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_rect,
 104                                        float contents_scale) const {
 105   RasterSourceHelper::PrepareForPlaybackToCanvas(
 106       canvas, canvas_rect, gfx::Rect(tiling_.tiling_size()), contents_scale,
 107       background_color_, clear_canvas_with_debug_color_, requires_clear_);
 108   RasterCommon(canvas, NULL, canvas_rect, contents_scale);
 109 }
 110
 111 void PicturePileImpl::CoalesceRasters(const gfx::Rect& canvas_rect,
 112                                       const gfx::Rect& content_rect,
 113                                       float contents_scale,
 114                                       PictureRegionMap* results) const {
 115   DCHECK(results);
 116   // Rasterize the collection of relevant picture piles.
 117   gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
 118       content_rect, 1.f / contents_scale);
 119
 120   // Make sure pictures don't overlap by keeping track of previous right/bottom.
 121   int min_content_left = -1;
 122   int min_content_top = -1;
 123   int last_row_index = -1;
 124   int last_col_index = -1;
 125   gfx::Rect last_content_rect;
 126
 127   // Coalesce rasters of the same picture into different rects:
 128   //  - Compute the clip of each of the pile chunks,
 129   //  - Subtract it from the canvas rect to get difference region
 130   //  - Later, use the difference region to subtract each of the comprising
 131   //    rects from the canvas.
 132   // Note that in essence, we're trying to mimic clipRegion with intersect op
 133   // that also respects the current canvas transform and clip. In order to use
 134   // the canvas transform, we must stick to clipRect operations (clipRegion
 135   // ignores the transform). Intersect then can be written as subtracting the
 136   // negation of the region we're trying to intersect. Luckily, we know that all
 137   // of the rects will have to fit into |content_rect|, so we can start with
 138   // that and subtract chunk rects to get the region that we need to subtract
 139   // from the canvas. Then, we can use clipRect with difference op to subtract
 140   // each rect in the region.
 141   bool include_borders = true;
 142   for (TilingData::Iterator tile_iter(&tiling_, layer_rect, include_borders);
 143        tile_iter;
 144        ++tile_iter) {
 145     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 146     if (map_iter == picture_map_.end())
 147       continue;
 148     const Picture* picture = map_iter->second.get();
 149     DCHECK(picture);
 150
 151     // This is intentionally *enclosed* rect, so that the clip is aligned on
 152     // integral post-scale content pixels and does not extend past the edges
 153     // of the picture chunk's layer rect.  The min_contents_scale enforces that
 154     // enough buffer pixels have been added such that the enclosed rect
 155     // encompasses all invalidated pixels at any larger scale level.
 156     gfx::Rect chunk_rect = PaddedRect(tile_iter.index());
 157     gfx::Rect content_clip =
 158         gfx::ScaleToEnclosedRect(chunk_rect, contents_scale);
 159     DCHECK(!content_clip.IsEmpty()) << "Layer rect: "
 160                                     << picture->LayerRect().ToString()
 161                                     << "Contents scale: " << contents_scale;
 162     content_clip.Intersect(canvas_rect);
 163
 164     // Make sure iterator goes top->bottom.
 165     DCHECK_GE(tile_iter.index_y(), last_row_index);
 166     if (tile_iter.index_y() > last_row_index) {
 167       // First tile in a new row.
 168       min_content_left = content_clip.x();
 169       min_content_top = last_content_rect.bottom();
 170     } else {
 171       // Make sure iterator goes left->right.
 172       DCHECK_GT(tile_iter.index_x(), last_col_index);
 173       min_content_left = last_content_rect.right();
 174       min_content_top = last_content_rect.y();
 175     }
 176
 177     last_col_index = tile_iter.index_x();
 178     last_row_index = tile_iter.index_y();
 179
 180     // Only inset if the content_clip is less than then previous min.
 181     int inset_left = std::max(0, min_content_left - content_clip.x());
 182     int inset_top = std::max(0, min_content_top - content_clip.y());
 183     content_clip.Inset(inset_left, inset_top, 0, 0);
 184
 185     PictureRegionMap::iterator it = results->find(picture);
 186     Region* clip_region;
 187     if (it == results->end()) {
 188       // The clip for a set of coalesced pictures starts out clipping the entire
 189       // canvas.  Each picture added to the set must subtract its own bounds
 190       // from the clip region, poking a hole so that the picture is unclipped.
 191       clip_region = &(*results)[picture];
 192       *clip_region = canvas_rect;
 193     } else {
 194       clip_region = &it->second;
 195     }
 196
 197     DCHECK(clip_region->Contains(content_clip))
 198         << "Content clips should not overlap.";
 199     clip_region->Subtract(content_clip);
 200     last_content_rect = content_clip;
 201   }
 202 }
 203
 204 void PicturePileImpl::RasterCommon(SkCanvas* canvas,
 205                                    SkPicture::AbortCallback* callback,
 206                                    const gfx::Rect& canvas_rect,
 207                                    float contents_scale) const {
 208   DCHECK(contents_scale >= min_contents_scale_);
 209
 210   canvas->translate(-canvas_rect.x(), -canvas_rect.y());
 211   gfx::Rect content_tiling_rect = gfx::ToEnclosingRect(
 212       gfx::ScaleRect(gfx::Rect(tiling_.tiling_size()), contents_scale));
 213   content_tiling_rect.Intersect(canvas_rect);
 214
 215   canvas->clipRect(gfx::RectToSkRect(content_tiling_rect),
 216                    SkRegion::kIntersect_Op);
 217
 218   PictureRegionMap picture_region_map;
 219   CoalesceRasters(
 220       canvas_rect, content_tiling_rect, contents_scale, &picture_region_map);
 221
 222 #ifndef NDEBUG
 223   Region total_clip;
 224 #endif  // NDEBUG
 225
 226   // Iterate the coalesced map and use each picture's region
 227   // to clip the canvas.
 228   for (PictureRegionMap::iterator it = picture_region_map.begin();
 229        it != picture_region_map.end();
 230        ++it) {
 231     const Picture* picture = it->first;
 232     Region negated_clip_region = it->second;
 233
 234 #ifndef NDEBUG
 235     Region positive_clip = content_tiling_rect;
 236     positive_clip.Subtract(negated_clip_region);
 237     // Make sure we never rasterize the same region twice.
 238     DCHECK(!total_clip.Intersects(positive_clip));
 239     total_clip.Union(positive_clip);
 240 #endif  // NDEBUG
 241
 242     int repeat_count = std::max(1, slow_down_raster_scale_factor_for_debug_);
 243
 244     for (int j = 0; j < repeat_count; ++j)
 245       picture->Raster(canvas, callback, negated_clip_region, contents_scale);
 246   }
 247
 248 #ifndef NDEBUG
 249   // Fill the clip with debug color. This allows us to
 250   // distinguish between non painted areas and problems with missing
 251   // pictures.
 252   SkPaint paint;
 253   for (Region::Iterator it(total_clip); it.has_rect(); it.next())
 254     canvas->clipRect(gfx::RectToSkRect(it.rect()), SkRegion::kDifference_Op);
 255   paint.setColor(DebugColors::MissingPictureFillColor());
 256   paint.setXfermodeMode(SkXfermode::kSrc_Mode);
 257   canvas->drawPaint(paint);
 258 #endif  // NDEBUG
 259 }
 260
 261 skia::RefPtr<SkPicture> PicturePileImpl::GetFlattenedPicture() {
 262   TRACE_EVENT0("cc", "PicturePileImpl::GetFlattenedPicture");
 263
 264   gfx::Rect tiling_rect(tiling_.tiling_size());
 265   SkPictureRecorder recorder;
 266   SkCanvas* canvas =
 267       recorder.beginRecording(tiling_rect.width(), tiling_rect.height());
 268   if (!tiling_rect.IsEmpty())
 269     PlaybackToCanvas(canvas, tiling_rect, 1.0);
 270   skia::RefPtr<SkPicture> picture =
 271       skia::AdoptRef(recorder.endRecordingAsPicture());
 272
 273   return picture;
 274 }
 275
 276 size_t PicturePileImpl::GetPictureMemoryUsage() const {
 277   return picture_memory_usage_;
 278 }
 279
 280 void PicturePileImpl::PerformSolidColorAnalysis(
 281     const gfx::Rect& content_rect,
 282     float contents_scale,
 283     RasterSource::SolidColorAnalysis* analysis) const {
 284   DCHECK(analysis);
 285   TRACE_EVENT0("cc", "PicturePileImpl::PerformSolidColorAnalysis");
 286
 287   gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
 288       content_rect, 1.0f / contents_scale);
 289
 290   layer_rect.Intersect(gfx::Rect(tiling_.tiling_size()));
 291
 292   skia::AnalysisCanvas canvas(layer_rect.width(), layer_rect.height());
 293
 294   RasterForAnalysis(&canvas, layer_rect, 1.0f);
 295
 296   analysis->is_solid_color = canvas.GetColorIfSolid(&analysis->solid_color);
 297 }
 298
 299 void PicturePileImpl::GatherPixelRefs(
 300     const gfx::Rect& content_rect,
 301     float contents_scale,
 302     std::vector<SkPixelRef*>* pixel_refs) const {
 303   DCHECK_EQ(0u, pixel_refs->size());
 304   for (PixelRefIterator iter(content_rect, contents_scale, this); iter;
 305        ++iter) {
 306     pixel_refs->push_back(*iter);
 307   }
 308 }
 309
 310 bool PicturePileImpl::CoversRect(const gfx::Rect& content_rect,
 311                                  float contents_scale) const {
 312   if (tiling_.tiling_size().IsEmpty())
 313     return false;
 314   gfx::Rect layer_rect =
 315       gfx::ScaleToEnclosingRect(content_rect, 1.f / contents_scale);
 316   layer_rect.Intersect(gfx::Rect(tiling_.tiling_size()));
 317
 318   // Common case inside of viewport to avoid the slower map lookups.
 319   if (recorded_viewport_.Contains(layer_rect)) {
 320     // Sanity check that there are no false positives in recorded_viewport_.
 321     DCHECK(CanRasterSlowTileCheck(layer_rect));
 322     return true;
 323   }
 324
 325   return CanRasterSlowTileCheck(layer_rect);
 326 }
 327
 328 gfx::Size PicturePileImpl::GetSize() const {
 329   return tiling_.tiling_size();
 330 }
 331
 332 bool PicturePileImpl::IsSolidColor() const {
 333   return is_solid_color_;
 334 }
 335
 336 SkColor PicturePileImpl::GetSolidColor() const {
 337   DCHECK(IsSolidColor());
 338   return solid_color_;
 339 }
 340
 341 bool PicturePileImpl::HasRecordings() const {
 342   return has_any_recordings_;
 343 }
 344
 345 gfx::Rect PicturePileImpl::PaddedRect(const PictureMapKey& key) const {
 346   gfx::Rect padded_rect = tiling_.TileBounds(key.first, key.second);
 347   padded_rect.Inset(-buffer_pixels(), -buffer_pixels(), -buffer_pixels(),
 348                     -buffer_pixels());
 349   return padded_rect;
 350 }
 351
 352 bool PicturePileImpl::CanRasterSlowTileCheck(
 353     const gfx::Rect& layer_rect) const {
 354   bool include_borders = false;
 355   for (TilingData::Iterator tile_iter(&tiling_, layer_rect, include_borders);
 356        tile_iter; ++tile_iter) {
 357     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 358     if (map_iter == picture_map_.end())
 359       return false;
 360   }
 361   return true;
 362 }
 363
 364 void PicturePileImpl::SetShouldAttemptToUseDistanceFieldText() {
 365   should_attempt_to_use_distance_field_text_ = true;
 366 }
 367
 368 bool PicturePileImpl::ShouldAttemptToUseDistanceFieldText() const {
 369   return should_attempt_to_use_distance_field_text_;
 370 }
 371
 372 void PicturePileImpl::AsValueInto(
 373     base::trace_event::TracedValue* pictures) const {
 374   gfx::Rect tiling_rect(tiling_.tiling_size());
 375   std::set<const void*> appended_pictures;
 376   bool include_borders = true;
 377   for (TilingData::Iterator tile_iter(&tiling_, tiling_rect, include_borders);
 378        tile_iter; ++tile_iter) {
 379     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 380     if (map_iter == picture_map_.end())
 381       continue;
 382
 383     const Picture* picture = map_iter->second.get();
 384     if (appended_pictures.count(picture) == 0) {
 385       appended_pictures.insert(picture);
 386       TracedValue::AppendIDRef(picture, pictures);
 387     }
 388   }
 389 }
 390
 391 bool PicturePileImpl::CanUseLCDText() const {
 392   return can_use_lcd_text_;
 393 }
 394
 395 scoped_refptr<RasterSource> PicturePileImpl::CreateCloneWithoutLCDText() const {
 396   DCHECK(CanUseLCDText());
 397   bool can_use_lcd_text = false;
 398   return scoped_refptr<RasterSource>(
 399       new PicturePileImpl(this, can_use_lcd_text));
 400 }
 401
 402 PicturePileImpl::PixelRefIterator::PixelRefIterator(
 403     const gfx::Rect& content_rect,
 404     float contents_scale,
 405     const PicturePileImpl* picture_pile)
 406     : picture_pile_(picture_pile),
 407       layer_rect_(
 408           gfx::ScaleToEnclosingRect(content_rect, 1.f / contents_scale)),
 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