cc/resources/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/resources/picture_pile_impl.h"
  13 #include "cc/resources/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 {
  20
  21 #ifdef NDEBUG
  22 const bool kDefaultClearCanvasSetting = false;
  23 #else
  24 const bool kDefaultClearCanvasSetting = true;
  25 #endif
  26
  27 }  // namespace
  28
  29 namespace cc {
  30
  31 scoped_refptr<PicturePileImpl> PicturePileImpl::CreateFromPicturePile(
  32     const PicturePile* other) {
  33   return make_scoped_refptr(new PicturePileImpl(other));
  34 }
  35
  36 PicturePileImpl::PicturePileImpl()
  37     : background_color_(SK_ColorTRANSPARENT),
  38       requires_clear_(true),
  39       can_use_lcd_text_(false),
  40       is_solid_color_(false),
  41       solid_color_(SK_ColorTRANSPARENT),
  42       has_any_recordings_(false),
  43       clear_canvas_with_debug_color_(kDefaultClearCanvasSetting),
  44       min_contents_scale_(0.f),
  45       slow_down_raster_scale_factor_for_debug_(0),
  46       should_attempt_to_use_distance_field_text_(false) {
  47 }
  48
  49 PicturePileImpl::PicturePileImpl(const PicturePile* other)
  50     : picture_map_(other->picture_map_),
  51       tiling_(other->tiling_),
  52       background_color_(SK_ColorTRANSPARENT),
  53       requires_clear_(true),
  54       can_use_lcd_text_(other->can_use_lcd_text_),
  55       is_solid_color_(other->is_solid_color_),
  56       solid_color_(other->solid_color_),
  57       recorded_viewport_(other->recorded_viewport_),
  58       has_any_recordings_(other->has_any_recordings_),
  59       clear_canvas_with_debug_color_(kDefaultClearCanvasSetting),
  60       min_contents_scale_(other->min_contents_scale_),
  61       slow_down_raster_scale_factor_for_debug_(
  62           other->slow_down_raster_scale_factor_for_debug_),
  63       should_attempt_to_use_distance_field_text_(false) {
  64 }
  65
  66 PicturePileImpl::~PicturePileImpl() {
  67 }
  68
  69 void PicturePileImpl::PlaybackToSharedCanvas(SkCanvas* canvas,
  70                                              const gfx::Rect& canvas_rect,
  71                                              float contents_scale) const {
  72   RasterCommon(canvas,
  73                NULL,
  74                canvas_rect,
  75                contents_scale,
  76                false);
  77 }
  78
  79 void PicturePileImpl::RasterForAnalysis(skia::AnalysisCanvas* canvas,
  80                                         const gfx::Rect& canvas_rect,
  81                                         float contents_scale) const {
  82   RasterCommon(canvas, canvas, canvas_rect, contents_scale, true);
  83 }
  84
  85 void PicturePileImpl::PlaybackToCanvas(SkCanvas* canvas,
  86                                        const gfx::Rect& canvas_rect,
  87                                        float contents_scale) const {
  88   RasterSourceHelper::PrepareForPlaybackToCanvas(
  89       canvas, canvas_rect, gfx::Rect(tiling_.tiling_size()), contents_scale,
  90       background_color_, clear_canvas_with_debug_color_, requires_clear_);
  91
  92   RasterCommon(canvas,
  93                NULL,
  94                canvas_rect,
  95                contents_scale,
  96                false);
  97 }
  98
  99 void PicturePileImpl::CoalesceRasters(const gfx::Rect& canvas_rect,
 100                                       const gfx::Rect& content_rect,
 101                                       float contents_scale,
 102                                       PictureRegionMap* results) const {
 103   DCHECK(results);
 104   // Rasterize the collection of relevant picture piles.
 105   gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
 106       content_rect, 1.f / contents_scale);
 107
 108   // Make sure pictures don't overlap by keeping track of previous right/bottom.
 109   int min_content_left = -1;
 110   int min_content_top = -1;
 111   int last_row_index = -1;
 112   int last_col_index = -1;
 113   gfx::Rect last_content_rect;
 114
 115   // Coalesce rasters of the same picture into different rects:
 116   //  - Compute the clip of each of the pile chunks,
 117   //  - Subtract it from the canvas rect to get difference region
 118   //  - Later, use the difference region to subtract each of the comprising
 119   //    rects from the canvas.
 120   // Note that in essence, we're trying to mimic clipRegion with intersect op
 121   // that also respects the current canvas transform and clip. In order to use
 122   // the canvas transform, we must stick to clipRect operations (clipRegion
 123   // ignores the transform). Intersect then can be written as subtracting the
 124   // negation of the region we're trying to intersect. Luckily, we know that all
 125   // of the rects will have to fit into |content_rect|, so we can start with
 126   // that and subtract chunk rects to get the region that we need to subtract
 127   // from the canvas. Then, we can use clipRect with difference op to subtract
 128   // each rect in the region.
 129   bool include_borders = true;
 130   for (TilingData::Iterator tile_iter(&tiling_, layer_rect, include_borders);
 131        tile_iter;
 132        ++tile_iter) {
 133     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 134     if (map_iter == picture_map_.end())
 135       continue;
 136     const PictureInfo& info = map_iter->second;
 137     const Picture* picture = info.GetPicture();
 138     if (!picture)
 139       continue;
 140
 141     // This is intentionally *enclosed* rect, so that the clip is aligned on
 142     // integral post-scale content pixels and does not extend past the edges
 143     // of the picture chunk's layer rect.  The min_contents_scale enforces that
 144     // enough buffer pixels have been added such that the enclosed rect
 145     // encompasses all invalidated pixels at any larger scale level.
 146     gfx::Rect chunk_rect = PaddedRect(tile_iter.index());
 147     gfx::Rect content_clip =
 148         gfx::ScaleToEnclosedRect(chunk_rect, contents_scale);
 149     DCHECK(!content_clip.IsEmpty()) << "Layer rect: "
 150                                     << picture->LayerRect().ToString()
 151                                     << "Contents scale: " << contents_scale;
 152     content_clip.Intersect(canvas_rect);
 153
 154     // Make sure iterator goes top->bottom.
 155     DCHECK_GE(tile_iter.index_y(), last_row_index);
 156     if (tile_iter.index_y() > last_row_index) {
 157       // First tile in a new row.
 158       min_content_left = content_clip.x();
 159       min_content_top = last_content_rect.bottom();
 160     } else {
 161       // Make sure iterator goes left->right.
 162       DCHECK_GT(tile_iter.index_x(), last_col_index);
 163       min_content_left = last_content_rect.right();
 164       min_content_top = last_content_rect.y();
 165     }
 166
 167     last_col_index = tile_iter.index_x();
 168     last_row_index = tile_iter.index_y();
 169
 170     // Only inset if the content_clip is less than then previous min.
 171     int inset_left = std::max(0, min_content_left - content_clip.x());
 172     int inset_top = std::max(0, min_content_top - content_clip.y());
 173     content_clip.Inset(inset_left, inset_top, 0, 0);
 174
 175     PictureRegionMap::iterator it = results->find(picture);
 176     Region* clip_region;
 177     if (it == results->end()) {
 178       // The clip for a set of coalesced pictures starts out clipping the entire
 179       // canvas.  Each picture added to the set must subtract its own bounds
 180       // from the clip region, poking a hole so that the picture is unclipped.
 181       clip_region = &(*results)[picture];
 182       *clip_region = canvas_rect;
 183     } else {
 184       clip_region = &it->second;
 185     }
 186
 187     DCHECK(clip_region->Contains(content_clip))
 188         << "Content clips should not overlap.";
 189     clip_region->Subtract(content_clip);
 190     last_content_rect = content_clip;
 191   }
 192 }
 193
 194 void PicturePileImpl::RasterCommon(
 195     SkCanvas* canvas,
 196     SkDrawPictureCallback* callback,
 197     const gfx::Rect& canvas_rect,
 198     float contents_scale,
 199     bool is_analysis) const {
 200   DCHECK(contents_scale >= min_contents_scale_);
 201
 202   canvas->translate(-canvas_rect.x(), -canvas_rect.y());
 203   gfx::Rect content_tiling_rect = gfx::ToEnclosingRect(
 204       gfx::ScaleRect(gfx::Rect(tiling_.tiling_size()), contents_scale));
 205   content_tiling_rect.Intersect(canvas_rect);
 206
 207   canvas->clipRect(gfx::RectToSkRect(content_tiling_rect),
 208                    SkRegion::kIntersect_Op);
 209
 210   PictureRegionMap picture_region_map;
 211   CoalesceRasters(
 212       canvas_rect, content_tiling_rect, contents_scale, &picture_region_map);
 213
 214 #ifndef NDEBUG
 215   Region total_clip;
 216 #endif  // NDEBUG
 217
 218   // Iterate the coalesced map and use each picture's region
 219   // to clip the canvas.
 220   for (PictureRegionMap::iterator it = picture_region_map.begin();
 221        it != picture_region_map.end();
 222        ++it) {
 223     const Picture* picture = it->first;
 224     Region negated_clip_region = it->second;
 225
 226 #ifndef NDEBUG
 227     Region positive_clip = content_tiling_rect;
 228     positive_clip.Subtract(negated_clip_region);
 229     // Make sure we never rasterize the same region twice.
 230     DCHECK(!total_clip.Intersects(positive_clip));
 231     total_clip.Union(positive_clip);
 232 #endif  // NDEBUG
 233
 234     int repeat_count = std::max(1, slow_down_raster_scale_factor_for_debug_);
 235
 236     for (int j = 0; j < repeat_count; ++j)
 237       picture->Raster(canvas, callback, negated_clip_region, contents_scale);
 238   }
 239
 240 #ifndef NDEBUG
 241   // Fill the clip with debug color. This allows us to
 242   // distinguish between non painted areas and problems with missing
 243   // pictures.
 244   SkPaint paint;
 245   for (Region::Iterator it(total_clip); it.has_rect(); it.next())
 246     canvas->clipRect(gfx::RectToSkRect(it.rect()), SkRegion::kDifference_Op);
 247   paint.setColor(DebugColors::MissingPictureFillColor());
 248   paint.setXfermodeMode(SkXfermode::kSrc_Mode);
 249   canvas->drawPaint(paint);
 250 #endif  // NDEBUG
 251 }
 252
 253 skia::RefPtr<SkPicture> PicturePileImpl::GetFlattenedPicture() {
 254   TRACE_EVENT0("cc", "PicturePileImpl::GetFlattenedPicture");
 255
 256   gfx::Rect tiling_rect(tiling_.tiling_size());
 257   SkPictureRecorder recorder;
 258   SkCanvas* canvas =
 259       recorder.beginRecording(tiling_rect.width(), tiling_rect.height());
 260   if (!tiling_rect.IsEmpty())
 261     PlaybackToCanvas(canvas, tiling_rect, 1.0);
 262   skia::RefPtr<SkPicture> picture = skia::AdoptRef(recorder.endRecording());
 263
 264   return picture;
 265 }
 266
 267 size_t PicturePileImpl::GetPictureMemoryUsage() const {
 268   // Place all pictures in a set to de-dupe.
 269   size_t total_size = 0;
 270   std::set<const Picture*> pictures_seen;
 271   for (const auto& map_value : picture_map_) {
 272     const Picture* picture = map_value.second.GetPicture();
 273     if (picture && pictures_seen.insert(picture).second)
 274       total_size += picture->ApproximateMemoryUsage();
 275   }
 276
 277   return total_size;
 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     if (!map_iter->second.GetPicture())
 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 void PicturePileImpl::SetBackgoundColor(SkColor background_color) {
 371   background_color_ = background_color;
 372 }
 373
 374 void PicturePileImpl::SetRequiresClear(bool requires_clear) {
 375   requires_clear_ = requires_clear;
 376 }
 377
 378 bool PicturePileImpl::ShouldAttemptToUseDistanceFieldText() const {
 379   return should_attempt_to_use_distance_field_text_;
 380 }
 381
 382 void PicturePileImpl::AsValueInto(
 383     base::trace_event::TracedValue* pictures) const {
 384   gfx::Rect tiling_rect(tiling_.tiling_size());
 385   std::set<const void*> appended_pictures;
 386   bool include_borders = true;
 387   for (TilingData::Iterator tile_iter(&tiling_, tiling_rect, include_borders);
 388        tile_iter; ++tile_iter) {
 389     PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
 390     if (map_iter == picture_map_.end())
 391       continue;
 392
 393     const Picture* picture = map_iter->second.GetPicture();
 394     if (picture && (appended_pictures.count(picture) == 0)) {
 395       appended_pictures.insert(picture);
 396       TracedValue::AppendIDRef(picture, pictures);
 397     }
 398   }
 399 }
 400
 401 bool PicturePileImpl::CanUseLCDText() const {
 402   return can_use_lcd_text_;
 403 }
 404
 405 PicturePileImpl::PixelRefIterator::PixelRefIterator(
 406     const gfx::Rect& content_rect,
 407     float contents_scale,
 408     const PicturePileImpl* picture_pile)
 409     : picture_pile_(picture_pile),
 410       layer_rect_(
 411           gfx::ScaleToEnclosingRect(content_rect, 1.f / contents_scale)),
 412       tile_iterator_(&picture_pile_->tiling_,
 413                      layer_rect_,
 414                      false /* include_borders */) {
 415   // Early out if there isn't a single tile.
 416   if (!tile_iterator_)
 417     return;
 418
 419   AdvanceToTilePictureWithPixelRefs();
 420 }
 421
 422 PicturePileImpl::PixelRefIterator::~PixelRefIterator() {
 423 }
 424
 425 PicturePileImpl::PixelRefIterator&
 426     PicturePileImpl::PixelRefIterator::operator++() {
 427   ++pixel_ref_iterator_;
 428   if (pixel_ref_iterator_)
 429     return *this;
 430
 431   ++tile_iterator_;
 432   AdvanceToTilePictureWithPixelRefs();
 433   return *this;
 434 }
 435
 436 void PicturePileImpl::PixelRefIterator::AdvanceToTilePictureWithPixelRefs() {
 437   for (; tile_iterator_; ++tile_iterator_) {
 438     PictureMap::const_iterator it =
 439         picture_pile_->picture_map_.find(tile_iterator_.index());
 440     if (it == picture_pile_->picture_map_.end())
 441       continue;
 442
 443     const Picture* picture = it->second.GetPicture();
 444     if (!picture || (processed_pictures_.count(picture) != 0) ||
 445         !picture->WillPlayBackBitmaps())
 446       continue;
 447
 448     processed_pictures_.insert(picture);
 449     pixel_ref_iterator_ = Picture::PixelRefIterator(layer_rect_, picture);
 450     if (pixel_ref_iterator_)
 451       break;
 452   }
 453 }
 454
 455 void PicturePileImpl::DidBeginTracing() {
 456   std::set<const void*> processed_pictures;
 457   for (PictureMap::iterator it = picture_map_.begin();
 458        it != picture_map_.end();
 459        ++it) {
 460     const Picture* picture = it->second.GetPicture();
 461     if (picture && (processed_pictures.count(picture) == 0)) {
 462       picture->EmitTraceSnapshot();
 463       processed_pictures.insert(picture);
 464     }
 465   }
 466 }
 467
 468 }  // namespace cc