cc/playback/picture_pile_impl.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <algorithm>
   6 #include <limits>
   7 #include <set>
   8
   9 #include "base/trace_event/trace_event.h"
  10 #include "cc/base/region.h"
  11 #include "cc/debug/debug_colors.h"
  12 #include "cc/playback/picture_pile_impl.h"
  13 #include "cc/playback/raster_source_helper.h"
  14 #include "skia/ext/analysis_canvas.h"
  15 #include "third_party/skia/include/core/SkCanvas.h"
  16 #include "third_party/skia/include/core/SkPictureRecorder.h"
  17 #include "ui/gfx/geometry/rect_conversions.h"
  18
  19 namespace cc {
  20
  21 scoped_refptr<PicturePileImpl> PicturePileImpl::CreateFromPicturePile(
  22     const PicturePile* other,
  23     bool can_use_lcd_text) {
  24   return make_scoped_refptr(new PicturePileImpl(other, can_use_lcd_text));
  25 }
  26
  27 PicturePileImpl::PicturePileImpl()
  28     : background_color_(SK_ColorTRANSPARENT),
  29       requires_clear_(true),
  30       can_use_lcd_text_(true),
  31       is_solid_color_(false),
  32       solid_color_(SK_ColorTRANSPARENT),
  33       has_any_recordings_(false),
  34       clear_canvas_with_debug_color_(false),
  35       min_contents_scale_(0.f),
  36       slow_down_raster_scale_factor_for_debug_(0),
  37       should_attempt_to_use_distance_field_text_(false),
  38       picture_memory_usage_(0) {
  39 }
  40
  41 PicturePileImpl::PicturePileImpl(const PicturePile* other,
  42                                  bool can_use_lcd_text)
  43     : picture_map_(other->picture_map_),
  44       tiling_(other->tiling_),
  45       background_color_(other->background_color_),
  46       requires_clear_(other->requires_clear_),
  47       can_use_lcd_text_(can_use_lcd_text),
  48       is_solid_color_(other->is_solid_color_),
  49       solid_color_(other->solid_color_),
  50       recorded_viewport_(other->recorded_viewport_),
  51       has_any_recordings_(other->has_any_recordings_),
  52       clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_),
  53       min_contents_scale_(other->min_contents_scale_),
  54       slow_down_raster_scale_factor_for_debug_(
  55           other->slow_down_raster_scale_factor_for_debug_),
  56       should_attempt_to_use_distance_field_text_(false),
  57       picture_memory_usage_(0) {
  58   // Figure out the picture size upon construction.
  59   base::hash_set<const Picture*> pictures_seen;
  60   for (const auto& map_value : picture_map_) {
  61     const Picture* picture = map_value.second.get();
  62     if (pictures_seen.insert(picture).second)
  63       picture_memory_usage_ += picture->ApproximateMemoryUsage();
  64   }
  65 }
  66
  67 PicturePileImpl::PicturePileImpl(const PicturePileImpl* other,
  68                                  bool can_use_lcd_text)
  69     : picture_map_(other->picture_map_),
  70       tiling_(other->tiling_),
  71       background_color_(other->background_color_),
  72       requires_clear_(other->requires_clear_),
  73       can_use_lcd_text_(can_use_lcd_text),
  74       is_solid_color_(other->is_solid_color_),
  75       solid_color_(other->solid_color_),
  76       recorded_viewport_(other->recorded_viewport_),
  77       has_any_recordings_(other->has_any_recordings_),
  78       clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_),
  79       min_contents_scale_(other->min_contents_scale_),
  80       slow_down_raster_scale_factor_for_debug_(
  81           other->slow_down_raster_scale_factor_for_debug_),
  82       should_attempt_to_use_distance_field_text_(
  83           other->should_attempt_to_use_distance_field_text_),
  84       picture_memory_usage_(other->picture_memory_usage_) {
  85 }
  86
  87 PicturePileImpl::~PicturePileImpl() {
  88 }
  89
  90 void PicturePileImpl::PlaybackToSharedCanvas(SkCanvas* canvas,
  91                                              const gfx::Rect& canvas_rect,
  92                                              float contents_scale) const {
  93   RasterCommon(canvas, NULL, canvas_rect, contents_scale);
  94 }
  95
  96 void PicturePileImpl::RasterForAnalysis(skia::AnalysisCanvas* canvas,
  97                                         const gfx::Rect& canvas_rect,
  98                                         float contents_scale) const {
  99   RasterCommon(canvas, canvas, canvas_rect, contents_scale);
 100 }
 101
 102 void PicturePileImpl::PlaybackToCanvas(SkCanvas* canvas,
 103                                        const gfx::Rect& canvas_bitmap_rect,
 104                                        const gfx::Rect& canvas_playback_rect,
 105                                        float contents_scale) const {
 106   RasterSourceHelper::PrepareForPlaybackToCanvas(
 107       canvas, canvas_bitmap_rect, canvas_bitmap_rect,
 108       gfx::Rect(tiling_.tiling_size()), contents_scale, background_color_,
 109       clear_canvas_with_debug_color_, requires_clear_);
 110   RasterCommon(canvas, NULL, canvas_bitmap_rect, contents_scale);
 111 }
 112
 113 void PicturePileImpl::CoalesceRasters(const gfx::Rect& canvas_rect,
 114                                       const gfx::Rect& content_rect,
 115                                       float contents_scale,
 116                                       PictureRegionMap* results) const {
 117   DCHECK(results);
 118   // Rasterize the collection of relevant picture piles.
 119   gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
 120       content_rect, 1.f / contents_scale);
 121
 122   // Make sure pictures don't overlap by keeping track of previous right/bottom.
 123   int min_content_left = -1;
 124   int min_content_top = -1;
 125   int last_row_index = -1;
 126   int last_col_index = -1;
 127   gfx::Rect last_content_rect;
 128
 129   // Coalesce rasters of the same picture into different rects:
 130   //  - Compute the clip of each of the pile chunks,
 131   //  - Subtract it from the canvas rect to get difference region
 132   //  - Later, use the difference region to subtract each of the comprising
 133   //    rects from the canvas.
 134   // Note that in essence, we're trying to mimic clipRegion with intersect op
 135   // that also respects the current canvas transform and clip. In order to use
 136   // the canvas transform, we must stick to clipRect operations (clipRegion
 137   // ignores the transform). Intersect then can be written as subtracting the
 138   // negation of the region we're trying to intersect. Luckily, we know that all
 139   // of the rects will have to fit into |content_rect|, so we can start with
 140   // that and subtract chunk rects to get the region that we need to subtract
 141   // from the canvas. Then, we can use clipRect with difference op to subtract
 142   // each rect in the region.
 143   bool include_borders = true;
 144   for (TilingData::Iterator tile_iter(&tiling_, layer_rect, include_borders);
 145        tile_iter;
 146        ++tile_iter) {
 147     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 148     if (map_iter == picture_map_.end())
 149       continue;
 150     const Picture* picture = map_iter->second.get();
 151     DCHECK(picture);
 152
 153     // This is intentionally *enclosed* rect, so that the clip is aligned on
 154     // integral post-scale content pixels and does not extend past the edges
 155     // of the picture chunk's layer rect.  The min_contents_scale enforces that
 156     // enough buffer pixels have been added such that the enclosed rect
 157     // encompasses all invalidated pixels at any larger scale level.
 158     gfx::Rect chunk_rect = PaddedRect(tile_iter.index());
 159     gfx::Rect content_clip =
 160         gfx::ScaleToEnclosedRect(chunk_rect, contents_scale);
 161     DCHECK(!content_clip.IsEmpty()) << "Layer rect: "
 162                                     << picture->LayerRect().ToString()
 163                                     << "Contents scale: " << contents_scale;
 164     content_clip.Intersect(canvas_rect);
 165
 166     // Make sure iterator goes top->bottom.
 167     DCHECK_GE(tile_iter.index_y(), last_row_index);
 168     if (tile_iter.index_y() > last_row_index) {
 169       // First tile in a new row.
 170       min_content_left = content_clip.x();
 171       min_content_top = last_content_rect.bottom();
 172     } else {
 173       // Make sure iterator goes left->right.
 174       DCHECK_GT(tile_iter.index_x(), last_col_index);
 175       min_content_left = last_content_rect.right();
 176       min_content_top = last_content_rect.y();
 177     }
 178
 179     last_col_index = tile_iter.index_x();
 180     last_row_index = tile_iter.index_y();
 181
 182     // Only inset if the content_clip is less than then previous min.
 183     int inset_left = std::max(0, min_content_left - content_clip.x());
 184     int inset_top = std::max(0, min_content_top - content_clip.y());
 185     content_clip.Inset(inset_left, inset_top, 0, 0);
 186
 187     PictureRegionMap::iterator it = results->find(picture);
 188     Region* clip_region;
 189     if (it == results->end()) {
 190       // The clip for a set of coalesced pictures starts out clipping the entire
 191       // canvas.  Each picture added to the set must subtract its own bounds
 192       // from the clip region, poking a hole so that the picture is unclipped.
 193       clip_region = &(*results)[picture];
 194       *clip_region = canvas_rect;
 195     } else {
 196       clip_region = &it->second;
 197     }
 198
 199     DCHECK(clip_region->Contains(content_clip))
 200         << "Content clips should not overlap.";
 201     clip_region->Subtract(content_clip);
 202     last_content_rect = content_clip;
 203   }
 204 }
 205
 206 void PicturePileImpl::RasterCommon(SkCanvas* canvas,
 207                                    SkPicture::AbortCallback* callback,
 208                                    const gfx::Rect& canvas_rect,
 209                                    float contents_scale) const {
 210   DCHECK(contents_scale >= min_contents_scale_);
 211
 212   canvas->translate(-canvas_rect.x(), -canvas_rect.y());
 213   gfx::Rect content_tiling_rect = gfx::ScaleToEnclosingRect(
 214       gfx::Rect(tiling_.tiling_size()), contents_scale);
 215   content_tiling_rect.Intersect(canvas_rect);
 216
 217   canvas->clipRect(gfx::RectToSkRect(content_tiling_rect),
 218                    SkRegion::kIntersect_Op);
 219
 220   PictureRegionMap picture_region_map;
 221   CoalesceRasters(
 222       canvas_rect, content_tiling_rect, contents_scale, &picture_region_map);
 223
 224 #ifndef NDEBUG
 225   Region total_clip;
 226 #endif  // NDEBUG
 227
 228   // Iterate the coalesced map and use each picture's region
 229   // to clip the canvas.
 230   for (PictureRegionMap::iterator it = picture_region_map.begin();
 231        it != picture_region_map.end();
 232        ++it) {
 233     const Picture* picture = it->first;
 234     Region negated_clip_region = it->second;
 235
 236 #ifndef NDEBUG
 237     Region positive_clip = content_tiling_rect;
 238     positive_clip.Subtract(negated_clip_region);
 239     // Make sure we never rasterize the same region twice.
 240     DCHECK(!total_clip.Intersects(positive_clip));
 241     total_clip.Union(positive_clip);
 242 #endif  // NDEBUG
 243
 244     int repeat_count = std::max(1, slow_down_raster_scale_factor_for_debug_);
 245
 246     for (int i = 0; i < repeat_count; ++i)
 247       picture->Raster(canvas, callback, negated_clip_region, contents_scale);
 248   }
 249
 250 #ifndef NDEBUG
 251   // Fill the clip with debug color. This allows us to
 252   // distinguish between non painted areas and problems with missing
 253   // pictures.
 254   SkPaint paint;
 255   for (Region::Iterator it(total_clip); it.has_rect(); it.next())
 256     canvas->clipRect(gfx::RectToSkRect(it.rect()), SkRegion::kDifference_Op);
 257   paint.setColor(DebugColors::MissingPictureFillColor());
 258   paint.setXfermodeMode(SkXfermode::kSrc_Mode);
 259   canvas->drawPaint(paint);
 260 #endif  // NDEBUG
 261 }
 262
 263 skia::RefPtr<SkPicture> PicturePileImpl::GetFlattenedPicture() {
 264   TRACE_EVENT0("cc", "PicturePileImpl::GetFlattenedPicture");
 265
 266   gfx::Rect tiling_rect(tiling_.tiling_size());
 267   SkPictureRecorder recorder;
 268   SkCanvas* canvas =
 269       recorder.beginRecording(tiling_rect.width(), tiling_rect.height());
 270   if (!tiling_rect.IsEmpty())
 271     PlaybackToCanvas(canvas, tiling_rect, tiling_rect, 1.0);
 272   skia::RefPtr<SkPicture> picture =
 273       skia::AdoptRef(recorder.endRecordingAsPicture());
 274
 275   return picture;
 276 }
 277
 278 size_t PicturePileImpl::GetPictureMemoryUsage() const {
 279   return picture_memory_usage_;
 280 }
 281
 282 void PicturePileImpl::PerformSolidColorAnalysis(
 283     const gfx::Rect& content_rect,
 284     float contents_scale,
 285     RasterSource::SolidColorAnalysis* analysis) const {
 286   DCHECK(analysis);
 287   TRACE_EVENT0("cc", "PicturePileImpl::PerformSolidColorAnalysis");
 288
 289   gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
 290       content_rect, 1.0f / contents_scale);
 291
 292   layer_rect.Intersect(gfx::Rect(tiling_.tiling_size()));
 293
 294   skia::AnalysisCanvas canvas(layer_rect.width(), layer_rect.height());
 295
 296   RasterForAnalysis(&canvas, layer_rect, 1.0f);
 297
 298   analysis->is_solid_color = canvas.GetColorIfSolid(&analysis->solid_color);
 299 }
 300
 301 void PicturePileImpl::GatherPixelRefs(
 302     const gfx::Rect& layer_rect,
 303     std::vector<skia::PositionPixelRef>* pixel_refs) const {
 304   DCHECK_EQ(0u, pixel_refs->size());
 305   for (PixelRefIterator iter(layer_rect, this); iter; ++iter) {
 306     pixel_refs->push_back(*iter);
 307   }
 308 }
 309
 310 bool PicturePileImpl::CoversRect(const gfx::Rect& layer_rect) const {
 311   if (tiling_.tiling_size().IsEmpty())
 312     return false;
 313   gfx::Rect bounded_rect = layer_rect;
 314   bounded_rect.Intersect(gfx::Rect(tiling_.tiling_size()));
 315
 316   // Common case inside of viewport to avoid the slower map lookups.
 317   if (recorded_viewport_.Contains(bounded_rect)) {
 318     // Sanity check that there are no false positives in recorded_viewport_.
 319     DCHECK(CanRasterSlowTileCheck(bounded_rect));
 320     return true;
 321   }
 322
 323   return CanRasterSlowTileCheck(bounded_rect);
 324 }
 325
 326 gfx::Size PicturePileImpl::GetSize() const {
 327   return tiling_.tiling_size();
 328 }
 329
 330 bool PicturePileImpl::IsSolidColor() const {
 331   return is_solid_color_;
 332 }
 333
 334 SkColor PicturePileImpl::GetSolidColor() const {
 335   DCHECK(IsSolidColor());
 336   return solid_color_;
 337 }
 338
 339 bool PicturePileImpl::HasRecordings() const {
 340   return has_any_recordings_;
 341 }
 342
 343 gfx::Rect PicturePileImpl::RecordedViewport() const {
 344   return recorded_viewport_;
 345 }
 346
 347 gfx::Rect PicturePileImpl::PaddedRect(const PictureMapKey& key) const {
 348   gfx::Rect padded_rect = tiling_.TileBounds(key.first, key.second);
 349   padded_rect.Inset(-buffer_pixels(), -buffer_pixels(), -buffer_pixels(),
 350                     -buffer_pixels());
 351   return padded_rect;
 352 }
 353
 354 bool PicturePileImpl::CanRasterSlowTileCheck(
 355     const gfx::Rect& layer_rect) const {
 356   bool include_borders = false;
 357   for (TilingData::Iterator tile_iter(&tiling_, layer_rect, include_borders);
 358        tile_iter; ++tile_iter) {
 359     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 360     if (map_iter == picture_map_.end())
 361       return false;
 362   }
 363   return true;
 364 }
 365
 366 void PicturePileImpl::SetShouldAttemptToUseDistanceFieldText() {
 367   should_attempt_to_use_distance_field_text_ = true;
 368 }
 369
 370 bool PicturePileImpl::ShouldAttemptToUseDistanceFieldText() const {
 371   return should_attempt_to_use_distance_field_text_;
 372 }
 373
 374 void PicturePileImpl::AsValueInto(
 375     base::trace_event::TracedValue* pictures) const {
 376   gfx::Rect tiling_rect(tiling_.tiling_size());
 377   std::set<const void*> appended_pictures;
 378   bool include_borders = true;
 379   for (TilingData::Iterator tile_iter(&tiling_, tiling_rect, include_borders);
 380        tile_iter; ++tile_iter) {
 381     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 382     if (map_iter == picture_map_.end())
 383       continue;
 384
 385     const Picture* picture = map_iter->second.get();
 386     if (appended_pictures.count(picture) == 0) {
 387       appended_pictures.insert(picture);
 388       TracedValue::AppendIDRef(picture, pictures);
 389     }
 390   }
 391 }
 392
 393 bool PicturePileImpl::CanUseLCDText() const {
 394   return can_use_lcd_text_;
 395 }
 396
 397 scoped_refptr<RasterSource> PicturePileImpl::CreateCloneWithoutLCDText() const {
 398   DCHECK(CanUseLCDText());
 399   bool can_use_lcd_text = false;
 400   return scoped_refptr<RasterSource>(
 401       new PicturePileImpl(this, can_use_lcd_text));
 402 }
 403
 404 PicturePileImpl::PixelRefIterator::PixelRefIterator(
 405     const gfx::Rect& layer_rect,
 406     const PicturePileImpl* picture_pile)
 407     : picture_pile_(picture_pile),
 408       layer_rect_(layer_rect),
 409       tile_iterator_(&picture_pile_->tiling_,
 410                      layer_rect_,
 411                      false /* include_borders */) {
 412   // Early out if there isn't a single tile.
 413   if (!tile_iterator_)
 414     return;
 415
 416   AdvanceToTilePictureWithPixelRefs();
 417 }
 418
 419 PicturePileImpl::PixelRefIterator::~PixelRefIterator() {
 420 }
 421
 422 PicturePileImpl::PixelRefIterator&
 423     PicturePileImpl::PixelRefIterator::operator++() {
 424   ++pixel_ref_iterator_;
 425   if (pixel_ref_iterator_)
 426     return *this;
 427
 428   ++tile_iterator_;
 429   AdvanceToTilePictureWithPixelRefs();
 430   return *this;
 431 }
 432
 433 void PicturePileImpl::PixelRefIterator::AdvanceToTilePictureWithPixelRefs() {
 434   for (; tile_iterator_; ++tile_iterator_) {
 435     PictureMap::const_iterator it =
 436         picture_pile_->picture_map_.find(tile_iterator_.index());
 437     if (it == picture_pile_->picture_map_.end())
 438       continue;
 439
 440     const Picture* picture = it->second.get();
 441     if ((processed_pictures_.count(picture) != 0) ||
 442         !picture->WillPlayBackBitmaps())
 443       continue;
 444
 445     processed_pictures_.insert(picture);
 446     pixel_ref_iterator_ = picture->GetPixelRefMapIterator(layer_rect_);
 447     if (pixel_ref_iterator_)
 448       break;
 449   }
 450 }
 451
 452 void PicturePileImpl::DidBeginTracing() {
 453   std::set<const void*> processed_pictures;
 454   for (const auto& map_pair : picture_map_) {
 455     const Picture* picture = map_pair.second.get();
 456     if (processed_pictures.count(picture) == 0) {
 457       picture->EmitTraceSnapshot();
 458       processed_pictures.insert(picture);
 459     }
 460   }
 461 }
 462
 463 }  // namespace cc