gdk-pixbuf/io-gif-animation.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */
   2 /* GdkPixbuf library - animated gif support
   3  *
   4  * Copyright (C) 1999 The Free Software Foundation
   5  *
   6  * Authors: Jonathan Blandford <jrb@redhat.com>
   7  *          Havoc Pennington <hp@redhat.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the
  21  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22  * Boston, MA 02111-1307, USA.
  23  */
  24
  25 #include "config.h"
  26 #include <errno.h>
  27 #include "gdk-pixbuf-private.h"
  28 #include "io-gif-animation.h"
  29
  30 static void gdk_pixbuf_gif_anim_class_init (GdkPixbufGifAnimClass *klass);
  31 static void gdk_pixbuf_gif_anim_finalize   (GObject        *object);
  32
  33 static gboolean                gdk_pixbuf_gif_anim_is_static_image  (GdkPixbufAnimation *animation);
  34 static GdkPixbuf*              gdk_pixbuf_gif_anim_get_static_image (GdkPixbufAnimation *animation);
  35
  36 static void                    gdk_pixbuf_gif_anim_get_size (GdkPixbufAnimation *anim,
  37                                                              int                *width,
  38                                                              int                *height);
  39 static GdkPixbufAnimationIter* gdk_pixbuf_gif_anim_get_iter (GdkPixbufAnimation *anim,
  40                                                              const GTimeVal     *start_time);
  41
  42
  43 \f
  44
  45 static gpointer parent_class;
  46
  47 GType
  48 gdk_pixbuf_gif_anim_get_type (void)
  49 {
  50         static GType object_type = 0;
  51
  52         if (!object_type) {
  53                 static const GTypeInfo object_info = {
  54                         sizeof (GdkPixbufGifAnimClass),
  55                         (GBaseInitFunc) NULL,
  56                         (GBaseFinalizeFunc) NULL,
  57                         (GClassInitFunc) gdk_pixbuf_gif_anim_class_init,
  58                         NULL,           /* class_finalize */
  59                         NULL,           /* class_data */
  60                         sizeof (GdkPixbufGifAnim),
  61                         0,              /* n_preallocs */
  62                         (GInstanceInitFunc) NULL,
  63                 };
  64
  65                 object_type = g_type_register_static (GDK_TYPE_PIXBUF_ANIMATION,
  66                                                       g_intern_static_string ("GdkPixbufGifAnim"),
  67                                                       &object_info, 0);
  68         }
  69
  70         return object_type;
  71 }
  72
  73 static void
  74 gdk_pixbuf_gif_anim_class_init (GdkPixbufGifAnimClass *klass)
  75 {
  76         GObjectClass *object_class = G_OBJECT_CLASS (klass);
  77         GdkPixbufAnimationClass *anim_class = GDK_PIXBUF_ANIMATION_CLASS (klass);
  78
  79         parent_class = g_type_class_peek_parent (klass);
  80
  81         object_class->finalize = gdk_pixbuf_gif_anim_finalize;
  82
  83         anim_class->is_static_image = gdk_pixbuf_gif_anim_is_static_image;
  84         anim_class->get_static_image = gdk_pixbuf_gif_anim_get_static_image;
  85         anim_class->get_size = gdk_pixbuf_gif_anim_get_size;
  86         anim_class->get_iter = gdk_pixbuf_gif_anim_get_iter;
  87 }
  88
  89 static void
  90 gdk_pixbuf_gif_anim_finalize (GObject *object)
  91 {
  92         GdkPixbufGifAnim *gif_anim = GDK_PIXBUF_GIF_ANIM (object);
  93
  94         GList *l;
  95         GdkPixbufFrame *frame;
  96
  97         for (l = gif_anim->frames; l; l = l->next) {
  98                 frame = l->data;
  99                 g_object_unref (frame->pixbuf);
 100                 if (frame->composited)
 101                         g_object_unref (frame->composited);
 102                 if (frame->revert)
 103                         g_object_unref (frame->revert);
 104                 g_free (frame);
 105         }
 106
 107         g_list_free (gif_anim->frames);
 108
 109         G_OBJECT_CLASS (parent_class)->finalize (object);
 110 }
 111
 112 static gboolean
 113 gdk_pixbuf_gif_anim_is_static_image  (GdkPixbufAnimation *animation)
 114 {
 115         GdkPixbufGifAnim *gif_anim;
 116
 117         gif_anim = GDK_PIXBUF_GIF_ANIM (animation);
 118
 119         return (gif_anim->frames != NULL &&
 120                 gif_anim->frames->next == NULL);
 121 }
 122
 123 static GdkPixbuf*
 124 gdk_pixbuf_gif_anim_get_static_image (GdkPixbufAnimation *animation)
 125 {
 126         GdkPixbufGifAnim *gif_anim;
 127
 128         gif_anim = GDK_PIXBUF_GIF_ANIM (animation);
 129
 130         if (gif_anim->frames == NULL)
 131                 return NULL;
 132         else
 133                 return GDK_PIXBUF (((GdkPixbufFrame*)gif_anim->frames->data)->pixbuf);
 134 }
 135
 136 static void
 137 gdk_pixbuf_gif_anim_get_size (GdkPixbufAnimation *anim,
 138                               int                *width,
 139                               int                *height)
 140 {
 141         GdkPixbufGifAnim *gif_anim;
 142
 143         gif_anim = GDK_PIXBUF_GIF_ANIM (anim);
 144
 145         if (width)
 146                 *width = gif_anim->width;
 147
 148         if (height)
 149                 *height = gif_anim->height;
 150 }
 151
 152
 153 static void
 154 iter_clear (GdkPixbufGifAnimIter *iter)
 155 {
 156         iter->current_frame = NULL;
 157 }
 158
 159 static void
 160 iter_restart (GdkPixbufGifAnimIter *iter)
 161 {
 162         iter_clear (iter);
 163
 164         iter->current_frame = iter->gif_anim->frames;
 165 }
 166
 167 static GdkPixbufAnimationIter*
 168 gdk_pixbuf_gif_anim_get_iter (GdkPixbufAnimation *anim,
 169                               const GTimeVal     *start_time)
 170 {
 171         GdkPixbufGifAnimIter *iter;
 172
 173         iter = g_object_new (GDK_TYPE_PIXBUF_GIF_ANIM_ITER, NULL);
 174
 175         iter->gif_anim = GDK_PIXBUF_GIF_ANIM (anim);
 176
 177         g_object_ref (iter->gif_anim);
 178
 179         iter_restart (iter);
 180
 181         iter->start_time = *start_time;
 182         iter->current_time = *start_time;
 183         iter->first_loop_slowness = 0;
 184
 185         return GDK_PIXBUF_ANIMATION_ITER (iter);
 186 }
 187
 188 \f
 189
 190 static void gdk_pixbuf_gif_anim_iter_class_init (GdkPixbufGifAnimIterClass *klass);
 191 static void gdk_pixbuf_gif_anim_iter_finalize   (GObject                   *object);
 192
 193 static int        gdk_pixbuf_gif_anim_iter_get_delay_time             (GdkPixbufAnimationIter *iter);
 194 static GdkPixbuf* gdk_pixbuf_gif_anim_iter_get_pixbuf                 (GdkPixbufAnimationIter *iter);
 195 static gboolean   gdk_pixbuf_gif_anim_iter_on_currently_loading_frame (GdkPixbufAnimationIter *iter);
 196 static gboolean   gdk_pixbuf_gif_anim_iter_advance                    (GdkPixbufAnimationIter *iter,
 197                                                                        const GTimeVal         *current_time);
 198
 199 \f
 200
 201 static gpointer iter_parent_class;
 202
 203 GType
 204 gdk_pixbuf_gif_anim_iter_get_type (void)
 205 {
 206         static GType object_type = 0;
 207
 208         if (!object_type) {
 209                 static const GTypeInfo object_info = {
 210                         sizeof (GdkPixbufGifAnimIterClass),
 211                         (GBaseInitFunc) NULL,
 212                         (GBaseFinalizeFunc) NULL,
 213                         (GClassInitFunc) gdk_pixbuf_gif_anim_iter_class_init,
 214                         NULL,           /* class_finalize */
 215                         NULL,           /* class_data */
 216                         sizeof (GdkPixbufGifAnimIter),
 217                         0,              /* n_preallocs */
 218                         (GInstanceInitFunc) NULL,
 219                 };
 220
 221                 object_type = g_type_register_static (GDK_TYPE_PIXBUF_ANIMATION_ITER,
 222                                                       g_intern_static_string ("GdkPixbufGifAnimIter"),
 223                                                       &object_info, 0);
 224         }
 225
 226         return object_type;
 227 }
 228
 229 static void
 230 gdk_pixbuf_gif_anim_iter_class_init (GdkPixbufGifAnimIterClass *klass)
 231 {
 232         GObjectClass *object_class = G_OBJECT_CLASS (klass);
 233         GdkPixbufAnimationIterClass *anim_iter_class =
 234                 GDK_PIXBUF_ANIMATION_ITER_CLASS (klass);
 235
 236         iter_parent_class = g_type_class_peek_parent (klass);
 237
 238         object_class->finalize = gdk_pixbuf_gif_anim_iter_finalize;
 239
 240         anim_iter_class->get_delay_time = gdk_pixbuf_gif_anim_iter_get_delay_time;
 241         anim_iter_class->get_pixbuf = gdk_pixbuf_gif_anim_iter_get_pixbuf;
 242         anim_iter_class->on_currently_loading_frame = gdk_pixbuf_gif_anim_iter_on_currently_loading_frame;
 243         anim_iter_class->advance = gdk_pixbuf_gif_anim_iter_advance;
 244 }
 245
 246 static void
 247 gdk_pixbuf_gif_anim_iter_finalize (GObject *object)
 248 {
 249         GdkPixbufGifAnimIter *iter = GDK_PIXBUF_GIF_ANIM_ITER (object);
 250
 251         iter_clear (iter);
 252
 253         g_object_unref (iter->gif_anim);
 254
 255         G_OBJECT_CLASS (iter_parent_class)->finalize (object);
 256 }
 257
 258 static gboolean
 259 gdk_pixbuf_gif_anim_iter_advance (GdkPixbufAnimationIter *anim_iter,
 260                                   const GTimeVal         *current_time)
 261 {
 262         GdkPixbufGifAnimIter *iter;
 263         gint elapsed;
 264         gint loop;
 265         GList *tmp;
 266         GList *old;
 267
 268         iter = GDK_PIXBUF_GIF_ANIM_ITER (anim_iter);
 269
 270         iter->current_time = *current_time;
 271
 272         /* We use milliseconds for all times */
 273         elapsed =
 274           (((iter->current_time.tv_sec - iter->start_time.tv_sec) * G_USEC_PER_SEC +
 275             iter->current_time.tv_usec - iter->start_time.tv_usec)) / 1000;
 276
 277         if (elapsed < 0) {
 278                 /* Try to compensate; probably the system clock
 279                  * was set backwards
 280                  */
 281                 iter->start_time = iter->current_time;
 282                 elapsed = 0;
 283         }
 284
 285         g_assert (iter->gif_anim->total_time > 0);
 286
 287         /* See how many times we've already played the full animation,
 288          * and subtract time for that.
 289          */
 290
 291         if (iter->gif_anim->loading)
 292                 loop = 0;
 293         else {
 294                 /* If current_frame is NULL at this point, we have loaded the
 295                  * animation from a source which fell behind the speed of the
 296                  * display. We remember how much slower the first loop was due
 297                  * to this and correct the position calculation in order to not
 298                  * jump in the middle of the second loop.
 299                  */
 300                 if (iter->current_frame == NULL)
 301                         iter->first_loop_slowness = MAX(0, elapsed - iter->gif_anim->total_time);
 302
 303                 loop = (elapsed - iter->first_loop_slowness) / iter->gif_anim->total_time;
 304                 elapsed = (elapsed - iter->first_loop_slowness) % iter->gif_anim->total_time;
 305         }
 306
 307         iter->position = elapsed;
 308
 309         /* Now move to the proper frame */
 310         if (iter->gif_anim->loop == 0 || loop < iter->gif_anim->loop)
 311                 tmp = iter->gif_anim->frames;
 312         else
 313                 tmp = NULL;
 314         while (tmp != NULL) {
 315                 GdkPixbufFrame *frame = tmp->data;
 316
 317                 if (iter->position >= frame->elapsed &&
 318                     iter->position < (frame->elapsed + frame->delay_time))
 319                         break;
 320
 321                 tmp = tmp->next;
 322         }
 323
 324         old = iter->current_frame;
 325
 326         iter->current_frame = tmp;
 327
 328         return iter->current_frame != old;
 329 }
 330
 331 int
 332 gdk_pixbuf_gif_anim_iter_get_delay_time (GdkPixbufAnimationIter *anim_iter)
 333 {
 334         GdkPixbufFrame *frame;
 335         GdkPixbufGifAnimIter *iter;
 336
 337         iter = GDK_PIXBUF_GIF_ANIM_ITER (anim_iter);
 338
 339         if (iter->current_frame) {
 340                 frame = iter->current_frame->data;
 341
 342 #if 0
 343                 g_print ("frame start: %d pos: %d frame len: %d frame remaining: %d\n",
 344                          frame->elapsed,
 345                          iter->position,
 346                          frame->delay_time,
 347                          frame->delay_time - (iter->position - frame->elapsed));
 348 #endif
 349
 350                 return frame->delay_time - (iter->position - frame->elapsed);
 351         } else
 352                 return -1; /* show last frame forever */
 353 }
 354
 355 void
 356 gdk_pixbuf_gif_anim_frame_composite (GdkPixbufGifAnim *gif_anim,
 357                                      GdkPixbufFrame   *frame)
 358 {
 359         GList *link;
 360         GList *tmp;
 361
 362         link = g_list_find (gif_anim->frames, frame);
 363
 364         if (frame->need_recomposite || frame->composited == NULL) {
 365                 /* For now, to composite we start with the last
 366                  * composited frame and composite everything up to
 367                  * here.
 368                  */
 369
 370                 /* Rewind to last composited frame. */
 371                 tmp = link;
 372                 while (tmp != NULL) {
 373                         GdkPixbufFrame *f = tmp->data;
 374
 375                         if (f->need_recomposite) {
 376                                 if (f->composited) {
 377                                         g_object_unref (f->composited);
 378                                         f->composited = NULL;
 379                                 }
 380                         }
 381
 382                         if (f->composited != NULL)
 383                                 break;
 384
 385                         tmp = tmp->prev;
 386                 }
 387
 388                 /* Go forward, compositing all frames up to the current frame */
 389                 if (tmp == NULL)
 390                         tmp = gif_anim->frames;
 391
 392                 while (tmp != NULL) {
 393                         GdkPixbufFrame *f = tmp->data;
 394                         gint clipped_width, clipped_height;
 395
 396                         if (f->pixbuf == NULL)
 397                                 return;
 398
 399                         clipped_width = MIN (gif_anim->width - f->x_offset, gdk_pixbuf_get_width (f->pixbuf));
 400                         clipped_height = MIN (gif_anim->height - f->y_offset, gdk_pixbuf_get_height (f->pixbuf));
 401
 402                         if (f->need_recomposite) {
 403                                 if (f->composited) {
 404                                         g_object_unref (f->composited);
 405                                         f->composited = NULL;
 406                                 }
 407                         }
 408
 409                         if (f->composited != NULL)
 410                                 goto next;
 411
 412                         if (tmp->prev == NULL) {
 413                                 /* First frame may be smaller than the whole image;
 414                                  * if so, we make the area outside it full alpha if the
 415                                  * image has alpha, and background color otherwise.
 416                                  * GIF spec doesn't actually say what to do about this.
 417                                  */
 418                                 f->composited = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
 419                                                                 TRUE,
 420                                                                 8, gif_anim->width, gif_anim->height);
 421
 422                                 if (f->composited == NULL)
 423                                         return;
 424
 425                                 /* alpha gets dumped if f->composited has no alpha */
 426
 427                                 gdk_pixbuf_fill (f->composited,
 428                                                  (gif_anim->bg_red << 24) |
 429                                                  (gif_anim->bg_green << 16) |
 430                                                  (gif_anim->bg_blue << 8));
 431
 432                                 if (clipped_width > 0 && clipped_height > 0)
 433                                         gdk_pixbuf_composite (f->pixbuf,
 434                                                               f->composited,
 435                                                               f->x_offset,
 436                                                               f->y_offset,
 437                                                               clipped_width,
 438                                                               clipped_height,
 439                                                               f->x_offset, f->y_offset,
 440                                                               1.0, 1.0,
 441                                                               GDK_INTERP_BILINEAR,
 442                                                               255);
 443
 444                                 if (f->action == GDK_PIXBUF_FRAME_REVERT)
 445                                         g_warning ("First frame of GIF has bad dispose mode, GIF loader should not have loaded this image");
 446
 447                                 f->need_recomposite = FALSE;
 448                         } else {
 449                                 GdkPixbufFrame *prev_frame;
 450                                 gint prev_clipped_width;
 451                                 gint prev_clipped_height;
 452
 453                                 prev_frame = tmp->prev->data;
 454
 455                                 prev_clipped_width = MIN (gif_anim->width - prev_frame->x_offset, gdk_pixbuf_get_width (prev_frame->pixbuf));
 456                                 prev_clipped_height = MIN (gif_anim->height - prev_frame->y_offset, gdk_pixbuf_get_height (prev_frame->pixbuf));
 457
 458                                 /* Init f->composited with what we should have after the previous
 459                                  * frame
 460                                  */
 461
 462                                 if (prev_frame->action == GDK_PIXBUF_FRAME_RETAIN) {
 463                                         f->composited = gdk_pixbuf_copy (prev_frame->composited);
 464
 465                                         if (f->composited == NULL)
 466                                                 return;
 467
 468                                 } else if (prev_frame->action == GDK_PIXBUF_FRAME_DISPOSE) {
 469                                         f->composited = gdk_pixbuf_copy (prev_frame->composited);
 470
 471                                         if (f->composited == NULL)
 472                                                 return;
 473
 474                                         if (prev_clipped_width > 0 && prev_clipped_height > 0) {
 475                                                 /* Clear area of previous frame to background */
 476                                                 GdkPixbuf *area;
 477
 478                                                 area = gdk_pixbuf_new_subpixbuf (f->composited,
 479                                                                                  prev_frame->x_offset,
 480                                                                                  prev_frame->y_offset,
 481                                                                                  prev_clipped_width,
 482                                                                                  prev_clipped_height);
 483
 484                                                 if (area == NULL)
 485                                                         return;
 486
 487                                                 gdk_pixbuf_fill (area,
 488                                                                  (gif_anim->bg_red << 24) |
 489                                                                  (gif_anim->bg_green << 16) |
 490                                                                  (gif_anim->bg_blue << 8));
 491
 492                                                 g_object_unref (area);
 493                                         }
 494                                 } else if (prev_frame->action == GDK_PIXBUF_FRAME_REVERT) {
 495                                         f->composited = gdk_pixbuf_copy (prev_frame->composited);
 496
 497                                         if (f->composited == NULL)
 498                                                 return;
 499
 500                                         if (prev_frame->revert != NULL &&
 501                                             prev_clipped_width > 0 && prev_clipped_height > 0) {
 502                                                 /* Copy in the revert frame */
 503                                                 gdk_pixbuf_copy_area (prev_frame->revert,
 504                                                                       0, 0,
 505                                                                       gdk_pixbuf_get_width (prev_frame->revert),
 506                                                                       gdk_pixbuf_get_height (prev_frame->revert),
 507                                                                       f->composited,
 508                                                                       prev_frame->x_offset,
 509                                                                       prev_frame->y_offset);
 510                                         }
 511                                 } else {
 512                                         g_warning ("Unknown revert action for GIF frame");
 513                                 }
 514
 515                                 if (f->revert == NULL &&
 516                                     f->action == GDK_PIXBUF_FRAME_REVERT) {
 517                                         if (clipped_width > 0 && clipped_height > 0) {
 518                                                 /* We need to save the contents before compositing */
 519                                                 GdkPixbuf *area;
 520
 521                                                 area = gdk_pixbuf_new_subpixbuf (f->composited,
 522                                                                                  f->x_offset,
 523                                                                                  f->y_offset,
 524                                                                                  clipped_width,
 525                                                                                  clipped_height);
 526
 527                                                 if (area == NULL)
 528                                                         return;
 529
 530                                                 f->revert = gdk_pixbuf_copy (area);
 531
 532                                                 g_object_unref (area);
 533
 534                                                 if (f->revert == NULL)
 535                                                         return;
 536                                         }
 537                                 }
 538
 539                                 if (clipped_width > 0 && clipped_height > 0 &&
 540                                     f->pixbuf != NULL && f->composited != NULL) {
 541                                         /* Put current frame onto f->composited */
 542                                         gdk_pixbuf_composite (f->pixbuf,
 543                                                               f->composited,
 544                                                               f->x_offset,
 545                                                               f->y_offset,
 546                                                               clipped_width,
 547                                                               clipped_height,
 548                                                               f->x_offset, f->y_offset,
 549                                                               1.0, 1.0,
 550                                                               GDK_INTERP_NEAREST,
 551                                                               255);
 552                                 }
 553
 554                                 f->need_recomposite = FALSE;
 555                         }
 556
 557                 next:
 558                         if (tmp == link)
 559                                 break;
 560
 561                         tmp = tmp->next;
 562                 }
 563         }
 564 }
 565
 566 GdkPixbuf*
 567 gdk_pixbuf_gif_anim_iter_get_pixbuf (GdkPixbufAnimationIter *anim_iter)
 568 {
 569         GdkPixbufGifAnimIter *iter;
 570         GdkPixbufFrame *frame;
 571
 572         iter = GDK_PIXBUF_GIF_ANIM_ITER (anim_iter);
 573
 574         frame = iter->current_frame ? iter->current_frame->data : g_list_last (iter->gif_anim->frames)->data;
 575
 576 #if 0
 577         if (FALSE && frame)
 578           g_print ("current frame %d dispose mode %d  %d x %d\n",
 579                    g_list_index (iter->gif_anim->frames,
 580                                  frame),
 581                    frame->action,
 582                    gdk_pixbuf_get_width (frame->pixbuf),
 583                    gdk_pixbuf_get_height (frame->pixbuf));
 584 #endif
 585
 586         if (frame == NULL)
 587                 return NULL;
 588
 589         gdk_pixbuf_gif_anim_frame_composite (iter->gif_anim, frame);
 590
 591         return frame->composited;
 592 }
 593
 594 static gboolean
 595 gdk_pixbuf_gif_anim_iter_on_currently_loading_frame (GdkPixbufAnimationIter *anim_iter)
 596 {
 597         GdkPixbufGifAnimIter *iter;
 598
 599         iter = GDK_PIXBUF_GIF_ANIM_ITER (anim_iter);
 600
 601         return iter->current_frame == NULL || iter->current_frame->next == NULL;
 602 }