libswfdec/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 void
  36 swfdec_draw_do_morph (SwfdecDraw* dest, SwfdecDraw *source, guint ratio)
  37 {
  38   swfdec_path_merge (&dest->path, &source->path, &source->end_path, ratio / 65535.);
  39 }
  40
  41 static void
  42 swfdec_draw_dispose (GObject *object)
  43 {
  44   SwfdecDraw *draw = SWFDEC_DRAW (object);
  45
  46   swfdec_path_reset (&draw->path);
  47   swfdec_path_reset (&draw->end_path);
  48
  49   G_OBJECT_CLASS (swfdec_draw_parent_class)->dispose (object);
  50 }
  51
  52 static void
  53 swfdec_draw_class_init (SwfdecDrawClass *klass)
  54 {
  55   GObjectClass *object_class = G_OBJECT_CLASS (klass);
  56
  57   object_class->dispose = swfdec_draw_dispose;
  58
  59   klass->morph = swfdec_draw_do_morph;
  60 }
  61
  62 static void
  63 swfdec_draw_init (SwfdecDraw *draw)
  64 {
  65   swfdec_path_init (&draw->path);
  66   swfdec_path_init (&draw->end_path);
  67 }
  68
  69 static gboolean
  70 swfdec_draw_can_morph (SwfdecDraw *draw)
  71 {
  72   return draw->end_path.num_data > 0;
  73 }
  74
  75 /**
  76  * swfdec_draw_morph:
  77  * @draw: a #SwfdecDraw
  78  * @ratio: ratio of the morph from 0 to 65535
  79  *
  80  * Applies a morph to the given drawing operation. If the drawing operation
  81  * can not be morphed, it is returned unchanged. Otherwise a new drawing
  82  * operation is created.
  83  *
  84  * Returns: a new reference to a #SwfdecDraw corresponding to the given morph
  85  *          ratio
  86  **/
  87 SwfdecDraw *
  88 swfdec_draw_morph (SwfdecDraw *draw, guint ratio)
  89 {
  90   SwfdecDrawClass *klass;
  91   SwfdecDraw *copy;
  92
  93   g_return_val_if_fail (SWFDEC_IS_DRAW (draw), NULL);
  94   g_return_val_if_fail (ratio < 65536, NULL);
  95
  96   if (!swfdec_draw_can_morph (draw) || ratio == 0) {
  97     /* not a morph */
  98     g_object_ref (draw);
  99     return draw;
 100   }
 101   klass = SWFDEC_DRAW_GET_CLASS (draw);
 102   g_assert (klass->morph);
 103   copy = g_object_new (G_OBJECT_CLASS_TYPE (klass), NULL);
 104   klass->morph (copy, draw, ratio);
 105   swfdec_draw_recompute (copy);
 106   return copy;
 107 }
 108
 109 /**
 110  * swfdec_draw_paint:
 111  * @draw: drawing operation to perform
 112  * @cr: context to perform the operation on
 113  * @trans: color transofrmation to apply
 114  *
 115  * Draws the given drawing operation on the given Cairo context.
 116  **/
 117 void
 118 swfdec_draw_paint (SwfdecDraw *draw, cairo_t *cr, const SwfdecColorTransform *trans)
 119 {
 120   SwfdecDrawClass *klass;
 121
 122   g_return_if_fail (SWFDEC_IS_DRAW (draw));
 123   g_return_if_fail (draw->path.num_data > 0);
 124   g_return_if_fail (cr != NULL);
 125   g_return_if_fail (trans != NULL);
 126
 127   klass = SWFDEC_DRAW_GET_CLASS (draw);
 128   g_assert (klass->paint);
 129   klass->paint (draw, cr, trans);
 130 }
 131
 132 static gpointer
 133 swfdec_draw_init_empty_surface (gpointer unused)
 134 {
 135   return cairo_image_surface_create (CAIRO_FORMAT_A1, 1, 1);
 136 }
 137
 138 /**
 139  * swfdec_draw_contains:
 140  * @draw: a #SwfdecDraw
 141  * @x: x coordinate to check
 142  * @y: y coordinate to check
 143  *
 144  * Checks if the given @x and @y coordinate is inside or outside the area drawn
 145  * by the given drawing operation.
 146  *
 147  * Returns: %TRUE if the coordinates are inside the drawing operation.
 148  **/
 149 gboolean
 150 swfdec_draw_contains (SwfdecDraw *draw, double x, double y)
 151 {
 152   static GOnce empty_surface = G_ONCE_INIT;
 153   SwfdecDrawClass *klass;
 154   cairo_t *cr;
 155   gboolean result;
 156
 157   g_return_val_if_fail (SWFDEC_IS_DRAW (draw), FALSE);
 158
 159   if (!swfdec_rect_contains (&draw->extents, x, y))
 160     return FALSE;
 161
 162   g_once (&empty_surface, swfdec_draw_init_empty_surface, NULL);
 163
 164   klass = SWFDEC_DRAW_GET_CLASS (draw);
 165   g_assert (klass->contains);
 166   cr = cairo_create (empty_surface.retval);
 167   result = klass->contains (draw, cr, x, y);
 168   cairo_destroy (cr);
 169   return result;
 170 }
 171
 172 /**
 173  * swfdec_draw_recompute:
 174  * @draw: a #SwfdecDraw
 175  *
 176  * This function must be called after a call to swfdec_draw_append_path() but
 177  * before using swfdec_draw_paint() again. It updates internal state and caches,
 178  * in particular the extents of this drawing operation.
 179  **/
 180 void
 181 swfdec_draw_recompute (SwfdecDraw *draw)
 182 {
 183   SwfdecDrawClass *klass;
 184
 185   g_return_if_fail (SWFDEC_IS_DRAW (draw));
 186
 187   klass = SWFDEC_DRAW_GET_CLASS (draw);
 188   g_assert (klass->compute_extents);
 189   klass->compute_extents (draw);
 190 }