#define GNOME_CANVAS_CLIPGROUP_C

/* Clipping group for GnomeCanvas
 *
 * GnomeCanvas 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.
 *
 * Copyright (C) 1998,1999 The Free Software Foundation
 *
 * Author:
 *          Lauris Kaplinski <lauris@ariman.ee>
 */

/* These includes are set up for standalone compile. If/when this codebase
   is integrated into libgnomeui, the includes will need to change. */

#include <math.h>
#include <string.h>

#include <gtk/gtkobject.h>
#include <gtk/gtkwidget.h>
#include <libgnomeui/gnome-canvas.h>
#include <libgnomeui/gnome-canvas-util.h>

#include "gnome-canvas-clipgroup.h"
#include <libart_lgpl/art_rect.h>
#include <libart_lgpl/art_vpath.h>
#include <libart_lgpl/art_bpath.h>
#include <libart_lgpl/art_vpath.h>
#include <libart_lgpl/art_vpath_bpath.h>
#include <libart_lgpl/art_svp.h>
#include <libart_lgpl/art_svp_vpath.h>
#include <libart_lgpl/art_vpath_dash.h>
#include <libart_lgpl/art_svp_wind.h>
#include <libart_lgpl/art_svp_point.h>
#include <libart_lgpl/art_svp_ops.h>

enum {
	ARG_0,
	ARG_PATH,
	ARG_WIND
};


static void gnome_canvas_clipgroup_class_init (GnomeCanvasClipgroupClass *class);
static void gnome_canvas_clipgroup_init       (GnomeCanvasClipgroup      *clipgroup);
static void gnome_canvas_clipgroup_destroy    (GtkObject               *object);
static void gnome_canvas_clipgroup_set_arg    (GtkObject               *object,
					   GtkArg                  *arg,
					   guint                    arg_id);
static void gnome_canvas_clipgroup_get_arg    (GtkObject               *object,
					   GtkArg                  *arg,
					   guint                    arg_id);

static void   gnome_canvas_clipgroup_update      (GnomeCanvasItem *item, double *affine, ArtSVP *clip_path, int flags);

#if 0
static void   gnome_canvas_clipgroup_realize     (GnomeCanvasItem *item);
static void   gnome_canvas_clipgroup_unrealize   (GnomeCanvasItem *item);
static void   gnome_canvas_clipgroup_draw        (GnomeCanvasItem *item, GdkDrawable *drawable,
						int x, int y, int width, int height);
static double gnome_canvas_clipgroup_point       (GnomeCanvasItem *item, double x, double y,
						int cx, int cy, GnomeCanvasItem **actual_item);
static void   gnome_canvas_clipgroup_render      (GnomeCanvasItem *item, GnomeCanvasBuf *buf);
#endif

static GnomeCanvasGroupClass *parent_class;

GtkType
gnome_canvas_clipgroup_get_type (void)
{
	static GtkType clipgroup_type = 0;

	if (!clipgroup_type) {
		GtkTypeInfo clipgroup_info = {
			"GnomeCanvasClipgroup",
			sizeof (GnomeCanvasClipgroup),
			sizeof (GnomeCanvasClipgroupClass),
			(GtkClassInitFunc) gnome_canvas_clipgroup_class_init,
			(GtkObjectInitFunc) gnome_canvas_clipgroup_init,
			NULL, /* reserved_1 */
			NULL, /* reserved_2 */
			(GtkClassInitFunc) NULL
		};

		clipgroup_type = gtk_type_unique (gnome_canvas_group_get_type (), &clipgroup_info);
	}

	return clipgroup_type;
}

static void
gnome_canvas_clipgroup_class_init (GnomeCanvasClipgroupClass *class)
{
	GtkObjectClass *object_class;
	GnomeCanvasItemClass *item_class;

	object_class = (GtkObjectClass *) class;
	item_class = (GnomeCanvasItemClass *) class;

	parent_class = gtk_type_class (gnome_canvas_group_get_type ());

	gtk_object_add_arg_type ("GnomeCanvasClipgroup::path", GTK_TYPE_POINTER, GTK_ARG_READWRITE, ARG_PATH);
	gtk_object_add_arg_type ("GnomeCanvasClipgroup::wind", GTK_TYPE_ENUM, GTK_ARG_READWRITE, ARG_WIND);

	object_class->destroy = gnome_canvas_clipgroup_destroy;
	object_class->set_arg = gnome_canvas_clipgroup_set_arg;
	object_class->get_arg = gnome_canvas_clipgroup_get_arg;

	item_class->update = gnome_canvas_clipgroup_update;

#if 0
	item_class->realize = gnome_canvas_clipgroup_realize;
	item_class->unrealize = gnome_canvas_clipgroup_unrealize;
	item_class->draw = gnome_canvas_clipgroup_draw;
	item_class->point = gnome_canvas_clipgroup_point;
	item_class->bounds = gnome_canvas_clipgroup_bounds;
	item_class->render = gnome_canvas_clipgroup_render;
#endif
}

static void
gnome_canvas_clipgroup_init (GnomeCanvasClipgroup *clipgroup)
{
	clipgroup->path = NULL;
	clipgroup->wind = ART_WIND_RULE_NONZERO; /* default winding rule */
	clipgroup->svp = NULL;
}

static void
gnome_canvas_clipgroup_destroy (GtkObject *object)
{
	GnomeCanvasClipgroup *clipgroup;

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

	clipgroup = GNOME_CANVAS_CLIPGROUP (object);

	if (clipgroup->path) {
		gp_path_unref (clipgroup->path);
		clipgroup->path = NULL;
	}
	
	if (clipgroup->svp) {
		art_svp_free (clipgroup->svp);
		clipgroup->svp = NULL;
	}

	if (GTK_OBJECT_CLASS (parent_class)->destroy)
		(* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
}


static void
gnome_canvas_clipgroup_set_arg (GtkObject *object, GtkArg *arg, guint arg_id)
{
	GnomeCanvasItem *item;
	GnomeCanvasClipgroup *cgroup;
	GPPath *gpp;

	item = GNOME_CANVAS_ITEM (object);
	cgroup = GNOME_CANVAS_CLIPGROUP (object);

	switch (arg_id) {
	case ARG_PATH:
		gpp = GTK_VALUE_POINTER (*arg);

		if (cgroup->path) {
			gp_path_unref (cgroup->path);
			cgroup->path = NULL;
		}
		if (gpp != NULL) {
			cgroup->path = gp_path_closed_parts (gpp);
		}

		gnome_canvas_item_request_update (item);
		break;

	case ARG_WIND:
		cgroup->wind = GTK_VALUE_ENUM (*arg);
		gnome_canvas_item_request_update (item);
		break;

	default:
		break;
	}
}

static void
gnome_canvas_clipgroup_get_arg (GtkObject *object, GtkArg *arg, guint arg_id)
{
	GnomeCanvasClipgroup * cgroup;

	cgroup = GNOME_CANVAS_CLIPGROUP (object);

	switch (arg_id) {
	case ARG_PATH:
		GTK_VALUE_POINTER (*arg) = cgroup->path;
		break;

	case ARG_WIND:
		GTK_VALUE_ENUM (*arg) = cgroup->wind;
		break;

	default:
		arg->type = GTK_TYPE_INVALID;
		break;
	}
}

static void
gnome_canvas_clipgroup_update (GnomeCanvasItem *item, double *affine, ArtSVP *clip_path, int flags)
{
	GnomeCanvasGroup * group;
	GnomeCanvasClipgroup * clipgroup;
	ArtBpath * bp;
	ArtBpath * bpath;
	ArtVpath * vpath1, * vpath2;
	ArtSVP * svp, * svp1, * svp2;

	group = GNOME_CANVAS_GROUP (item);
	clipgroup = GNOME_CANVAS_CLIPGROUP (item);

	if (clipgroup->svp) {
		art_svp_free (clipgroup->svp);
		clipgroup->svp = NULL;
	}

	if (clipgroup->path) {
		bp = gp_path_bpath (clipgroup->path);
		bpath = art_bpath_affine_transform (bp, affine);

		vpath1 = art_bez_path_to_vec (bpath, 0.25);
		art_free (bpath);

		vpath2 = art_vpath_perturb (vpath1);
		art_free (vpath1);

		svp1 = art_svp_from_vpath (vpath2);
		art_free (vpath2);
		
		svp2 = art_svp_uncross (svp1);
		art_svp_free (svp1);

		svp1 = art_svp_rewind_uncrossed (svp2, clipgroup->wind);
		art_svp_free (svp2);

		if (clip_path != NULL) {
			svp = art_svp_intersect (svp1, clip_path);
			art_svp_free (svp1);
		} else {
			svp = svp1;
		}

	} else {
		svp = clip_path;
	}

	clipgroup->svp = svp;

	if (GNOME_CANVAS_ITEM_CLASS (parent_class)->update)
		(GNOME_CANVAS_ITEM_CLASS (parent_class)->update) (item, affine, svp, flags);

}