src/cairo-analysis-surface.c

   1 /*
   2  * Copyright © 2006 Keith Packard
   3  * Copyright © 2007 Adrian Johnson
   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 Keith Packard
  31  *
  32  * Contributor(s):
  33  *      Keith Packard <keithp@keithp.com>
  34  *      Adrian Johnson <ajohnson@redneon.com>
  35  */
  36
  37 #include "cairoint.h"
  38
  39 #include "cairo-analysis-surface-private.h"
  40 #include "cairo-box-inline.h"
  41 #include "cairo-default-context-private.h"
  42 #include "cairo-error-private.h"
  43 #include "cairo-paginated-private.h"
  44 #include "cairo-recording-surface-inline.h"
  45 #include "cairo-surface-snapshot-inline.h"
  46 #include "cairo-surface-subsurface-inline.h"
  47 #include "cairo-region-private.h"
  48
  49 typedef struct {
  50     cairo_surface_t base;
  51
  52     cairo_surface_t *target;
  53
  54     cairo_bool_t first_op;
  55     cairo_bool_t has_supported;
  56     cairo_bool_t has_unsupported;
  57
  58     cairo_region_t supported_region;
  59     cairo_region_t fallback_region;
  60     cairo_box_t page_bbox;
  61
  62     cairo_bool_t has_ctm;
  63     cairo_matrix_t ctm;
  64
  65 } cairo_analysis_surface_t;
  66
  67 cairo_int_status_t
  68 _cairo_analysis_surface_merge_status (cairo_int_status_t status_a,
  69                                       cairo_int_status_t status_b)
  70 {
  71     /* fatal errors should be checked and propagated at source */
  72     assert (! _cairo_int_status_is_error (status_a));
  73     assert (! _cairo_int_status_is_error (status_b));
  74
  75     /* return the most important status */
  76     if (status_a == CAIRO_INT_STATUS_UNSUPPORTED ||
  77         status_b == CAIRO_INT_STATUS_UNSUPPORTED)
  78         return CAIRO_INT_STATUS_UNSUPPORTED;
  79
  80     if (status_a == CAIRO_INT_STATUS_IMAGE_FALLBACK ||
  81         status_b == CAIRO_INT_STATUS_IMAGE_FALLBACK)
  82         return CAIRO_INT_STATUS_IMAGE_FALLBACK;
  83
  84     if (status_a == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN ||
  85         status_b == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN)
  86         return CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN;
  87
  88     if (status_a == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY ||
  89         status_b == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY)
  90         return CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY;
  91
  92     /* at this point we have checked all the valid internal codes, so... */
  93     assert (status_a == CAIRO_INT_STATUS_SUCCESS &&
  94             status_b == CAIRO_INT_STATUS_SUCCESS);
  95
  96     return CAIRO_INT_STATUS_SUCCESS;
  97 }
  98
  99 struct proxy {
 100     cairo_surface_t base;
 101     cairo_surface_t *target;
 102 };
 103
 104 static cairo_status_t
 105 proxy_finish (void *abstract_surface)
 106 {
 107     return CAIRO_STATUS_SUCCESS;
 108 }
 109
 110 static const cairo_surface_backend_t proxy_backend  = {
 111     CAIRO_INTERNAL_SURFACE_TYPE_NULL,
 112     proxy_finish,
 113 };
 114
 115 static cairo_surface_t *
 116 attach_proxy (cairo_surface_t *source,
 117               cairo_surface_t *target)
 118 {
 119     struct proxy *proxy;
 120
 121     proxy = malloc (sizeof (*proxy));
 122     if (unlikely (proxy == NULL))
 123         return _cairo_surface_create_in_error (CAIRO_STATUS_NO_MEMORY);
 124
 125     _cairo_surface_init (&proxy->base, &proxy_backend, NULL, target->content);
 126
 127     proxy->target = target;
 128     _cairo_surface_attach_snapshot (source, &proxy->base, NULL);
 129
 130     return &proxy->base;
 131 }
 132
 133 static void
 134 detach_proxy (cairo_surface_t *proxy)
 135 {
 136     cairo_surface_finish (proxy);
 137     cairo_surface_destroy (proxy);
 138 }
 139
 140 static cairo_int_status_t
 141 _analyze_recording_surface_pattern (cairo_analysis_surface_t *surface,
 142                                     const cairo_pattern_t    *pattern)
 143 {
 144     const cairo_surface_pattern_t *surface_pattern;
 145     cairo_analysis_surface_t *tmp;
 146     cairo_surface_t *source, *proxy;
 147     cairo_matrix_t p2d;
 148     cairo_status_t status, analysis_status;
 149
 150     assert (pattern->type == CAIRO_PATTERN_TYPE_SURFACE);
 151     surface_pattern = (const cairo_surface_pattern_t *) pattern;
 152     assert (surface_pattern->surface->type == CAIRO_SURFACE_TYPE_RECORDING);
 153     source = surface_pattern->surface;
 154
 155     proxy = _cairo_surface_has_snapshot (source, &proxy_backend);
 156     if (proxy != NULL) {
 157         /* nothing untoward found so far */
 158         return CAIRO_STATUS_SUCCESS;
 159     }
 160
 161     tmp = (cairo_analysis_surface_t *)
 162         _cairo_analysis_surface_create (surface->target);
 163     if (unlikely (tmp->base.status))
 164         return tmp->base.status;
 165     proxy = attach_proxy (source, &tmp->base);
 166
 167     p2d = pattern->matrix;
 168     status = cairo_matrix_invert (&p2d);
 169     assert (status == CAIRO_STATUS_SUCCESS);
 170
 171     cairo_matrix_multiply (&tmp->ctm, &p2d, &surface->ctm);
 172     tmp->has_ctm = ! _cairo_matrix_is_identity (&tmp->ctm);
 173
 174     source = _cairo_surface_get_source (source, NULL);
 175     status = _cairo_recording_surface_replay_and_create_regions (source,
 176                                                                  &tmp->base);
 177     analysis_status = tmp->has_unsupported ? CAIRO_INT_STATUS_IMAGE_FALLBACK : CAIRO_INT_STATUS_SUCCESS;
 178     detach_proxy (proxy);
 179     cairo_surface_destroy (&tmp->base);
 180
 181     if (unlikely (status))
 182         return status;
 183
 184     return analysis_status;
 185 }
 186
 187 static cairo_int_status_t
 188 _add_operation (cairo_analysis_surface_t *surface,
 189                 cairo_rectangle_int_t    *rect,
 190                 cairo_int_status_t        backend_status)
 191 {
 192     cairo_int_status_t status;
 193     cairo_box_t bbox;
 194
 195     if (rect->width == 0 || rect->height == 0) {
 196         /* Even though the operation is not visible we must be careful
 197          * to not allow unsupported operations to be replayed to the
 198          * backend during CAIRO_PAGINATED_MODE_RENDER */
 199         if (backend_status == CAIRO_INT_STATUS_SUCCESS ||
 200             backend_status == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY ||
 201             backend_status == CAIRO_INT_STATUS_NOTHING_TO_DO)
 202         {
 203             return CAIRO_INT_STATUS_SUCCESS;
 204         }
 205         else
 206         {
 207             return CAIRO_INT_STATUS_IMAGE_FALLBACK;
 208         }
 209     }
 210
 211     _cairo_box_from_rectangle (&bbox, rect);
 212
 213     if (surface->has_ctm) {
 214         int tx, ty;
 215
 216         if (_cairo_matrix_is_integer_translation (&surface->ctm, &tx, &ty)) {
 217             rect->x += tx;
 218             rect->y += ty;
 219
 220             tx = _cairo_fixed_from_int (tx);
 221             bbox.p1.x += tx;
 222             bbox.p2.x += tx;
 223
 224             ty = _cairo_fixed_from_int (ty);
 225             bbox.p1.y += ty;
 226             bbox.p2.y += ty;
 227         } else {
 228             _cairo_matrix_transform_bounding_box_fixed (&surface->ctm,
 229                                                         &bbox, NULL);
 230
 231             if (bbox.p1.x == bbox.p2.x || bbox.p1.y == bbox.p2.y) {
 232                 /* Even though the operation is not visible we must be
 233                  * careful to not allow unsupported operations to be
 234                  * replayed to the backend during
 235                  * CAIRO_PAGINATED_MODE_RENDER */
 236                 if (backend_status == CAIRO_INT_STATUS_SUCCESS ||
 237                     backend_status == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY ||
 238                     backend_status == CAIRO_INT_STATUS_NOTHING_TO_DO)
 239                 {
 240                     return CAIRO_INT_STATUS_SUCCESS;
 241                 }
 242                 else
 243                 {
 244                     return CAIRO_INT_STATUS_IMAGE_FALLBACK;
 245                 }
 246             }
 247
 248             _cairo_box_round_to_rectangle (&bbox, rect);
 249         }
 250     }
 251
 252     if (surface->first_op) {
 253         surface->first_op = FALSE;
 254         surface->page_bbox = bbox;
 255     } else
 256         _cairo_box_add_box(&surface->page_bbox, &bbox);
 257
 258     /* If the operation is completely enclosed within the fallback
 259      * region there is no benefit in emitting a native operation as
 260      * the fallback image will be painted on top.
 261      */
 262     if (cairo_region_contains_rectangle (&surface->fallback_region, rect) == CAIRO_REGION_OVERLAP_IN)
 263         return CAIRO_INT_STATUS_IMAGE_FALLBACK;
 264
 265     if (backend_status == CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY) {
 266         /* A status of CAIRO_INT_STATUS_FLATTEN_TRANSPARENCY indicates
 267          * that the backend only supports this operation if the
 268          * transparency removed. If the extents of this operation does
 269          * not intersect any other native operation, the operation is
 270          * natively supported and the backend will blend the
 271          * transparency into the white background.
 272          */
 273         if (cairo_region_contains_rectangle (&surface->supported_region, rect) == CAIRO_REGION_OVERLAP_OUT)
 274             backend_status = CAIRO_INT_STATUS_SUCCESS;
 275     }
 276
 277     if (backend_status == CAIRO_INT_STATUS_SUCCESS) {
 278         /* Add the operation to the supported region. Operations in
 279          * this region will be emitted as native operations.
 280          */
 281         surface->has_supported = TRUE;
 282         return cairo_region_union_rectangle (&surface->supported_region, rect);
 283     }
 284
 285     /* Add the operation to the unsupported region. This region will
 286      * be painted as an image after all native operations have been
 287      * emitted.
 288      */
 289     surface->has_unsupported = TRUE;
 290     status = cairo_region_union_rectangle (&surface->fallback_region, rect);
 291
 292     /* The status CAIRO_INT_STATUS_IMAGE_FALLBACK is used to indicate
 293      * unsupported operations to the recording surface as using
 294      * CAIRO_INT_STATUS_UNSUPPORTED would cause cairo-surface to
 295      * invoke the cairo-surface-fallback path then return
 296      * CAIRO_STATUS_SUCCESS.
 297      */
 298     if (status == CAIRO_INT_STATUS_SUCCESS)
 299         return CAIRO_INT_STATUS_IMAGE_FALLBACK;
 300     else
 301         return status;
 302 }
 303
 304 static cairo_status_t
 305 _cairo_analysis_surface_finish (void *abstract_surface)
 306 {
 307     cairo_analysis_surface_t    *surface = (cairo_analysis_surface_t *) abstract_surface;
 308
 309     _cairo_region_fini (&surface->supported_region);
 310     _cairo_region_fini (&surface->fallback_region);
 311
 312     cairo_surface_destroy (surface->target);
 313
 314     return CAIRO_STATUS_SUCCESS;
 315 }
 316
 317 static cairo_bool_t
 318 _cairo_analysis_surface_get_extents (void                       *abstract_surface,
 319                                      cairo_rectangle_int_t      *rectangle)
 320 {
 321     cairo_analysis_surface_t *surface = abstract_surface;
 322
 323     return _cairo_surface_get_extents (surface->target, rectangle);
 324 }
 325
 326 static void
 327 _rectangle_intersect_clip (cairo_rectangle_int_t *extents, const cairo_clip_t *clip)
 328 {
 329     if (clip != NULL)
 330         _cairo_rectangle_intersect (extents, _cairo_clip_get_extents (clip));
 331 }
 332
 333 static void
 334 _cairo_analysis_surface_operation_extents (cairo_analysis_surface_t *surface,
 335                                            cairo_operator_t op,
 336                                            const cairo_pattern_t *source,
 337                                            const cairo_clip_t *clip,
 338                                            cairo_rectangle_int_t *extents)
 339 {
 340     cairo_bool_t is_empty;
 341
 342     is_empty = _cairo_surface_get_extents (&surface->base, extents);
 343
 344     if (_cairo_operator_bounded_by_source (op)) {
 345         cairo_rectangle_int_t source_extents;
 346
 347         _cairo_pattern_get_extents (source, &source_extents);
 348         _cairo_rectangle_intersect (extents, &source_extents);
 349     }
 350
 351     _rectangle_intersect_clip (extents, clip);
 352 }
 353
 354 static cairo_int_status_t
 355 _cairo_analysis_surface_paint (void                     *abstract_surface,
 356                                cairo_operator_t         op,
 357                                const cairo_pattern_t    *source,
 358                                const cairo_clip_t               *clip)
 359 {
 360     cairo_analysis_surface_t *surface = abstract_surface;
 361     cairo_int_status_t       backend_status;
 362     cairo_rectangle_int_t  extents;
 363
 364     if (surface->target->backend->paint == NULL) {
 365         backend_status = CAIRO_INT_STATUS_UNSUPPORTED;
 366     } else {
 367         backend_status =
 368             surface->target->backend->paint (surface->target,
 369                                              op, source, clip);
 370         if (_cairo_int_status_is_error (backend_status))
 371             return backend_status;
 372     }
 373
 374     if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN)
 375         backend_status = _analyze_recording_surface_pattern (surface, source);
 376
 377     _cairo_analysis_surface_operation_extents (surface,
 378                                                op, source, clip,
 379                                                &extents);
 380
 381     return _add_operation (surface, &extents, backend_status);
 382 }
 383
 384 static cairo_int_status_t
 385 _cairo_analysis_surface_mask (void                      *abstract_surface,
 386                               cairo_operator_t           op,
 387                               const cairo_pattern_t     *source,
 388                               const cairo_pattern_t     *mask,
 389                               const cairo_clip_t                *clip)
 390 {
 391     cairo_analysis_surface_t *surface = abstract_surface;
 392     cairo_int_status_t        backend_status;
 393     cairo_rectangle_int_t   extents;
 394
 395     if (surface->target->backend->mask == NULL) {
 396         backend_status = CAIRO_INT_STATUS_UNSUPPORTED;
 397     } else {
 398         backend_status =
 399             surface->target->backend->mask (surface->target,
 400                                             op, source, mask, clip);
 401         if (_cairo_int_status_is_error (backend_status))
 402             return backend_status;
 403     }
 404
 405     if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN) {
 406         cairo_int_status_t backend_source_status = CAIRO_STATUS_SUCCESS;
 407         cairo_int_status_t backend_mask_status = CAIRO_STATUS_SUCCESS;
 408
 409         if (source->type == CAIRO_PATTERN_TYPE_SURFACE) {
 410             cairo_surface_t *src_surface = ((cairo_surface_pattern_t *)source)->surface;
 411             src_surface = _cairo_surface_get_source (src_surface, NULL);
 412             if (_cairo_surface_is_recording (src_surface)) {
 413                 backend_source_status =
 414                     _analyze_recording_surface_pattern (surface, source);
 415                 if (_cairo_int_status_is_error (backend_source_status))
 416                     return backend_source_status;
 417             }
 418         }
 419
 420         if (mask->type == CAIRO_PATTERN_TYPE_SURFACE) {
 421             cairo_surface_t *mask_surface = ((cairo_surface_pattern_t *)mask)->surface;
 422             mask_surface = _cairo_surface_get_source (mask_surface, NULL);
 423             if (_cairo_surface_is_recording (mask_surface)) {
 424                 backend_mask_status =
 425                     _analyze_recording_surface_pattern (surface, mask);
 426                 if (_cairo_int_status_is_error (backend_mask_status))
 427                     return backend_mask_status;
 428             }
 429         }
 430
 431         backend_status =
 432             _cairo_analysis_surface_merge_status (backend_source_status,
 433                                                   backend_mask_status);
 434     }
 435
 436     _cairo_analysis_surface_operation_extents (surface,
 437                                                op, source, clip,
 438                                                &extents);
 439
 440     if (_cairo_operator_bounded_by_mask (op)) {
 441         cairo_rectangle_int_t mask_extents;
 442
 443         _cairo_pattern_get_extents (mask, &mask_extents);
 444         _cairo_rectangle_intersect (&extents, &mask_extents);
 445     }
 446
 447     return _add_operation (surface, &extents, backend_status);
 448 }
 449
 450 static cairo_int_status_t
 451 _cairo_analysis_surface_stroke (void                    *abstract_surface,
 452                                 cairo_operator_t         op,
 453                                 const cairo_pattern_t   *source,
 454                                 const cairo_path_fixed_t        *path,
 455                                 const cairo_stroke_style_t      *style,
 456                                 const cairo_matrix_t            *ctm,
 457                                 const cairo_matrix_t            *ctm_inverse,
 458                                 double                   tolerance,
 459                                 cairo_antialias_t        antialias,
 460                                 const cairo_clip_t              *clip)
 461 {
 462     cairo_analysis_surface_t *surface = abstract_surface;
 463     cairo_int_status_t       backend_status;
 464     cairo_rectangle_int_t    extents;
 465
 466     if (surface->target->backend->stroke == NULL) {
 467         backend_status = CAIRO_INT_STATUS_UNSUPPORTED;
 468     } else {
 469         backend_status =
 470             surface->target->backend->stroke (surface->target, op,
 471                                               source, path, style,
 472                                               ctm, ctm_inverse,
 473                                               tolerance, antialias,
 474                                               clip);
 475         if (_cairo_int_status_is_error (backend_status))
 476             return backend_status;
 477     }
 478
 479     if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN)
 480         backend_status = _analyze_recording_surface_pattern (surface, source);
 481
 482     _cairo_analysis_surface_operation_extents (surface,
 483                                                op, source, clip,
 484                                                &extents);
 485
 486     if (_cairo_operator_bounded_by_mask (op)) {
 487         cairo_rectangle_int_t mask_extents;
 488         cairo_int_status_t status;
 489
 490         status = _cairo_path_fixed_stroke_extents (path, style,
 491                                                    ctm, ctm_inverse,
 492                                                    tolerance,
 493                                                    &mask_extents);
 494         if (unlikely (status))
 495             return status;
 496
 497         _cairo_rectangle_intersect (&extents, &mask_extents);
 498     }
 499
 500     return _add_operation (surface, &extents, backend_status);
 501 }
 502
 503 static cairo_int_status_t
 504 _cairo_analysis_surface_fill (void                      *abstract_surface,
 505                               cairo_operator_t           op,
 506                               const cairo_pattern_t     *source,
 507                               const cairo_path_fixed_t  *path,
 508                               cairo_fill_rule_t          fill_rule,
 509                               double                     tolerance,
 510                               cairo_antialias_t          antialias,
 511                               const cairo_clip_t                *clip)
 512 {
 513     cairo_analysis_surface_t *surface = abstract_surface;
 514     cairo_int_status_t       backend_status;
 515     cairo_rectangle_int_t    extents;
 516
 517     if (surface->target->backend->fill == NULL) {
 518         backend_status = CAIRO_INT_STATUS_UNSUPPORTED;
 519     } else {
 520         backend_status =
 521             surface->target->backend->fill (surface->target, op,
 522                                             source, path, fill_rule,
 523                                             tolerance, antialias,
 524                                             clip);
 525         if (_cairo_int_status_is_error (backend_status))
 526             return backend_status;
 527     }
 528
 529     if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN)
 530         backend_status = _analyze_recording_surface_pattern (surface, source);
 531
 532     _cairo_analysis_surface_operation_extents (surface,
 533                                                op, source, clip,
 534                                                &extents);
 535
 536     if (_cairo_operator_bounded_by_mask (op)) {
 537         cairo_rectangle_int_t mask_extents;
 538
 539         _cairo_path_fixed_fill_extents (path, fill_rule, tolerance,
 540                                         &mask_extents);
 541
 542         _cairo_rectangle_intersect (&extents, &mask_extents);
 543     }
 544
 545     return _add_operation (surface, &extents, backend_status);
 546 }
 547
 548 static cairo_int_status_t
 549 _cairo_analysis_surface_show_glyphs (void                 *abstract_surface,
 550                                      cairo_operator_t      op,
 551                                      const cairo_pattern_t *source,
 552                                      cairo_glyph_t        *glyphs,
 553                                      int                   num_glyphs,
 554                                      cairo_scaled_font_t  *scaled_font,
 555                                      const cairo_clip_t         *clip)
 556 {
 557     cairo_analysis_surface_t *surface = abstract_surface;
 558     cairo_int_status_t       status, backend_status;
 559     cairo_rectangle_int_t    extents, glyph_extents;
 560
 561     /* Adapted from _cairo_surface_show_glyphs */
 562     if (surface->target->backend->show_glyphs != NULL) {
 563         backend_status =
 564             surface->target->backend->show_glyphs (surface->target, op,
 565                                                    source,
 566                                                    glyphs, num_glyphs,
 567                                                    scaled_font,
 568                                                    clip);
 569         if (_cairo_int_status_is_error (backend_status))
 570             return backend_status;
 571     }
 572     else if (surface->target->backend->show_text_glyphs != NULL)
 573     {
 574         backend_status =
 575             surface->target->backend->show_text_glyphs (surface->target, op,
 576                                                         source,
 577                                                         NULL, 0,
 578                                                         glyphs, num_glyphs,
 579                                                         NULL, 0,
 580                                                         FALSE,
 581                                                         scaled_font,
 582                                                         clip);
 583         if (_cairo_int_status_is_error (backend_status))
 584             return backend_status;
 585     }
 586     else
 587     {
 588         backend_status = CAIRO_INT_STATUS_UNSUPPORTED;
 589     }
 590
 591     if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN)
 592         backend_status = _analyze_recording_surface_pattern (surface, source);
 593
 594     _cairo_analysis_surface_operation_extents (surface,
 595                                                op, source, clip,
 596                                                &extents);
 597
 598     if (_cairo_operator_bounded_by_mask (op)) {
 599         status = _cairo_scaled_font_glyph_device_extents (scaled_font,
 600                                                           glyphs,
 601                                                           num_glyphs,
 602                                                           &glyph_extents,
 603                                                           NULL);
 604         if (unlikely (status))
 605             return status;
 606
 607         _cairo_rectangle_intersect (&extents, &glyph_extents);
 608     }
 609
 610     return _add_operation (surface, &extents, backend_status);
 611 }
 612
 613 static cairo_bool_t
 614 _cairo_analysis_surface_has_show_text_glyphs (void *abstract_surface)
 615 {
 616     cairo_analysis_surface_t *surface = abstract_surface;
 617
 618     return cairo_surface_has_show_text_glyphs (surface->target);
 619 }
 620
 621 static cairo_int_status_t
 622 _cairo_analysis_surface_show_text_glyphs (void                      *abstract_surface,
 623                                           cairo_operator_t           op,
 624                                           const cairo_pattern_t     *source,
 625                                           const char                *utf8,
 626                                           int                        utf8_len,
 627                                           cairo_glyph_t             *glyphs,
 628                                           int                        num_glyphs,
 629                                           const cairo_text_cluster_t *clusters,
 630                                           int                        num_clusters,
 631                                           cairo_text_cluster_flags_t cluster_flags,
 632                                           cairo_scaled_font_t       *scaled_font,
 633                                           const cairo_clip_t                *clip)
 634 {
 635     cairo_analysis_surface_t *surface = abstract_surface;
 636     cairo_int_status_t       status, backend_status;
 637     cairo_rectangle_int_t    extents, glyph_extents;
 638
 639     /* Adapted from _cairo_surface_show_glyphs */
 640     backend_status = CAIRO_INT_STATUS_UNSUPPORTED;
 641     if (surface->target->backend->show_text_glyphs != NULL) {
 642         backend_status =
 643             surface->target->backend->show_text_glyphs (surface->target, op,
 644                                                         source,
 645                                                         utf8, utf8_len,
 646                                                         glyphs, num_glyphs,
 647                                                         clusters, num_clusters,
 648                                                         cluster_flags,
 649                                                         scaled_font,
 650                                                         clip);
 651         if (_cairo_int_status_is_error (backend_status))
 652             return backend_status;
 653     }
 654     if (backend_status == CAIRO_INT_STATUS_UNSUPPORTED &&
 655         surface->target->backend->show_glyphs != NULL)
 656     {
 657         backend_status =
 658             surface->target->backend->show_glyphs (surface->target, op,
 659                                                    source,
 660                                                    glyphs, num_glyphs,
 661                                                    scaled_font,
 662                                                    clip);
 663         if (_cairo_int_status_is_error (backend_status))
 664             return backend_status;
 665     }
 666
 667     if (backend_status == CAIRO_INT_STATUS_ANALYZE_RECORDING_SURFACE_PATTERN)
 668         backend_status = _analyze_recording_surface_pattern (surface, source);
 669
 670     _cairo_analysis_surface_operation_extents (surface,
 671                                                op, source, clip,
 672                                                &extents);
 673
 674     if (_cairo_operator_bounded_by_mask (op)) {
 675         status = _cairo_scaled_font_glyph_device_extents (scaled_font,
 676                                                           glyphs,
 677                                                           num_glyphs,
 678                                                           &glyph_extents,
 679                                                           NULL);
 680         if (unlikely (status))
 681             return status;
 682
 683         _cairo_rectangle_intersect (&extents, &glyph_extents);
 684     }
 685
 686     return _add_operation (surface, &extents, backend_status);
 687 }
 688
 689 static const cairo_surface_backend_t cairo_analysis_surface_backend = {
 690     CAIRO_INTERNAL_SURFACE_TYPE_ANALYSIS,
 691
 692     _cairo_analysis_surface_finish,
 693     NULL,
 694
 695     NULL, /* create_similar */
 696     NULL, /* create_similar_image */
 697     NULL, /* map_to_image */
 698     NULL, /* unmap */
 699
 700     NULL, /* source */
 701     NULL, /* acquire_source_image */
 702     NULL, /* release_source_image */
 703     NULL, /* snapshot */
 704
 705     NULL, /* copy_page */
 706     NULL, /* show_page */
 707
 708     _cairo_analysis_surface_get_extents,
 709     NULL, /* get_font_options */
 710
 711     NULL, /* flush */
 712     NULL, /* mark_dirty_rectangle */
 713
 714     _cairo_analysis_surface_paint,
 715     _cairo_analysis_surface_mask,
 716     _cairo_analysis_surface_stroke,
 717     _cairo_analysis_surface_fill,
 718     NULL, /* fill_stroke */
 719     _cairo_analysis_surface_show_glyphs,
 720     _cairo_analysis_surface_has_show_text_glyphs,
 721     _cairo_analysis_surface_show_text_glyphs
 722 };
 723
 724 cairo_surface_t *
 725 _cairo_analysis_surface_create (cairo_surface_t         *target)
 726 {
 727     cairo_analysis_surface_t *surface;
 728     cairo_status_t status;
 729
 730     status = target->status;
 731     if (unlikely (status))
 732         return _cairo_surface_create_in_error (status);
 733
 734     surface = malloc (sizeof (cairo_analysis_surface_t));
 735     if (unlikely (surface == NULL))
 736         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
 737
 738     /* I believe the content type here is truly arbitrary. I'm quite
 739      * sure nothing will ever use this value. */
 740     _cairo_surface_init (&surface->base,
 741                          &cairo_analysis_surface_backend,
 742                          NULL, /* device */
 743                          CAIRO_CONTENT_COLOR_ALPHA);
 744
 745     cairo_matrix_init_identity (&surface->ctm);
 746     surface->has_ctm = FALSE;
 747
 748     surface->target = cairo_surface_reference (target);
 749     surface->first_op  = TRUE;
 750     surface->has_supported = FALSE;
 751     surface->has_unsupported = FALSE;
 752
 753     _cairo_region_init (&surface->supported_region);
 754     _cairo_region_init (&surface->fallback_region);
 755
 756     surface->page_bbox.p1.x = 0;
 757     surface->page_bbox.p1.y = 0;
 758     surface->page_bbox.p2.x = 0;
 759     surface->page_bbox.p2.y = 0;
 760
 761     return &surface->base;
 762 }
 763
 764 void
 765 _cairo_analysis_surface_set_ctm (cairo_surface_t *abstract_surface,
 766                                  const cairo_matrix_t  *ctm)
 767 {
 768     cairo_analysis_surface_t    *surface;
 769
 770     if (abstract_surface->status)
 771         return;
 772
 773     surface = (cairo_analysis_surface_t *) abstract_surface;
 774
 775     surface->ctm = *ctm;
 776     surface->has_ctm = ! _cairo_matrix_is_identity (&surface->ctm);
 777 }
 778
 779 void
 780 _cairo_analysis_surface_get_ctm (cairo_surface_t *abstract_surface,
 781                                  cairo_matrix_t  *ctm)
 782 {
 783     cairo_analysis_surface_t    *surface = (cairo_analysis_surface_t *) abstract_surface;
 784
 785     *ctm = surface->ctm;
 786 }
 787
 788
 789 cairo_region_t *
 790 _cairo_analysis_surface_get_supported (cairo_surface_t *abstract_surface)
 791 {
 792     cairo_analysis_surface_t    *surface = (cairo_analysis_surface_t *) abstract_surface;
 793
 794     return &surface->supported_region;
 795 }
 796
 797 cairo_region_t *
 798 _cairo_analysis_surface_get_unsupported (cairo_surface_t *abstract_surface)
 799 {
 800     cairo_analysis_surface_t    *surface = (cairo_analysis_surface_t *) abstract_surface;
 801
 802     return &surface->fallback_region;
 803 }
 804
 805 cairo_bool_t
 806 _cairo_analysis_surface_has_supported (cairo_surface_t *abstract_surface)
 807 {
 808     cairo_analysis_surface_t    *surface = (cairo_analysis_surface_t *) abstract_surface;
 809
 810     return surface->has_supported;
 811 }
 812
 813 cairo_bool_t
 814 _cairo_analysis_surface_has_unsupported (cairo_surface_t *abstract_surface)
 815 {
 816     cairo_analysis_surface_t    *surface = (cairo_analysis_surface_t *) abstract_surface;
 817
 818     return surface->has_unsupported;
 819 }
 820
 821 void
 822 _cairo_analysis_surface_get_bounding_box (cairo_surface_t *abstract_surface,
 823                                           cairo_box_t     *bbox)
 824 {
 825     cairo_analysis_surface_t    *surface = (cairo_analysis_surface_t *) abstract_surface;
 826
 827     *bbox = surface->page_bbox;
 828 }
 829
 830 /* null surface type: a surface that does nothing (has no side effects, yay!) */
 831
 832 static cairo_int_status_t
 833 _return_success (void)
 834 {
 835     return CAIRO_STATUS_SUCCESS;
 836 }
 837
 838 /* These typedefs are just to silence the compiler... */
 839 typedef cairo_int_status_t
 840 (*_paint_func)                  (void                   *surface,
 841                                  cairo_operator_t        op,
 842                                  const cairo_pattern_t  *source,
 843                                  const cairo_clip_t             *clip);
 844
 845 typedef cairo_int_status_t
 846 (*_mask_func)                   (void                   *surface,
 847                                  cairo_operator_t        op,
 848                                  const cairo_pattern_t  *source,
 849                                  const cairo_pattern_t  *mask,
 850                                  const cairo_clip_t             *clip);
 851
 852 typedef cairo_int_status_t
 853 (*_stroke_func)                 (void                   *surface,
 854                                  cairo_operator_t        op,
 855                                  const cairo_pattern_t  *source,
 856                                  const cairo_path_fixed_t       *path,
 857                                  const cairo_stroke_style_t     *style,
 858                                  const cairo_matrix_t           *ctm,
 859                                  const cairo_matrix_t           *ctm_inverse,
 860                                  double                  tolerance,
 861                                  cairo_antialias_t       antialias,
 862                                  const cairo_clip_t             *clip);
 863
 864 typedef cairo_int_status_t
 865 (*_fill_func)                   (void                   *surface,
 866                                  cairo_operator_t        op,
 867                                  const cairo_pattern_t  *source,
 868                                  const cairo_path_fixed_t       *path,
 869                                  cairo_fill_rule_t       fill_rule,
 870                                  double                  tolerance,
 871                                  cairo_antialias_t       antialias,
 872                                  const cairo_clip_t             *clip);
 873
 874 typedef cairo_int_status_t
 875 (*_show_glyphs_func)            (void                   *surface,
 876                                  cairo_operator_t        op,
 877                                  const cairo_pattern_t  *source,
 878                                  cairo_glyph_t          *glyphs,
 879                                  int                     num_glyphs,
 880                                  cairo_scaled_font_t    *scaled_font,
 881                                  const cairo_clip_t             *clip);
 882
 883 static const cairo_surface_backend_t cairo_null_surface_backend = {
 884     CAIRO_INTERNAL_SURFACE_TYPE_NULL,
 885     NULL, /* finish */
 886
 887     NULL, /* only accessed through the surface functions */
 888
 889     NULL, /* create_similar */
 890     NULL, /* create similar image */
 891     NULL, /* map to image */
 892     NULL, /* unmap image*/
 893
 894     NULL, /* source */
 895     NULL, /* acquire_source_image */
 896     NULL, /* release_source_image */
 897     NULL, /* snapshot */
 898
 899     NULL, /* copy_page */
 900     NULL, /* show_page */
 901
 902     NULL, /* get_extents */
 903     NULL, /* get_font_options */
 904
 905     NULL, /* flush */
 906     NULL, /* mark_dirty_rectangle */
 907
 908     (_paint_func) _return_success,          /* paint */
 909     (_mask_func) _return_success,           /* mask */
 910     (_stroke_func) _return_success,         /* stroke */
 911     (_fill_func) _return_success,           /* fill */
 912     NULL, /* fill_stroke */
 913     (_show_glyphs_func) _return_success,    /* show_glyphs */
 914     NULL, /* has_show_text_glyphs */
 915     NULL  /* show_text_glyphs */
 916 };
 917
 918 cairo_surface_t *
 919 _cairo_null_surface_create (cairo_content_t content)
 920 {
 921     cairo_surface_t *surface;
 922
 923     surface = malloc (sizeof (cairo_surface_t));
 924     if (unlikely (surface == NULL)) {
 925         return _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
 926     }
 927
 928     _cairo_surface_init (surface,
 929                          &cairo_null_surface_backend,
 930                          NULL, /* device */
 931                          content);
 932
 933     return surface;
 934 }