ngspice/src/frontend/plotting/x11.c

/**********
Copyright 1990 Regents of the University of California.  All rights reserved.
Author: 1988 Jeffrey M. Hsu
$Id$
**********/

/*
    X11 drivers.
*/

#include <ngspice/ngspice.h>

#ifndef X_DISPLAY_MISSING

#  include <sys/time.h>
#  include <sys/types.h>  /* PN */
#  include <unistd.h>     /* PN */

#  include <ngspice/graph.h>
#  include <ngspice/ftedbgra.h>
#  include <ngspice/ftedev.h>
#  include <ngspice/fteinput.h>
#  include <ngspice/cpdefs.h>
#  include <ngspice/ftedefs.h>
#  include <variable.h>
#  include "../com_hardcopy.h"

/* Added X11/ prefix to the next includes - ER */

#  include <X11/IntrinsicP.h>
#  include <X11/Xatom.h>
#  include <X11/StringDefs.h>
#  include <X11/Xutil.h>
#  include <X11/cursorfont.h>
#  include <X11/Xaw/Box.h>
#  include <X11/Xaw/Command.h>
#  include <X11/Xaw/Form.h>
#  include <X11/Shell.h>
#  include <X11/Intrinsic.h>

#  ifdef DEBUG
#     include <X11/Xlib.h> /* for _Xdebug */
#  endif

#include "x11.h"
#include "graphdb.h"
#include "display.h"
#include "graf.h"
#include "../error.h"

#define RAD_TO_DEG	(180.0 / M_PI)

/* X dependent default parameters */
#define DEF_FONT "10x14"
#define NUMLINESTYLES 8
#define MW_LINEWIDTH 2  /* MW. I want larger lines */
#define NXPLANES 5      /* note: What is this used for? */
#define BOXSIZE 30      /* initial size of bounding box for zoomin */

#define NUMCOLORS 20

typedef struct x11info {
    Window window;
    int	isopen;
    Widget shell, form, view, buttonbox, buttons[2];
    XFontStruct *font;
    GC gc;
    int lastx, lasty;   /* used in X_DrawLine */
    int lastlinestyle;  /* used in X_DrawLine */
    Pixel colors[NUMCOLORS];
} X11devdep;

#define DEVDEP(g) (*((X11devdep *) (g)->devdep))

static Display *display;
static GC xorgc;
static char *xlinestyles[NUMLINESTYLES] = {	/* test patterns XXX */
    "\001\001\001\001",	/* solid */
    "\001\002\001\002",	/* dots */
    "\007\007\007\007",	/* longdash */
    "\003\003\003\003",	/* shortdash */
    "\007\002\002\002",	/* dots longdash */
    "\003\002\001\002",	/* dots shortdash */
    "\003\003\007\003",	/* short/longdash */
};

/* atoms for catching window delet by WM x-button */
static Atom atom_wm_delete_window;
static Atom atom_wm_protocols;

static Widget toplevel;
static Bool noclear = False;
static GRAPH *lasthardcopy; /* graph user selected */
static int X11_Open = 0;
static int numdispplanes;

/* static functions */
static void initlinestyles (void);
static void initcolors (GRAPH *graph);
static void X_ScreentoData (GRAPH *graph, int x, int y, double *fx, double *fy);
static void linear_arc(int x0, int y0, int radius, double theta, double delta_theta);
static void slopelocation(GRAPH *graph, int x0, int y0);
static void zoomin(GRAPH *graph);

//XtEventHandler
static void handlekeypressed(Widget w, XtPointer clientdata, XEvent *ev, Boolean *continue_dispatch);
static void handlebuttonev(Widget w, XtPointer graph, XEvent *ev, Boolean *continue_dispatch);
static void redraw(Widget w, XtPointer client_data, XEvent *ev, Boolean *continue_dispatch);
static void resize(Widget w, XtPointer client_data, XEvent *ev, Boolean *continue_dispatch);

//XtCallbackProc
static void hardcopy(Widget w, XtPointer client_data, XtPointer call_data);
static void killwin(Widget w, XtPointer client_data, XtPointer call_data);


static int
errorhandler(Display *display, XErrorEvent *errorev)
{
    XGetErrorText(display, errorev->error_code, ErrorMessage, 1024);
    externalerror(ErrorMessage);
    return 0;
}



int
X11_Init(void)
{

    char buf[512];
    char *displayname;

    XGCValues gcvalues;

    /* grrr, Xtk forced contortions */
    char *argv[2];
    int argc = 2;

    if (cp_getvar("display", CP_STRING, buf)) {
      displayname = buf;
    } else if (!(displayname = getenv("DISPLAY"))) {
      internalerror("Can't open X display.");
      return (1);
    }

#  ifdef DEBUG
    _Xdebug = 1;
#  endif

    argv[0] = "ngspice";
    argv[1] = displayname;
/*
    argv[2] = "-geometry";
    argv[3] = "=1x1+2+2";
*/

    /* initialize X toolkit */
    toplevel = XtInitialize("ngspice", "Nutmeg", NULL, 0, &argc, argv);

    display = XtDisplay(toplevel);

    X11_Open = 1;

    /* "invert" works better than "xor" for B&W */

    /* xor gc should be a function of the pixels that are written on */
    /* gcvalues.function = GXxor; */
    /* this patch makes lines visible on true color displays
    Guenther Roehrich 22-Jan-99 */
    gcvalues.function = GXinvert;
    gcvalues.line_width = 1;
    gcvalues.foreground = 1;
    gcvalues.background = 0;

    xorgc = XCreateGC(display, DefaultRootWindow(display),
	    GCLineWidth | GCFunction | GCForeground | GCBackground,
	    &gcvalues);

    /* set correct information */
    dispdev->numlinestyles = NUMLINESTYLES;
    dispdev->numcolors = NUMCOLORS;

    dispdev->width = DisplayWidth(display, DefaultScreen(display));
    dispdev->height = DisplayHeight(display, DefaultScreen(display));

    /* we don't want non-fatal X errors to call exit */
    XSetErrorHandler(errorhandler);

    numdispplanes = DisplayPlanes(display, DefaultScreen(display));

    return (0);

}

static void
initlinestyles(void)
{

    int i;

    if (numdispplanes > 1) {
      /* Dotted lines are a distraction when we have colors. */
      for (i = 2; i < NUMLINESTYLES; i++) {
	  xlinestyles[i] = xlinestyles[0];
      }
    }

}

static void
initcolors(GRAPH *graph)
{
    int i;
    static char *colornames[] = {   "black",    /* white */
	"white", "red", "blue",
	"orange", "green", "pink",
	"brown", "khaki", "plum",
	"orchid", "violet", "maroon",
	"turquoise", "sienna", "coral",
	"cyan", "magenta", "gold",
	"yellow", ""
	};

    XColor visualcolor, exactcolor;
    char buf[BSIZE_SP], colorstring[BSIZE_SP];
    int xmaxcolors = NUMCOLORS; /* note: can we get rid of this? */

    if (numdispplanes == 1) {
	/* black and white */
	xmaxcolors = 2;
	DEVDEP(graph).colors[0] = DEVDEP(graph).view->core.background_pixel;
	if (DEVDEP(graph).colors[0] == WhitePixel(display, DefaultScreen(display)))
	    DEVDEP(graph).colors[1] = BlackPixel(display, DefaultScreen(display));
	else
	    DEVDEP(graph).colors[1] = WhitePixel(display, DefaultScreen(display));

    } else {
	if (numdispplanes < NXPLANES)
	    xmaxcolors = 1 << numdispplanes;

	for (i = 0; i < xmaxcolors; i++) {
	    (void) sprintf(buf, "color%d", i);
	    if (!cp_getvar(buf, CP_STRING, colorstring))
	    (void) strcpy(colorstring, colornames[i]);
	    if (!XAllocNamedColor(display,
		    DefaultColormap(display, DefaultScreen(display)),
		    colorstring, &visualcolor, &exactcolor)) {
		(void) sprintf(ErrorMessage,
		    "can't get color %s\n", colorstring);
		externalerror(ErrorMessage);
		DEVDEP(graph).colors[i] = i ? BlackPixel(display,
		    DefaultScreen(display))
		    : WhitePixel(display, DefaultScreen(display));
		continue;
	    }
	    DEVDEP(graph).colors[i] = visualcolor.pixel;
	    
	    
	/* MW. I don't need this, everyone must know what he is doing
	    if (i > 0 &&
		DEVDEP(graph).colors[i] == DEVDEP(graph).view->core.background_pixel) {
		DEVDEP(graph).colors[i] = DEVDEP(graph).colors[0];
	    } */
	    
	}
	/* MW. Set Beackgroound here */
	XSetWindowBackground(display, DEVDEP(graph).window, DEVDEP(graph).colors[0]);
		
/*	if (DEVDEP(graph).colors[0] != DEVDEP(graph).view->core.background_pixel) {
	    DEVDEP(graph).colors[0] = DEVDEP(graph).view->core.background_pixel;
	 } */
    }

    for (i = xmaxcolors; i < NUMCOLORS; i++) {
	DEVDEP(graph).colors[i] = DEVDEP(graph).colors[i + 1 - xmaxcolors];
    }
}


static void
handlekeypressed(Widget w, XtPointer client_data, XEvent *ev, Boolean *continue_dispatch)
{

    XKeyEvent *keyev = & ev->xkey;
    GRAPH *graph = (GRAPH *) client_data;
    char text[4];
    int nbytes;

    NG_IGNORE(w);
    NG_IGNORE(continue_dispatch);

    nbytes = XLookupString(keyev, text, 4, NULL, NULL);
    if (!nbytes) return;
    /* write it */
    PushGraphContext(graph);
    text[nbytes] = '\0';
    SetColor(1);
    DevDrawText(text, keyev->x, graph->absolute.height - keyev->y);
    /* save it */
    SaveText(graph, text, keyev->x, graph->absolute.height - keyev->y);
    /* warp mouse so user can type in sequence */
    XWarpPointer(display, None, DEVDEP(graph).window, 0, 0, 0, 0,
	keyev->x + XTextWidth(DEVDEP(graph).font, text, nbytes),
	keyev->y);
    PopGraphContext();

}



static void
handlebuttonev(Widget w, XtPointer client_data, XEvent *ev, Boolean *continue_dispatch)
{
    GRAPH *graph = (GRAPH *) client_data;

    NG_IGNORE(w);
    NG_IGNORE(continue_dispatch);

    switch (ev->xbutton.button) {
      case Button1:
	slopelocation(graph, ev->xbutton.x, ev->xbutton.y);
	break;
      case Button3:
	zoomin(graph);
	break;
    }

}

/* callback function for catching window deletion by WM x-button */
static void
handle_wm_messages(Widget w, XtPointer client_data, XEvent *ev, Boolean *cont)
{
    GRAPH *graph = (GRAPH *) client_data;

    NG_IGNORE(w);
    NG_IGNORE(cont);

    if (ev->type == ClientMessage
            && ev->xclient.message_type == atom_wm_protocols
            && (Atom) ev->xclient.data.l[0] == atom_wm_delete_window) {

        RemoveWindow(graph);
    }
}


/* Recover from bad NewViewPort call. */
#define RECOVERNEWVIEWPORT()    tfree(graph);\
	            graph = NULL; 
	    /* need to do this or else DestroyGraph will free it again */

/* NewViewport is responsible for filling in graph->viewport */
int
X11_NewViewport(GRAPH *graph)
{

    char fontname[513]; /* who knows . . . */
    char *p, *q;
    Cursor cursor;
    XSetWindowAttributes	w_attrs;
    XGCValues gcvalues;


    static Arg formargs[ ] = {
	{ XtNleft, (XtArgVal) XtChainLeft },
	{ XtNresizable, (XtArgVal) TRUE }
    };
    static Arg bboxargs[ ] = {
	{ XtNfromHoriz, (XtArgVal) NULL },
	{ XtNbottom, (XtArgVal) XtChainTop },
	{ XtNtop, (XtArgVal) XtChainTop },
	{ XtNleft, (XtArgVal) XtChainRight },
	{ XtNright, (XtArgVal) XtChainRight }
    };
    static Arg buttonargs[ ] = {
	{ XtNlabel, (XtArgVal) NULL },
	{ XtNfromVert, (XtArgVal) NULL },
	{ XtNbottom, (XtArgVal) XtChainTop },
	{ XtNtop, (XtArgVal) XtChainTop },
	{ XtNleft, (XtArgVal) XtRubber },
	{ XtNright, (XtArgVal) XtRubber },
	{ XtNresizable, (XtArgVal) TRUE }
    };
    static Arg viewargs[] = {
	{ XtNresizable, (XtArgVal) TRUE },
	{ XtNwidth, (XtArgVal) 300 },
	{ XtNheight, (XtArgVal) 300 },
	{ XtNright, (XtArgVal) XtChainRight }
    };
    int	trys;

    graph->devdep = TMALLOC(X11devdep, 1);

    /* set up new shell */
    DEVDEP(graph).shell = XtCreateApplicationShell("shell",
	    topLevelShellWidgetClass, NULL, 0);

    /* set up form widget */
    DEVDEP(graph).form = XtCreateManagedWidget("form",
	formWidgetClass, DEVDEP(graph).shell, formargs, XtNumber(formargs));

    /* set up viewport */
    DEVDEP(graph).view = XtCreateManagedWidget("viewport", widgetClass,
					       DEVDEP(graph).form,
					       viewargs,
					       XtNumber(viewargs));
    XtAddEventHandler(DEVDEP(graph).view, ButtonPressMask, FALSE,
		      handlebuttonev, graph);
    XtAddEventHandler(DEVDEP(graph).view, KeyPressMask, FALSE,
		      handlekeypressed, graph);
    XtAddEventHandler(DEVDEP(graph).view, StructureNotifyMask, FALSE,
		      resize, graph);
    XtAddEventHandler(DEVDEP(graph).view, ExposureMask, FALSE,
                      redraw, graph);

    /* set up button box */
    XtSetArg(bboxargs[1], XtNfromHoriz, DEVDEP(graph).view);
    DEVDEP(graph).buttonbox = XtCreateManagedWidget("buttonbox",
	boxWidgetClass, DEVDEP(graph).form, bboxargs, XtNumber(bboxargs));

    /* set up buttons */
    XtSetArg(buttonargs[0], XtNlabel, "quit");
    XtSetArg(bboxargs[1], XtNfromVert, NULL);
    DEVDEP(graph).buttons[0] = XtCreateManagedWidget("quit",
	commandWidgetClass, DEVDEP(graph).buttonbox,
	buttonargs, 1);
    XtAddCallback(DEVDEP(graph).buttons[0], XtNcallback, killwin, graph);

    XtSetArg(buttonargs[0], XtNlabel, "hardcopy");
    XtSetArg(bboxargs[1], XtNfromVert, DEVDEP(graph).buttons[0]);
    DEVDEP(graph).buttons[1] = XtCreateManagedWidget("hardcopy",
	commandWidgetClass, DEVDEP(graph).buttonbox,
	buttonargs, 1);
    XtAddCallback(DEVDEP(graph).buttons[1], XtNcallback, hardcopy, graph);

    /* set up fonts */
    if (!cp_getvar("font", CP_STRING, fontname)) {
	(void) strcpy(fontname, DEF_FONT);
    }

    for (p = fontname; *p && *p <= ' '; p++)
	;
    if (p != fontname) {
	for (q = fontname; *p; *q++ = *p++)
		;
	*q = 0;
    }

    trys = 1;
    while (!(DEVDEP(graph).font = XLoadQueryFont(display, fontname))) {
      sprintf(ErrorMessage, "can't open font %s", fontname);
      strcpy(fontname, "fixed");
      if (trys > 1) {
	  internalerror(ErrorMessage);
	  RECOVERNEWVIEWPORT();
	  return(1);
      }
      trys += 1;
    }

    graph->fontwidth = DEVDEP(graph).font->max_bounds.rbearing -
	    DEVDEP(graph).font->min_bounds.lbearing + 1;
    graph->fontheight = DEVDEP(graph).font->max_bounds.ascent +
	    DEVDEP(graph).font->max_bounds.descent + 1;

    XtRealizeWidget(DEVDEP(graph).shell);

    DEVDEP(graph).window = XtWindow(DEVDEP(graph).view);
    DEVDEP(graph).isopen = 0;
    w_attrs.bit_gravity = ForgetGravity;
    XChangeWindowAttributes(display, DEVDEP(graph).window, CWBitGravity,
	    &w_attrs);
    /* have to note font and set mask GCFont in XCreateGC, p.w.h. */
    gcvalues.font = DEVDEP(graph).font->fid;
    gcvalues.line_width = MW_LINEWIDTH;
    gcvalues.cap_style = CapNotLast;
    gcvalues.function = GXcopy;
    DEVDEP(graph).gc = XCreateGC(display, DEVDEP(graph).window,
	    GCFont | GCLineWidth | GCCapStyle | GCFunction, &gcvalues);

    /* should absolute.positions really be shell.pos? */
    graph->absolute.xpos = DEVDEP(graph).view->core.x;
    graph->absolute.ypos = DEVDEP(graph).view->core.y;
    graph->absolute.width = DEVDEP(graph).view->core.width;
    graph->absolute.height = DEVDEP(graph).view->core.height;

    initlinestyles();
    initcolors(graph);

    /* set up cursor */
    cursor = XCreateFontCursor(display, XC_left_ptr);
    XDefineCursor(display, DEVDEP(graph).window, cursor);

    /* WM_DELETE_WINDOW protocol */
    atom_wm_protocols = XInternAtom(display, "WM_PROTOCOLS", False);
    atom_wm_delete_window = XInternAtom(display, "WM_DELETE_WINDOW", False);
    XtAddEventHandler(DEVDEP(graph).shell, NoEventMask, True, handle_wm_messages,graph);
    XSetWMProtocols(display, XtWindow(DEVDEP(graph).shell), &atom_wm_delete_window, 1);


    return (0);
}



/* This routine closes the X connection.
	It is not to be called for finishing a graph. */
int
X11_Close(void)
{
    XCloseDisplay(display);
    return 0;
}

int
X11_DrawLine(int x1, int y1, int x2, int y2)
{

    if (DEVDEP(currentgraph).isopen)
	XDrawLine(display, DEVDEP(currentgraph).window,
		DEVDEP(currentgraph).gc,
		x1, currentgraph->absolute.height - y1,
		x2, currentgraph->absolute.height - y2);

    return 0;
}


int

X11_Arc(int x0, int y0, int radius, double theta, double delta_theta)
{

    int	t1, t2;

    if (0 && !cp_getvar("x11lineararcs", CP_BOOL, NULL)) {
	linear_arc(x0, y0, radius, theta, delta_theta);
    }

    if (DEVDEP(currentgraph).isopen) {
	t1 = (int) (64 * (180.0 / M_PI) * theta);
	t2 = (int) (64 * (180.0 / M_PI) * delta_theta);
	if (t2 == 0)
		return 0;
	XDrawArc(display, DEVDEP(currentgraph).window, DEVDEP(currentgraph).gc,
		x0 - radius,
		currentgraph->absolute.height - radius - y0,
		(Dimension) (2 * radius), (Dimension) (2 * radius), t1, t2);
    }
    return 0;
}

/* note: x and y are the LOWER left corner of text */
int
X11_Text(char *text, int x, int y)
{

    /* We specify text position by lower left corner, so have to adjust for
	X11's font nonsense. */

    if (DEVDEP(currentgraph).isopen)
	    XDrawString(display, DEVDEP(currentgraph).window,
		DEVDEP(currentgraph).gc, x,
		currentgraph->absolute.height
		    - (y + DEVDEP(currentgraph).font->max_bounds.descent),
		text, (int) strlen(text));

    /* note: unlike before, we do not save any text here */
    return 0;
}


int
X11_DefineColor(int colorid, double red, double green, double blue)
{
    NG_IGNORE(blue);
    NG_IGNORE(green);
    NG_IGNORE(red);
    NG_IGNORE(colorid);

    internalerror("X11_DefineColor not implemented.");
    return 0;
}


int
X11_DefineLinestyle(int linestyleid, int mask)
{
    NG_IGNORE(mask);
    NG_IGNORE(linestyleid);

    internalerror("X11_DefineLinestyle not implemented.");
    return 0;
}

int
X11_SetLinestyle(int linestyleid)
{
    XGCValues values;

    if (currentgraph->linestyle != linestyleid) {

      if ((linestyleid == 0 || numdispplanes > 1) && linestyleid != 1) {
	/* solid if linestyle 0 or if has color, allow only one
	 * dashed linestyle */
	values.line_style = LineSolid;
      } else {
	values.line_style = LineOnOffDash;
      }
      XChangeGC(display, DEVDEP(currentgraph).gc, GCLineStyle, &values);

      currentgraph->linestyle = linestyleid;
      XSetDashes(display, DEVDEP(currentgraph).gc, 0,
	    xlinestyles[linestyleid], 4);
    }
    return 0;
}

int
X11_SetColor(int colorid)
{

    currentgraph->currentcolor = colorid;
    XSetForeground(display, DEVDEP(currentgraph).gc,
	    DEVDEP(currentgraph).colors[colorid]);
    return 0;
}

int
X11_Update(void)
{

    if (X11_Open)
	    XSync(display, 0);
    return 0;
}

int
X11_Clear(void)
{

    if (!noclear) /* hack so exposures look like they're handled nicely */
      XClearWindow(display, DEVDEP(currentgraph).window);
    return 0;
}

static void
X_ScreentoData(GRAPH *graph, int x, int y, double *fx, double *fy)
{
    double	lmin, lmax;

    if (graph->grid.gridtype == GRID_XLOG
	    || graph->grid.gridtype == GRID_LOGLOG)
    {
	    lmin = log10(graph->datawindow.xmin);
	    lmax = log10(graph->datawindow.xmax);
	    *fx = exp(((x - graph->viewportxoff)
		    * (lmax - lmin) / graph->viewport.width + lmin)
		    * M_LN10);
    } else {
	    *fx = (x - graph->viewportxoff) * graph->aspectratiox +
		    graph->datawindow.xmin;
    }

    if (graph->grid.gridtype == GRID_YLOG
	    || graph->grid.gridtype == GRID_LOGLOG)
    {
	    lmin = log10(graph->datawindow.ymin);
	    lmax = log10(graph->datawindow.ymax);
	    *fy = exp(((graph->absolute.height - y - graph->viewportxoff)
		    * (lmax - lmin) / graph->viewport.height + lmin)
		    * M_LN10);
    } else {
	    *fy = ((graph->absolute.height - y) - graph->viewportyoff)
		    * graph->aspectratioy + graph->datawindow.ymin;
    }

}



static void
slopelocation(GRAPH *graph, int x0, int y0)
             
                    /* initial position of mouse */
{

    int x1, y1;
    int x, y;
    Window rootwindow, childwindow;
    int rootx, rooty;
    unsigned int state;
    double fx0, fx1, fy0, fy1;
    double angle;

    x1 = x0;
    y1 = y0;
    XQueryPointer(display, DEVDEP(graph).window, &rootwindow, &childwindow,
	    &rootx, &rooty, &x, &y, &state);
    XDrawLine(display, DEVDEP(graph).window, xorgc, x0, y0, x0, y1-1);
    XDrawLine(display, DEVDEP(graph).window, xorgc, x0, y1, x1, y1);
    while (state & Button1Mask) {
      if (x != x1 || y != y1) {
	XDrawLine(display, DEVDEP(graph).window, xorgc,
	    x0, y0, x0, y1-1);
	XDrawLine(display, DEVDEP(graph).window, xorgc,
	    x0, y1, x1, y1);
	x1 = x;
	y1 = y;
	XDrawLine(display, DEVDEP(graph).window, xorgc, x0, y0, x0, y1-1);
	XDrawLine(display, DEVDEP(graph).window, xorgc, x0, y1, x1, y1);
      }
      XQueryPointer(display, DEVDEP(graph).window, &rootwindow,
	    &childwindow, &rootx, &rooty, &x, &y, &state);
    }
    XDrawLine(display, DEVDEP(graph).window, xorgc, x0, y0, x0, y1-1);
    XDrawLine(display, DEVDEP(graph).window, xorgc, x0, y1, x1, y1);

    X_ScreentoData(graph, x0, y0, &fx0, &fy0);
    X_ScreentoData(graph, x1, y1, &fx1, &fy1);

    /* print it out */
    if (x1 == x0 && y1 == y0) {     /* only one location */
	fprintf(stdout, "\nx0 = %g, y0 = %g\n", fx0, fy0);
	if (graph->grid.gridtype == GRID_POLAR
	    || graph->grid.gridtype == GRID_SMITH
	    || graph->grid.gridtype == GRID_SMITHGRID)
	{
	    angle = RAD_TO_DEG * atan2( fy0, fx0 );
	    fprintf(stdout, "r0 = %g, a0 = %g\n",
		sqrt( fx0*fx0 + fy0*fy0 ),
		(angle>0)?angle:360.0+angle);
	}


    } else {    /* need to print info about two points */
      fprintf(stdout, "\nx0 = %g, y0 = %g    x1 = %g, y1 = %g\n",
	  fx0, fy0, fx1, fy1);
      fprintf(stdout, "dx = %g, dy = %g\n", fx1-fx0, fy1 - fy0);
      if (x1 != x0 && y1 != y0) {
    /* add slope info if both dx and dy are zero,
	 because otherwise either dy/dx or dx/dy is zero,
	 which is uninteresting
    */
	fprintf(stdout, "dy/dx = %g    dx/dy = %g\n",
	(fy1-fy0)/(fx1-fx0), (fx1-fx0)/(fy1-fy0));
      }
    }

    return;

}

/* should be able to do this by sleight of hand on graph parameters */
static void
zoomin(GRAPH *graph)
{
/* note: need to add circular boxes XXX */

    int x0, y0, x1, y1;
    double fx0, fx1, fy0, fy1, ftemp;
    char buf[BSIZE_SP];
    char buf2[128];
    char *t;

    Window rootwindow, childwindow;
    int rootx, rooty;
    unsigned int state;
    int x, y, upperx, uppery;
    unsigned width, height;

    /* open box and get area to zoom in on */

    XQueryPointer(display, DEVDEP(graph).window, &rootwindow,
	    &childwindow, &rootx, &rooty, &x0, &y0, &state);

    x = x1 = x0 + BOXSIZE;
    y = y1 = y0 + BOXSIZE;

    upperx = x0;
    uppery = y0;

    width  = BOXSIZE;
    height = BOXSIZE;

    XDrawRectangle(display, DEVDEP(graph).window, xorgc,
	    upperx, uppery, width, height);

    XWarpPointer(display, None, DEVDEP(graph).window, 0, 0, 0, 0, x1, y1);

    while (state & Button3Mask) {
      if (x != x1 || y != y1) {

	x1 = x;
	y1 = y;

	XDrawRectangle(display, DEVDEP(graph).window, xorgc,
	    upperx, uppery, width, height);

        upperx = MIN(x1, x0);
        uppery = MIN(y1, y0);

        width  = (unsigned) ABS(x1 - x0);
        height = (unsigned) ABS(y1 - y0);

	XDrawRectangle(display, DEVDEP(graph).window, xorgc,
	    upperx, uppery, width, height);
      }
      XQueryPointer(display, DEVDEP(graph).window, &rootwindow,
	       &childwindow, &rootx, &rooty, &x, &y, &state);
    }
    XDrawRectangle(display, DEVDEP(graph).window, xorgc,
	    upperx, uppery, width, height);

    X_ScreentoData(graph, x0, y0, &fx0, &fy0);
    X_ScreentoData(graph, x1, y1, &fx1, &fy1);

    if (fx0 > fx1) {
      ftemp = fx0;
      fx0 = fx1;
      fx1 = ftemp;
    }
    if (fy0 > fy1) {
      ftemp = fy0;
      fy0 = fy1;
      fy1 = ftemp;
    }

    strncpy(buf2, graph->plotname, sizeof(buf2));
    if ((t = strchr(buf2, ':')) != NULL)
	    *t = 0;

    if (!eq(plot_cur->pl_typename, buf2)) {
      (void) sprintf(buf,
"setplot %s; %s xlimit %.20e %.20e ylimit %.20e %.20e; setplot $curplot\n",
       buf2, graph->commandline, fx0, fx1, fy0, fy1);
    } else {
      (void) sprintf(buf, "%s xlimit %e %e ylimit %e %e\n",
	    graph->commandline, fx0, fx1, fy0, fy1);
    }

/* don't use the following if using GNU Readline or BSD EditLine */
#if !defined(HAVE_GNUREADLINE) && !defined(HAVE_BSDEDITLINE)
    {
	wordlist *wl;
	
	/* hack for Gordon Jacobs */
	/* add to history list if plothistory is set */
	if (cp_getvar("plothistory", CP_BOOL, NULL)) {
	  wl = cp_parse(buf);
	  (void) cp_addhistent(cp_event++, wl);
	}
    }
#endif /* !defined(HAVE_GNUREADLINE) && !defined(HAVE_BSDEDITLINE) */

    (void) cp_evloop(buf);

}

static void
hardcopy(Widget w, XtPointer client_data, XtPointer call_data)
{
	NG_IGNORE(call_data);
	NG_IGNORE(w);

	/* com_hardcopy() -> gr_resize() -> setcolor() dirung postscript
	printing will act on currentgraph with a DEVDEP inherited from PSdevdep.
	But currentgraph had not changed its devdep, which was derived from
	incompatible X11devdep, thus overwriting some variables. Here you find a
	temporary remedy, until there will be a cleanup of graph handling. E.g.
	CopyGraph() does not make a copy of its devdep, but just copies the pointer,
	so keeping the old devdep. */

    lasthardcopy = (GRAPH *) client_data;

    /* FIXME #1: this should print currentgraph with
    *            currentgraph dynamically bound to client_data
    *  FIXME #2: the !currentgraphs case,
    *            don't bother do call com_hardcopy
    */

    if (currentgraph) {
        void *devdep = currentgraph->devdep;
        com_hardcopy(NULL);
        currentgraph->devdep = devdep;
    } else {
        com_hardcopy(NULL);
    }
}

static void
killwin(Widget w, XtPointer client_data, XtPointer call_data)
{

    GRAPH *graph = (GRAPH *) client_data;

    NG_IGNORE(call_data);
    NG_IGNORE(w);

    RemoveWindow(graph);
}

/* called from postcoms.c 
   In the command 'destroy ac2' Will remove window associated with 
   the plot (e.g. ac2) just before data of the plot are deleted.*/
void 
RemoveWindow(GRAPH *graph)
{
    if(graph->devdep) {
        /* Iplots are done asynchronously */
        DEVDEP(graph).isopen = 0;
        /* MW. Not sure but DestroyGraph might free() to much - try Xt...() first */
        XtDestroyWidget(DEVDEP(graph).shell);
    }

    if (graph == currentgraph)
        currentgraph = NULL;

    DestroyGraph(graph->graphid);
}


/* call higher gr_redraw routine */
static void
redraw(Widget w, XtPointer client_data, XEvent *event, Boolean *continue_dispatch)
{

    GRAPH *graph = (GRAPH *) client_data;
    XExposeEvent *pev = & event->xexpose;
    XEvent ev;
    XRectangle rects[30];
    int n = 1;

    NG_IGNORE(w);
    NG_IGNORE(continue_dispatch);

    DEVDEP(graph).isopen = 1;


    rects[0].x = (Position) pev->x;
    rects[0].y = (Position) pev->y;
    rects[0].width  = (Dimension) pev->width;
    rects[0].height = (Dimension) pev->height;

    /* XXX */
    /* pull out all other expose regions that need to be redrawn */
    while (n < 30 && XCheckWindowEvent(display, DEVDEP(graph).window,
	    ExposureMask, &ev)) {
      pev = (XExposeEvent *) &ev;
      rects[n].x = (Position) pev->x;
      rects[n].y = (Position) pev->y;
      rects[n].width  = (Dimension) pev->width;
      rects[n].height = (Dimension) pev->height;
      n++;
    }
    XSetClipRectangles(display, DEVDEP(graph).gc, 0, 0,
	    rects, n, Unsorted);

    noclear = True;
    {
        GRAPH *tmp = currentgraph;
        currentgraph = graph;
        gr_redraw(graph);
        currentgraph = tmp;
    }
    noclear = False;

    XSetClipMask(display, DEVDEP(graph).gc, None);

}

static void
resize(Widget w, XtPointer client_data, XEvent *call_data, Boolean *continue_dispatch)
{

    GRAPH *graph = (GRAPH *) client_data;
    XEvent ev;

    NG_IGNORE(call_data);
    NG_IGNORE(continue_dispatch);

    /* pull out all other exposure events
       Also, get rid of other StructureNotify events on this window. */

    while (XCheckWindowEvent(display, DEVDEP(graph).window,
	    /* ExposureMask | */ StructureNotifyMask, &ev))
	    ;

    XClearWindow(display, DEVDEP(graph).window);
    graph->absolute.width = w->core.width;
    graph->absolute.height = w->core.height;
    {
        GRAPH *tmp = currentgraph;
        currentgraph = graph;
        gr_resize(graph);
        currentgraph = tmp;
    }

}



int
X11_Input(REQUEST *request, RESPONSE *response)
{

    XEvent ev;
    int nfds;
    fd_set rfds;

    switch (request->option) {
	
	  case char_option:
		nfds = ConnectionNumber(display) > fileno(request->fp) ?
		    ConnectionNumber(display) :
		    fileno(request->fp);

		for (;;) {

		      /* first read off the queue before doing the select */
		      while (XtPending()) {
			    XtNextEvent(&ev);
			    XtDispatchEvent(&ev);
		      }

		      /* block on ConnectionNumber and request->fp */
		      /* PN: added fd_set * casting */
		      FD_ZERO(&rfds);
		      FD_SET(fileno(request->fp), &rfds);
		      FD_SET(ConnectionNumber(display), &rfds);
		      select (nfds + 1,
			      &rfds,
			      NULL,
			      NULL,
			      NULL);
		      
		      /* handle X events first */
		      if (FD_ISSET (ConnectionNumber(display), &rfds)) {
			    /* handle ALL X events */
			    while (XtPending()) {
				  XtNextEvent(&ev);
				  XtDispatchEvent(&ev);
			    }
		      }

		      if (FD_ISSET (fileno(request->fp), &rfds)) {
			    goto out;
		      }

		}
		break;

	  case click_option:
		/* let's fake this */
		response->reply.graph = lasthardcopy;
		break;

	  case button_option:
		/* sit and handle events until get a button selection */
		internalerror("button_option not implemented");
		response->option = error_option;
		return 1;
		break;

	  case checkup_option:
		/* first read off the queue before doing the select */
		while (XtPending()) {
		    XtNextEvent(&ev);
		    XtDispatchEvent(&ev);
		}
		break;

	  default:
		internalerror("unrecognized input type");
		response->option = error_option;
		return 1;
		break;
    }

out:
    if (response)
	response->option = request->option;
    return 0;

}

static void
linear_arc(int x0, int y0, int radius, double theta, double delta_theta)
              /* x coordinate of center */
              /* y coordinate of center */
	      /* radius of arc */
	      /* initial angle ( +x axis = 0 rad ) */
	      /* delta angle */
    /*
     * Notes:
     *    Draws an arc of radius and center at (x0,y0) beginning at
     *    angle theta (in rad) and ending at theta + delta_theta
     */
{
    int x1, y1, x2, y2;
    int i, s = 60;
    double dphi;

    x2 = x0 + (int) (radius * cos(theta));
    y2 = y0 + (int) (radius * sin(theta));

    dphi = delta_theta / s;


    for(i=1; i<=s; i++) {
	x1 = x2;
	y1 = y2;
	x2 = x0 + (int)(radius * cos(theta + i*dphi));
	y2 = y0 + (int)(radius * sin(theta + i*dphi));
	X11_DrawLine(x1,y1,x2,y2);
    }
}

#else 
int x11_dummy_symbol;
/* otherwise, some linkers get upset */
#endif /* X_DISPLAY_MISSING */