src/cairo-surface-subsurface.c

   1 /* cairo - a vector graphics library with display and print output
   2  *
   3  * Copyright © 2009 Intel Corporation
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it either under the terms of the GNU Lesser General Public
   7  * License version 2.1 as published by the Free Software Foundation
   8  * (the "LGPL") or, at your option, under the terms of the Mozilla
   9  * Public License Version 1.1 (the "MPL"). If you do not alter this
  10  * notice, a recipient may use your version of this file under either
  11  * the MPL or the LGPL.
  12  *
  13  * You should have received a copy of the LGPL along with this library
  14  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  16  * You should have received a copy of the MPL along with this library
  17  * in the file COPYING-MPL-1.1
  18  *
  19  * The contents of this file are subject to the Mozilla Public License
  20  * Version 1.1 (the "License"); you may not use this file except in
  21  * compliance with the License. You may obtain a copy of the License at
  22  * http://www.mozilla.org/MPL/
  23  *
  24  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  25  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  26  * the specific language governing rights and limitations.
  27  *
  28  * The Original Code is the cairo graphics library.
  29  *
  30  * The Initial Developer of the Original Code is Intel Corporation.
  31  *
  32  * Contributor(s):
  33  *      Chris Wilson <chris@chris-wilson.co.uk>
  34  */
  35
  36 #include "cairoint.h"
  37
  38 #include "cairo-clip-inline.h"
  39 #include "cairo-error-private.h"
  40 #include "cairo-image-surface-private.h"
  41 #include "cairo-recording-surface-private.h"
  42 #include "cairo-surface-offset-private.h"
  43 #include "cairo-surface-snapshot-private.h"
  44 #include "cairo-surface-subsurface-private.h"
  45
  46 static const cairo_surface_backend_t _cairo_surface_subsurface_backend;
  47
  48 static cairo_status_t
  49 _cairo_surface_subsurface_finish (void *abstract_surface)
  50 {
  51     cairo_surface_subsurface_t *surface = abstract_surface;
  52
  53     cairo_surface_destroy (surface->target);
  54     cairo_surface_destroy (surface->snapshot);
  55
  56     return CAIRO_STATUS_SUCCESS;
  57 }
  58
  59 static cairo_surface_t *
  60 _cairo_surface_subsurface_create_similar (void *other,
  61                                           cairo_content_t content,
  62                                           int width, int height)
  63 {
  64     cairo_surface_subsurface_t *surface = other;
  65
  66     if (surface->target->backend->create_similar == NULL)
  67         return NULL;
  68
  69     return surface->target->backend->create_similar (surface->target, content, width, height);
  70 }
  71
  72 static cairo_surface_t *
  73 _cairo_surface_subsurface_create_similar_image (void *other,
  74                                                 cairo_format_t format,
  75                                                 int width, int height)
  76 {
  77     cairo_surface_subsurface_t *surface = other;
  78
  79     if (surface->target->backend->create_similar_image == NULL)
  80         return NULL;
  81
  82     return surface->target->backend->create_similar_image (surface->target,
  83                                                            format,
  84                                                            width, height);
  85 }
  86
  87 static cairo_surface_t *
  88 _cairo_surface_subsurface_map_to_image (void *abstract_surface,
  89                                         const cairo_rectangle_int_t *extents)
  90 {
  91     cairo_surface_subsurface_t *surface = abstract_surface;
  92     cairo_rectangle_int_t target_extents;
  93
  94     if (surface->target->backend->map_to_image == NULL)
  95         return NULL;
  96
  97     target_extents.x = extents->x + surface->extents.x;
  98     target_extents.y = extents->y + surface->extents.y;
  99     target_extents.width  = extents->width;
 100     target_extents.height = extents->height;
 101
 102     return surface->target->backend->map_to_image (surface->target,
 103                                                    &target_extents);
 104 }
 105
 106 static cairo_int_status_t
 107 _cairo_surface_subsurface_unmap_image (void *abstract_surface,
 108                                        cairo_image_surface_t *image)
 109 {
 110     cairo_surface_subsurface_t *surface = abstract_surface;
 111
 112     if (surface->target->backend->unmap_image == NULL)
 113         return CAIRO_INT_STATUS_UNSUPPORTED;
 114
 115     return surface->target->backend->unmap_image (surface->target, image);
 116 }
 117
 118 static cairo_int_status_t
 119 _cairo_surface_subsurface_paint (void *abstract_surface,
 120                                  cairo_operator_t op,
 121                                  const cairo_pattern_t *source,
 122                                  const cairo_clip_t *clip)
 123 {
 124     cairo_surface_subsurface_t *surface = abstract_surface;
 125     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 126     cairo_status_t status;
 127     cairo_clip_t *target_clip;
 128
 129     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 130     status = _cairo_surface_offset_paint (surface->target,
 131                                          -surface->extents.x, -surface->extents.y,
 132                                           op, source, target_clip);
 133     _cairo_clip_destroy (target_clip);
 134     return status;
 135 }
 136
 137 static cairo_int_status_t
 138 _cairo_surface_subsurface_mask (void *abstract_surface,
 139                                 cairo_operator_t op,
 140                                 const cairo_pattern_t *source,
 141                                 const cairo_pattern_t *mask,
 142                                 const cairo_clip_t *clip)
 143 {
 144     cairo_surface_subsurface_t *surface = abstract_surface;
 145     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 146     cairo_status_t status;
 147     cairo_clip_t *target_clip;
 148
 149     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 150     status = _cairo_surface_offset_mask (surface->target,
 151                                          -surface->extents.x, -surface->extents.y,
 152                                          op, source, mask, target_clip);
 153     _cairo_clip_destroy (target_clip);
 154     return status;
 155 }
 156
 157 static cairo_int_status_t
 158 _cairo_surface_subsurface_fill (void                    *abstract_surface,
 159                                 cairo_operator_t         op,
 160                                 const cairo_pattern_t   *source,
 161                                 const cairo_path_fixed_t        *path,
 162                                 cairo_fill_rule_t        fill_rule,
 163                                 double                   tolerance,
 164                                 cairo_antialias_t        antialias,
 165                                 const cairo_clip_t              *clip)
 166 {
 167     cairo_surface_subsurface_t *surface = abstract_surface;
 168     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 169     cairo_status_t status;
 170     cairo_clip_t *target_clip;
 171
 172     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 173     status = _cairo_surface_offset_fill (surface->target,
 174                                          -surface->extents.x, -surface->extents.y,
 175                                          op, source, path, fill_rule, tolerance, antialias,
 176                                          target_clip);
 177     _cairo_clip_destroy (target_clip);
 178     return status;
 179 }
 180
 181 static cairo_int_status_t
 182 _cairo_surface_subsurface_stroke (void                          *abstract_surface,
 183                                   cairo_operator_t               op,
 184                                   const cairo_pattern_t         *source,
 185                                   const cairo_path_fixed_t              *path,
 186                                   const cairo_stroke_style_t    *stroke_style,
 187                                   const cairo_matrix_t          *ctm,
 188                                   const cairo_matrix_t          *ctm_inverse,
 189                                   double                         tolerance,
 190                                   cairo_antialias_t              antialias,
 191                                   const cairo_clip_t                    *clip)
 192 {
 193     cairo_surface_subsurface_t *surface = abstract_surface;
 194     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 195     cairo_status_t status;
 196     cairo_clip_t *target_clip;
 197
 198     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 199     status = _cairo_surface_offset_stroke (surface->target,
 200                                            -surface->extents.x, -surface->extents.y,
 201                                            op, source, path, stroke_style, ctm, ctm_inverse,
 202                                            tolerance, antialias,
 203                                            target_clip);
 204     _cairo_clip_destroy (target_clip);
 205     return status;
 206 }
 207
 208 static cairo_int_status_t
 209 _cairo_surface_subsurface_glyphs (void                  *abstract_surface,
 210                                   cairo_operator_t       op,
 211                                   const cairo_pattern_t *source,
 212                                   cairo_glyph_t         *glyphs,
 213                                   int                    num_glyphs,
 214                                   cairo_scaled_font_t   *scaled_font,
 215                                   const cairo_clip_t    *clip)
 216 {
 217     cairo_surface_subsurface_t *surface = abstract_surface;
 218     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 219     cairo_status_t status;
 220     cairo_clip_t *target_clip;
 221
 222     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 223     status = _cairo_surface_offset_glyphs (surface->target,
 224                                            -surface->extents.x, -surface->extents.y,
 225                                            op, source,
 226                                            scaled_font, glyphs, num_glyphs,
 227                                            target_clip);
 228     _cairo_clip_destroy (target_clip);
 229     return status;
 230 }
 231
 232 static cairo_status_t
 233 _cairo_surface_subsurface_flush (void *abstract_surface)
 234 {
 235     cairo_surface_subsurface_t *surface = abstract_surface;
 236
 237     cairo_surface_flush (surface->target);
 238     return surface->target->status;
 239 }
 240
 241 static cairo_status_t
 242 _cairo_surface_subsurface_mark_dirty (void *abstract_surface,
 243                                       int x, int y,
 244                                       int width, int height)
 245 {
 246     cairo_surface_subsurface_t *surface = abstract_surface;
 247     cairo_status_t status;
 248
 249     status = CAIRO_STATUS_SUCCESS;
 250     if (surface->target->backend->mark_dirty_rectangle != NULL) {
 251         cairo_rectangle_int_t rect, extents;
 252
 253         rect.x = x;
 254         rect.y = y;
 255         rect.width  = width;
 256         rect.height = height;
 257
 258         extents.x = extents.y = 0;
 259         extents.width  = surface->extents.width;
 260         extents.height = surface->extents.height;
 261
 262         if (_cairo_rectangle_intersect (&rect, &extents)) {
 263             status = surface->target->backend->mark_dirty_rectangle (surface->target,
 264                                                                      rect.x + surface->extents.x,
 265                                                                      rect.y + surface->extents.y,
 266                                                                      rect.width, rect.height);
 267         }
 268     }
 269
 270     return status;
 271 }
 272
 273 static cairo_bool_t
 274 _cairo_surface_subsurface_get_extents (void *abstract_surface,
 275                                        cairo_rectangle_int_t *extents)
 276 {
 277     cairo_surface_subsurface_t *surface = abstract_surface;
 278
 279     extents->x = 0;
 280     extents->y = 0;
 281     extents->width  = surface->extents.width;
 282     extents->height = surface->extents.height;
 283
 284     return TRUE;
 285 }
 286
 287 static void
 288 _cairo_surface_subsurface_get_font_options (void *abstract_surface,
 289                                             cairo_font_options_t *options)
 290 {
 291     cairo_surface_subsurface_t *surface = abstract_surface;
 292
 293     if (surface->target->backend->get_font_options != NULL)
 294         surface->target->backend->get_font_options (surface->target, options);
 295 }
 296
 297 static cairo_surface_t *
 298 _cairo_surface_subsurface_source (void *abstract_surface,
 299                                   cairo_rectangle_int_t *extents)
 300 {
 301     cairo_surface_subsurface_t *surface = abstract_surface;
 302     cairo_surface_t *source;
 303
 304     source = _cairo_surface_get_source (surface->target, extents);
 305     if (extents)
 306         *extents = surface->extents;
 307
 308     return source;
 309 }
 310
 311 static cairo_status_t
 312 _cairo_surface_subsurface_acquire_source_image (void                    *abstract_surface,
 313                                                 cairo_image_surface_t  **image_out,
 314                                                 void                   **extra_out)
 315 {
 316     cairo_surface_subsurface_t *surface = abstract_surface;
 317     cairo_surface_pattern_t pattern;
 318     cairo_surface_t *image;
 319     cairo_status_t status;
 320
 321     image = _cairo_image_surface_create_with_content (surface->base.content,
 322                                                       surface->extents.width,
 323                                                       surface->extents.height);
 324     if (unlikely (image->status))
 325         return image->status;
 326
 327     _cairo_pattern_init_for_surface (&pattern, surface->target);
 328     cairo_matrix_init_translate (&pattern.base.matrix,
 329                                  surface->extents.x,
 330                                  surface->extents.y);
 331     pattern.base.filter = CAIRO_FILTER_NEAREST;
 332     status = _cairo_surface_paint (image,
 333                                    CAIRO_OPERATOR_SOURCE,
 334                                    &pattern.base, NULL);
 335     _cairo_pattern_fini (&pattern.base);
 336     if (unlikely (status)) {
 337         cairo_surface_destroy (image);
 338         return status;
 339     }
 340
 341     *image_out = (cairo_image_surface_t *)image;
 342     *extra_out = NULL;
 343     return CAIRO_STATUS_SUCCESS;
 344 }
 345
 346 static void
 347 _cairo_surface_subsurface_release_source_image (void                   *abstract_surface,
 348                                                 cairo_image_surface_t  *image,
 349                                                 void                   *abstract_extra)
 350 {
 351     cairo_surface_destroy (&image->base);
 352 }
 353
 354 static cairo_surface_t *
 355 _cairo_surface_subsurface_snapshot (void *abstract_surface)
 356 {
 357     cairo_surface_subsurface_t *surface = abstract_surface;
 358     cairo_surface_pattern_t pattern;
 359     cairo_surface_t *clone;
 360     cairo_status_t status;
 361
 362     TRACE ((stderr, "%s: target=%d\n", __FUNCTION__, surface->target->unique_id));
 363
 364     clone = _cairo_surface_create_similar_scratch (surface->target,
 365                                                    surface->target->content,
 366                                                    surface->extents.width,
 367                                                    surface->extents.height);
 368     if (unlikely (clone->status))
 369         return clone;
 370
 371     _cairo_pattern_init_for_surface (&pattern, surface->target);
 372     cairo_matrix_init_translate (&pattern.base.matrix,
 373                                  surface->extents.x, surface->extents.y);
 374     pattern.base.filter = CAIRO_FILTER_NEAREST;
 375     status = _cairo_surface_paint (clone,
 376                                    CAIRO_OPERATOR_SOURCE,
 377                                    &pattern.base, NULL);
 378     _cairo_pattern_fini (&pattern.base);
 379
 380     if (unlikely (status)) {
 381         cairo_surface_destroy (clone);
 382         clone = _cairo_surface_create_in_error (status);
 383     }
 384
 385     return clone;
 386 }
 387
 388 static cairo_t *
 389 _cairo_surface_subsurface_create_context(void *target)
 390 {
 391     cairo_surface_subsurface_t *surface = target;
 392     return surface->target->backend->create_context (&surface->base);
 393 }
 394
 395 static const cairo_surface_backend_t _cairo_surface_subsurface_backend = {
 396     CAIRO_SURFACE_TYPE_SUBSURFACE,
 397     _cairo_surface_subsurface_finish,
 398
 399     _cairo_surface_subsurface_create_context,
 400
 401     _cairo_surface_subsurface_create_similar,
 402     _cairo_surface_subsurface_create_similar_image,
 403     _cairo_surface_subsurface_map_to_image,
 404     _cairo_surface_subsurface_unmap_image,
 405
 406     _cairo_surface_subsurface_source,
 407     _cairo_surface_subsurface_acquire_source_image,
 408     _cairo_surface_subsurface_release_source_image,
 409     _cairo_surface_subsurface_snapshot,
 410
 411     NULL, /* copy_page */
 412     NULL, /* show_page */
 413
 414     _cairo_surface_subsurface_get_extents,
 415     _cairo_surface_subsurface_get_font_options,
 416
 417     _cairo_surface_subsurface_flush,
 418     _cairo_surface_subsurface_mark_dirty,
 419
 420     _cairo_surface_subsurface_paint,
 421     _cairo_surface_subsurface_mask,
 422     _cairo_surface_subsurface_stroke,
 423     _cairo_surface_subsurface_fill,
 424     NULL, /* fill/stroke */
 425     _cairo_surface_subsurface_glyphs,
 426 };
 427
 428 /**
 429  * cairo_surface_create_for_rectangle:
 430  * @target: an existing surface for which the sub-surface will point to
 431  * @x: the x-origin of the sub-surface from the top-left of the target surface (in device-space units)
 432  * @y: the y-origin of the sub-surface from the top-left of the target surface (in device-space units)
 433  * @width: width of the sub-surface (in device-space units)
 434  * @height: height of the sub-surface (in device-space units)
 435  *
 436  * Create a new surface that is a rectangle within the target surface.
 437  * All operations drawn to this surface are then clipped and translated
 438  * onto the target surface. Nothing drawn via this sub-surface outside of
 439  * its bounds is drawn onto the target surface, making this a useful method
 440  * for passing constrained child surfaces to library routines that draw
 441  * directly onto the parent surface, i.e. with no further backend allocations,
 442  * double buffering or copies.
 443  *
 444  * <note><para>The semantics of subsurfaces have not been finalized yet
 445  * unless the rectangle is in full device units, is contained within
 446  * the extents of the target surface, and the target or subsurface's
 447  * device transforms are not changed.</para></note>
 448  *
 449  * Return value: a pointer to the newly allocated surface. The caller
 450  * owns the surface and should call cairo_surface_destroy() when done
 451  * with it.
 452  *
 453  * This function always returns a valid pointer, but it will return a
 454  * pointer to a "nil" surface if @other is already in an error state
 455  * or any other error occurs.
 456  *
 457  * Since: 1.10
 458  **/
 459 cairo_surface_t *
 460 cairo_surface_create_for_rectangle (cairo_surface_t *target,
 461                                     double x, double y,
 462                                     double width, double height)
 463 {
 464     cairo_surface_subsurface_t *surface;
 465
 466     if (unlikely (width < 0 || height < 0))
 467         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_SIZE));
 468
 469     if (unlikely (target->status))
 470         return _cairo_surface_create_in_error (target->status);
 471     if (unlikely (target->finished))
 472         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
 473
 474     surface = malloc (sizeof (cairo_surface_subsurface_t));
 475     if (unlikely (surface == NULL))
 476         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
 477
 478     assert (_cairo_matrix_is_translation (&target->device_transform));
 479     x += target->device_transform.x0;
 480     y += target->device_transform.y0;
 481
 482     _cairo_surface_init (&surface->base,
 483                          &_cairo_surface_subsurface_backend,
 484                          NULL, /* device */
 485                          target->content);
 486
 487     /* XXX forced integer alignment */
 488     surface->extents.x = ceil (x);
 489     surface->extents.y = ceil (y);
 490     surface->extents.width = floor (x + width) - surface->extents.x;
 491     surface->extents.height = floor (y + height) - surface->extents.y;
 492     if ((surface->extents.width | surface->extents.height) < 0)
 493         surface->extents.width = surface->extents.height = 0;
 494
 495     if (target->backend->type == CAIRO_SURFACE_TYPE_SUBSURFACE) {
 496         /* Maintain subsurfaces as 1-depth */
 497         cairo_surface_subsurface_t *sub = (cairo_surface_subsurface_t *) target;
 498         surface->extents.x += sub->extents.x;
 499         surface->extents.y += sub->extents.y;
 500         target = sub->target;
 501     }
 502
 503     surface->target = cairo_surface_reference (target);
 504     surface->base.type = surface->target->type;
 505
 506     surface->snapshot = NULL;
 507
 508     return &surface->base;
 509 }
 510
 511 cairo_surface_t *
 512 _cairo_surface_create_for_rectangle_int (cairo_surface_t *target,
 513                                          const cairo_rectangle_int_t *extents)
 514 {
 515     cairo_surface_subsurface_t *surface;
 516
 517     if (unlikely (target->status))
 518         return _cairo_surface_create_in_error (target->status);
 519     if (unlikely (target->finished))
 520         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
 521
 522     assert (target->backend->type != CAIRO_SURFACE_TYPE_SUBSURFACE);
 523
 524     surface = malloc (sizeof (cairo_surface_subsurface_t));
 525     if (unlikely (surface == NULL))
 526         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
 527
 528     assert (_cairo_matrix_is_translation (&target->device_transform));
 529
 530     _cairo_surface_init (&surface->base,
 531                          &_cairo_surface_subsurface_backend,
 532                          NULL, /* device */
 533                          target->content);
 534
 535     surface->extents = *extents;
 536     surface->extents.x += target->device_transform.x0;
 537     surface->extents.y += target->device_transform.y0;
 538
 539     surface->target = cairo_surface_reference (target);
 540     surface->base.type = surface->target->type;
 541
 542     surface->snapshot = NULL;
 543
 544     return &surface->base;
 545 }
 546 /* XXX observe mark-dirty */
 547
 548 static void
 549 _cairo_surface_subsurface_detach_snapshot (cairo_surface_t *surface)
 550 {
 551     cairo_surface_subsurface_t *ss = (cairo_surface_subsurface_t *) surface;
 552
 553     TRACE ((stderr, "%s: target=%d\n", __FUNCTION__, ss->target->unique_id));
 554
 555     cairo_surface_destroy (ss->snapshot);
 556     ss->snapshot = NULL;
 557 }
 558
 559 void
 560 _cairo_surface_subsurface_set_snapshot (cairo_surface_t *surface,
 561                                         cairo_surface_t *snapshot)
 562 {
 563     cairo_surface_subsurface_t *ss = (cairo_surface_subsurface_t *) surface;
 564
 565     TRACE ((stderr, "%s: target=%d, snapshot=%d\n", __FUNCTION__,
 566             ss->target->unique_id, snapshot->unique_id));
 567
 568     /* FIXME: attaching the subsurface as a snapshot to its target creates
 569      * a reference cycle.  Let's make this call as a no-op until that bug
 570      * is fixed.
 571      */
 572     return;
 573
 574     if (ss->snapshot)
 575         _cairo_surface_detach_snapshot (ss->snapshot);
 576
 577     ss->snapshot = cairo_surface_reference (snapshot);
 578
 579     _cairo_surface_attach_snapshot (ss->target, &ss->base,
 580                                     _cairo_surface_subsurface_detach_snapshot);
 581 }