cc/playback/display_list_recording_source.cc

   1 // Copyright 2014 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 "cc/playback/display_list_recording_source.h"
   6
   7 #include <algorithm>
   8
   9 #include "cc/base/histograms.h"
  10 #include "cc/base/region.h"
  11 #include "cc/layers/content_layer_client.h"
  12 #include "cc/playback/display_item_list.h"
  13 #include "cc/playback/display_list_raster_source.h"
  14 #include "skia/ext/analysis_canvas.h"
  15
  16 namespace {
  17
  18 // Layout pixel buffer around the visible layer rect to record.  Any base
  19 // picture that intersects the visible layer rect expanded by this distance
  20 // will be recorded.
  21 const int kPixelDistanceToRecord = 8000;
  22 // We don't perform solid color analysis on images that have more than 10 skia
  23 // operations.
  24 const int kOpCountThatIsOkToAnalyze = 10;
  25
  26 // This is the distance, in layer space, by which the recorded viewport has to
  27 // change before causing a paint of the new content. For example, it means
  28 // that one has to scroll a very large page by 512 pixels before we will
  29 // re-record a new DisplayItemList for an updated recorded viewport.
  30 const int kMinimumDistanceBeforeUpdatingRecordedViewport = 512;
  31
  32 #ifdef NDEBUG
  33 const bool kDefaultClearCanvasSetting = false;
  34 #else
  35 const bool kDefaultClearCanvasSetting = true;
  36 #endif
  37
  38 DEFINE_SCOPED_UMA_HISTOGRAM_AREA_TIMER(
  39     ScopedDisplayListRecordingSourceUpdateTimer,
  40     "Compositing.DisplayListRecordingSource.UpdateUs",
  41     "Compositing.DisplayListRecordingSource.UpdateInvalidatedAreaPerMs");
  42
  43 }  // namespace
  44
  45 namespace cc {
  46
  47 DisplayListRecordingSource::DisplayListRecordingSource(
  48     const gfx::Size& grid_cell_size)
  49     : slow_down_raster_scale_factor_for_debug_(0),
  50       gather_pixel_refs_(false),
  51       requires_clear_(false),
  52       is_solid_color_(false),
  53       clear_canvas_with_debug_color_(kDefaultClearCanvasSetting),
  54       solid_color_(SK_ColorTRANSPARENT),
  55       background_color_(SK_ColorTRANSPARENT),
  56       pixel_record_distance_(kPixelDistanceToRecord),
  57       grid_cell_size_(grid_cell_size),
  58       painter_reported_memory_usage_(0),
  59       is_suitable_for_gpu_rasterization_(true) {}
  60
  61 DisplayListRecordingSource::~DisplayListRecordingSource() {
  62 }
  63
  64 // This method only really makes sense to call if the size of the layer didn't
  65 // change.
  66 bool DisplayListRecordingSource::ExposesEnoughNewArea(
  67     const gfx::Rect& current_recorded_viewport,
  68     const gfx::Rect& potential_new_recorded_viewport,
  69     const gfx::Size& layer_size) {
  70   // If both are empty, nothing to do.
  71   if (current_recorded_viewport.IsEmpty() &&
  72       potential_new_recorded_viewport.IsEmpty())
  73     return false;
  74
  75   // Re-record when going from empty to not-empty, to cover cases where
  76   // the layer is recorded for the first time, or otherwise becomes visible.
  77   if (current_recorded_viewport.IsEmpty())
  78     return true;
  79
  80   // Re-record if the new viewport includes area outside of a skirt around the
  81   // existing viewport.
  82   gfx::Rect expanded_viewport(current_recorded_viewport);
  83   expanded_viewport.Inset(-kMinimumDistanceBeforeUpdatingRecordedViewport,
  84                           -kMinimumDistanceBeforeUpdatingRecordedViewport);
  85   if (!expanded_viewport.Contains(potential_new_recorded_viewport))
  86     return true;
  87
  88   // Even if the new viewport doesn't include enough new area to satisfy the
  89   // condition above, re-record anyway if touches a layer edge not touched by
  90   // the existing viewport. Viewports are clipped to layer boundaries, so if the
  91   // new viewport touches a layer edge not touched by the existing viewport,
  92   // the new viewport must expose new area that touches this layer edge. Since
  93   // this new area touches a layer edge, it's impossible to expose more area in
  94   // that direction, so recording cannot be deferred until the exposed new area
  95   // satisfies the condition above.
  96   if (potential_new_recorded_viewport.x() == 0 &&
  97       current_recorded_viewport.x() != 0)
  98     return true;
  99   if (potential_new_recorded_viewport.y() == 0 &&
 100       current_recorded_viewport.y() != 0)
 101     return true;
 102   if (potential_new_recorded_viewport.right() == layer_size.width() &&
 103       current_recorded_viewport.right() != layer_size.width())
 104     return true;
 105   if (potential_new_recorded_viewport.bottom() == layer_size.height() &&
 106       current_recorded_viewport.bottom() != layer_size.height())
 107     return true;
 108
 109   return false;
 110 }
 111
 112 bool DisplayListRecordingSource::UpdateAndExpandInvalidation(
 113     ContentLayerClient* painter,
 114     Region* invalidation,
 115     const gfx::Size& layer_size,
 116     const gfx::Rect& visible_layer_rect,
 117     int frame_number,
 118     RecordingMode recording_mode) {
 119   ScopedDisplayListRecordingSourceUpdateTimer timer;
 120   bool updated = false;
 121
 122   if (size_ != layer_size) {
 123     size_ = layer_size;
 124     updated = true;
 125   }
 126
 127   // The recorded viewport is the visible layer rect, expanded
 128   // by the pixel record distance, up to a maximum of the total
 129   // layer size.
 130   gfx::Rect potential_new_recorded_viewport = visible_layer_rect;
 131   potential_new_recorded_viewport.Inset(-pixel_record_distance_,
 132                                         -pixel_record_distance_);
 133   potential_new_recorded_viewport.Intersect(gfx::Rect(GetSize()));
 134
 135   if (updated ||
 136       ExposesEnoughNewArea(recorded_viewport_, potential_new_recorded_viewport,
 137                            GetSize())) {
 138     gfx::Rect old_recorded_viewport = recorded_viewport_;
 139     recorded_viewport_ = potential_new_recorded_viewport;
 140
 141     // Invalidate newly-exposed and no-longer-exposed areas.
 142     Region newly_exposed_region(recorded_viewport_);
 143     newly_exposed_region.Subtract(old_recorded_viewport);
 144     invalidation->Union(newly_exposed_region);
 145
 146     Region no_longer_exposed_region(old_recorded_viewport);
 147     no_longer_exposed_region.Subtract(recorded_viewport_);
 148     invalidation->Union(no_longer_exposed_region);
 149
 150     updated = true;
 151   }
 152
 153   // Count the area that is being invalidated.
 154   Region recorded_invalidation(*invalidation);
 155   recorded_invalidation.Intersect(recorded_viewport_);
 156   for (Region::Iterator it(recorded_invalidation); it.has_rect(); it.next())
 157     timer.AddArea(it.rect().size().GetArea());
 158
 159   if (!updated && !invalidation->Intersects(recorded_viewport_))
 160     return false;
 161
 162   ContentLayerClient::PaintingControlSetting painting_control =
 163       ContentLayerClient::PAINTING_BEHAVIOR_NORMAL;
 164
 165   switch (recording_mode) {
 166     case RECORD_NORMALLY:
 167       // Already setup for normal recording.
 168       break;
 169     case RECORD_WITH_PAINTING_DISABLED:
 170       painting_control = ContentLayerClient::DISPLAY_LIST_PAINTING_DISABLED;
 171       break;
 172     case RECORD_WITH_CACHING_DISABLED:
 173       painting_control = ContentLayerClient::DISPLAY_LIST_CACHING_DISABLED;
 174       break;
 175     case RECORD_WITH_CONSTRUCTION_DISABLED:
 176       painting_control = ContentLayerClient::DISPLAY_LIST_CONSTRUCTION_DISABLED;
 177       break;
 178     default:
 179       // case RecordingSource::RECORD_WITH_SK_NULL_CANVAS should not be reached
 180       NOTREACHED();
 181   }
 182
 183   // TODO(vmpstr): Add a slow_down_recording_scale_factor_for_debug_ to be able
 184   // to slow down recording.
 185   display_list_ =
 186       painter->PaintContentsToDisplayList(recorded_viewport_, painting_control);
 187   painter_reported_memory_usage_ = painter->GetApproximateUnsharedMemoryUsage();
 188
 189   is_suitable_for_gpu_rasterization_ =
 190       display_list_->IsSuitableForGpuRasterization();
 191   DetermineIfSolidColor();
 192   display_list_->EmitTraceSnapshot();
 193   if (gather_pixel_refs_)
 194     display_list_->GatherPixelRefs(grid_cell_size_);
 195
 196   return true;
 197 }
 198
 199 gfx::Size DisplayListRecordingSource::GetSize() const {
 200   return size_;
 201 }
 202
 203 void DisplayListRecordingSource::SetEmptyBounds() {
 204   size_ = gfx::Size();
 205   Clear();
 206 }
 207
 208 void DisplayListRecordingSource::SetSlowdownRasterScaleFactor(int factor) {
 209   slow_down_raster_scale_factor_for_debug_ = factor;
 210 }
 211
 212 void DisplayListRecordingSource::SetGatherPixelRefs(bool gather_pixel_refs) {
 213   gather_pixel_refs_ = gather_pixel_refs;
 214 }
 215
 216 void DisplayListRecordingSource::SetBackgroundColor(SkColor background_color) {
 217   background_color_ = background_color;
 218 }
 219
 220 void DisplayListRecordingSource::SetRequiresClear(bool requires_clear) {
 221   requires_clear_ = requires_clear;
 222 }
 223
 224 void DisplayListRecordingSource::SetUnsuitableForGpuRasterizationForTesting() {
 225   is_suitable_for_gpu_rasterization_ = false;
 226 }
 227
 228 bool DisplayListRecordingSource::IsSuitableForGpuRasterization() const {
 229   return is_suitable_for_gpu_rasterization_;
 230 }
 231
 232 scoped_refptr<RasterSource> DisplayListRecordingSource::CreateRasterSource(
 233     bool can_use_lcd_text) const {
 234   return scoped_refptr<RasterSource>(
 235       DisplayListRasterSource::CreateFromDisplayListRecordingSource(
 236           this, can_use_lcd_text));
 237 }
 238
 239 gfx::Size DisplayListRecordingSource::GetTileGridSizeForTesting() const {
 240   return gfx::Size();
 241 }
 242
 243 void DisplayListRecordingSource::DetermineIfSolidColor() {
 244   DCHECK(display_list_.get());
 245   is_solid_color_ = false;
 246   solid_color_ = SK_ColorTRANSPARENT;
 247
 248   if (display_list_->ApproximateOpCount() > kOpCountThatIsOkToAnalyze)
 249     return;
 250
 251   gfx::Size layer_size = GetSize();
 252   skia::AnalysisCanvas canvas(layer_size.width(), layer_size.height());
 253   display_list_->Raster(&canvas, nullptr, gfx::Rect(), 1.f);
 254   is_solid_color_ = canvas.GetColorIfSolid(&solid_color_);
 255 }
 256
 257 void DisplayListRecordingSource::Clear() {
 258   recorded_viewport_ = gfx::Rect();
 259   display_list_ = NULL;
 260   painter_reported_memory_usage_ = 0;
 261   is_solid_color_ = false;
 262 }
 263
 264 }  // namespace cc