]);
   }
-  printf("modified=%d\n", modified);
+  printf("xctx->modified=%d\n", xctx->modified);
   printf("color_ps=%d\n", color_ps);
   printf("a3page=%d\n", a3page);
   printf("hilight_nets=%d\n", hilight_nets);
-  printf("need_rebuild_selected_array=%d\n", need_rebuild_selected_array);
+  printf("xctx->need_reb_sel_arr=%d\n", xctx->need_reb_sel_arr);
   printf("******* end global variables:*******\n");
  } else if(!strcmp(argv[1],"help")) {
   printf("xschem : function used to communicate with the C program\n");
   printf("Usage:\n");
-  printf("      xschem callback X-event_type mousex mousey Xkeysym mouse_button Xstate\n");
+  printf("      xschem callback X-event_type xctx->mousex xctx->mousey Xkeysym mouse_button Xstate\n");
   printf("                   can be used to send any event to the application\n");
   printf("      xschem netlist\n");
   printf("                   generates a netlist in the selected format for the current schematic\n");
@@ -1165,15 +1165,15 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
 
  else if(!strcmp(argv[1],"edit_file") ) {
     rebuild_selected_array();
-    if(lastselected==0 ) {
+    if(xctx->lastsel==0 ) {
       save_schematic(xctx->sch[xctx->currsch]); /* sync data with disk file before editing file */
       my_snprintf(name, S(name), "edit_file {%s}",
           abs_sym_path(xctx->sch[xctx->currsch], ""));
       tcleval(name);
     }
-    else if(selectedgroup[0].type==ELEMENT) {
+    else if(xctx->sel_array[0].type==ELEMENT) {
       my_snprintf(name, S(name), "edit_file {%s}",
-          abs_sym_path(xctx->inst[selectedgroup[0].n].name, ""));
+          abs_sym_path(xctx->inst[xctx->sel_array[0].n].name, ""));
       tcleval(name);
 
     }
@@ -1277,7 +1277,7 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
  {
     tcleval("catch { ngspice::resetdata }");
     if(argc==3) {
-      if(!has_x || !modified  || !save(1) ) { /* save(1)==1 --> user cancel */
+      if(!has_x || !xctx->modified  || !save(1) ) { /* save(1)==1 --> user cancel */
         dbg(1, "scheduler(): load: filename=%s\n", argv[2]);
         delete_hilight_net();
         xctx->currsch = 0;
@@ -1494,7 +1494,7 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
 
  else if(!strcmp(argv[1],"flip"))
  {
-   if(! (ui_state & (STARTMOVE | STARTCOPY) ) ) { 
+   if(! (xctx->ui_state & (STARTMOVE | STARTCOPY) ) ) { 
      rebuild_selected_array();
      move_objects(START,0,0,0);
      move_objects(FLIP|ROTATELOCAL,0,0,0);
@@ -1510,7 +1510,7 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
  {
 
 
-   if(! (ui_state & (STARTMOVE | STARTCOPY) ) ) { 
+   if(! (xctx->ui_state & (STARTMOVE | STARTCOPY) ) ) { 
      rebuild_selected_array();
      move_objects(START,0,0,0);
      move_objects(ROTATE|ROTATELOCAL,0,0,0);
@@ -1924,8 +1924,8 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
   else if(!strcmp(argv[2],"cadsnap_default"))  {
         Tcl_AppendResult(interp, tclgetvar("snap"),NULL);
   }
-  else if(!strcmp(argv[2],"user_top_netl_name"))  {
-    Tcl_AppendResult(interp, user_top_netl_name);
+  else if(!strcmp(argv[2],"xctx->netlist_name"))  {
+    Tcl_AppendResult(interp, xctx->netlist_name);
   }
   else if(!strcmp(argv[2],"cadsnap"))  {
         char s[30]; /* overflow safe 20161212 */
@@ -1962,9 +1962,9 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
         my_snprintf(s, S(s), "%d",draw_window);
         Tcl_AppendResult(interp, s,NULL);
   }
-  else if(!strcmp(argv[2],"ui_state"))  {
+  else if(!strcmp(argv[2],"xctx->ui_state"))  {
         char s[30]; /* overflow safe 20161122 */
-        my_snprintf(s, S(s), "%d",ui_state);
+        my_snprintf(s, S(s), "%d",xctx->ui_state);
         Tcl_AppendResult(interp, s,NULL);
   }
   else if(!strcmp(argv[2],"netlist_dir"))  {
@@ -2087,8 +2087,8 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
    if(!strcmp(argv[2],"cairo_font_name"))  {
      if( strlen(argv[3]) < sizeof(cairo_font_name) ) {
        my_strncpy(cairo_font_name, argv[3], S(cairo_font_name));
-       cairo_select_font_face (cairo_ctx, cairo_font_name, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
-       cairo_select_font_face (cairo_save_ctx, cairo_font_name, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
+       cairo_select_font_face(cairo_ctx, cairo_font_name, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
+       cairo_select_font_face(cairo_save_ctx, cairo_font_name, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
      }
    } else
    #endif
@@ -2108,8 +2108,8 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
      int s = atoi(argv[3]);
      show_pin_net_names=s;
    }
-   else if(!strcmp(argv[2],"user_top_netl_name"))  {
-     my_strncpy(user_top_netl_name, argv[3], S(user_top_netl_name));
+   else if(!strcmp(argv[2],"xctx->netlist_name"))  {
+     my_strncpy(xctx->netlist_name, argv[3], S(xctx->netlist_name));
    }
    else if(!strcmp(argv[2],"dim"))  {
      double s = atof(argv[3]);
@@ -2209,7 +2209,7 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
       rectcolor=atoi(argv[3]);
       tcleval("reconfigure_layers_button");
       rebuild_selected_array();
-      if(lastselected) {
+      if(xctx->lastsel) {
         change_layer();
       }
    }
@@ -2219,8 +2219,8 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
    else if(!strcmp(argv[2],"draw_window"))  {
       draw_window=atoi(argv[3]);
    }
-   else if(!strcmp(argv[2],"ui_state"))  {
-      ui_state=atoi(argv[3]);
+   else if(!strcmp(argv[2],"xctx->ui_state"))  {
+      xctx->ui_state=atoi(argv[3]);
    }
    else {
      Tcl_AppendResult(interp, "xschem set ", argv[1], argv[3], ": invalid command.", NULL);
diff --git a/src/select.c b/src/select.c
index b9210a49..a79e634a 100644
--- a/src/select.c
+++ b/src/select.c
@@ -215,23 +215,23 @@ void delete(void)
   j = 0;
   bbox(START, 0.0 , 0.0 , 0.0 , 0.0);
   rebuild_selected_array();
-  if(lastselected) push_undo();
+  if(xctx->lastsel) push_undo();
 
 
 
-  /* first calculate bbox, because symbol_bbox() needs translate (@#0:net_name) which needs prepare_netlist_structs
-   * which needs a consistent xctx->inst[] data structure */
+  /* first calculate bbox, because symbol_bbox() needs translate (@#0:net_name) which
+   *  needs prepare_netlist_structs which needs a consistent xctx->inst[] data structure */
 
    /* does not seem to be needed
-   prepared_netlist_structs=0;
-   prepared_hilight_structs=0;
-   */
+    * xctx->prep_net_structs=0;
+    * xctx->prep_hi_structs=0;
+    */
    if(show_pin_net_names) {
      prepare_netlist_structs(0);
    }
-   for(i = 0; i < lastselected; i++) {
-     n = selectedgroup[i].n;
-     if(selectedgroup[i].type == ELEMENT) {
+   for(i = 0; i < xctx->lastsel; i++) {
+     n = xctx->sel_array[i].n;
+     if(xctx->sel_array[i].type == ELEMENT) {
        int p;
        char *type = (xctx->inst[n].ptr + xctx->sym)->type;
        symbol_bbox(n, &xctx->inst[n].x1, &xctx->inst[n].y1, &xctx->inst[n].x2, &xctx->inst[n].y2 );
@@ -244,7 +244,7 @@ void delete(void)
          }
        }
      }
-     if(show_pin_net_names && selectedgroup[i].type == WIRE && xctx->wire[n].node) {
+     if(show_pin_net_names && xctx->sel_array[i].type == WIRE && xctx->wire[n].node) {
        find_inst_to_be_redrawn(xctx->wire[n].node);
      }
    }
@@ -322,9 +322,9 @@ void delete(void)
   xctx->instances-=j;
 
   if(j) {
-    prepared_hash_instances=0;
-    prepared_netlist_structs=0;
-    prepared_hilight_structs=0;
+    xctx->prep_hash_inst=0;
+    xctx->prep_net_structs=0;
+    xctx->prep_hi_structs=0;
   }
   j = 0;
   for(i=0;i<xctx->wires;i++)
@@ -357,18 +357,18 @@ void delete(void)
   }
   xctx->wires -= j;
   if(j) {
-    prepared_hash_wires=0;
-    prepared_netlist_structs=0;
-    prepared_hilight_structs=0;
+    xctx->prep_hash_wires=0;
+    xctx->prep_net_structs=0;
+    xctx->prep_hi_structs=0;
   }
 
   del_rect_line_arc_poly();
   update_conn_cues(0, 0);
-  lastselected = 0;
+  xctx->lastsel = 0;
   bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
   draw();
   bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
-  ui_state &= ~SELECTION;
+  xctx->ui_state &= ~SELECTION;
 }
 
 
@@ -376,11 +376,11 @@ void delete_only_rect_line_arc_poly(void)
 {
  bbox(START, 0.0 , 0.0 , 0.0 , 0.0);
  del_rect_line_arc_poly();
- lastselected = 0;
+ xctx->lastsel = 0;
  bbox(SET , 0.0 , 0.0 , 0.0 , 0.0);
  draw();
  bbox(END , 0.0 , 0.0 , 0.0 , 0.0);
- ui_state &= ~SELECTION;
+ xctx->ui_state &= ~SELECTION;
 }
 
 
@@ -403,12 +403,12 @@ void bbox(int what,double x1,double y1, double x2, double y2)
    bbx2 = 0;
    bby1 = 300000000;
    bby2 = 0;
-   savex1 = areax1;
-   savex2 = areax2;
-   savey1 = areay1;
-   savey2 = areay2;
-   savew = areaw;
-   saveh = areah;
+   savex1 = xctx->areax1;
+   savex2 = xctx->areax2;
+   savey1 = xctx->areay1;
+   savey2 = xctx->areay2;
+   savew = xctx->areaw;
+   saveh = xctx->areah;
    sem=1;
    break;
   case ADD:
@@ -432,16 +432,16 @@ void bbox(int what,double x1,double y1, double x2, double y2)
    if(y1 > bby2) bby2 = (int) y1;
    break;
   case END:
-   areax1 = savex1;
-   areax2 = savex2;
-   areay1 = savey1;
-   areay2 = savey2;
-   areaw =  savew;
-   areah =  saveh;
+   xctx->areax1 = savex1;
+   xctx->areax2 = savex2;
+   xctx->areay1 = savey1;
+   xctx->areay2 = savey2;
+   xctx->areaw =  savew;
+   xctx->areah =  saveh;
    xrect[0].x = 0;
    xrect[0].y = 0;
-   xrect[0].width = areaw-4*INT_WIDTH(xctx->lw);
-   xrect[0].height = areah-4*INT_WIDTH(xctx->lw);
+   xrect[0].width = xctx->areaw-4*INT_WIDTH(xctx->lw);
+   xrect[0].height = xctx->areah-4*INT_WIDTH(xctx->lw);
 
    XSetClipMask(display, gctiled, None); /* 20171110 optimization, clipping already done in software */
 
@@ -461,12 +461,12 @@ void bbox(int what,double x1,double y1, double x2, double y2)
      fprintf(errfp, "ERROR: bbox(SET) call before bbox(START)\n");
      tcleval("alert_ {ERROR: bbox(SET) call before bbox(START)} {}");
    }
-   areax1 = bbx1-2*INT_WIDTH(xctx->lw);
-   areax2 = bbx2+2*INT_WIDTH(xctx->lw);
-   areay1 = bby1-2*INT_WIDTH(xctx->lw);
-   areay2 = bby2+2*INT_WIDTH(xctx->lw);
-   areaw = (areax2-areax1);
-   areah = (areay2-areay1);
+   xctx->areax1 = bbx1-2*INT_WIDTH(xctx->lw);
+   xctx->areax2 = bbx2+2*INT_WIDTH(xctx->lw);
+   xctx->areay1 = bby1-2*INT_WIDTH(xctx->lw);
+   xctx->areay2 = bby2+2*INT_WIDTH(xctx->lw);
+   xctx->areaw = (xctx->areax2-xctx->areax1);
+   xctx->areah = (xctx->areay2-xctx->areay1);
 
    xrect[0].x = bbx1-INT_WIDTH(xctx->lw);
    xrect[0].y = bby1-INT_WIDTH(xctx->lw);
@@ -478,7 +478,7 @@ void bbox(int what,double x1,double y1, double x2, double y2)
      XSetClipRectangles(display, gcstipple[i], 0,0, xrect, 1, Unsorted);
    }
    XSetClipRectangles(display, gctiled, 0,0, xrect, 1, Unsorted);
-   dbg(1, "bbox(): bbox= %d %d %d %d\n",areax1,areay1,areax2,areay2);
+   dbg(1, "bbox(): bbox= %d %d %d %d\n",xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2);
    #ifdef HAS_CAIRO
    cairo_rectangle(cairo_ctx, xrect[0].x, xrect[0].y, xrect[0].width, xrect[0].height);
    cairo_clip(cairo_ctx);
@@ -498,8 +498,8 @@ void unselect_all(void)
  #ifdef HAS_CAIRO
  int customfont;
  #endif
-    ui_state = 0;
-    lastselected = 0;
+    xctx->ui_state = 0;
+    xctx->lastsel = 0;
 
      for(i=0;i<xctx->wires;i++)
      {
@@ -587,7 +587,7 @@ void unselect_all(void)
     drawtemparc(gctiled, END, 0.0, 0.0, 0.0, 0.0, 0.0);
     drawtemprect(gctiled, END, 0.0, 0.0, 0.0, 0.0);
     drawtempline(gctiled,END, 0.0, 0.0, 0.0, 0.0);
-    ui_state &= ~SELECTION;
+    xctx->ui_state &= ~SELECTION;
     /*\statusmsg("",2); */
     my_snprintf(str, S(str), "%s/%s", user_conf_dir, ".selection.sch"); /* 20161115  PWD->HOME */
     xunlink(str);
@@ -605,7 +605,8 @@ void select_wire(int i,unsigned short select_mode, int fast)
            xctx->wire[i].prop_ptr? xctx->wire[i].prop_ptr: "(null)");
     statusmsg(str,2);
 
-   my_snprintf(str, S(str), "n=%4d x = %.16g  y = %.16g  w = %.16g h = %.16g",i, xctx->wire[i].x1, xctx->wire[i].y1,
+   my_snprintf(str, S(str), "n=%4d x = %.16g  y = %.16g  w = %.16g h = %.16g",
+      i, xctx->wire[i].x1, xctx->wire[i].y1,
       xctx->wire[i].x2-xctx->wire[i].x1, xctx->wire[i].y2-xctx->wire[i].y1
    );
    statusmsg(str,1);
@@ -628,7 +629,7 @@ void select_wire(int i,unsigned short select_mode, int fast)
    else
      drawtempline(gctiled, NOW, xctx->wire[i].x1, xctx->wire[i].y1, xctx->wire[i].x2, xctx->wire[i].y2);
   }
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
 }
 
 void select_element(int i,unsigned short select_mode, int fast, int override_lock)
@@ -677,7 +678,7 @@ void select_element(int i,unsigned short select_mode, int fast, int override_loc
       draw_temp_symbol(NOW, gctiled, i,c,0,0,0.0,0.0);
     }
   }
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
 }
 
 void select_text(int i,unsigned short select_mode, int fast)
@@ -713,7 +714,7 @@ void select_text(int i,unsigned short select_mode, int fast)
   #ifdef HAS_CAIRO
   if(customfont) cairo_restore(cairo_ctx);
   #endif
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
 }
 
 void select_box(int c, int i, unsigned short select_mode, int fast)
@@ -748,7 +749,7 @@ void select_box(int c, int i, unsigned short select_mode, int fast)
 
   if( xctx->rect[c][i].sel == (SELECTED1|SELECTED2|SELECTED3|SELECTED4)) xctx->rect[c][i].sel = SELECTED;
 
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
 }
 
 
@@ -779,7 +780,7 @@ void select_arc(int c, int i, unsigned short select_mode, int fast)
 
   /*if( xctx->arc[c][i].sel == (SELECTED1|SELECTED2|SELECTED3|SELECTED4)) xctx->arc[c][i].sel = SELECTED; */
 
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
 }
 
 void select_polygon(int c, int i, unsigned short select_mode, int fast )
@@ -801,7 +802,7 @@ void select_polygon(int c, int i, unsigned short select_mode, int fast )
   }
   else
    drawtemppolygon(gctiled, NOW, xctx->poly[c][i].x, xctx->poly[c][i].y, xctx->poly[c][i].points);
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
 }
 
 void select_line(int c, int i, unsigned short select_mode, int fast )
@@ -840,14 +841,14 @@ void select_line(int c, int i, unsigned short select_mode, int fast )
    else
      drawtempline(gctiled, NOW, xctx->line[c][i].x1, xctx->line[c][i].y1,
                                 xctx->line[c][i].x2, xctx->line[c][i].y2);
-  need_rebuild_selected_array=1;
+  xctx->need_reb_sel_arr=1;
 }
 
 /* 20160503 return type field */
-unsigned short select_object(double mousex,double mousey, unsigned short select_mode, int override_lock)
+unsigned short select_object(double mx,double my, unsigned short select_mode, int override_lock)
 {
    Selected sel;
-   sel = find_closest_obj(mousex,mousey);
+   sel = find_closest_obj(mx, my);
 
    dbg(1, "select_object(): sel.n=%d, sel.col=%d, sel.type=%d\n", sel.n, sel.col, sel.type);
 
@@ -882,7 +883,7 @@ unsigned short select_object(double mousex,double mousey, unsigned short select_
    drawtemprect(gc[SELLAYER], END, 0.0, 0.0, 0.0, 0.0);
    drawtempline(gc[SELLAYER], END, 0.0, 0.0, 0.0, 0.0);
 
-   if(sel.type)  ui_state |= SELECTION;
+   if(sel.type)  xctx->ui_state |= SELECTION;
    return sel.type;
 }
 
@@ -899,17 +900,17 @@ void select_inside(double x1,double y1, double x2, double y2, int sel) /* 201509
  {
   if(RECTINSIDE(xctx->wire[i].x1,xctx->wire[i].y1,xctx->wire[i].x2,xctx->wire[i].y2, x1,y1,x2,y2))
   {
-   ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+   xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
    sel ? select_wire(i,SELECTED, 1): select_wire(i,0, 1);
   }
   else if( sel && enable_stretch && POINTINSIDE(xctx->wire[i].x1,xctx->wire[i].y1, x1,y1,x2,y2) )
   {
-   ui_state |= SELECTION;
+   xctx->ui_state |= SELECTION;
    select_wire(i,SELECTED1, 1);
   }
   else if( sel && enable_stretch && POINTINSIDE(xctx->wire[i].x2,xctx->wire[i].y2, x1,y1,x2,y2) )
   {
-   ui_state |= SELECTION;
+   xctx->ui_state |= SELECTION;
    select_wire(i,SELECTED2, 1);
   }
  }
@@ -930,7 +931,7 @@ void select_inside(double x1,double y1, double x2, double y2, int sel) /* 201509
   #endif
   if(RECTINSIDE(xx1,yy1, xx2, yy2,x1,y1,x2,y2))
   {
-   ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+   xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
    sel ? select_text(i, SELECTED, 1): select_text(i, 0, 1);
   }
  }
@@ -938,7 +939,7 @@ void select_inside(double x1,double y1, double x2, double y2, int sel) /* 201509
  {
   if(RECTINSIDE(xctx->inst[i].xx1, xctx->inst[i].yy1, xctx->inst[i].xx2, xctx->inst[i].yy2, x1,y1,x2,y2))
   {
-   ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+   xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
    sel ? select_element(i,SELECTED,1, 0): select_element(i,0,1, 0);
   }
  }
@@ -965,10 +966,11 @@ void select_inside(double x1,double y1, double x2, double y2, int sel) /* 201509
         select_polygon(c, i, 0, 1);
       }
       if(selected_points==xctx->poly[c][i].points) {
-        ui_state |= SELECTION;
+        xctx->ui_state |= SELECTION;
         select_polygon(c, i, SELECTED, 1);
       } else if(selected_points) {
-        if(sel && enable_stretch) select_polygon(c, i, SELECTED1,1); /* for polygon, SELECTED1 means partial sel */
+        /* for polygon, SELECTED1 means partial sel */
+        if(sel && enable_stretch) select_polygon(c, i, SELECTED1,1);
       }
     }
 
@@ -977,17 +979,17 @@ void select_inside(double x1,double y1, double x2, double y2, int sel) /* 201509
   {
    if(RECTINSIDE(xctx->line[c][i].x1,xctx->line[c][i].y1,xctx->line[c][i].x2,xctx->line[c][i].y2, x1,y1,x2,y2))
    {
-    ui_state |= SELECTION;
+    xctx->ui_state |= SELECTION;
     sel? select_line(c,i,SELECTED,1): select_line(c,i,0,1);
    }
    else if( sel && enable_stretch && POINTINSIDE(xctx->line[c][i].x1,xctx->line[c][i].y1, x1,y1,x2,y2) )
    {
-    ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+    xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
     select_line(c, i,SELECTED1,1);
    }
    else if( sel && enable_stretch && POINTINSIDE(xctx->line[c][i].x2,xctx->line[c][i].y2, x1,y1,x2,y2) )
    {
-    ui_state |= SELECTION;
+    xctx->ui_state |= SELECTION;
     select_line(c, i,SELECTED2,1);
    }
   }
@@ -1003,22 +1005,22 @@ void select_inside(double x1,double y1, double x2, double y2, int sel) /* 201509
     yb = y - r * sin((a+b) * XSCH_PI/180.);
     arc_bbox(x, y, r, a, b, &tmp.x1, &tmp.y1, &tmp.x2, &tmp.y2);
     if(RECTINSIDE(tmp.x1, tmp.y1, tmp.x2, tmp.y2, x1,y1,x2,y2)) {
-      ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+      xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
       sel? select_arc(c, i, SELECTED,1): select_arc(c, i, 0,1);
     }
     else if( sel && enable_stretch && POINTINSIDE(x, y, x1, y1, x2, y2) )
     {
-     ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+     xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
      select_arc(c, i,SELECTED1,1);
     }
     else if( sel && enable_stretch && POINTINSIDE(xb, yb, x1, y1, x2, y2) )
     {
-     ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+     xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
      select_arc(c, i,SELECTED3,1);
     }
     else if( sel && enable_stretch && POINTINSIDE(xa, ya, x1, y1, x2, y2) )
     {
-     ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+     xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
      select_arc(c, i,SELECTED2,1);
     }
   }
@@ -1026,28 +1028,28 @@ void select_inside(double x1,double y1, double x2, double y2, int sel) /* 201509
   {
    if(RECTINSIDE(xctx->rect[c][i].x1,xctx->rect[c][i].y1,xctx->rect[c][i].x2,xctx->rect[c][i].y2, x1,y1,x2,y2))
    {
-    ui_state |= SELECTION; /* set ui_state to SELECTION also if unselecting by area ???? */
+    xctx->ui_state |= SELECTION; /* set xctx->ui_state to SELECTION also if unselecting by area ???? */
     sel? select_box(c,i, SELECTED, 1): select_box(c,i, 0, 1);
    }
    else {
      if( sel && enable_stretch && POINTINSIDE(xctx->rect[c][i].x1,xctx->rect[c][i].y1, x1,y1,x2,y2) )
      {                                  /*20070302 added stretch select */
-      ui_state |= SELECTION;
+      xctx->ui_state |= SELECTION;
       select_box(c, i,SELECTED1,1);
      }
      if( sel && enable_stretch && POINTINSIDE(xctx->rect[c][i].x2,xctx->rect[c][i].y1, x1,y1,x2,y2) )
      {
-      ui_state |= SELECTION;
+      xctx->ui_state |= SELECTION;
       select_box(c, i,SELECTED2,1);
      }
      if( sel && enable_stretch && POINTINSIDE(xctx->rect[c][i].x1,xctx->rect[c][i].y2, x1,y1,x2,y2) )
      {
-      ui_state |= SELECTION;
+      xctx->ui_state |= SELECTION;
       select_box(c, i,SELECTED3,1);
      }
      if( sel && enable_stretch && POINTINSIDE(xctx->rect[c][i].x2,xctx->rect[c][i].y2, x1,y1,x2,y2) )
      {
-      ui_state |= SELECTION;
+      xctx->ui_state |= SELECTION;
       select_box(c, i,SELECTED4,1);
      }
    }
@@ -1063,7 +1065,7 @@ void select_all(void)
 {
  int c,i;
 
- ui_state |= SELECTION;
+ xctx->ui_state |= SELECTION;
  for(i=0;i<xctx->wires;i++)
  {
    select_wire(i,SELECTED, 1);
diff --git a/src/spice_netlist.c b/src/spice_netlist.c
index 856f24cd..e23bd42d 100644
--- a/src/spice_netlist.c
+++ b/src/spice_netlist.c
@@ -41,7 +41,7 @@ void global_spice_netlist(int global)  /* netlister driver */
  char cellname[PATH_MAX]; /* 20081211 overflow safe 20161122 */
  char *subckt_name;
 
- if(modified) {
+ if(xctx->modified) {
    save_ok = save_schematic(xctx->sch[xctx->currsch]);
    if(save_ok == -1) return;
  }
@@ -64,8 +64,8 @@ void global_spice_netlist(int global)  /* netlister driver */
  dbg(1, "global_spice_netlist(): opening %s for writing\n",netl_filename);
  fd=fopen(netl_filename, "w");
 
- if(user_top_netl_name[0]) {
-   my_snprintf(cellname, S(cellname), "%s", get_cell(user_top_netl_name, 0));
+ if(xctx->netlist_name[0]) {
+   my_snprintf(cellname, S(cellname), "%s", get_cell(xctx->netlist_name, 0));
  } else {
    my_snprintf(cellname, S(cellname), "%s.spice", skip_dir(xctx->sch[xctx->currsch]));
  }
@@ -372,9 +372,8 @@ void spice_netlist(FILE *fd, int spice_stop )
   int i;
   char *type=NULL;
  
-  prepared_netlist_structs = 0;
+  xctx->prep_net_structs = 0;
   prepare_netlist_structs(1);
-  /* set_modify(1); */ /* 20160302 prepare_netlist_structs could change schematic (wire node naming for example) */
   traverse_node_hash();  /* print all warnings about unconnected floatings etc */
   if(!spice_stop) {
     for(i=0;i<xctx->instances;i++) /* print first ipin/opin defs ... */
@@ -399,7 +398,8 @@ void spice_netlist(FILE *fd, int spice_stop )
      my_strdup(390, &type,(xctx->inst[i].ptr+ xctx->sym)->type);
  
      if( type && !IS_LABEL_OR_PIN(type) ) {
-       if(!strcmp(type,"netlist_commands") && netlist_count==0) continue; /* already done in global_spice_netlist */
+       /* already done in global_spice_netlist */
+       if(!strcmp(type,"netlist_commands") && netlist_count==0) continue;
        if(netlist_count &&
           !strcmp(get_tok_value(xctx->inst[i].prop_ptr, "only_toplevel", 0), "true")) continue;
        if(!strcmp(type,"netlist_commands")) {
diff --git a/src/store.c b/src/store.c
index b7064a15..7ab17264 100644
--- a/src/store.c
+++ b/src/store.c
@@ -34,10 +34,10 @@ void check_wire_storage(void)
 
 void check_selected_storage(void)
 {
- if(lastselected >= max_selected)
+ if(xctx->lastsel >= xctx->maxsel)
  {
-  max_selected=(1+lastselected / MAXGROUP) * MAXGROUP;
-  my_realloc(393, &selectedgroup, sizeof(Selected)*max_selected);
+  xctx->maxsel=(1+xctx->lastsel / MAXGROUP) * MAXGROUP;
+  my_realloc(393, &xctx->sel_array, sizeof(Selected)*xctx->maxsel);
  }
 }
 
diff --git a/src/svgdraw.c b/src/svgdraw.c
index ee310c2e..2b2fcaab 100644
--- a/src/svgdraw.c
+++ b/src/svgdraw.c
@@ -75,7 +75,7 @@ static void svg_drawpolygon(int c, int what, double *x, double *y, int points, i
   y1=Y_TO_SVG(y1);
   x2=X_TO_SVG(x2);
   y2=Y_TO_SVG(y2);
-  if( !rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) ) {
+  if( !rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) ) {
     return;
   }
   fprintf(fd, "<path class=\"l%d\" ", c);
@@ -102,7 +102,7 @@ static void svg_filledrect(int gc, double rectx1,double recty1,double rectx2,dou
   y1=Y_TO_SVG(recty1);
   x2=X_TO_SVG(rectx2);
   y2=Y_TO_SVG(recty2);
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
    svg_xfillrectangle(gc, x1,y1,x2,y2, dash);
   }
@@ -122,7 +122,7 @@ static void svg_drawcircle(int gc, int fillarc, double x,double y,double r,doubl
   x2=X_TO_SVG(x2);
   y2=Y_TO_SVG(y2);
 
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
     fprintf(fd, "<circle class=\"l%d\" cx=\"%g\" cy=\"%g\" r=\"%g\"/>\n", gc, xx, yy, rr);
   }
@@ -144,7 +144,7 @@ static void svg_drawarc(int gc, int fillarc, double x,double y,double r,double a
   x2=X_TO_SVG(x2);
   y2=Y_TO_SVG(y2);
 
-  if( rectclip(areax1,areay1,areax2,areay2,&x1,&y1,&x2,&y2) )
+  if( rectclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,&x1,&y1,&x2,&y2) )
   {
     if(b == 360.) {
       fprintf(fd, "<circle class=\"l%d\" cx=\"%g\" cy=\"%g\" r=\"%g\" ", gc, xx, yy, rr);
@@ -258,7 +258,7 @@ static void svg_draw_string(int layer, const char *str, int rot, int flip, int h
   descent = size*xctx->mooz * 0.219;
 
   text_bbox(str, xscale, yscale, rot, flip, hcenter, vcenter, x,y, &textx1,&texty1,&textx2,&texty2);
-  if(!textclip(areax1,areay1,areax2,areay2,textx1,texty1,textx2,texty2)) {
+  if(!textclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,textx1,texty1,textx2,texty2)) {
     return;
   }
   if(hcenter) {
@@ -321,7 +321,7 @@ static void old_svg_draw_string(int layer, const char *str,
  #endif
  xscale*=nocairo_font_xscale;
  yscale*=nocairo_font_yscale;
- if(!textclip(areax1,areay1,areax2,areay2,rx1,ry1,rx2,ry2)) return;
+ if(!textclip(xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2,rx1,ry1,rx2,ry2)) return;
  x=rx1;y=ry1;
  if(rot&1) {y=ry2;rot=3;}
  else rot=0;
@@ -361,18 +361,18 @@ static void svg_drawgrid()
  delta=cadgrid* xctx->mooz;
  while(delta<CADGRIDTHRESHOLD) delta*=CADGRIDMULTIPLY;  /* <-- to be improved,but works */
  x = xctx->xorigin* xctx->mooz;y = xctx->yorigin* xctx->mooz;
- if(y>areay1 && y<areay2)
+ if(y>xctx->areay1 && y<xctx->areay2)
  {
-  svg_xdrawline(GRIDLAYER, 0, areax1+1,(int)y, areax2-1, (int)y, 0);
+  svg_xdrawline(GRIDLAYER, 0, xctx->areax1+1,(int)y, xctx->areax2-1, (int)y, 0);
  }
- if(x>areax1 && x<areax2)
+ if(x>xctx->areax1 && x<xctx->areax2)
  {
-  svg_xdrawline(GRIDLAYER, 0, (int)x,areay1+1, (int)x, areay2-1, 0);
+  svg_xdrawline(GRIDLAYER, 0, (int)x,xctx->areay1+1, (int)x, xctx->areay2-1, 0);
  }
- tmp = floor((areay1+1)/delta)*delta-fmod(-xctx->yorigin* xctx->mooz,delta);
- for(x=floor((areax1+1)/delta)*delta-fmod(-xctx->xorigin* xctx->mooz,delta);x<areax2;x+=delta)
+ tmp = floor((xctx->areay1+1)/delta)*delta-fmod(-xctx->yorigin* xctx->mooz,delta);
+ for(x=floor((xctx->areax1+1)/delta)*delta-fmod(-xctx->xorigin* xctx->mooz,delta);x<xctx->areax2;x+=delta)
  {
-  for(y=tmp;y<areay2;y+=delta)
+  for(y=tmp;y<xctx->areay2;y+=delta)
   {
    svg_xdrawpoint(GRIDLAYER, (int)(x), (int)(y));
   }
@@ -404,7 +404,7 @@ static void svg_draw_symbol(int n,int layer,int tmp_flip, int rot,
    x2=X_TO_SVG(xctx->inst[n].x2);
    y1=Y_TO_SVG(xctx->inst[n].y1);
    y2=Y_TO_SVG(xctx->inst[n].y2);
-   if(OUTSIDE(x1,y1,x2,y2,areax1,areay1,areax2,areay2))
+   if(OUTSIDE(x1,y1,x2,y2,xctx->areax1,xctx->areay1,xctx->areax2,xctx->areay2))
    {
     xctx->inst[n].flags|=1;
     return;
@@ -590,12 +590,12 @@ void svg_draw(void)
  old_grid=draw_grid;
  draw_grid=0;
 
- dx=areax2-areax1;
- dy=areay2-areay1;
+ dx=xctx->areax2-xctx->areax1;
+ dy=xctx->areay2-xctx->areay1;
  dbg(1, "svg_draw(): dx=%g  dy=%g\n", dx, dy);
 
 
- modified_save=modified;
+ modified_save=xctx->modified;
  push_undo();
  trim_wires();    /* 20161121 add connection boxes on wires but undo at end */
 
@@ -702,7 +702,8 @@ void svg_draw(void)
 
    for(i=0;i<xctx->wires;i++)
    {
-      svg_drawline(WIRELAYER, xctx->wire[i].bus, xctx->wire[i].x1,xctx->wire[i].y1,xctx->wire[i].x2,xctx->wire[i].y2, 0);
+     svg_drawline(WIRELAYER, xctx->wire[i].bus, xctx->wire[i].x1, 
+      xctx->wire[i].y1,xctx->wire[i].x2,xctx->wire[i].y2, 0);
    }
    {
      double x1, y1, x2, y2;
@@ -710,10 +711,10 @@ void svg_draw(void)
      int i;
      update_conn_cues(0, 0);
      /* draw connecting dots */
-     x1 = X_TO_XSCHEM(areax1);
-     y1 = Y_TO_XSCHEM(areay1);
-     x2 = X_TO_XSCHEM(areax2);
-     y2 = Y_TO_XSCHEM(areay2);
+     x1 = X_TO_XSCHEM(xctx->areax1);
+     y1 = Y_TO_XSCHEM(xctx->areay1);
+     x2 = X_TO_XSCHEM(xctx->areax2);
+     y2 = Y_TO_XSCHEM(xctx->areay2);
      for(init_wire_iterator(x1, y1, x2, y2); ( wireptr = wire_iterator_next() ) ;) {
        i = wireptr->n;
        if( xctx->wire[i].end1 >1 ) { /* 20150331 draw_dots */
@@ -732,7 +733,7 @@ void svg_draw(void)
  my_free(964, &svg_colors);
 
  pop_undo(0);
- modified=modified_save;
+ xctx->modified=modified_save;
 
 }
 
diff --git a/src/tedax_netlist.c b/src/tedax_netlist.c
index 71146458..8e942d90 100644
--- a/src/tedax_netlist.c
+++ b/src/tedax_netlist.c
@@ -32,7 +32,7 @@ void global_tedax_netlist(int global)  /* netlister driver */
  char tcl_cmd_netlist[PATH_MAX + 100]; /* 20081211 overflow safe 20161122 */
  char cellname[PATH_MAX]; /* 20081211 overflow safe 20161122 */
 
- if(modified) {
+ if(xctx->modified) {
    save_ok = save_schematic(xctx->sch[xctx->currsch]);
    if(save_ok == -1) return;
  }
@@ -50,8 +50,8 @@ void global_tedax_netlist(int global)  /* netlister driver */
    netlist_dir, skip_dir(xctx->sch[xctx->currsch]), getpid());
  fd=fopen(netl_filename, "w");
 
- if(user_top_netl_name[0]) {
-   my_snprintf(cellname, S(cellname), "%s", get_cell(user_top_netl_name, 0));
+ if(xctx->netlist_name[0]) {
+   my_snprintf(cellname, S(cellname), "%s", get_cell(xctx->netlist_name, 0));
  } else {
    my_snprintf(cellname, S(cellname), "%s.tdx", skip_dir(xctx->sch[xctx->currsch]));
  }
@@ -194,9 +194,8 @@ void tedax_netlist(FILE *fd, int tedax_stop )
   int i;
   char *type=NULL;
 
-  prepared_netlist_structs = 0;
+  xctx->prep_net_structs = 0;
   prepare_netlist_structs(1);
-  /* set_modify(1); */ /* 20160302 prepare_netlist_structs could change schematic (wire node naming for example) */
   traverse_node_hash();  /* print all warnings about unconnected floatings etc */
   if(!tedax_stop) {
     for(i=0;i<xctx->instances;i++) /* print first ipin/opin defs ... */
@@ -221,7 +220,8 @@ void tedax_netlist(FILE *fd, int tedax_stop )
      my_strdup(423, &type,(xctx->inst[i].ptr+ xctx->sym)->type);
 
      if( type && !IS_LABEL_OR_PIN(type) ) {
-       if(!strcmp(type,"netlist_commands") && netlist_count==0) continue; /* already done in global_tedax_netlist */
+       /* already done in global_tedax_netlist */
+       if(!strcmp(type,"netlist_commands") && netlist_count==0) continue;
        if(netlist_count &&
           !strcmp(get_tok_value(xctx->inst[i].prop_ptr, "only_toplevel", 0), "true")) continue;
        if(!strcmp(type,"netlist_commands")) {
diff --git a/src/token.c b/src/token.c
index 9a1e799d..175082ec 100644
--- a/src/token.c
+++ b/src/token.c
@@ -216,9 +216,9 @@ void check_unique_names(int rename)
             if(first) {
               bbox(START,0.0,0.0,0.0,0.0);
               set_modify(1); push_undo();
-              prepared_hash_instances=0;
-              prepared_netlist_structs=0;
-              prepared_hilight_structs=0;
+              xctx->prep_hash_inst=0;
+              xctx->prep_net_structs=0;
+              xctx->prep_hi_structs=0;
               first = 0;
             }
             bbox(ADD, xctx->inst[i].x1, xctx->inst[i].y1, xctx->inst[i].x2, xctx->inst[i].y2);
@@ -278,7 +278,7 @@ int match_symbol(const char *name)  /* never returns -1, if symbol not found loa
 
 /* update **s modifying only the token values that are */
 /* different between *new and *old */
-/* return 1 if s modified 20081221 */
+/* return 1 if s xctx->modified 20081221 */
 int set_different_token(char **s,const char *new, const char *old, int object, int n)
 {
  register int c, state=TOK_BEGIN, space;
@@ -910,7 +910,8 @@ const char *subst_token(const char *s, const char *tok, const char *new_val)
       if(!new_val_copy[0]) new_val_copy = "\"\"";
       tmp = strlen(new_val_copy) + strlen(tok) + 2;
       STR_ALLOC(&result, tmp + result_pos, &size);
-      my_snprintf(result + result_pos - 1, size, " %s=%s", tok, new_val_copy ); /* result_pos guaranteed to be > 0 */
+      /* result_pos guaranteed to be > 0 */
+      my_snprintf(result + result_pos - 1, size, " %s=%s", tok, new_val_copy );
     }
   }
   dbg(2, "subst_token(): returning: %s\n",result);
diff --git a/src/verilog_netlist.c b/src/verilog_netlist.c
index 8810307e..cc6bdbc1 100644
--- a/src/verilog_netlist.c
+++ b/src/verilog_netlist.c
@@ -39,7 +39,7 @@ void global_verilog_netlist(int global)  /* netlister driver */
  struct stat buf;
  char *subckt_name;
 
- if(modified) {
+ if(xctx->modified) {
    save_ok = save_schematic(xctx->sch[xctx->currsch]);
    if(save_ok == -1) return;
  }
@@ -53,8 +53,8 @@ void global_verilog_netlist(int global)  /* netlister driver */
    netlist_dir, skip_dir(xctx->sch[xctx->currsch]),getpid());
  fd=fopen(netl_filename, "w");
 
- if(user_top_netl_name[0]) {
-   my_snprintf(cellname, S(cellname), "%s", get_cell(user_top_netl_name, 0));
+ if(xctx->netlist_name[0]) {
+   my_snprintf(cellname, S(cellname), "%s", get_cell(xctx->netlist_name, 0));
  } else {
    my_snprintf(cellname, S(cellname), "%s.v", skip_dir(xctx->sch[xctx->currsch]));
  }
@@ -365,7 +365,8 @@ void verilog_block_netlist(FILE *fd, int i)
 
 
   if(split_files) {
-    my_snprintf(netl_filename, S(netl_filename), "%s/.%s_%d", netlist_dir,  skip_dir(xctx->sym[i].name), getpid());
+    my_snprintf(netl_filename, S(netl_filename), "%s/.%s_%d",
+       netlist_dir,  skip_dir(xctx->sym[i].name), getpid());
     dbg(1, "global_vhdl_netlist(): split_files: netl_filename=%s\n", netl_filename);
     fd=fopen(netl_filename, "w");
     my_snprintf(cellname, S(cellname), "%s.v", skip_dir(xctx->sym[i].name) );
@@ -500,7 +501,7 @@ void verilog_netlist(FILE *fd , int verilog_stop)
  int i;
  char *type=NULL;
 
- prepared_netlist_structs = 0;
+ xctx->prep_net_structs = 0;
  prepare_netlist_structs(1);
  /* set_modify(1); */ /* 20160302 prepare_netlist_structs could change schematic (wire node naming for example) */
  dbg(2, "verilog_netlist(): end prepare_netlist_structs\n");
@@ -532,7 +533,7 @@ void verilog_netlist(FILE *fd , int verilog_stop)
          strcmp(type,"verilog_preprocessor")
        ))
     {
-     if(lastselected)
+     if(xctx->lastsel)
      {
       if(xctx->inst[i].sel==SELECTED) print_verilog_element(fd, i) ;
      }
diff --git a/src/vhdl_netlist.c b/src/vhdl_netlist.c
index 64678972..7a81c799 100644
--- a/src/vhdl_netlist.c
+++ b/src/vhdl_netlist.c
@@ -43,7 +43,7 @@ void global_vhdl_netlist(int global)  /* netlister driver */
  /* top sch properties used for library use declarations and type definitions */
  /* to be printed before any entity declarations */
 
- if(modified) {
+ if(xctx->modified) {
    save_ok = save_schematic(xctx->sch[xctx->currsch]);
    if(save_ok == -1) return;
  }
@@ -54,8 +54,8 @@ void global_vhdl_netlist(int global)  /* netlister driver */
  fd=fopen(netl_filename, "w");
 
 
- if(user_top_netl_name[0]) {
-   my_snprintf(cellname, S(cellname), "%s", get_cell(user_top_netl_name, 0));
+ if(xctx->netlist_name[0]) {
+   my_snprintf(cellname, S(cellname), "%s", get_cell(xctx->netlist_name, 0));
  } else {
    my_snprintf(cellname, S(cellname), "%s.vhdl", skip_dir(xctx->sch[xctx->currsch]));
  }
@@ -605,7 +605,7 @@ void vhdl_netlist(FILE *fd , int vhdl_stop)
  int i,l;
  char *type=NULL;
 
- prepared_netlist_structs = 0;
+ xctx->prep_net_structs = 0;
  prepare_netlist_structs(1);
  /* set_modify(1); */ /* 20160302 prepare_netlist_structs could change schematic (wire node naming for example) */
  traverse_node_hash();  /* print all warnings about unconnected floatings etc */
@@ -671,7 +671,7 @@ void vhdl_netlist(FILE *fd , int vhdl_stop)
          strcmp(type,"arch_declarations")
        ))
     {
-     if(lastselected)
+     if(xctx->lastsel)
      {
       if(xctx->inst[i].sel==SELECTED) {
         print_vhdl_element(fd, i) ;
diff --git a/src/xinit.c b/src/xinit.c
index a993d518..c520e2f4 100644
--- a/src/xinit.c
+++ b/src/xinit.c
@@ -387,6 +387,16 @@ void alloc_xschem_data()
   xctx->schverilogprop=NULL;/* verilog */
   xctx->version_string = NULL;
   xctx->currsch = 0;
+  xctx->ui_state = 0;
+  xctx->need_reb_sel_arr = 1;
+  xctx->lastsel = 0;
+  xctx->maxsel = 0;
+  xctx->prep_net_structs = 0;
+  xctx->prep_hi_structs = 0;
+  xctx->prep_hash_inst = 0;
+  xctx->prep_hash_wires = 0;
+  xctx->modified = 0;
+  xctx->netlist_name[0] = '\0';
   for(i=0;i<CADMAXHIER;i++) xctx->sch_path[i]=NULL;
   my_strdup(1187, &xctx->sch_path[0],".");
   xctx->sch_inst_number[0] = 1;
@@ -553,9 +563,9 @@ void alloc_data()
  alloc_xschem_data();
  /* global context / graphic preferences/settings */
 
- max_selected=MAXGROUP;
- selectedgroup=my_calloc(619, max_selected, sizeof(Selected));
- if(selectedgroup==NULL){
+ xctx->maxsel=MAXGROUP;
+ xctx->sel_array=my_calloc(619, xctx->maxsel, sizeof(Selected));
+ if(xctx->sel_array==NULL){
    fprintf(errfp, "Tcl_AppInit(): calloc error\n");tcleval( "exit");
  }
 
@@ -664,7 +674,7 @@ void xwin_exit(void)
    my_free(1101, &color_array[i]);
    my_free(1102, &pixdata[i]);
  }
- my_free(1108, &selectedgroup);
+ my_free(1108, &xctx->sel_array);
  my_free(1120, &fill_type);
  my_free(1121, &active_layer);
  my_free(1122, &pixdata);
@@ -846,7 +856,7 @@ void preview_window(const char *what, const char *tk_win_path, const char *filen
     /* save some relevant global context */
     save_window = window;
     save_save_pixmap = save_pixmap;
-    save_mod = modified;
+    save_mod = xctx->modified;
     save_show_pin = show_pin_net_names;
     show_pin_net_names = 0;
     my_strdup(117, &saveptr, tclgetvar("current_dirname"));
@@ -870,8 +880,8 @@ void preview_window(const char *what, const char *tk_win_path, const char *filen
 
     show_pin_net_names = save_show_pin;
     xctx = save_xctx; /* restore schematic */
-    modified = save_mod;
-    set_modify(modified);
+    xctx->modified = save_mod;
+    set_modify(xctx->modified);
     /* free the pixmap (if a different one) used for preview */
 #ifdef __unix__
     if (save_pixmap != save_save_pixmap)
@@ -996,7 +1006,8 @@ int Tcl_AppInit(Tcl_Interp *inter)
    int dir_len=strlen(install_dir);
    if (dir_len>11)
      install_dir[dir_len-11] = '\0'; /* 11 = remove /xschem.exe */
-   my_snprintf(tmp, S(tmp), "regexp {bin$} \"%s\"", install_dir); /* debugging in Visual Studio will not have bin */
+   /* debugging in Visual Studio will not have bin */
+   my_snprintf(tmp, S(tmp), "regexp {bin$} \"%s\"", install_dir);
    tcleval(tmp);
    running_in_src_dir = 0;
    if (atoi(tclresult()) == 0)
@@ -1246,14 +1257,14 @@ int Tcl_AppInit(Tcl_Interp *inter)
  tclsetvar("menu_tcl_debug",debug_var ? "1" : "0" );
  if(flat_netlist) tclsetvar("flat_netlist","1");
 
- xschem_w = CADWIDTH;
- xschem_h = CADHEIGHT;
- areaw = CADWIDTH+4*INT_WIDTH(xctx->lw);  /* clip area extends 1 pixel beyond physical window area */
- areah = CADHEIGHT+4*INT_WIDTH(xctx->lw); /* to avoid drawing clipped rectangle borders at window edges */
- areax1 = -2*INT_WIDTH(xctx->lw);
- areay1 = -2*INT_WIDTH(xctx->lw);
- areax2 = areaw-2*INT_WIDTH(xctx->lw);
- areay2 = areah-2*INT_WIDTH(xctx->lw);
+ xctx->xschem_w = CADWIDTH;
+ xctx->xschem_h = CADHEIGHT;
+ xctx->areaw = CADWIDTH+4*INT_WIDTH(xctx->lw);  /* clip area extends 1 pixel beyond physical window area */
+ xctx->areah = CADHEIGHT+4*INT_WIDTH(xctx->lw); /* to avoid drawing clipped rectangle borders at window edges */
+ xctx->areax1 = -2*INT_WIDTH(xctx->lw);
+ xctx->areay1 = -2*INT_WIDTH(xctx->lw);
+ xctx->areax2 = xctx->areaw-2*INT_WIDTH(xctx->lw);
+ xctx->areay2 = xctx->areah-2*INT_WIDTH(xctx->lw);
  xrect[0].x = 0;
  xrect[0].y = 0;
  xrect[0].width = CADWIDTH;
@@ -1267,7 +1278,8 @@ int Tcl_AppInit(Tcl_Interp *inter)
  compile_font();
  /* restore current dir after loading font */
  if(tcleval("info exists env(PWD)")[0] == '1') {
-   tcleval("set current_dirname $env(PWD)"); /* $env(PWD) better than pwd_dir as it does not dereference symlinks */
+   /* $env(PWD) better than pwd_dir as it does not dereference symlinks */
+   tcleval("set current_dirname $env(PWD)");
  } else {
    Tcl_VarEval(interp, "set current_dirname ", pwd_dir, NULL);
  }
diff --git a/src/xschem.h b/src/xschem.h
index 9f4be380..a03615a7 100644
--- a/src/xschem.h
+++ b/src/xschem.h
@@ -508,6 +508,23 @@ typedef struct {
   double zoom;
   double mooz;
   double lw;
+  unsigned long ui_state ; /* this signals that we are doing a net place,panning etc.
+                            * used to prevent nesting of some commands */
+  double mousex,mousey; /* mouse coord. */
+  double mousex_snap,mousey_snap; /* mouse coord. snapped to grid */
+  double mx_double_save, my_double_save;
+  int areax1,areay1,areax2,areay2,areaw,areah; /* window corners / size, line width beyond screen edges */
+  int xschem_h, xschem_w; /* true window size from XGetWindowAttributes */
+  int need_reb_sel_arr;
+  int lastsel;
+  int maxsel;
+  Selected *sel_array;
+  int prep_net_structs;
+  int prep_hi_structs;
+  int prep_hash_inst;
+  int prep_hash_wires;
+  int modified;
+  char netlist_name[PATH_MAX];
 } Xschem_ctx;
 
 struct Lcc { /* used for symbols containing schematics as instances (LCC, Local Custom Cell) */
@@ -647,10 +664,6 @@ extern int split_files;
 extern char *netlist_dir;
 extern char user_top_netl_name[PATH_MAX];
 extern char bus_replacement_char[];
-
-extern unsigned long ui_state ; /*  this signals that we are doing a net place, */
-                              /*  panning etc... */
-
 extern char *undo_dirname;
 extern int cur_undo_ptr;
 extern int tail_undo_ptr;