path: root/eel/eel-canvas-rect-ellipse.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: 8; c-basic-offset: 8 -*- */
/*
 * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
 * All rights reserved.
 *
 * This file is part of the Gnome Library.
 *
 * The Gnome Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * The Gnome Library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the Gnome Library; see the file COPYING.LIB.  If not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
/*
  @NOTATION@
 */
/* Rectangle and ellipse item types for EelCanvas widget
 *
 * EelCanvas is basically a port of the Tk toolkit's most excellent canvas widget.  Tk is
 * copyrighted by the Regents of the University of California, Sun Microsystems, and other parties.
 *
 *
 * Author: Federico Mena <federico@nuclecu.unam.mx>
 */

#include <config.h>
#include <math.h>
#include "eel-canvas-rect-ellipse.h"
#include "eel-canvas-util.h"
#include <string.h>

#ifdef HAVE_RENDER
#include <gdk/gdkx.h>
#include <X11/extensions/Xrender.h>
#endif

/* Base class for rectangle and ellipse item types */

#define noVERBOSE

enum {
	PROP_0,
	PROP_X1,
	PROP_Y1,
	PROP_X2,
	PROP_Y2,
	PROP_FILL_COLOR_RGBA,
	PROP_OUTLINE_COLOR_RGBA,
	PROP_OUTLINE_STIPPLING,
	PROP_WIDTH_PIXELS,
	PROP_WIDTH_UNITS
};


static void eel_canvas_re_class_init (EelCanvasREClass *klass);
static void eel_canvas_re_init       (EelCanvasRE      *re);
static void eel_canvas_re_set_property (GObject              *object,
					  guint                 param_id,
					  const GValue         *value,
					  GParamSpec           *pspec);
static void eel_canvas_re_get_property (GObject              *object,
					  guint                 param_id,
					  GValue               *value,
					  GParamSpec           *pspec);

static void eel_canvas_re_update_shared (EelCanvasItem *item,
					   double i2w_dx, double i2w_dy, int flags);
static void eel_canvas_re_realize     (EelCanvasItem *item);
static void eel_canvas_re_unrealize   (EelCanvasItem *item);
static void eel_canvas_re_bounds      (EelCanvasItem *item, double *x1, double *y1, double *x2, double *y2);
static void eel_canvas_re_translate   (EelCanvasItem *item, double dx, double dy);
static void eel_canvas_rect_update      (EelCanvasItem *item, double i2w_dx, double i2w_dy, int flags);
static void eel_canvas_ellipse_update      (EelCanvasItem *item, double i2w_dx, double i2w_dy, int flags);

typedef struct {
  /*< public >*/
  int x0, y0, x1, y1;
}  Rect;

static Rect make_rect (int x0, int y0, int x1, int y1);
static void  diff_rects (Rect r1, Rect r2, int *count, Rect result[4]);

static EelCanvasItemClass *re_parent_class;
static EelCanvasREClass *rect_parent_class;


GType
eel_canvas_re_get_type (void)
{
	static GType re_type = 0;

	if (!re_type) {
		GTypeInfo re_info = {
		  sizeof (EelCanvasREClass),
		  (GBaseInitFunc) NULL,
		  (GBaseFinalizeFunc) NULL,
		  (GClassInitFunc) eel_canvas_re_class_init,
		  NULL,           /* class_finalize */
		  NULL,           /* class_data */
		  sizeof (EelCanvasRE),
		  0,              /* n_preallocs */
		  (GInstanceInitFunc) eel_canvas_re_init
		};

		re_type = g_type_register_static (eel_canvas_item_get_type (),
						  "EelCanvasRE",
						  &re_info,
						  0);
	}

	return re_type;
}

static void
eel_canvas_re_class_init (EelCanvasREClass *klass)
{
	GObjectClass *gobject_class;
	EelCanvasItemClass *item_class;

	gobject_class = (GObjectClass *) klass;
	item_class = (EelCanvasItemClass *) klass;

	re_parent_class = g_type_class_peek_parent (klass);

	gobject_class->set_property = eel_canvas_re_set_property;
	gobject_class->get_property = eel_canvas_re_get_property;

        g_object_class_install_property
                (gobject_class,
                 PROP_X1,
                 g_param_spec_double ("x1", NULL, NULL,
				      -G_MAXDOUBLE, G_MAXDOUBLE, 0,
				      G_PARAM_READWRITE));
        g_object_class_install_property
                (gobject_class,
                 PROP_Y1,
                 g_param_spec_double ("y1", NULL, NULL,
				      -G_MAXDOUBLE, G_MAXDOUBLE, 0,
				      G_PARAM_READWRITE));
        g_object_class_install_property
                (gobject_class,
                 PROP_X2,
                 g_param_spec_double ("x2", NULL, NULL,
				      -G_MAXDOUBLE, G_MAXDOUBLE, 0,
				      G_PARAM_READWRITE));
        g_object_class_install_property
                (gobject_class,
                 PROP_Y2,
                 g_param_spec_double ("y2", NULL, NULL,
				      -G_MAXDOUBLE, G_MAXDOUBLE, 0,
				      G_PARAM_READWRITE));
        g_object_class_install_property
                (gobject_class,
                 PROP_FILL_COLOR_RGBA,
                 g_param_spec_boxed ("fill-color-rgba", NULL, NULL,
				     GDK_TYPE_RGBA,
				     G_PARAM_READWRITE));
        g_object_class_install_property
                (gobject_class,
                 PROP_OUTLINE_COLOR_RGBA,
                 g_param_spec_boxed ("outline-color-rgba", NULL, NULL,
				     GDK_TYPE_RGBA,
				     G_PARAM_READWRITE));
	g_object_class_install_property
		(gobject_class,
		 PROP_OUTLINE_STIPPLING,
		 g_param_spec_boolean ("outline-stippling", NULL, NULL,
				       FALSE, G_PARAM_READWRITE));
        g_object_class_install_property
                (gobject_class,
                 PROP_WIDTH_PIXELS,
                 g_param_spec_uint ("width-pixels", NULL, NULL,
				    0, G_MAXUINT, 0,
				    G_PARAM_READWRITE));
        g_object_class_install_property
                (gobject_class,
                 PROP_WIDTH_UNITS,
                 g_param_spec_double ("width-units", NULL, NULL,
				      0.0, G_MAXDOUBLE, 0.0,
				      G_PARAM_READWRITE));

	item_class->realize = eel_canvas_re_realize;
	item_class->unrealize = eel_canvas_re_unrealize;
	item_class->translate = eel_canvas_re_translate;
	item_class->bounds = eel_canvas_re_bounds;
}

static void
eel_canvas_re_init (EelCanvasRE *re)
{
	re->x1 = 0.0;
	re->y1 = 0.0;
	re->x2 = 0.0;
	re->y2 = 0.0;
	re->width = 0.0;
}

static void get_bounds (EelCanvasRE *re, double *px1, double *py1, double *px2, double *py2)
{
	EelCanvasItem *item;
	double x1, y1, x2, y2;
	int cx1, cy1, cx2, cy2;
	double hwidth;

#ifdef VERBOSE
	g_print ("re get_bounds\n");
#endif
	item = EEL_CANVAS_ITEM (re);

	if (re->width_pixels)
		hwidth = (re->width / item->canvas->pixels_per_unit) / 2.0;
	else
		hwidth = re->width / 2.0;

	x1 = re->x1;
	y1 = re->y1;
	x2 = re->x2;
	y2 = re->y2;

	eel_canvas_item_i2w (item, &x1, &y1);
	eel_canvas_item_i2w (item, &x2, &y2);
	eel_canvas_w2c (item->canvas, x1 - hwidth, y1 - hwidth, &cx1, &cy1);
	eel_canvas_w2c (item->canvas, x2 + hwidth, y2 + hwidth, &cx2, &cy2);
	*px1 = cx1;
	*py1 = cy1;
	*px2 = cx2;
	*py2 = cy2;

	/* Some safety fudging */

	*px1 -= 2;
	*py1 -= 2;
	*px2 += 2;
	*py2 += 2;
}

static void
eel_canvas_re_set_fill (EelCanvasRE *re, gboolean fill_set)
{
	if (re->fill_set != fill_set) {
		re->fill_set = fill_set;
		eel_canvas_item_request_update (EEL_CANVAS_ITEM (re));
	}
}

static void
eel_canvas_re_set_outline (EelCanvasRE *re, gboolean outline_set)
{
	if (re->outline_set != outline_set) {
		re->outline_set = outline_set;
		eel_canvas_item_request_update (EEL_CANVAS_ITEM (re));
	}
}

static void
eel_canvas_re_set_property (GObject              *object,
			      guint                 param_id,
			      const GValue         *value,
			      GParamSpec           *pspec)
{
	EelCanvasItem *item;
	EelCanvasRE *re;

	g_return_if_fail (object != NULL);
	g_return_if_fail (EEL_IS_CANVAS_RE (object));

	item = EEL_CANVAS_ITEM (object);
	re = EEL_CANVAS_RE (object);

	switch (param_id) {
	case PROP_X1:
		re->x1 = g_value_get_double (value);

		eel_canvas_item_request_update (item);
		break;

	case PROP_Y1:
		re->y1 = g_value_get_double (value);

		eel_canvas_item_request_update (item);
		break;

	case PROP_X2:
		re->x2 = g_value_get_double (value);

		eel_canvas_item_request_update (item);
		break;

	case PROP_Y2:
		re->y2 = g_value_get_double (value);

		eel_canvas_item_request_update (item);
		break;

	case PROP_FILL_COLOR_RGBA: {
		GdkRGBA *color;

		color = g_value_get_boxed (value);

		eel_canvas_re_set_fill (re, color != NULL);

		if (color != NULL) {
			re->fill_color = *color;
		}

		eel_canvas_item_request_redraw (item);		
		break;
	}

	case PROP_OUTLINE_COLOR_RGBA: {
		GdkRGBA *color;

		color = g_value_get_boxed (value);

		eel_canvas_re_set_outline (re, color != NULL);

		if (color != NULL) {
			re->outline_color = *color;
		}

		eel_canvas_item_request_redraw (item);		
		break;
	}

	case PROP_OUTLINE_STIPPLING:
		re->outline_stippling = g_value_get_boolean (value);

		eel_canvas_item_request_redraw (item);
		break;

	case PROP_WIDTH_PIXELS:
		re->width = g_value_get_uint (value);
		re->width_pixels = TRUE;

		eel_canvas_item_request_update (item);
		break;

	case PROP_WIDTH_UNITS:
		re->width = fabs (g_value_get_double (value));
		re->width_pixels = FALSE;

		eel_canvas_item_request_update (item);
		break;

	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
		break;
	}
}

static void
eel_canvas_re_get_property (GObject              *object,
			      guint                 param_id,
			      GValue               *value,
			      GParamSpec           *pspec)
{
	EelCanvasRE *re;

	g_return_if_fail (object != NULL);
	g_return_if_fail (EEL_IS_CANVAS_RE (object));

	re = EEL_CANVAS_RE (object);

	switch (param_id) {
	case PROP_X1:
		g_value_set_double (value,  re->x1);
		break;

	case PROP_Y1:
		g_value_set_double (value,  re->y1);
		break;

	case PROP_X2:
		g_value_set_double (value,  re->x2);
		break;

	case PROP_Y2:
		g_value_set_double (value,  re->y2);
		break;

	case PROP_FILL_COLOR_RGBA:
		g_value_set_boxed (value,  &re->fill_color);
		break;

	case PROP_OUTLINE_COLOR_RGBA:
		g_value_set_boxed (value,  &re->outline_color);
		break;

	case PROP_OUTLINE_STIPPLING:
		g_value_set_boolean (value, re->outline_stippling);
		break;

	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
		break;
	}
}

static void
eel_canvas_re_update_shared (EelCanvasItem *item, double i2w_dx, double i2w_dy, int flags)
{
#ifdef VERBOSE
	g_print ("eel_canvas_re_update_shared\n");
#endif
	if (re_parent_class->update)
		(* re_parent_class->update) (item, i2w_dx, i2w_dy, flags);
}

static void
eel_canvas_re_realize (EelCanvasItem *item)
{
#ifdef VERBOSE
	g_print ("eel_canvas_re_realize\n");
#endif
	if (re_parent_class->realize)
		(* re_parent_class->realize) (item);
}

static void
eel_canvas_re_unrealize (EelCanvasItem *item)
{
	if (re_parent_class->unrealize)
		(* re_parent_class->unrealize) (item);
}

static void
eel_canvas_re_translate (EelCanvasItem *item, double dx, double dy)
{
	EelCanvasRE *re;

#ifdef VERBOSE
	g_print ("eel_canvas_re_translate\n");
#endif
	re = EEL_CANVAS_RE (item);

	re->x1 += dx;
	re->y1 += dy;
	re->x2 += dx;
	re->y2 += dy;
}


static void
eel_canvas_re_bounds (EelCanvasItem *item, double *x1, double *y1, double *x2, double *y2)
{
	EelCanvasRE *re;
	double hwidth;

#ifdef VERBOSE
	g_print ("eel_canvas_re_bounds\n");
#endif
	re = EEL_CANVAS_RE (item);

	if (re->width_pixels)
		hwidth = (re->width / item->canvas->pixels_per_unit) / 2.0;
	else
		hwidth = re->width / 2.0;

	*x1 = re->x1 - hwidth;
	*y1 = re->y1 - hwidth;
	*x2 = re->x2 + hwidth;
	*y2 = re->y2 + hwidth;
}

/* Rectangle item */


static void eel_canvas_rect_class_init (EelCanvasRectClass *klass);
static void eel_canvas_rect_init (EelCanvasRect *rect);
static void eel_canvas_rect_finalize (GObject *object);
static void eel_canvas_rect_realize  (EelCanvasItem *item);

static void   eel_canvas_rect_draw   (EelCanvasItem *item, cairo_t *cr, cairo_region_t *region);
static double eel_canvas_rect_point  (EelCanvasItem *item, double x, double y, int cx, int cy,
				        EelCanvasItem **actual_item);

struct _EelCanvasRectPrivate {
	Rect last_update_rect;
	Rect last_outline_update_rect;
	int last_outline_update_width;

#ifdef HAVE_RENDER
	gboolean use_render;
	XRenderPictFormat *format;
#endif
};

GType
eel_canvas_rect_get_type (void)
{
	static GType rect_type = 0;

	if (!rect_type) {
		GTypeInfo rect_info = {
		  sizeof (EelCanvasRectClass),
		  (GBaseInitFunc) NULL,
		  (GBaseFinalizeFunc) NULL,
		  (GClassInitFunc) eel_canvas_rect_class_init,
		  NULL,           /* class_finalize */
		  NULL,           /* class_data */
		  sizeof (EelCanvasRect),
		  0,              /* n_preallocs */
		  (GInstanceInitFunc) eel_canvas_rect_init
		};

		rect_type = g_type_register_static (eel_canvas_re_get_type (),
						    "EelCanvasRect",
						    &rect_info,
						    0);
	}

	return rect_type;
}

static void
eel_canvas_rect_class_init (EelCanvasRectClass *klass)
{
	EelCanvasItemClass *item_class;

	rect_parent_class = g_type_class_peek_parent (klass);

	item_class = (EelCanvasItemClass *) klass;

	item_class->draw = eel_canvas_rect_draw;
	item_class->point = eel_canvas_rect_point;
	item_class->update = eel_canvas_rect_update;
	item_class->realize = eel_canvas_rect_realize;

	G_OBJECT_CLASS (klass)->finalize = eel_canvas_rect_finalize;
	
}

static void
eel_canvas_rect_init (EelCanvasRect *rect)
{
	rect->priv = g_new0 (EelCanvasRectPrivate, 1);
}

static void
eel_canvas_rect_finalize (GObject *object)
{
	EelCanvasRect *rect = EEL_CANVAS_RECT (object);

	if (rect->priv) {
		g_free (rect->priv);
	}

	G_OBJECT_CLASS (rect_parent_class)->finalize (object);
}

static void
eel_canvas_rect_realize  (EelCanvasItem *item)
{
#ifdef HAVE_RENDER
	EelCanvasRectPrivate *priv;
	int event_base, error_base;
	Display *dpy;

	priv = EEL_CANVAS_RECT (item)->priv;

	dpy = GDK_WINDOW_XDISPLAY (gtk_widget_get_window (GTK_WIDGET (item->canvas)));
	priv->use_render = XRenderQueryExtension (dpy, &event_base, &error_base);

	if (priv->use_render) {
		GdkVisual *gdk_visual;
		Visual *visual;

		gdk_visual = gtk_widget_get_visual (GTK_WIDGET (item->canvas));
		visual = gdk_x11_visual_get_xvisual (gdk_visual);

		priv->format = XRenderFindVisualFormat (dpy, visual);
	}
#endif
	
	if (EEL_CANVAS_ITEM_CLASS (rect_parent_class)->realize) {
		(* EEL_CANVAS_ITEM_CLASS (rect_parent_class)->realize) (item);
	}
}

static void
eel_canvas_set_source_color (cairo_t *cr,
			     GdkRGBA *rgba)
{
	gdk_cairo_set_source_rgba (cr, rgba);
}

#define DASH_ON 0.8
#define DASH_OFF 1.7
static void
eel_canvas_rect_draw (EelCanvasItem *item, cairo_t *cr, cairo_region_t *region)
{
	EelCanvasRE *re;
	double x1, y1, x2, y2;
	int cx1, cy1, cx2, cy2;
	double i2w_dx, i2w_dy;

	re = EEL_CANVAS_RE (item);

	/* Get canvas pixel coordinates */
	i2w_dx = 0.0;
	i2w_dy = 0.0;
	eel_canvas_item_i2w (item, &i2w_dx, &i2w_dy);
	
	x1 = re->x1 + i2w_dx;
	y1 = re->y1 + i2w_dy;
	x2 = re->x2 + i2w_dx;
	y2 = re->y2 + i2w_dy;

	eel_canvas_w2c (item->canvas, x1, y1, &cx1, &cy1);
	eel_canvas_w2c (item->canvas, x2, y2, &cx2, &cy2);
	
	if (cx2 <= cx1 || cy2 <= cy1 ) {
		return;
	}

	cairo_save (cr);

	if (re->fill_set) {
		eel_canvas_set_source_color (cr, &re->fill_color);
		cairo_rectangle (cr,
				 cx1, cy1,
				 cx2 - cx1 + 1,
				 cy2 - cy1 + 1);
		cairo_fill (cr);
	}

	if (re->outline_set) {
		eel_canvas_set_source_color (cr, &re->outline_color);
		if (re->width_pixels) {
			cairo_set_line_width (cr, (int) re->width);
		} else {
			cairo_set_line_width (cr, (int) (re->width * re->item.canvas->pixels_per_unit + 0.5));
		}

		if (re->outline_stippling) {
			double dash[2] = { DASH_ON, DASH_OFF };

			cairo_set_dash (cr, dash, G_N_ELEMENTS (dash), 0);
		}

		cairo_rectangle (cr,
				 cx1 + 0.5, cy1 + 0.5,
				 cx2 - cx1,
				 cy2 - cy1);
		cairo_stroke (cr);
	}

	cairo_restore (cr);
}

static double
eel_canvas_rect_point (EelCanvasItem *item, double x, double y, int cx, int cy, EelCanvasItem **actual_item)
{
	EelCanvasRE *re;
	double x1, y1, x2, y2;
	double hwidth;
	double dx, dy;
	double tmp;

#ifdef VERBOSE
	g_print ("eel_canvas_rect_point\n");
#endif
	re = EEL_CANVAS_RE (item);

	*actual_item = item;

	/* Find the bounds for the rectangle plus its outline width */

	x1 = re->x1;
	y1 = re->y1;
	x2 = re->x2;
	y2 = re->y2;

	if (re->outline_set) {
		if (re->width_pixels)
			hwidth = (re->width / item->canvas->pixels_per_unit) / 2.0;
		else
			hwidth = re->width / 2.0;

		x1 -= hwidth;
		y1 -= hwidth;
		x2 += hwidth;
		y2 += hwidth;
	} else
		hwidth = 0.0;

	/* Is point inside rectangle (which can be hollow if it has no fill set)? */

	if ((x >= x1) && (y >= y1) && (x <= x2) && (y <= y2)) {
		if (re->fill_set || !re->outline_set)
			return 0.0;

		dx = x - x1;
		tmp = x2 - x;
		if (tmp < dx)
			dx = tmp;

		dy = y - y1;
		tmp = y2 - y;
		if (tmp < dy)
			dy = tmp;

		if (dy < dx)
			dx = dy;

		dx -= 2.0 * hwidth;

		if (dx < 0.0)
			return 0.0;
		else
			return dx;
	}

	/* Point is outside rectangle */

	if (x < x1)
		dx = x1 - x;
	else if (x > x2)
		dx = x - x2;
	else
		dx = 0.0;

	if (y < y1)
		dy = y1 - y;
	else if (y > y2)
		dy = y - y2;
	else
		dy = 0.0;

	return sqrt (dx * dx + dy * dy);
}

static void
request_redraw_borders (EelCanvas *canvas,
			Rect     *update_rect,
			int     width)
{
	eel_canvas_request_redraw (canvas,
				   update_rect->x0, update_rect->y0,
				   update_rect->x1, update_rect->y0 + width);
	eel_canvas_request_redraw (canvas,
				   update_rect->x0, update_rect->y1-width,
				   update_rect->x1, update_rect->y1);
	eel_canvas_request_redraw (canvas,
				   update_rect->x0,       update_rect->y0,
				   update_rect->x0+width, update_rect->y1);
	eel_canvas_request_redraw (canvas,
				   update_rect->x1-width, update_rect->y0,
				   update_rect->x1,       update_rect->y1);
}


static void
eel_canvas_rect_update (EelCanvasItem *item, double i2w_dx, double i2w_dy, gint flags)
{
	EelCanvasRE *re;
	double x1, y1, x2, y2;
	int cx1, cy1, cx2, cy2;
	int repaint_rects_count, i;
	int width_pixels;
	int width_lt, width_rb;
	Rect update_rect, repaint_rects[4];
	EelCanvasRectPrivate *priv;

	eel_canvas_re_update_shared (item, i2w_dx, i2w_dy, flags);

	re = EEL_CANVAS_RE (item);
	priv = EEL_CANVAS_RECT (item)->priv;
	
	x1 = re->x1 + i2w_dx;
	y1 = re->y1 + i2w_dy;
	x2 = re->x2 + i2w_dx;
	y2 = re->y2 + i2w_dy;

	eel_canvas_w2c (item->canvas, x1, y1, &cx1, &cy1);
	eel_canvas_w2c (item->canvas, x2, y2, &cx2, &cy2);

	update_rect = make_rect (cx1, cy1, cx2+1, cy2+1);
#if 0
	eel_canvas_request_redraw (item->canvas,
				   update_rect.x0, update_rect.y0,
				   update_rect.x1, update_rect.y1);
	eel_canvas_request_redraw (item->canvas,
				   priv->last_update_rect.x0, priv->last_update_rect.y0,
				   priv->last_update_rect.x1, priv->last_update_rect.y1);
#else
	diff_rects (update_rect, priv->last_update_rect,
		    &repaint_rects_count, repaint_rects);
	for (i = 0; i < repaint_rects_count; i++) {
		eel_canvas_request_redraw (item->canvas,
					   repaint_rects[i].x0, repaint_rects[i].y0,
					   repaint_rects[i].x1, repaint_rects[i].y1);
	}
#endif
	priv->last_update_rect = update_rect;

	if (re->outline_set) {
		/* Outline and bounding box */
		if (re->width_pixels)
			width_pixels = (int) re->width;
		else
			width_pixels = (int) floor (re->width * re->item.canvas->pixels_per_unit + 0.5);

		width_lt = width_pixels / 2;
		width_rb = (width_pixels + 1) / 2;
		
		cx1 -= width_lt;
		cy1 -= width_lt;
		cx2 += width_rb;
		cy2 += width_rb;

		update_rect = make_rect (cx1, cy1, cx2, cy2);
		request_redraw_borders (item->canvas, &update_rect,
					(width_lt + width_rb));
		request_redraw_borders (item->canvas, &priv->last_outline_update_rect,
					priv->last_outline_update_width);
		priv->last_outline_update_rect = update_rect;
		priv->last_outline_update_width = width_lt + width_rb;
		
		item->x1 = cx1;
		item->y1 = cy1;
		item->x2 = cx2+1;
		item->y2 = cy2+1;
	} else {
		item->x1 = cx1;
		item->y1 = cy1;
		item->x2 = cx2+1;
		item->y2 = cy2+1;
	}
}

/* Ellipse item */


static void eel_canvas_ellipse_class_init (EelCanvasEllipseClass *klass);

static void   eel_canvas_ellipse_draw   (EelCanvasItem *item, cairo_t *cr, cairo_region_t *region);
static double eel_canvas_ellipse_point  (EelCanvasItem *item, double x, double y, int cx, int cy,
					   EelCanvasItem **actual_item);


GType
eel_canvas_ellipse_get_type (void)
{
	static GType ellipse_type = 0;

	if (!ellipse_type) {
		GTypeInfo ellipse_info = {
		  sizeof (EelCanvasEllipseClass),
		  (GBaseInitFunc) NULL,
		  (GBaseFinalizeFunc) NULL,
		  (GClassInitFunc) eel_canvas_ellipse_class_init,
		  NULL,           /* class_finalize */
		  NULL,           /* class_data */
		  sizeof (EelCanvasEllipse),
		  0,              /* n_preallocs */
		  (GInstanceInitFunc) NULL

		};

		ellipse_type = g_type_register_static (eel_canvas_re_get_type (),
						       "EelCanvasEllipse",
						       &ellipse_info,
						       0);
	}

	return ellipse_type;
}

static void
eel_canvas_ellipse_class_init (EelCanvasEllipseClass *klass)
{
	EelCanvasItemClass *item_class;

	item_class = (EelCanvasItemClass *) klass;

	item_class->draw = eel_canvas_ellipse_draw;
	item_class->point = eel_canvas_ellipse_point;
	item_class->update = eel_canvas_ellipse_update;
}

static void
eel_canvas_ellipse_draw (EelCanvasItem *item, cairo_t *cr, cairo_region_t *region)
{
	EelCanvasRE *re;
	int x1, y1, x2, y2;
	double i2w_dx, i2w_dy;

	re = EEL_CANVAS_RE (item);

	/* Get canvas pixel coordinates */

	i2w_dx = 0.0;
	i2w_dy = 0.0;
	eel_canvas_item_i2w (item, &i2w_dx, &i2w_dy);
	
	eel_canvas_w2c (item->canvas,
			  re->x1 + i2w_dx,
			  re->y1 + i2w_dy,
			  &x1, &y1);
	eel_canvas_w2c (item->canvas,
			  re->x2 + i2w_dx,
			  re->y2 + i2w_dy,
			  &x2, &y2);

        cairo_save (cr);

	cairo_save (cr);
	cairo_translate (cr, (x1 + x2) / 2., (y1 + y2) / 2.);
	cairo_scale (cr, (x2 - x1), (y2 - y1));
	cairo_arc (cr, 0, 0, 1, 0, 2 * G_PI);
	cairo_restore (cr);

	if (re->fill_set) {
		eel_canvas_set_source_color (cr, &re->fill_color);
		cairo_fill_preserve (cr);
        }

	if (re->outline_set) {
		eel_canvas_set_source_color (cr, &re->outline_color);
		if (re->width_pixels) {
			cairo_set_line_width (cr, (int) re->width);
		} else {
			cairo_set_line_width (cr, (int) (re->width * re->item.canvas->pixels_per_unit + 0.5));
		}

		cairo_stroke_preserve (cr);
        }

	cairo_restore (cr);
}

static double
eel_canvas_ellipse_point (EelCanvasItem *item, double x, double y, int cx, int cy, EelCanvasItem **actual_item)
{
	EelCanvasRE *re;
	double dx, dy;
	double scaled_dist;
	double outline_dist;
	double center_dist;
	double width;
	double a, b;
	double diamx, diamy;

	re = EEL_CANVAS_RE (item);

	*actual_item = item;

	if (re->outline_set) {
		if (re->width_pixels)
			width = re->width / item->canvas->pixels_per_unit;
		else
			width = re->width;
	} else
		width = 0.0;

	/* Compute the distance between the center of the ellipse and the point, with the ellipse
	 * considered as being scaled to a circle.
	 */

	dx = x - (re->x1 + re->x2) / 2.0;
	dy = y - (re->y1 + re->y2) / 2.0;
	center_dist = sqrt (dx * dx + dy * dy);

	a = dx / ((re->x2 + width - re->x1) / 2.0);
	b = dy / ((re->y2 + width - re->y1) / 2.0);
	scaled_dist = sqrt (a * a + b * b);

	/* If the scaled distance is greater than 1, then we are outside.  Compute the distance from
	 * the point to the edge of the circle, then scale back to the original un-scaled coordinate
	 * system.
	 */

	if (scaled_dist > 1.0)
		return (center_dist / scaled_dist) * (scaled_dist - 1.0);

	/* We are inside the outer edge of the ellipse.  If it is filled, then we are "inside".
	 * Otherwise, do the same computation as above, but also check whether we are inside the
	 * outline.
	 */

	if (re->fill_set)
		return 0.0;

	if (scaled_dist > EEL_CANVAS_EPSILON)
		outline_dist = (center_dist / scaled_dist) * (1.0 - scaled_dist) - width;
	else {
		/* Handle very small distance */

		diamx = re->x2 - re->x1;
		diamy = re->y2 - re->y1;

		if (diamx < diamy)
			outline_dist = (diamx - width) / 2.0;
		else
			outline_dist = (diamy - width) / 2.0;
	}

	if (outline_dist < 0.0)
		return 0.0;

	return outline_dist;
}

static void
eel_canvas_ellipse_update (EelCanvasItem *item, double i2w_dx, double i2w_dy, gint flags)
{
	EelCanvasRE *re;
	double x0, y0, x1, y1;

#ifdef VERBOSE
	g_print ("eel_canvas_sllipse_update item %x\n", item);
#endif

	eel_canvas_re_update_shared (item, i2w_dx, i2w_dy, flags);
	re = EEL_CANVAS_RE (item);

	get_bounds (re, &x0, &y0, &x1, &y1);
	eel_canvas_update_bbox (item, x0, y0, x1, y1);
}

static int
rect_empty (const Rect *src) {
  return (src->x1 <= src->x0 || src->y1 <= src->y0);
}

static Rect
make_rect (int x0, int y0, int x1, int y1)
{
	Rect r;

	r.x0 = x0;
	r.y0 = y0;
	r.x1 = x1;
	r.y1 = y1;
	return r;
}

static gboolean
rects_intersect (Rect r1, Rect r2)
{
	if (r1.x0 >= r2.x1) {
		return FALSE;
	}
	if (r2.x0 >= r1.x1) {
		return FALSE;
	}
	if (r1.y0 >= r2.y1) {
		return FALSE;
	}
	if (r2.y0 >= r1.y1) {
		return FALSE;
	}
	return TRUE;
}

static void
diff_rects_guts (Rect ra, Rect rb, int *count, Rect result[4])
{
	if (ra.x0 < rb.x0) {
		result[(*count)++] = make_rect (ra.x0, ra.y0, rb.x0, ra.y1);
	}
	if (ra.y0 < rb.y0) {
		result[(*count)++] = make_rect (ra.x0, ra.y0, ra.x1, rb.y0);
	}
	if (ra.x1 < rb.x1) {
		result[(*count)++] = make_rect (ra.x1, rb.y0, rb.x1, rb.y1);
	}
	if (ra.y1 < rb.y1) {
		result[(*count)++] = make_rect (rb.x0, ra.y1, rb.x1, rb.y1);
	}
}

static void
diff_rects (Rect r1, Rect r2, int *count, Rect result[4])
{
	g_assert (count != NULL);
	g_assert (result != NULL);

	*count = 0;

	if (rects_intersect (r1, r2)) {
		diff_rects_guts (r1, r2, count, result);
		diff_rects_guts (r2, r1, count, result);
	} else {
		if (!rect_empty (&r1)) {
			result[(*count)++] = r1;
		}
		if (!rect_empty (&r2)) {
			result[(*count)++] = r2;
		}
	}
}