path: root/libgnomecanvas/gnome-canvas-rect-ellipse.c

/*
 * 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 GnomeCanvas widget
 *
 * 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.
 *
 *
 * Authors: Federico Mena <federico@nuclecu.unam.mx>
 *          Rusty Conover <rconover@bangtail.net>
 */

#include <config.h>
#include <math.h>
#include "gnome-canvas-rect-ellipse.h"
#include "gnome-canvas-util.h"
#include "gnome-canvas-shape.h"

#include <libart_lgpl/art_vpath.h>
#include <libart_lgpl/art_svp.h>
#include <libart_lgpl/art_svp_vpath.h>
#include <libart_lgpl/art_rgb_svp.h>

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

#define noVERBOSE

enum {
    PROP_0,
    PROP_X1,
    PROP_Y1,
    PROP_X2,
    PROP_Y2
};

static void gnome_canvas_re_class_init (GnomeCanvasREClass *class);
static void gnome_canvas_re_init       (GnomeCanvasRE      *re);
static void gnome_canvas_re_set_property (GObject              *object,
                      guint                 param_id,
                      const GValue         *value,
                      GParamSpec           *pspec);
static void gnome_canvas_re_get_property (GObject              *object,
                      guint                 param_id,
                      GValue               *value,
                      GParamSpec           *pspec);

static void gnome_canvas_rect_update      (GnomeCanvasItem *item, gdouble *affine, ArtSVP *clip_path, gint flags);
static void gnome_canvas_ellipse_update      (GnomeCanvasItem *item, gdouble *affine, ArtSVP *clip_path, gint flags);

static GnomeCanvasItemClass *re_parent_class;

GType
gnome_canvas_re_get_type (void)
{
    static GType re_type;

    if (!re_type) {
        const GTypeInfo object_info = {
            sizeof (GnomeCanvasREClass),
            (GBaseInitFunc) NULL,
            (GBaseFinalizeFunc) NULL,
            (GClassInitFunc) gnome_canvas_re_class_init,
            (GClassFinalizeFunc) NULL,
            NULL,           /* class_data */
            sizeof (GnomeCanvasRE),
            0,          /* n_preallocs */
            (GInstanceInitFunc) gnome_canvas_re_init,
            NULL            /* value_table */
        };

        re_type = g_type_register_static (GNOME_TYPE_CANVAS_SHAPE, "GnomeCanvasRE",
                          &object_info, 0);
    }

    return re_type;
}

static void
gnome_canvas_re_class_init (GnomeCanvasREClass *class)
{
    GObjectClass *gobject_class;

    gobject_class = (GObjectClass *) class;

    re_parent_class = g_type_class_peek_parent (class);

    gobject_class->set_property = gnome_canvas_re_set_property;
    gobject_class->get_property = gnome_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_READABLE | G_PARAM_WRITABLE)));
        g_object_class_install_property
                (gobject_class,
                 PROP_Y1,
                 g_param_spec_double ("y1", NULL, NULL,
                      -G_MAXDOUBLE, G_MAXDOUBLE, 0,
                      (G_PARAM_READABLE | G_PARAM_WRITABLE)));
        g_object_class_install_property
                (gobject_class,
                 PROP_X2,
                 g_param_spec_double ("x2", NULL, NULL,
                      -G_MAXDOUBLE, G_MAXDOUBLE, 0,
                      (G_PARAM_READABLE | G_PARAM_WRITABLE)));
        g_object_class_install_property
                (gobject_class,
                 PROP_Y2,
                 g_param_spec_double ("y2", NULL, NULL,
                      -G_MAXDOUBLE, G_MAXDOUBLE, 0,
                      (G_PARAM_READABLE | G_PARAM_WRITABLE)));
}

static void
gnome_canvas_re_init (GnomeCanvasRE *re)
{
    re->x1 = 0.0;
    re->y1 = 0.0;
    re->x2 = 0.0;
    re->y2 = 0.0;
    re->path_dirty = 0;
}

static void
gnome_canvas_re_set_property (GObject              *object,
                  guint                 param_id,
                  const GValue         *value,
                  GParamSpec           *pspec)
{
    GnomeCanvasItem *item;
    GnomeCanvasRE *re;

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

    item = GNOME_CANVAS_ITEM (object);
    re = GNOME_CANVAS_RE (object);

    switch (param_id) {
    case PROP_X1:
        re->x1 = g_value_get_double (value);
        re->path_dirty = 1;
        gnome_canvas_item_request_update (item);
        break;

    case PROP_Y1:
        re->y1 = g_value_get_double (value);
        re->path_dirty = 1;
        gnome_canvas_item_request_update (item);
        break;

    case PROP_X2:
        re->x2 = g_value_get_double (value);
        re->path_dirty = 1;
        gnome_canvas_item_request_update (item);
        break;

    case PROP_Y2:
        re->y2 = g_value_get_double (value);
        re->path_dirty = 1;
        gnome_canvas_item_request_update (item);
        break;

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

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

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

    re = GNOME_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;

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

/* Rectangle item */
static void gnome_canvas_rect_class_init (GnomeCanvasRectClass *class);

GType
gnome_canvas_rect_get_type (void)
{
    static GType rect_type;

    if (!rect_type) {
        const GTypeInfo object_info = {
            sizeof (GnomeCanvasRectClass),
            (GBaseInitFunc) NULL,
            (GBaseFinalizeFunc) NULL,
            (GClassInitFunc) gnome_canvas_rect_class_init,
            (GClassFinalizeFunc) NULL,
            NULL,           /* class_data */
            sizeof (GnomeCanvasRect),
            0,          /* n_preallocs */
            (GInstanceInitFunc) NULL,
            NULL            /* value_table */
        };

        rect_type = g_type_register_static (GNOME_TYPE_CANVAS_RE, "GnomeCanvasRect",
                            &object_info, 0);
    }

    return rect_type;
}

static void
gnome_canvas_rect_class_init (GnomeCanvasRectClass *class)
{
    GnomeCanvasItemClass *item_class;

    item_class = (GnomeCanvasItemClass *) class;

    item_class->update = gnome_canvas_rect_update;
}

static void
gnome_canvas_rect_update (GnomeCanvasItem *item, gdouble affine[6], ArtSVP *clip_path, gint flags)
{   GnomeCanvasRE *re;

    GnomeCanvasPathDef *path_def;

    re = GNOME_CANVAS_RE (item);

    if (re->path_dirty) {
        path_def = gnome_canvas_path_def_new ();

        gnome_canvas_path_def_moveto (path_def, re->x1, re->y1);
        gnome_canvas_path_def_lineto (path_def, re->x2, re->y1);
        gnome_canvas_path_def_lineto (path_def, re->x2, re->y2);
        gnome_canvas_path_def_lineto (path_def, re->x1, re->y2);
        gnome_canvas_path_def_lineto (path_def, re->x1, re->y1);
        gnome_canvas_path_def_closepath_current (path_def);
        gnome_canvas_shape_set_path_def (GNOME_CANVAS_SHAPE (item), path_def);
        gnome_canvas_path_def_unref (path_def);
        re->path_dirty = 0;
    }

    if (re_parent_class->update)
        (* re_parent_class->update) (item, affine, clip_path, flags);
}

/* Ellipse item */

static void gnome_canvas_ellipse_class_init (GnomeCanvasEllipseClass *class);

GType
gnome_canvas_ellipse_get_type (void)
{
    static GType ellipse_type;

    if (!ellipse_type) {
        const GTypeInfo object_info = {
            sizeof (GnomeCanvasEllipseClass),
            (GBaseInitFunc) NULL,
            (GBaseFinalizeFunc) NULL,
            (GClassInitFunc) gnome_canvas_ellipse_class_init,
            (GClassFinalizeFunc) NULL,
            NULL,           /* class_data */
            sizeof (GnomeCanvasEllipse),
            0,          /* n_preallocs */
            (GInstanceInitFunc) NULL,
            NULL            /* value_table */
        };

        ellipse_type = g_type_register_static (GNOME_TYPE_CANVAS_RE, "GnomeCanvasEllipse",
                               &object_info, 0);
    }

    return ellipse_type;
}

static void
gnome_canvas_ellipse_class_init (GnomeCanvasEllipseClass *class)
{
    GnomeCanvasItemClass *item_class;

    item_class = (GnomeCanvasItemClass *) class;

    item_class->update = gnome_canvas_ellipse_update;
}

#define N_PTS 90

static void
gnome_canvas_ellipse_update (GnomeCanvasItem *item, gdouble affine[6], ArtSVP *clip_path, gint flags) {
    GnomeCanvasPathDef *path_def;
    GnomeCanvasRE *re;

    re = GNOME_CANVAS_RE (item);

    if (re->path_dirty) {
        gdouble cx, cy, rx, ry;
        gdouble beta = 0.26521648983954400922; /* 4*(1-cos (pi/8))/(3*sin (pi/8)) */
        gdouble sincosA = 0.70710678118654752440; /* sin (pi/4), cos (pi/4) */
        gdouble dx1, dy1, dx2, dy2;
        gdouble mx, my;

        path_def = gnome_canvas_path_def_new ();

        cx = (re->x2 + re->x1) * 0.5;
        cy = (re->y2 + re->y1) * 0.5;
        rx = re->x2 - cx;
        ry = re->y2 - cy;

        dx1 = beta * rx;
        dy1 = beta * ry;
        dx2 = beta * rx * sincosA;
        dy2 = beta * ry * sincosA;
        mx = rx * sincosA;
        my = ry * sincosA;

        gnome_canvas_path_def_moveto (path_def, cx + rx, cy);
        gnome_canvas_path_def_curveto (path_def,
                           cx + rx, cy - dy1,
                           cx + mx + dx2, cy - my + dy2,
                           cx + mx, cy - my);
        gnome_canvas_path_def_curveto (path_def,
                           cx + mx - dx2, cy - my - dy2,
                           cx + dx1, cy - ry,
                           cx, cy - ry);
        gnome_canvas_path_def_curveto (path_def,
                           cx - dx1, cy - ry,
                           cx - mx + dx2, cy - my - dy2,
                           cx - mx, cy - my);
        gnome_canvas_path_def_curveto (path_def,
                           cx - mx - dx2, cy - my + dy2,
                           cx - rx, cy - dy1,
                           cx - rx, cy);

        gnome_canvas_path_def_curveto (path_def,
                           cx - rx, cy + dy1,
                           cx - mx - dx2, cy + my - dy2,
                           cx - mx, cy + my);
        gnome_canvas_path_def_curveto (path_def,
                           cx - mx + dx2, cy + my + dy2,
                           cx - dx1, cy + ry,
                           cx, cy + ry);
        gnome_canvas_path_def_curveto (path_def,
                           cx + dx1, cy + ry,
                           cx + mx - dx2, cy + my + dy2,
                           cx + mx, cy + my);
        gnome_canvas_path_def_curveto (path_def,
                           cx + mx + dx2, cy + my - dy2,
                           cx + rx, cy + dy1,
                           cx + rx, cy);

        gnome_canvas_path_def_closepath_current (path_def);

        gnome_canvas_shape_set_path_def (GNOME_CANVAS_SHAPE (item), path_def);
        gnome_canvas_path_def_unref (path_def);
        re->path_dirty = 0;
    }

    if (re_parent_class->update)
        (* re_parent_class->update) (item, affine, clip_path, flags);
}