diff --git a/src/actions.c b/src/actions.c
index 58df511e..44a890db 100644
--- a/src/actions.c
+++ b/src/actions.c
@@ -298,7 +298,9 @@ void set_snap(double newsnap) /*  20161212 set new snap factor and just notify n
         tclvareval(xctx->top_path, ".statusbar.3 configure -background OrangeRed", NULL);
       }
     }
+    xctx->cadhalfdotsize = CADHALFDOTSIZE * (cs < 10. ? cs : 10.) / 10.;
     tclsetdoublevar("cadsnap", cs);
+    draw();
 }
 
 void set_grid(double newgrid)
@@ -2485,11 +2487,11 @@ void calc_drawing_bbox(xRect *boundbox, int selected)
        !xctx->wire[i].node[0] || !bus_hilight_hash_lookup(xctx->wire[i].node, 0,XLOOKUP)) continue;
    }
    if(xctx->wire[i].bus){
-     ov = INT_BUS_WIDTH(xctx->lw)> cadhalfdotsize ? INT_BUS_WIDTH(xctx->lw) : CADHALFDOTSIZE;
+     ov = INT_BUS_WIDTH(xctx->lw)> xctx->cadhalfdotsize ? INT_BUS_WIDTH(xctx->lw) : CADHALFDOTSIZE;
      if(xctx->wire[i].y1 < xctx->wire[i].y2) { y1 = xctx->wire[i].y1-ov; y2 = xctx->wire[i].y2+ov; }
      else                        { y1 = xctx->wire[i].y1+ov; y2 = xctx->wire[i].y2-ov; }
    } else {
-     ov = cadhalfdotsize;
+     ov = xctx->cadhalfdotsize;
      if(xctx->wire[i].y1 < xctx->wire[i].y2) { y1 = xctx->wire[i].y1-ov; y2 = xctx->wire[i].y2+ov; }
      else                        { y1 = xctx->wire[i].y1+ov; y2 = xctx->wire[i].y2-ov; }
    }
@@ -2597,8 +2599,8 @@ void zoom_full(int dr, int sel, int flags, double shrink)
   dbg(1, "zoom_full(): dr=%d sel=%d flags=%d areaw=%d, areah=%d\n", sel, dr, flags, xctx->areaw, xctx->areah);
   if(flags & 1) change_linewidth(-1.);
   /* we do this here since change_linewidth may not be called  if flags & 1 == 0*/
-  /* cadhalfdotsize = CADHALFDOTSIZE +  0.04 * (tclgetdoublevar("cadsnap")-10); */
-  cadhalfdotsize = 4.0 * (cs < 10. ? cs : 10.) / 10.;
+  /* xctx->cadhalfdotsize = CADHALFDOTSIZE +  0.04 * (tclgetdoublevar("cadsnap")-10); */
+  xctx->cadhalfdotsize = 4.0 * (cs < 10. ? cs : 10.) / 10.;
   if(dr && has_x) {
     draw();
     redraw_w_a_l_r_p_rubbers();
diff --git a/src/callback.c b/src/callback.c
index 9d2edff9..67be0ad4 100644
--- a/src/callback.c
+++ b/src/callback.c
@@ -1305,6 +1305,7 @@ int rstate; /* (reduced state, without ShiftMask) */
       break;
     }
 
+    dbg(1, "ui_state=%d deltax=%g\n", xctx->ui_state, xctx->deltax);
     if(xctx->ui_state) {
       if(abs(mx-xctx->mx_save) > 8 || abs(my-xctx->my_save) > 8 ) {
         my_snprintf(str, S(str), "mouse = %.16g %.16g - selected: %d w=%.16g h=%.16g",
@@ -1316,11 +1317,15 @@ int rstate; /* (reduced state, without ShiftMask) */
       }
     }
     if(xctx->ui_state & STARTZOOM)   zoom_rectangle(RUBBER);
+
+    /* determine direction of a rectangle selection  (or unselection with ALT key) */
     if(xctx->ui_state & STARTSELECT && !(xctx->ui_state & (PLACE_SYMBOL | STARTPAN | PLACE_TEXT)) ) {
-      if( (state & Button1Mask)  && SET_MODMASK) { /* 20171026 added unselect by area  */
+      /* Unselect by area : determine direction */
+      if( (state & Button1Mask)  && SET_MODMASK) { 
         if(mx >= xctx->mx_save) xctx->nl_dir = 0;
         else  xctx->nl_dir = 1;
         select_rect(RUBBER,0);
+      /* select by area : determine direction */
       } else if(state & Button1Mask) {
         if(mx >= xctx->mx_save) xctx->nl_dir = 0;
         else  xctx->nl_dir = 1;
@@ -1339,12 +1344,13 @@ int rstate; /* (reduced state, without ShiftMask) */
     }
 
     redraw_w_a_l_r_p_rubbers();
-    /* start of a mouse area select. No shift pressed */
+    /* start of a mouse area select. Button1 pressed. No shift pressed */
     if(!(xctx->ui_state & STARTPOLYGON) && (state&Button1Mask) && !(xctx->ui_state & STARTWIRE) && 
        !(xctx->ui_state & STARTPAN) && !(SET_MODMASK) &&
        !(state & ShiftMask) && !(xctx->ui_state & (PLACE_SYMBOL | PLACE_TEXT)))
     {
-      if(mx != xctx->mx_save || my != xctx->my_save) {
+
+      if(!xctx->poly_point_selected && (mx != xctx->mx_save || my != xctx->my_save)) {
         if( !(xctx->ui_state & STARTSELECT)) {
           select_rect(START,1);
           xctx->onetime=1;
@@ -3128,13 +3134,45 @@ int rstate; /* (reduced state, without ShiftMask) */
      if( !(xctx->ui_state & STARTSELECT) && !(xctx->ui_state & STARTWIRE) && !(xctx->ui_state & STARTLINE)  ) {
        Selected sel;
        int prev_last_sel = xctx->lastsel;
+       int polygon_n = -1, polygon_c = -1;
+       xctx->poly_point_selected = 0;
        xctx->mx_save = mx; xctx->my_save = my;
        xctx->mx_double_save=xctx->mousex_snap;
        xctx->my_double_save=xctx->mousey_snap;
+
+       if(xctx->lastsel == 1 && xctx->sel_array[0].type==POLYGON) {
+          dbg(1, "1 Polygon selected\n");
+          polygon_n = xctx->sel_array[0].n;
+          polygon_c = xctx->sel_array[0].col;
+       }
        if( !(state & ShiftMask) && !(SET_MODMASK) ) {
          unselect_all(1);
        }
-       sel = select_object(xctx->mousex, xctx->mousey, SELECTED, 0);
+       /* Check is user is clicking a control point of a polygon */
+       if(polygon_n >= 0) {
+         int i;
+         double ds = xctx->cadhalfdotsize;
+         xPoly *p = &xctx->poly[polygon_c][polygon_n];
+         for(i = 0; i < p->points; i++) {
+           if(
+               POINTINSIDE(xctx->mousex, xctx->mousey, p->x[i] - ds, p->y[i] - ds, 
+                             p->x[i] + ds, p->y[i] + ds)
+             ) {
+               dbg(1, "selecting point %d\n", i);
+               xctx->poly[polygon_c][polygon_n].selected_point[i] = 1;
+               xctx->poly_point_selected = 1;
+           }
+         }
+         if(xctx->poly_point_selected) { 
+           /* select_polygon(polygon_c, polygon_n, SELECTED1,1); */
+           xctx->poly[polygon_c][polygon_n].sel = SELECTED1;
+           xctx->need_reb_sel_arr=1;
+           move_objects(START,0,0,0);
+          }
+       }
+       if(!xctx->poly_point_selected) {
+         sel = select_object(xctx->mousex, xctx->mousey, SELECTED, 0);
+       }
        rebuild_selected_array();
        #ifndef __unix__
        draw_selection(xctx->gc[SELLAYER], 0);
@@ -3164,6 +3202,23 @@ int rstate; /* (reduced state, without ShiftMask) */
    } /* button==Button1 */
    break;
   case ButtonRelease:
+
+   /* if a polygon/bezier control point was clicked, end point move operation
+    * and set polygon state back to SELECTED from SELECTED1 */
+   if((xctx->ui_state & (STARTMOVE | SELECTION)) && xctx->poly_point_selected) {
+     if(xctx->lastsel == 1 && xctx->sel_array[0].type==POLYGON) {
+        int k;
+        int n = xctx->sel_array[0].n;
+        int c = xctx->sel_array[0].col;
+        move_objects(END,0,0,0);
+        xctx->poly[c][n].sel = SELECTED;
+        for(k=0; k<xctx->poly[c][n].points; ++k) {
+          xctx->poly[c][n].selected_point[k] = 0;
+        }
+        xctx->need_reb_sel_arr=1;
+     }
+   }
+
    if(waves_selected(event, key, state, button)) {
      waves_callback(event, mx, my, key, button, aux, state);
      break;
@@ -3186,8 +3241,11 @@ int rstate; /* (reduced state, without ShiftMask) */
        tclsetboolvar("enable_stretch", es);
        break;
      } else {
-       /* 20150927 filter out button4 and button5 events */
-       if(!(state&(Button4Mask|Button5Mask) ) ) select_rect(END,-1);
+       /* Button1 release: end of rectangle select */
+       if(!(state & (Button4Mask|Button5Mask) ) ) {
+ 
+         select_rect(END,-1);
+       }
      }
      if(draw_xhair) draw_crosshair(0);
      rebuild_selected_array();
diff --git a/src/check.c b/src/check.c
index 1b0b12c1..5ed485c8 100644
--- a/src/check.c
+++ b/src/check.c
@@ -58,7 +58,7 @@ void update_conn_cues(int layer, int draw_cues, int dr_win)
   hash_wires(); /* must be done also if wires==0 to clear wire_spatial_table */
   if(!xctx->wires) return;
   if(!xctx->draw_dots) return;
-  if(cadhalfdotsize*xctx->mooz<0.7) return;
+  if(xctx->cadhalfdotsize*xctx->mooz<0.7) return;
   x1 = X_TO_XSCHEM(xctx->areax1);
   y1 = Y_TO_XSCHEM(xctx->areay1);
   x2 = X_TO_XSCHEM(xctx->areax2);
@@ -107,10 +107,10 @@ void update_conn_cues(int layer, int draw_cues, int dr_win)
       if(LINE_OUTSIDE(wire[i].x1, wire[i].y1,
                       wire[i].x2, wire[i].y2, x1, y1, x2, y2)) continue;
       if( wire[i].end1 >1 ) {
-        filledarc(layer, ADD, wire[i].x1, wire[i].y1, cadhalfdotsize, 0, 360);
+        filledarc(layer, ADD, wire[i].x1, wire[i].y1, xctx->cadhalfdotsize, 0, 360);
       }
       if( wire[i].end2 >1 ) {
-        filledarc(layer, ADD, wire[i].x2, wire[i].y2, cadhalfdotsize, 0, 360);
+        filledarc(layer, ADD, wire[i].x2, wire[i].y2, xctx->cadhalfdotsize, 0, 360);
       }
     }
     filledarc(layer, END, 0.0, 0.0, 0.0, 0.0, 0.0);
@@ -527,7 +527,7 @@ void break_wires_at_point(double x0, double y0, int align)
     draw();
     xctx->draw_window = 1;
     xctx->draw_pixmap = 0;
-    filledarc(PINLAYER, NOW, x0, y0, cadhalfdotsize, 0, 360);
+    filledarc(PINLAYER, NOW, x0, y0, xctx->cadhalfdotsize, 0, 360);
     xctx->draw_window = w;
     xctx->draw_pixmap = p;
 
diff --git a/src/draw.c b/src/draw.c
index f92a229d..fa5d34f2 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -1735,7 +1735,7 @@ void drawbezier(Drawable w, GC gc, int c, double *x, double *y, int points, int
   #if 0
   if(points == 4) {
     if(gc == xctx->gc[SELLAYER]) for(i = 0; i < points; i++) {
-      drawtemparc(gc, NOW, x[i], y[i], cadhalfdotsize, 0., 360.);
+      drawtemparc(gc, NOW, x[i], y[i], xctx->cadhalfdotsize, 0., 360.);
     }
     i = 0;
     for(t = 0; t <= 1.0; t += bez_steps) {
@@ -1839,14 +1839,14 @@ void drawtemppolygon(GC gc, int what, double *x, double *y, int points, int flag
     bezier = flags  && (points > 2);
     if((fix_broken_tiled_fill || !_unix) && gc == xctx->gctiled) {
       MyXCopyAreaDouble(display, xctx->save_pixmap, xctx->window, xctx->gc[0],
-          x1 - cadhalfdotsize, y1 - cadhalfdotsize,
-          x2 + cadhalfdotsize, y2 + cadhalfdotsize,
-          x1 - cadhalfdotsize, y1 - cadhalfdotsize, xctx->lw);
+          x1 - xctx->cadhalfdotsize, y1 - xctx->cadhalfdotsize,
+          x2 + xctx->cadhalfdotsize, y2 + xctx->cadhalfdotsize,
+          x1 - xctx->cadhalfdotsize, y1 - xctx->cadhalfdotsize, xctx->lw);
     } else {
       if(gc == xctx->gc[SELLAYER]) for(i = 0; i < points; i++) {
         if( POINTINSIDE(X_TO_SCREEN(x[i]), Y_TO_SCREEN(y[i]), xctx->areax1, xctx->areay1,
                xctx->areax2, xctx->areay2)) {
-          drawtemparc(gc, NOW, x[i], y[i], cadhalfdotsize, 0., 360.);
+          drawtemparc(gc, NOW, x[i], y[i], xctx->cadhalfdotsize, 0., 360.);
         }
       }
       if(bezier) {
@@ -4158,13 +4158,17 @@ void draw(void)
   int cc, c, i = 0 /*, floaters = 0 */;
   xSymbol *symptr;
   int textlayer;
+  double cs;
   #if HAS_CAIRO==1
   const char *textfont;
   #endif
 
   dbg(1, "draw()\n");
 
+  
   if(!xctx || xctx->no_draw) return;
+  cs = tclgetdoublevar("cadsnap");
+  xctx->cadhalfdotsize = 4.0 * (cs < 10. ? cs : 10.) / 10.;
   xctx->crosshair_layer = tclgetintvar("crosshair_layer");
   if(xctx->crosshair_layer < 0 ) xctx->crosshair_layer = 2;
   if(xctx->crosshair_layer >= cadlayers ) xctx->crosshair_layer = 2;
diff --git a/src/editprop.c b/src/editprop.c
index 1046f2ad..7c91cba4 100644
--- a/src/editprop.c
+++ b/src/editprop.c
@@ -1036,7 +1036,7 @@ static int edit_wire_property(void)
       bus_ptr = get_tok_value(xctx->wire[k].prop_ptr,"bus",0);
       if(!strboolcmp(bus_ptr, "true")) {
         double ov, y1, y2;
-        ov = INT_BUS_WIDTH(xctx->lw) > cadhalfdotsize ? INT_BUS_WIDTH(xctx->lw) : CADHALFDOTSIZE;
+        ov = INT_BUS_WIDTH(xctx->lw) > xctx->cadhalfdotsize ? INT_BUS_WIDTH(xctx->lw) : CADHALFDOTSIZE;
         if(xctx->wire[k].y1 < xctx->wire[k].y2) { y1 = xctx->wire[k].y1-ov; y2 = xctx->wire[k].y2+ov; }
         else { y1 = xctx->wire[k].y1+ov; y2 = xctx->wire[k].y2-ov; }
         bbox(ADD, xctx->wire[k].x1-ov, y1 , xctx->wire[k].x2+ov , y2 );
@@ -1044,7 +1044,7 @@ static int edit_wire_property(void)
       } else {
         if(oldbus){
           double ov, y1, y2;
-          ov = INT_BUS_WIDTH(xctx->lw)> cadhalfdotsize ? INT_BUS_WIDTH(xctx->lw) : CADHALFDOTSIZE;
+          ov = INT_BUS_WIDTH(xctx->lw)> xctx->cadhalfdotsize ? INT_BUS_WIDTH(xctx->lw) : CADHALFDOTSIZE;
           if(xctx->wire[k].y1 < xctx->wire[k].y2) { y1 = xctx->wire[k].y1-ov; y2 = xctx->wire[k].y2+ov; }
           else                        { y1 = xctx->wire[k].y1+ov; y2 = xctx->wire[k].y2-ov; }
           bbox(ADD, xctx->wire[k].x1-ov, y1 , xctx->wire[k].x2+ov , y2 );
@@ -1190,7 +1190,8 @@ static int edit_polygon_property(void)
          if(k==0 || xctx->poly[c][i].x[k] > x2) x2 = xctx->poly[c][i].x[k];
          if(k==0 || xctx->poly[c][i].y[k] > y2) y2 = xctx->poly[c][i].y[k];
        }
-       bbox(ADD, x1-cadhalfdotsize, y1-cadhalfdotsize, x2+cadhalfdotsize, y2+cadhalfdotsize);
+       bbox(ADD, x1-xctx->cadhalfdotsize, y1-xctx->cadhalfdotsize,
+                    x2+xctx->cadhalfdotsize, y2+xctx->cadhalfdotsize);
      }
    }
    if(drw) {
diff --git a/src/globals.c b/src/globals.c
index 9519b918..7a5b04ee 100644
--- a/src/globals.c
+++ b/src/globals.c
@@ -179,7 +179,6 @@ char pwd_dir[PATH_MAX];  /* obtained via getcwd() */
 int tcp_port = 0;
 int text_svg=1; /* use <text> svg element for text instead of xschem's internal vector font */
 int text_ps=1;  /* use ps font for text instead of xschem's internal vector font */
-double cadhalfdotsize = CADHALFDOTSIZE;
 char bus_char[3] = {0, 0, 0};
 int yyparse_error = 0;
 char *xschem_executable=NULL;
diff --git a/src/hilight.c b/src/hilight.c
index 975a976c..c9506269 100644
--- a/src/hilight.c
+++ b/src/hilight.c
@@ -2045,12 +2045,14 @@ void draw_hilight_net(int on_window)
      else
        drawline(get_color(entry->value), NOW,
           xctx->wire[i].x1, xctx->wire[i].y1, xctx->wire[i].x2, xctx->wire[i].y2, 0, NULL);
-     if(cadhalfdotsize*xctx->mooz>=0.7) {
+     if(xctx->cadhalfdotsize*xctx->mooz>=0.7) {
        if( xctx->wire[i].end1 >1 ) {
-         filledarc(get_color(entry->value), NOW, xctx->wire[i].x1, xctx->wire[i].y1, cadhalfdotsize, 0, 360);
+         filledarc(get_color(entry->value), NOW, xctx->wire[i].x1, xctx->wire[i].y1,
+            xctx->cadhalfdotsize, 0, 360);
        }
        if( xctx->wire[i].end2 >1 ) {
-         filledarc(get_color(entry->value), NOW, xctx->wire[i].x2, xctx->wire[i].y2, cadhalfdotsize, 0, 360);
+         filledarc(get_color(entry->value), NOW, xctx->wire[i].x2, xctx->wire[i].y2,
+            xctx->cadhalfdotsize, 0, 360);
        }
      }
    }
diff --git a/src/move.c b/src/move.c
index 19a2b707..7b3c62b2 100644
--- a/src/move.c
+++ b/src/move.c
@@ -882,6 +882,7 @@ void move_objects(int what, int merge, double dx, double dy)
   xLine ** const line = xctx->line;
   xWire * const wire = xctx->wire;
  
+  dbg(1, "move_objects: what=%d, dx=%g, dy=%g\n", what, dx, dy);
   if(what & START)
   {
    xctx->rotatelocal=0;
diff --git a/src/psprint.c b/src/psprint.c
index 1b266f5e..24a901c2 100644
--- a/src/psprint.c
+++ b/src/psprint.c
@@ -1306,10 +1306,10 @@ void create_ps(char **psfile, int what, int fullzoom, int eps)
         }
         i = wireptr->n;
         if( xctx->wire[i].end1 >1 ) {
-          ps_drawarc(WIRELAYER, 1, xctx->wire[i].x1, xctx->wire[i].y1, cadhalfdotsize, 0, 360, 0);
+          ps_drawarc(WIRELAYER, 1, xctx->wire[i].x1, xctx->wire[i].y1, xctx->cadhalfdotsize, 0, 360, 0);
         }
         if( xctx->wire[i].end2 >1 ) {
-          ps_drawarc(WIRELAYER, 1, xctx->wire[i].x2, xctx->wire[i].y2, cadhalfdotsize, 0, 360, 0);
+          ps_drawarc(WIRELAYER, 1, xctx->wire[i].x2, xctx->wire[i].y2, xctx->cadhalfdotsize, 0, 360, 0);
         }
       }
     }
diff --git a/src/svgdraw.c b/src/svgdraw.c
index 6513661f..c9e3980b 100644
--- a/src/svgdraw.c
+++ b/src/svgdraw.c
@@ -878,10 +878,10 @@ void svg_draw(void)
           color = get_color(entry->value);
         }
         if( xctx->wire[i].end1 >1 ) {
-          svg_drawcircle(color, 1, xctx->wire[i].x1, xctx->wire[i].y1, cadhalfdotsize, 0, 360);
+          svg_drawcircle(color, 1, xctx->wire[i].x1, xctx->wire[i].y1, xctx->cadhalfdotsize, 0, 360);
         }
         if( xctx->wire[i].end2 >1 ) {
-          svg_drawcircle(color, 1, xctx->wire[i].x2, xctx->wire[i].y2, cadhalfdotsize, 0, 360);
+          svg_drawcircle(color, 1, xctx->wire[i].x2, xctx->wire[i].y2, xctx->cadhalfdotsize, 0, 360);
         }
       }
     }
diff --git a/src/xinit.c b/src/xinit.c
index 0847f03e..396f62f6 100644
--- a/src/xinit.c
+++ b/src/xinit.c
@@ -579,6 +579,7 @@ static void alloc_xschem_data(const char *top_path, const char *win_path)
   xctx->nl_sel = xctx->nl_sem = xctx->nl_dir = 0;
 
   xctx->hilight_time = 0; /* timestamp for sims */
+  xctx->poly_point_selected = 0;
   xctx->hilight_nets = 0;
   xctx->hilight_color = 0;
   for(i=0;i<CADMAXHIER; ++i) {
@@ -1998,8 +1999,8 @@ void change_linewidth(double w)
     double cs = tclgetdoublevar("cadsnap");
     if(tclgetboolvar("change_lw"))  {
       xctx->lw=xctx->mooz * 0.09 * cs;
-      cadhalfdotsize = CADHALFDOTSIZE * (cs < 10. ? cs : 10.) / 10.;
-      /* cadhalfdotsize = CADHALFDOTSIZE +  0.04 * (cs-10); */
+      xctx->cadhalfdotsize = CADHALFDOTSIZE * (cs < 10. ? cs : 10.) / 10.;
+      /* xctx->cadhalfdotsize = CADHALFDOTSIZE +  0.04 * (cs-10); */
     }
   /* explicitly set line width */
   } else {
diff --git a/src/xschem.h b/src/xschem.h
index a5716dbb..976de503 100644
--- a/src/xschem.h
+++ b/src/xschem.h
@@ -983,7 +983,7 @@ typedef struct {
   Int_hashtable floater_inst_table;
   Node_hashentry **node_table;
   Hilight_hashentry **hilight_table;
-
+  int poly_point_selected;
   int hilight_nets;
   int hilight_color;
   int hilight_time; /* timestamp for sims */
@@ -1123,6 +1123,7 @@ typedef struct {
   int draw_pixmap; /* pixmap used as 2nd buffer */
   int draw_window;  /* MIRRORED IN TCL */
   int do_copy_area;
+  double cadhalfdotsize;
   time_t time_last_modify;
   int undo_type; /* 0: on disk, 1: in memory */
   void (*push_undo)(void);