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_image_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     target_extents.x = extents->x + surface->extents.x;
  95     target_extents.y = extents->y + surface->extents.y;
  96     target_extents.width  = extents->width;
  97     target_extents.height = extents->height;
  98
  99     return _cairo_surface_map_to_image (surface->target, &target_extents);
 100 }
 101
 102 static cairo_int_status_t
 103 _cairo_surface_subsurface_unmap_image (void *abstract_surface,
 104                                        cairo_image_surface_t *image)
 105 {
 106     cairo_surface_subsurface_t *surface = abstract_surface;
 107     return _cairo_surface_unmap_image (surface->target, image);
 108 }
 109
 110 static cairo_int_status_t
 111 _cairo_surface_subsurface_paint (void *abstract_surface,
 112                                  cairo_operator_t op,
 113                                  const cairo_pattern_t *source,
 114                                  const cairo_clip_t *clip)
 115 {
 116     cairo_surface_subsurface_t *surface = abstract_surface;
 117     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 118     cairo_status_t status;
 119     cairo_clip_t *target_clip;
 120
 121     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 122     status = _cairo_surface_offset_paint (surface->target,
 123                                          -surface->extents.x, -surface->extents.y,
 124                                           op, source, target_clip);
 125     _cairo_clip_destroy (target_clip);
 126     return status;
 127 }
 128
 129 static cairo_int_status_t
 130 _cairo_surface_subsurface_mask (void *abstract_surface,
 131                                 cairo_operator_t op,
 132                                 const cairo_pattern_t *source,
 133                                 const cairo_pattern_t *mask,
 134                                 const cairo_clip_t *clip)
 135 {
 136     cairo_surface_subsurface_t *surface = abstract_surface;
 137     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 138     cairo_status_t status;
 139     cairo_clip_t *target_clip;
 140
 141     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 142     status = _cairo_surface_offset_mask (surface->target,
 143                                          -surface->extents.x, -surface->extents.y,
 144                                          op, source, mask, target_clip);
 145     _cairo_clip_destroy (target_clip);
 146     return status;
 147 }
 148
 149 static cairo_int_status_t
 150 _cairo_surface_subsurface_fill (void                    *abstract_surface,
 151                                 cairo_operator_t         op,
 152                                 const cairo_pattern_t   *source,
 153                                 const cairo_path_fixed_t        *path,
 154                                 cairo_fill_rule_t        fill_rule,
 155                                 double                   tolerance,
 156                                 cairo_antialias_t        antialias,
 157                                 const cairo_clip_t              *clip)
 158 {
 159     cairo_surface_subsurface_t *surface = abstract_surface;
 160     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 161     cairo_status_t status;
 162     cairo_clip_t *target_clip;
 163
 164     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 165     status = _cairo_surface_offset_fill (surface->target,
 166                                          -surface->extents.x, -surface->extents.y,
 167                                          op, source, path, fill_rule, tolerance, antialias,
 168                                          target_clip);
 169     _cairo_clip_destroy (target_clip);
 170     return status;
 171 }
 172
 173 static cairo_int_status_t
 174 _cairo_surface_subsurface_stroke (void                          *abstract_surface,
 175                                   cairo_operator_t               op,
 176                                   const cairo_pattern_t         *source,
 177                                   const cairo_path_fixed_t              *path,
 178                                   const cairo_stroke_style_t    *stroke_style,
 179                                   const cairo_matrix_t          *ctm,
 180                                   const cairo_matrix_t          *ctm_inverse,
 181                                   double                         tolerance,
 182                                   cairo_antialias_t              antialias,
 183                                   const cairo_clip_t                    *clip)
 184 {
 185     cairo_surface_subsurface_t *surface = abstract_surface;
 186     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 187     cairo_status_t status;
 188     cairo_clip_t *target_clip;
 189
 190     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 191     status = _cairo_surface_offset_stroke (surface->target,
 192                                            -surface->extents.x, -surface->extents.y,
 193                                            op, source, path, stroke_style, ctm, ctm_inverse,
 194                                            tolerance, antialias,
 195                                            target_clip);
 196     _cairo_clip_destroy (target_clip);
 197     return status;
 198 }
 199
 200 static cairo_int_status_t
 201 _cairo_surface_subsurface_glyphs (void                  *abstract_surface,
 202                                   cairo_operator_t       op,
 203                                   const cairo_pattern_t *source,
 204                                   cairo_glyph_t         *glyphs,
 205                                   int                    num_glyphs,
 206                                   cairo_scaled_font_t   *scaled_font,
 207                                   const cairo_clip_t    *clip)
 208 {
 209     cairo_surface_subsurface_t *surface = abstract_surface;
 210     cairo_rectangle_int_t rect = { 0, 0, surface->extents.width, surface->extents.height };
 211     cairo_status_t status;
 212     cairo_clip_t *target_clip;
 213
 214     target_clip = _cairo_clip_copy_intersect_rectangle (clip, &rect);
 215     status = _cairo_surface_offset_glyphs (surface->target,
 216                                            -surface->extents.x, -surface->extents.y,
 217                                            op, source,
 218                                            scaled_font, glyphs, num_glyphs,
 219                                            target_clip);
 220     _cairo_clip_destroy (target_clip);
 221     return status;
 222 }
 223
 224 static cairo_status_t
 225 _cairo_surface_subsurface_flush (void *abstract_surface, unsigned flags)
 226 {
 227     cairo_surface_subsurface_t *surface = abstract_surface;
 228     return _cairo_surface_flush (surface->target, flags);
 229 }
 230
 231 static cairo_status_t
 232 _cairo_surface_subsurface_mark_dirty (void *abstract_surface,
 233                                       int x, int y,
 234                                       int width, int height)
 235 {
 236     cairo_surface_subsurface_t *surface = abstract_surface;
 237     cairo_status_t status;
 238
 239     status = CAIRO_STATUS_SUCCESS;
 240     if (surface->target->backend->mark_dirty_rectangle != NULL) {
 241         cairo_rectangle_int_t rect, extents;
 242
 243         rect.x = x;
 244         rect.y = y;
 245         rect.width  = width;
 246         rect.height = height;
 247
 248         extents.x = extents.y = 0;
 249         extents.width  = surface->extents.width;
 250         extents.height = surface->extents.height;
 251
 252         if (_cairo_rectangle_intersect (&rect, &extents)) {
 253             status = surface->target->backend->mark_dirty_rectangle (surface->target,
 254                                                                      rect.x + surface->extents.x,
 255                                                                      rect.y + surface->extents.y,
 256                                                                      rect.width, rect.height);
 257         }
 258     }
 259
 260     return status;
 261 }
 262
 263 static cairo_bool_t
 264 _cairo_surface_subsurface_get_extents (void *abstract_surface,
 265                                        cairo_rectangle_int_t *extents)
 266 {
 267     cairo_surface_subsurface_t *surface = abstract_surface;
 268
 269     extents->x = 0;
 270     extents->y = 0;
 271     extents->width  = surface->extents.width;
 272     extents->height = surface->extents.height;
 273
 274     return TRUE;
 275 }
 276
 277 static void
 278 _cairo_surface_subsurface_get_font_options (void *abstract_surface,
 279                                             cairo_font_options_t *options)
 280 {
 281     cairo_surface_subsurface_t *surface = abstract_surface;
 282
 283     if (surface->target->backend->get_font_options != NULL)
 284         surface->target->backend->get_font_options (surface->target, options);
 285 }
 286
 287 static cairo_surface_t *
 288 _cairo_surface_subsurface_source (void *abstract_surface,
 289                                   cairo_rectangle_int_t *extents)
 290 {
 291     cairo_surface_subsurface_t *surface = abstract_surface;
 292     cairo_surface_t *source;
 293
 294     source = _cairo_surface_get_source (surface->target, extents);
 295     if (extents)
 296         *extents = surface->extents;
 297
 298     return source;
 299 }
 300
 301 static cairo_status_t
 302 _cairo_surface_subsurface_acquire_source_image (void                    *abstract_surface,
 303                                                 cairo_image_surface_t  **image_out,
 304                                                 void                   **extra_out)
 305 {
 306     cairo_surface_subsurface_t *surface = abstract_surface;
 307     cairo_surface_pattern_t pattern;
 308     cairo_surface_t *image;
 309     cairo_status_t status;
 310
 311     image = _cairo_image_surface_create_with_content (surface->base.content,
 312                                                       surface->extents.width,
 313                                                       surface->extents.height);
 314     if (unlikely (image->status)) {
 315         status = image->status;
 316         cairo_surface_destroy (image);
 317         return status;
 318     }
 319
 320     _cairo_pattern_init_for_surface (&pattern, surface->target);
 321     cairo_matrix_init_translate (&pattern.base.matrix,
 322                                  surface->extents.x,
 323                                  surface->extents.y);
 324     pattern.base.filter = CAIRO_FILTER_NEAREST;
 325     status = _cairo_surface_paint (image,
 326                                    CAIRO_OPERATOR_SOURCE,
 327                                    &pattern.base, NULL);
 328     _cairo_pattern_fini (&pattern.base);
 329     if (unlikely (status)) {
 330         cairo_surface_destroy (image);
 331         return status;
 332     }
 333
 334     *image_out = (cairo_image_surface_t *)image;
 335     *extra_out = NULL;
 336     return CAIRO_STATUS_SUCCESS;
 337 }
 338
 339 static void
 340 _cairo_surface_subsurface_release_source_image (void                   *abstract_surface,
 341                                                 cairo_image_surface_t  *image,
 342                                                 void                   *abstract_extra)
 343 {
 344     cairo_surface_destroy (&image->base);
 345 }
 346
 347 static cairo_surface_t *
 348 _cairo_surface_subsurface_snapshot (void *abstract_surface)
 349 {
 350     cairo_surface_subsurface_t *surface = abstract_surface;
 351     cairo_surface_pattern_t pattern;
 352     cairo_surface_t *clone;
 353     cairo_status_t status;
 354
 355     TRACE ((stderr, "%s: target=%d\n", __FUNCTION__, surface->target->unique_id));
 356
 357     clone = _cairo_surface_create_similar_scratch (surface->target,
 358                                                    surface->target->content,
 359                                                    surface->extents.width,
 360                                                    surface->extents.height);
 361     if (unlikely (clone->status))
 362         return clone;
 363
 364     _cairo_pattern_init_for_surface (&pattern, surface->target);
 365     cairo_matrix_init_translate (&pattern.base.matrix,
 366                                  surface->extents.x, surface->extents.y);
 367     pattern.base.filter = CAIRO_FILTER_NEAREST;
 368     status = _cairo_surface_paint (clone,
 369                                    CAIRO_OPERATOR_SOURCE,
 370                                    &pattern.base, NULL);
 371     _cairo_pattern_fini (&pattern.base);
 372
 373     if (unlikely (status)) {
 374         cairo_surface_destroy (clone);
 375         clone = _cairo_surface_create_in_error (status);
 376     }
 377
 378     return clone;
 379 }
 380
 381 static cairo_t *
 382 _cairo_surface_subsurface_create_context(void *target)
 383 {
 384     cairo_surface_subsurface_t *surface = target;
 385     return surface->target->backend->create_context (&surface->base);
 386 }
 387
 388 static const cairo_surface_backend_t _cairo_surface_subsurface_backend = {
 389     CAIRO_SURFACE_TYPE_SUBSURFACE,
 390     _cairo_surface_subsurface_finish,
 391
 392     _cairo_surface_subsurface_create_context,
 393
 394     _cairo_surface_subsurface_create_similar,
 395     _cairo_surface_subsurface_create_similar_image,
 396     _cairo_surface_subsurface_map_to_image,
 397     _cairo_surface_subsurface_unmap_image,
 398
 399     _cairo_surface_subsurface_source,
 400     _cairo_surface_subsurface_acquire_source_image,
 401     _cairo_surface_subsurface_release_source_image,
 402     _cairo_surface_subsurface_snapshot,
 403
 404     NULL, /* copy_page */
 405     NULL, /* show_page */
 406
 407     _cairo_surface_subsurface_get_extents,
 408     _cairo_surface_subsurface_get_font_options,
 409
 410     _cairo_surface_subsurface_flush,
 411     _cairo_surface_subsurface_mark_dirty,
 412
 413     _cairo_surface_subsurface_paint,
 414     _cairo_surface_subsurface_mask,
 415     _cairo_surface_subsurface_stroke,
 416     _cairo_surface_subsurface_fill,
 417     NULL, /* fill/stroke */
 418     _cairo_surface_subsurface_glyphs,
 419 };
 420
 421 /**
 422  * cairo_surface_create_for_rectangle:
 423  * @target: an existing surface for which the sub-surface will point to
 424  * @x: the x-origin of the sub-surface from the top-left of the target surface (in device-space units)
 425  * @y: the y-origin of the sub-surface from the top-left of the target surface (in device-space units)
 426  * @width: width of the sub-surface (in device-space units)
 427  * @height: height of the sub-surface (in device-space units)
 428  *
 429  * Create a new surface that is a rectangle within the target surface.
 430  * All operations drawn to this surface are then clipped and translated
 431  * onto the target surface. Nothing drawn via this sub-surface outside of
 432  * its bounds is drawn onto the target surface, making this a useful method
 433  * for passing constrained child surfaces to library routines that draw
 434  * directly onto the parent surface, i.e. with no further backend allocations,
 435  * double buffering or copies.
 436  *
 437  * <note><para>The semantics of subsurfaces have not been finalized yet
 438  * unless the rectangle is in full device units, is contained within
 439  * the extents of the target surface, and the target or subsurface's
 440  * device transforms are not changed.</para></note>
 441  *
 442  * Return value: a pointer to the newly allocated surface. The caller
 443  * owns the surface and should call cairo_surface_destroy() when done
 444  * with it.
 445  *
 446  * This function always returns a valid pointer, but it will return a
 447  * pointer to a "nil" surface if @other is already in an error state
 448  * or any other error occurs.
 449  *
 450  * Since: 1.10
 451  **/
 452 cairo_surface_t *
 453 cairo_surface_create_for_rectangle (cairo_surface_t *target,
 454                                     double x, double y,
 455                                     double width, double height)
 456 {
 457     cairo_surface_subsurface_t *surface;
 458
 459     if (unlikely (width < 0 || height < 0))
 460         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_SIZE));
 461
 462     if (unlikely (target->status))
 463         return _cairo_surface_create_in_error (target->status);
 464     if (unlikely (target->finished))
 465         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
 466
 467     surface = malloc (sizeof (cairo_surface_subsurface_t));
 468     if (unlikely (surface == NULL))
 469         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
 470
 471     assert (_cairo_matrix_is_translation (&target->device_transform));
 472     x += target->device_transform.x0;
 473     y += target->device_transform.y0;
 474
 475     _cairo_surface_init (&surface->base,
 476                          &_cairo_surface_subsurface_backend,
 477                          NULL, /* device */
 478                          target->content);
 479
 480     /* XXX forced integer alignment */
 481     surface->extents.x = ceil (x);
 482     surface->extents.y = ceil (y);
 483     surface->extents.width = floor (x + width) - surface->extents.x;
 484     surface->extents.height = floor (y + height) - surface->extents.y;
 485     if ((surface->extents.width | surface->extents.height) < 0)
 486         surface->extents.width = surface->extents.height = 0;
 487
 488     if (target->backend->type == CAIRO_SURFACE_TYPE_SUBSURFACE) {
 489         /* Maintain subsurfaces as 1-depth */
 490         cairo_surface_subsurface_t *sub = (cairo_surface_subsurface_t *) target;
 491         surface->extents.x += sub->extents.x;
 492         surface->extents.y += sub->extents.y;
 493         target = sub->target;
 494     }
 495
 496     surface->target = cairo_surface_reference (target);
 497     surface->base.type = surface->target->type;
 498
 499     surface->snapshot = NULL;
 500
 501     return &surface->base;
 502 }
 503
 504 cairo_surface_t *
 505 _cairo_surface_create_for_rectangle_int (cairo_surface_t *target,
 506                                          const cairo_rectangle_int_t *extents)
 507 {
 508     cairo_surface_subsurface_t *surface;
 509
 510     if (unlikely (target->status))
 511         return _cairo_surface_create_in_error (target->status);
 512     if (unlikely (target->finished))
 513         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_SURFACE_FINISHED));
 514
 515     assert (target->backend->type != CAIRO_SURFACE_TYPE_SUBSURFACE);
 516
 517     surface = malloc (sizeof (cairo_surface_subsurface_t));
 518     if (unlikely (surface == NULL))
 519         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
 520
 521     assert (_cairo_matrix_is_translation (&target->device_transform));
 522
 523     _cairo_surface_init (&surface->base,
 524                          &_cairo_surface_subsurface_backend,
 525                          NULL, /* device */
 526                          target->content);
 527
 528     surface->extents = *extents;
 529     surface->extents.x += target->device_transform.x0;
 530     surface->extents.y += target->device_transform.y0;
 531
 532     surface->target = cairo_surface_reference (target);
 533     surface->base.type = surface->target->type;
 534
 535     surface->snapshot = NULL;
 536
 537     return &surface->base;
 538 }
 539 /* XXX observe mark-dirty */
 540
 541 static void
 542 _cairo_surface_subsurface_detach_snapshot (cairo_surface_t *surface)
 543 {
 544     cairo_surface_subsurface_t *ss = (cairo_surface_subsurface_t *) surface;
 545
 546     TRACE ((stderr, "%s: target=%d\n", __FUNCTION__, ss->target->unique_id));
 547
 548     cairo_surface_destroy (ss->snapshot);
 549     ss->snapshot = NULL;
 550 }
 551
 552 void
 553 _cairo_surface_subsurface_set_snapshot (cairo_surface_t *surface,
 554                                         cairo_surface_t *snapshot)
 555 {
 556     cairo_surface_subsurface_t *ss = (cairo_surface_subsurface_t *) surface;
 557
 558     TRACE ((stderr, "%s: target=%d, snapshot=%d\n", __FUNCTION__,
 559             ss->target->unique_id, snapshot->unique_id));
 560
 561     /* FIXME: attaching the subsurface as a snapshot to its target creates
 562      * a reference cycle.  Let's make this call as a no-op until that bug
 563      * is fixed.
 564      */
 565     return;
 566
 567     if (ss->snapshot)
 568         _cairo_surface_detach_snapshot (ss->snapshot);
 569
 570     ss->snapshot = cairo_surface_reference (snapshot);
 571
 572     _cairo_surface_attach_snapshot (ss->target, &ss->base,
 573                                     _cairo_surface_subsurface_detach_snapshot);
 574 }