/* $XConsortium: Eyes.c,v 1.28 94/04/17 20:45:22 eswu Exp $ */
/*

Copyright (c) 1991  X Consortium

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of the X Consortium shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from the X Consortium.

*/

/*
 * Eyes.c
 *
 * a widget which follows the mouse around
 */

# include <X11/Xos.h>
# include <stdio.h>
# include <X11/IntrinsicP.h>
# include <X11/StringDefs.h>
# include <X11/Xmu/Converters.h>
# include "EyesP.h"
# include <math.h>
# include <X11/extensions/shape.h>

#if (defined(SVR4) || defined(SYSV) && defined(SYSV386)) && __STDC__
extern double hypot(double, double);
#endif

#define offset(field) XtOffsetOf(EyesRec, eyes.field)
#define goffset(field) XtOffsetOf(WidgetRec, core.field)

static XtResource resources[] = {
    {XtNwidth, XtCWidth, XtRDimension, sizeof(Dimension),
	goffset(width), XtRImmediate, (XtPointer) 150},
    {XtNheight, XtCHeight, XtRDimension, sizeof(Dimension),
	goffset(height), XtRImmediate, (XtPointer) 100},
    {XtNforeground, XtCForeground, XtRPixel, sizeof(Pixel),
        offset(puppixel), XtRString, XtDefaultForeground},
    {XtNoutline, XtCForeground, XtRPixel, sizeof(Pixel),
        offset(outline), XtRString, XtDefaultForeground},
    {XtNcenterColor, XtCBackground, XtRPixel, sizeof (Pixel),
    	offset(center), XtRString, XtDefaultBackground},
    {XtNreverseVideo, XtCReverseVideo, XtRBoolean, sizeof (Boolean),
	offset (reverse_video), XtRImmediate, (XtPointer) FALSE},
    {XtNbackingStore, XtCBackingStore, XtRBackingStore, sizeof (int),
    	offset (backing_store), XtRString, "default"},
    {XtNshapeWindow, XtCShapeWindow, XtRBoolean, sizeof (Boolean),
	offset (shape_window), XtRImmediate, (XtPointer) TRUE},
};

#undef offset
#undef goffset

# define NUM_EYES	2
# define EYE_X(n)	((n) * 2.0)
# define EYE_Y(n)	(0.0)
# define EYE_OFFSET	(0.1)	/* padding between eyes */
# define EYE_THICK	(0.175)	/* thickness of eye rim */
# define BALL_WIDTH	(0.3)
# define BALL_PAD	(0.05)
# define EYE_WIDTH	(2.0 - (EYE_THICK + EYE_OFFSET) * 2)
# define EYE_HEIGHT	EYE_WIDTH
# define EYE_HWIDTH	(EYE_WIDTH / 2.0)
# define EYE_HHEIGHT	(EYE_HEIGHT / 2.0)
# define BALL_HEIGHT	BALL_WIDTH
# define BALL_DIST	((EYE_WIDTH - BALL_WIDTH) / 2.0 - BALL_PAD)
# define W_MIN_X	(-1.0 + EYE_OFFSET)
# define W_MAX_X	(3.0 - EYE_OFFSET)
# define W_MIN_Y	(-1.0 + EYE_OFFSET)
# define W_MAX_Y	(1.0 - EYE_OFFSET)

# define TPointEqual(a, b)  ((a).x == (b).x && (a).y == (b).y)
# define XPointEqual(a, b)  ((a).x == (b).x && (a).y == (b).y)

static int delays[] = { 50, 100, 200, 400, 0 };

static void Initialize(), Realize(), Destroy();
static void Redisplay(), Resize ();
static Boolean SetValues();
static int repaint_window();
static void draw_it ();

static void ClassInitialize();

EyesClassRec eyesClassRec = {
    { /* core fields */
    /* superclass		*/	&widgetClassRec,
    /* class_name		*/	"Eyes",
    /* size			*/	sizeof(EyesRec),
    /* class_initialize		*/	ClassInitialize,
    /* class_part_initialize	*/	NULL,
    /* class_inited		*/	FALSE,
    /* initialize		*/	Initialize,
    /* initialize_hook		*/	NULL,
    /* realize			*/	Realize,
    /* actions			*/	NULL,
    /* num_actions		*/	0,
    /* resources		*/	resources,
    /* num_resources		*/	XtNumber(resources),
    /* xrm_class		*/	NULLQUARK,
    /* compress_motion		*/	TRUE,
    /* compress_exposure	*/	TRUE,
    /* compress_enterleave	*/	TRUE,
    /* visible_interest		*/	FALSE,
    /* destroy			*/	Destroy,
    /* resize			*/	Resize,
    /* expose			*/	Redisplay,
    /* set_values		*/	SetValues,
    /* set_values_hook		*/	NULL,
    /* set_values_almost	*/	NULL,
    /* get_values_hook		*/	NULL,
    /* accept_focus		*/	NULL,
    /* version			*/	XtVersion,
    /* callback_private		*/	NULL,
    /* tm_table			*/	NULL,
    /* query_geometry		*/	XtInheritQueryGeometry,
    }
};

static void ClassInitialize()
{
    XtAddConverter( XtRString, XtRBackingStore, XmuCvtStringToBackingStore,
		    NULL, 0 );
}

WidgetClass eyesWidgetClass = (WidgetClass) &eyesClassRec;

/* ARGSUSED */
static void Initialize (greq, gnew, args, num_args)
    Widget greq, gnew;
    ArgList args;
    Cardinal *num_args;
{
    EyesWidget w = (EyesWidget)gnew;
    XtGCMask	valuemask;
    XGCValues	myXGCV;
    int shape_event_base, shape_error_base;

    /*
     * set the colors if reverse video; these are the colors used:
     *
     *     background - paper		white
     *     foreground - text, ticks	black
     *     border - border		black (foreground)
     *
     * This doesn't completely work since the parent has already made up a 
     * border.  Sigh.
     */
    if (w->eyes.reverse_video) {
	Pixel fg = w->eyes.puppixel;
	Pixel bg = w->core.background_pixel;

	if (w->core.border_pixel == fg)
 	    w->core.border_pixel = bg;
	if (w->eyes.outline == fg)
	    w->eyes.outline = bg;
	if (w->eyes.center == bg)
	    w->eyes.center = fg;
	w->eyes.puppixel = bg;
	w->core.background_pixel = fg;
    }

    myXGCV.foreground = w->eyes.puppixel;
    myXGCV.background = w->core.background_pixel;
    valuemask = GCForeground | GCBackground;
    w->eyes.pupGC = XtGetGC(gnew, valuemask, &myXGCV);

    myXGCV.foreground = w->eyes.outline;
    valuemask = GCForeground | GCBackground;
    w->eyes.outGC = XtGetGC(gnew, valuemask, &myXGCV);

    myXGCV.foreground = w->eyes.center;
    myXGCV.background = w->eyes.puppixel;
    valuemask = GCForeground | GCBackground;
    w->eyes.centerGC = XtGetGC(gnew, valuemask, &myXGCV);

    w->eyes.update = 0;
    /* wait for Realize to add the timeout */
    w->eyes.interval_id = 0;

    w->eyes.pupil[0].x = w->eyes.pupil[1].x = -1000;
    w->eyes.pupil[0].y = w->eyes.pupil[1].y = -1000;

    if (w->eyes.shape_window && !XShapeQueryExtension (XtDisplay (w),
						       &shape_event_base,
						       &shape_error_base))
	w->eyes.shape_window = False;
    w->eyes.shape_mask = 0;
    w->eyes.shapeGC = 0;
}

static void Resize (gw)
    Widget	gw;
{
    EyesWidget	w = (EyesWidget) gw;
    XGCValues	xgcv;
    Widget	parent;
    int		x, y;

    if (XtIsRealized (gw))
    {
    	XClearWindow (XtDisplay (w), XtWindow (w));
    	SetTransform (&w->eyes.t,
		    	0, w->core.width,
 		    	w->core.height, 0,
		    	W_MIN_X, W_MAX_X,
		    	W_MIN_Y, W_MAX_Y);
    	if (w->eyes.shape_window) {
    	    w->eyes.shape_mask = XCreatePixmap (XtDisplay (w), XtWindow (w),
	    	    w->core.width, w->core.height, 1);
    	    if (!w->eyes.shapeGC)
            	w->eyes.shapeGC = XCreateGC (XtDisplay (w), w->eyes.shape_mask, 0, &xgcv);
    	    XSetForeground (XtDisplay (w), w->eyes.shapeGC, 0);
    	    XFillRectangle (XtDisplay (w), w->eyes.shape_mask, w->eyes.shapeGC, 0, 0,
	    	w->core.width, w->core.height);
    	    XSetForeground (XtDisplay (w), w->eyes.shapeGC, 1);
    	    eyeLiner (w, w->eyes.shape_mask, w->eyes.shapeGC, (GC) 0, 0);
    	    eyeLiner (w, w->eyes.shape_mask, w->eyes.shapeGC, (GC) 0, 1);
	    x = y = 0;
	    for (parent = (Widget) w; XtParent (parent); parent = XtParent (parent)) {
	    	x += parent->core.x + parent->core.border_width;
	    	x += parent->core.y + parent->core.border_width;
	    }
    	    XShapeCombineMask (XtDisplay (parent), XtWindow (parent), ShapeBounding,
		       	       x, y, w->eyes.shape_mask, ShapeSet);
    	    XFreePixmap (XtDisplay (w), w->eyes.shape_mask);
    	}
    }
}

static void Realize (gw, valueMask, attrs)
     Widget gw;
     XtValueMask *valueMask;
     XSetWindowAttributes *attrs;
{
    EyesWidget	w = (EyesWidget)gw;

    if (w->eyes.backing_store != Always + WhenMapped + NotUseful) {
     	attrs->backing_store = w->eyes.backing_store;
	*valueMask |= CWBackingStore;
    }
    XtCreateWindow( gw, (unsigned)InputOutput, (Visual *)CopyFromParent,
		     *valueMask, attrs );
    Resize (gw);
    w->eyes.interval_id =
	XtAppAddTimeOut(XtWidgetToApplicationContext(gw),
			delays[w->eyes.update], draw_it, (XtPointer)gw);
}

static void Destroy (gw)
     Widget gw;
{
     EyesWidget w = (EyesWidget)gw;

     if (w->eyes.interval_id)
	XtRemoveTimeOut (w->eyes.interval_id);
     XtReleaseGC(gw, w->eyes.pupGC);
     XtReleaseGC(gw, w->eyes.outGC);
     XtReleaseGC(gw, w->eyes.centerGC);
}

/* ARGSUSED */
static void Redisplay(gw, event, region)
     Widget gw;
     XEvent *event;
     Region region;
{
    EyesWidget	w;

    w = (EyesWidget) gw;
    w->eyes.pupil[0].x = -1000;
    w->eyes.pupil[0].y = -1000;
    w->eyes.pupil[1].x = -1000;
    w->eyes.pupil[1].y = -1000;
    (void) repaint_window ((EyesWidget)gw);
}

static TPoint computePupil (num, mouse)
    int		num;
    TPoint	mouse;
{
	double	cx, cy;
	double	dist;
	double	angle;
	double	x, y;
	double	h;
	double	dx, dy;
	double	cosa, sina;
	TPoint	ret;

	dx = mouse.x - EYE_X(num);
	dy = mouse.y - EYE_Y(num);
	if (dx == 0 && dy == 0) {
		cx = EYE_X(num);
		cy = EYE_Y(num);
	} else {
		angle = atan2 ((double) dy, (double) dx);
		cosa = cos (angle);
		sina = sin (angle);
		h = hypot (EYE_HHEIGHT * cosa, EYE_HWIDTH * sina);
		x = (EYE_HWIDTH * EYE_HHEIGHT) * cosa / h;
		y = (EYE_HWIDTH * EYE_HHEIGHT) * sina / h;
		dist = BALL_DIST * hypot (x, y);
		if (dist > hypot ((double) dx, (double) dy)) {
			cx = dx + EYE_X(num);
			cy = dy + EYE_Y(num);
		} else {
			cx = dist * cosa + EYE_X(num);
			cy = dist * sina + EYE_Y(num);
		}
	}
	ret.x = cx;
	ret.y = cy;
	return ret;
}

static void computePupils (mouse, pupils)
    TPoint	mouse;
    TPoint	pupils[2];
{
    pupils[0] = computePupil (0, mouse);
    pupils[1] = computePupil (1, mouse);
}

/* ARGSUSED */
static void draw_it(client_data, id)
     XtPointer client_data;
     XtIntervalId *id;		/* unused */
{
        EyesWidget	w = (EyesWidget)client_data;
	Window		rep_root, rep_child;
	int		rep_rootx, rep_rooty;
	unsigned int	rep_mask;
	int		dx, dy;
	TPoint		mouse;
	Display		*dpy = XtDisplay (w);
	Window		win = XtWindow (w);
	TPoint		newpupil[2];
	XPoint		xnewpupil, xpupil;

	if (XtIsRealized((Widget)w)) {
    		XQueryPointer (dpy, win, &rep_root, &rep_child,
 			&rep_rootx, &rep_rooty, &dx, &dy, &rep_mask);
		mouse.x = Tx(dx, dy, &w->eyes.t);
		mouse.y = Ty(dx, dy, &w->eyes.t);
		if (!TPointEqual (mouse, w->eyes.mouse)) {
			computePupils (mouse, newpupil);
			xpupil.x = Xx(w->eyes.pupil[0].x, w->eyes.pupil[0].y, &w->eyes.t);
			xpupil.y = Xy(w->eyes.pupil[0].x, w->eyes.pupil[0].y, &w->eyes.t);
			xnewpupil.x =  Xx(newpupil[0].x, newpupil[0].y, &w->eyes.t);
			xnewpupil.y =  Xy(newpupil[0].x, newpupil[0].y, &w->eyes.t);
			if (!XPointEqual (xpupil, xnewpupil)) {
			    if (w->eyes.pupil[0].x != -1000 || w->eyes.pupil[0].y != -1000)
				eyeBall (w, w->eyes.centerGC, 0);
			    w->eyes.pupil[0] = newpupil[0];
			    eyeBall (w, w->eyes.pupGC, 0);
			}
			xpupil.x = Xx(w->eyes.pupil[1].x, w->eyes.pupil[1].y, &w->eyes.t);
			xpupil.y = Xy(w->eyes.pupil[1].x, w->eyes.pupil[1].y, &w->eyes.t);
			xnewpupil.x =  Xx(newpupil[1].x, newpupil[1].y, &w->eyes.t);
			xnewpupil.y =  Xy(newpupil[1].x, newpupil[1].y, &w->eyes.t);
			if (!XPointEqual (xpupil, xnewpupil)) {
			    if (w->eyes.pupil[1].x != -1 || w->eyes.pupil[1].y != -1)
				eyeBall (w, w->eyes.centerGC, 1);
			    w->eyes.pupil[1] = newpupil[1];
			    eyeBall (w, w->eyes.pupGC, 1);
			}
			w->eyes.mouse = mouse;
			w->eyes.update = 0;
		} else {
			if (delays[w->eyes.update + 1] != 0)
				++w->eyes.update;
		}
	}
	w->eyes.interval_id =
		XtAppAddTimeOut(XtWidgetToApplicationContext((Widget) w),
				delays[w->eyes.update], draw_it, (XtPointer)w);
} /* draw_it */

static
repaint_window (w)
    EyesWidget	w;
{
	if (XtIsRealized ((Widget) w)) {
		eyeLiner (w, XtWindow (w), w->eyes.outGC, w->eyes.centerGC, 0);
		eyeLiner (w, XtWindow (w), w->eyes.outGC, w->eyes.centerGC, 1);
		computePupils (w->eyes.mouse, w->eyes.pupil);
		eyeBall (w, w->eyes.pupGC, 0);
		eyeBall (w, w->eyes.pupGC, 1);
	}
}
    
/* ARGSUSED */
static Boolean SetValues (current, request, new, args, num_args)
    Widget current, request, new;
    ArgList args;
    Cardinal *num_args;
{
    return( FALSE );
}

eyeLiner (w, d, outgc, centergc, num)
EyesWidget	w;
Drawable	d;
GC		outgc, centergc;
int		num;
{
	Display *dpy = XtDisplay(w);

	TFillArc (dpy, d, outgc, &w->eyes.t,
		  EYE_X(num) - EYE_HWIDTH - EYE_THICK,
 		  EYE_Y(num) - EYE_HHEIGHT - EYE_THICK,
		  EYE_WIDTH + EYE_THICK * 2.0,
 		  EYE_HEIGHT + EYE_THICK * 2.0,
 		  90 * 64, 360 * 64);
	if (centergc) {
    	    TFillArc (dpy, d, centergc, &w->eyes.t,
		  EYE_X(num) - EYE_HWIDTH,
 		  EYE_Y(num) - EYE_HHEIGHT,
		  EYE_WIDTH, EYE_HEIGHT,
		  90 * 64, 360 * 64);
	}
}

eyeBall (w, gc, num)
EyesWidget	w;
GC	gc;
int	num;
{
	Display *dpy = XtDisplay(w);
	Window win = XtWindow(w);

	TFillArc (dpy, win, gc, &w->eyes.t,
		   w->eyes.pupil[num].x - BALL_WIDTH / 2.0,
		   w->eyes.pupil[num].y - BALL_HEIGHT / 2.0,
		   BALL_WIDTH, BALL_HEIGHT,
		  90 * 64, 360 * 64);
}