swfdec/swfdec_draw.c

   1 /* Swfdec
   2  * Copyright (C) 2007 Benjamin Otte <otte@gnome.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301  USA
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <string.h>
  25
  26 #include "swfdec_draw.h"
  27 #include "swfdec_color.h"
  28 #include "swfdec_debug.h"
  29 #include "swfdec_path.h"
  30
  31 /*** DRAW ***/
  32
  33 G_DEFINE_ABSTRACT_TYPE (SwfdecDraw, swfdec_draw, G_TYPE_OBJECT);
  34
  35 static gboolean
  36 swfdec_draw_can_morph (SwfdecDraw *draw)
  37 {
  38   return draw->end_path.num_data > 0;
  39 }
  40
  41 static void
  42 swfdec_draw_do_morph (SwfdecDraw* dest, SwfdecDraw *source, guint ratio)
  43 {
  44   if (swfdec_draw_can_morph (source)) {
  45     swfdec_path_merge (&dest->path, &source->path, &source->end_path, ratio / 65535.);
  46   } else {
  47     swfdec_path_copy (&dest->path, &source->path);
  48   }
  49 }
  50
  51 static void
  52 swfdec_draw_dispose (GObject *object)
  53 {
  54   SwfdecDraw *draw = SWFDEC_DRAW (object);
  55
  56   swfdec_path_reset (&draw->path);
  57   swfdec_path_reset (&draw->end_path);
  58
  59   G_OBJECT_CLASS (swfdec_draw_parent_class)->dispose (object);
  60 }
  61
  62 static void
  63 swfdec_draw_class_init (SwfdecDrawClass *klass)
  64 {
  65   GObjectClass *object_class = G_OBJECT_CLASS (klass);
  66
  67   object_class->dispose = swfdec_draw_dispose;
  68
  69   klass->morph = swfdec_draw_do_morph;
  70 }
  71
  72 static void
  73 swfdec_draw_init (SwfdecDraw *draw)
  74 {
  75   swfdec_path_init (&draw->path);
  76   swfdec_path_init (&draw->end_path);
  77 }
  78
  79 /**
  80  * swfdec_draw_morph:
  81  * @draw: a #SwfdecDraw
  82  * @ratio: ratio of the morph from 0 to 65535
  83  *
  84  * Applies a morph to the given drawing operation. If the drawing operation
  85  * can not be morphed, it is returned unchanged. Otherwise a new drawing
  86  * operation is created.
  87  *
  88  * Returns: a new reference to a #SwfdecDraw corresponding to the given morph
  89  *          ratio
  90  **/
  91 SwfdecDraw *
  92 swfdec_draw_morph (SwfdecDraw *draw, guint ratio)
  93 {
  94   SwfdecDrawClass *klass;
  95   SwfdecDraw *copy;
  96
  97   g_return_val_if_fail (SWFDEC_IS_DRAW (draw), NULL);
  98   g_return_val_if_fail (ratio < 65536, NULL);
  99
 100   if (!swfdec_draw_can_morph (draw) || ratio == 0) {
 101     /* not a morph */
 102     g_object_ref (draw);
 103     return draw;
 104   }
 105   klass = SWFDEC_DRAW_GET_CLASS (draw);
 106   g_assert (klass->morph);
 107   copy = g_object_new (G_OBJECT_CLASS_TYPE (klass), NULL);
 108   klass->morph (copy, draw, ratio);
 109   swfdec_draw_recompute (copy);
 110   return copy;
 111 }
 112
 113 SwfdecDraw *
 114 swfdec_draw_copy (SwfdecDraw *draw)
 115 {
 116   SwfdecDrawClass *klass;
 117   SwfdecDraw *copy;
 118
 119   g_return_val_if_fail (SWFDEC_IS_DRAW (draw), NULL);
 120
 121   klass = SWFDEC_DRAW_GET_CLASS (draw);
 122   g_assert (klass->morph);
 123   copy = g_object_new (G_OBJECT_CLASS_TYPE (klass), NULL);
 124   klass->morph (copy, draw, 0);
 125   swfdec_draw_recompute (copy);
 126   return copy;
 127 }
 128
 129 /**
 130  * swfdec_draw_paint:
 131  * @draw: drawing operation to perform
 132  * @cr: context to perform the operation on
 133  * @trans: color transofrmation to apply
 134  *
 135  * Draws the given drawing operation on the given Cairo context.
 136  **/
 137 void
 138 swfdec_draw_paint (SwfdecDraw *draw, cairo_t *cr, const SwfdecColorTransform *trans)
 139 {
 140   SwfdecDrawClass *klass;
 141
 142   g_return_if_fail (SWFDEC_IS_DRAW (draw));
 143   g_return_if_fail (draw->path.num_data > 0);
 144   g_return_if_fail (cr != NULL);
 145   g_return_if_fail (trans != NULL);
 146
 147   klass = SWFDEC_DRAW_GET_CLASS (draw);
 148   g_assert (klass->paint);
 149   klass->paint (draw, cr, trans);
 150 }
 151
 152 static gpointer
 153 swfdec_draw_init_empty_surface (gpointer unused)
 154 {
 155   return cairo_image_surface_create (CAIRO_FORMAT_A1, 1, 1);
 156 }
 157
 158 /**
 159  * swfdec_draw_contains:
 160  * @draw: a #SwfdecDraw
 161  * @x: x coordinate to check
 162  * @y: y coordinate to check
 163  *
 164  * Checks if the given @x and @y coordinate is inside or outside the area drawn
 165  * by the given drawing operation.
 166  *
 167  * Returns: %TRUE if the coordinates are inside the drawing operation.
 168  **/
 169 gboolean
 170 swfdec_draw_contains (SwfdecDraw *draw, double x, double y)
 171 {
 172   static GOnce empty_surface = G_ONCE_INIT;
 173   SwfdecDrawClass *klass;
 174   cairo_t *cr;
 175   gboolean result;
 176
 177   g_return_val_if_fail (SWFDEC_IS_DRAW (draw), FALSE);
 178
 179   if (!swfdec_rect_contains (&draw->extents, x, y))
 180     return FALSE;
 181
 182   g_once (&empty_surface, swfdec_draw_init_empty_surface, NULL);
 183
 184   klass = SWFDEC_DRAW_GET_CLASS (draw);
 185   g_assert (klass->contains);
 186   cr = cairo_create (empty_surface.retval);
 187   result = klass->contains (draw, cr, x, y);
 188   cairo_destroy (cr);
 189   return result;
 190 }
 191
 192 /**
 193  * swfdec_draw_recompute:
 194  * @draw: a #SwfdecDraw
 195  *
 196  * This function must be called after a call to swfdec_draw_append_path() but
 197  * before using swfdec_draw_paint() again. It updates internal state and caches,
 198  * in particular the extents of this drawing operation.
 199  **/
 200 void
 201 swfdec_draw_recompute (SwfdecDraw *draw)
 202 {
 203   SwfdecDrawClass *klass;
 204
 205   g_return_if_fail (SWFDEC_IS_DRAW (draw));
 206
 207   klass = SWFDEC_DRAW_GET_CLASS (draw);
 208   g_assert (klass->compute_extents);
 209   klass->compute_extents (draw);
 210 }