cc/playback/display_item_list.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_item_list.h"
   6
   7 #include <string>
   8
   9 #include "base/trace_event/trace_event.h"
  10 #include "base/trace_event/trace_event_argument.h"
  11 #include "cc/base/math_util.h"
  12 #include "cc/debug/picture_debug_util.h"
  13 #include "cc/debug/traced_picture.h"
  14 #include "cc/debug/traced_value.h"
  15 #include "cc/playback/largest_display_item.h"
  16 #include "third_party/skia/include/core/SkCanvas.h"
  17 #include "third_party/skia/include/core/SkPictureRecorder.h"
  18 #include "third_party/skia/include/utils/SkPictureUtils.h"
  19 #include "ui/gfx/skia_util.h"
  20
  21 namespace cc {
  22
  23 namespace {
  24
  25 bool PictureTracingEnabled() {
  26   bool tracing_enabled;
  27   TRACE_EVENT_CATEGORY_GROUP_ENABLED(
  28     TRACE_DISABLED_BY_DEFAULT("cc.debug.picture") ","
  29     TRACE_DISABLED_BY_DEFAULT("devtools.timeline.picture"),
  30     &tracing_enabled);
  31   return tracing_enabled;
  32 }
  33
  34 const int kDefaultNumDisplayItemsToReserve = 100;
  35
  36 }  // namespace
  37
  38 DisplayItemList::DisplayItemList(gfx::Rect layer_rect,
  39                                  bool use_cached_picture,
  40                                  bool retain_individual_display_items)
  41     : items_(LargestDisplayItemSize(), kDefaultNumDisplayItemsToReserve),
  42       use_cached_picture_(use_cached_picture),
  43       retain_individual_display_items_(retain_individual_display_items),
  44       layer_rect_(layer_rect),
  45       is_suitable_for_gpu_rasterization_(true),
  46       approximate_op_count_(0),
  47       picture_memory_usage_(0) {
  48 #if DCHECK_IS_ON()
  49   needs_process_ = false;
  50 #endif
  51   if (use_cached_picture_) {
  52     SkRTreeFactory factory;
  53     recorder_.reset(new SkPictureRecorder());
  54     canvas_ = skia::SharePtr(recorder_->beginRecording(
  55         layer_rect_.width(), layer_rect_.height(), &factory));
  56     canvas_->translate(-layer_rect_.x(), -layer_rect_.y());
  57     canvas_->clipRect(gfx::RectToSkRect(layer_rect_));
  58   }
  59 }
  60
  61 DisplayItemList::DisplayItemList(gfx::Rect layer_rect, bool use_cached_picture)
  62     : DisplayItemList(layer_rect,
  63                       use_cached_picture,
  64                       !use_cached_picture || PictureTracingEnabled()) {
  65 }
  66
  67 scoped_refptr<DisplayItemList> DisplayItemList::Create(
  68     gfx::Rect layer_rect,
  69     bool use_cached_picture) {
  70   return make_scoped_refptr(
  71       new DisplayItemList(layer_rect, use_cached_picture));
  72 }
  73
  74 DisplayItemList::~DisplayItemList() {
  75 }
  76
  77 void DisplayItemList::Raster(SkCanvas* canvas,
  78                              SkPicture::AbortCallback* callback,
  79                              float contents_scale) const {
  80   DCHECK(ProcessAppendedItemsCalled());
  81   if (!use_cached_picture_) {
  82     canvas->save();
  83     canvas->scale(contents_scale, contents_scale);
  84     for (auto* item : items_)
  85       item->Raster(canvas, callback);
  86     canvas->restore();
  87   } else {
  88     DCHECK(picture_);
  89
  90     canvas->save();
  91     canvas->scale(contents_scale, contents_scale);
  92     canvas->translate(layer_rect_.x(), layer_rect_.y());
  93     if (callback) {
  94       // If we have a callback, we need to call |draw()|, |drawPicture()|
  95       // doesn't take a callback.  This is used by |AnalysisCanvas| to early
  96       // out.
  97       picture_->playback(canvas, callback);
  98     } else {
  99       // Prefer to call |drawPicture()| on the canvas since it could place the
 100       // entire picture on the canvas instead of parsing the skia operations.
 101       canvas->drawPicture(picture_.get());
 102     }
 103     canvas->restore();
 104   }
 105 }
 106
 107 void DisplayItemList::ProcessAppendedItemsOnTheFly() {
 108   if (retain_individual_display_items_)
 109     return;
 110   if (items_.size() >= kDefaultNumDisplayItemsToReserve) {
 111     ProcessAppendedItems();
 112     // This function exists to keep the |items_| from growing indefinitely if
 113     // we're not going to store them anyway. So the items better be deleted
 114     // after |items_| grows too large and we process it.
 115     DCHECK(items_.empty());
 116   }
 117 }
 118
 119 void DisplayItemList::ProcessAppendedItems() {
 120 #if DCHECK_IS_ON()
 121   needs_process_ = false;
 122 #endif
 123   for (DisplayItem* item : items_) {
 124     is_suitable_for_gpu_rasterization_ &=
 125         item->is_suitable_for_gpu_rasterization();
 126     approximate_op_count_ += item->approximate_op_count();
 127
 128     if (use_cached_picture_) {
 129       DCHECK(canvas_);
 130       item->Raster(canvas_.get(), NULL);
 131     }
 132
 133     if (retain_individual_display_items_) {
 134       // Warning: this double-counts SkPicture data if use_cached_picture_ is
 135       // also true.
 136       picture_memory_usage_ += item->picture_memory_usage();
 137     }
 138   }
 139
 140   if (!retain_individual_display_items_)
 141     items_.clear();
 142 }
 143
 144 void DisplayItemList::CreateAndCacheSkPicture() {
 145   DCHECK(ProcessAppendedItemsCalled());
 146   // Convert to an SkPicture for faster rasterization.
 147   DCHECK(use_cached_picture_);
 148   DCHECK(!picture_);
 149   picture_ = skia::AdoptRef(recorder_->endRecordingAsPicture());
 150   DCHECK(picture_);
 151   picture_memory_usage_ += SkPictureUtils::ApproximateBytesUsed(picture_.get());
 152   recorder_.reset();
 153   canvas_.clear();
 154 }
 155
 156 bool DisplayItemList::IsSuitableForGpuRasterization() const {
 157   DCHECK(ProcessAppendedItemsCalled());
 158   // This is more permissive than Picture's implementation, since none of the
 159   // items might individually trigger a veto even though they collectively have
 160   // enough "bad" operations that a corresponding Picture would get vetoed.
 161   return is_suitable_for_gpu_rasterization_;
 162 }
 163
 164 int DisplayItemList::ApproximateOpCount() const {
 165   DCHECK(ProcessAppendedItemsCalled());
 166   return approximate_op_count_;
 167 }
 168
 169 size_t DisplayItemList::PictureMemoryUsage() const {
 170   DCHECK(ProcessAppendedItemsCalled());
 171   // We double-count in this case. Produce zero to avoid being misleading.
 172   if (use_cached_picture_ && retain_individual_display_items_)
 173     return 0;
 174
 175   DCHECK_IMPLIES(use_cached_picture_, picture_);
 176   return picture_memory_usage_;
 177 }
 178
 179 scoped_refptr<base::trace_event::ConvertableToTraceFormat>
 180 DisplayItemList::AsValue() const {
 181   DCHECK(ProcessAppendedItemsCalled());
 182   scoped_refptr<base::trace_event::TracedValue> state =
 183       new base::trace_event::TracedValue();
 184
 185   state->SetInteger("length", items_.size());
 186   state->BeginArray("params.items");
 187   for (const DisplayItem* item : items_) {
 188     item->AsValueInto(state.get());
 189   }
 190   state->EndArray();
 191   state->SetValue("params.layer_rect", MathUtil::AsValue(layer_rect_));
 192
 193   SkPictureRecorder recorder;
 194   SkCanvas* canvas =
 195       recorder.beginRecording(layer_rect_.width(), layer_rect_.height());
 196   canvas->translate(-layer_rect_.x(), -layer_rect_.y());
 197   canvas->clipRect(gfx::RectToSkRect(layer_rect_));
 198   Raster(canvas, NULL, 1.f);
 199   skia::RefPtr<SkPicture> picture =
 200       skia::AdoptRef(recorder.endRecordingAsPicture());
 201
 202   std::string b64_picture;
 203   PictureDebugUtil::SerializeAsBase64(picture.get(), &b64_picture);
 204   state->SetString("skp64", b64_picture);
 205
 206   return state;
 207 }
 208
 209 void DisplayItemList::EmitTraceSnapshot() const {
 210   DCHECK(ProcessAppendedItemsCalled());
 211   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
 212       TRACE_DISABLED_BY_DEFAULT("cc.debug.picture") ","
 213       TRACE_DISABLED_BY_DEFAULT("devtools.timeline.picture"),
 214       "cc::DisplayItemList", this, AsValue());
 215 }
 216
 217 void DisplayItemList::GatherPixelRefs(const gfx::Size& grid_cell_size) {
 218   DCHECK(ProcessAppendedItemsCalled());
 219   // This should be only called once, and only after CreateAndCacheSkPicture.
 220   DCHECK(picture_);
 221   DCHECK(!pixel_refs_);
 222   pixel_refs_ = make_scoped_ptr(new PixelRefMap(grid_cell_size));
 223   if (!picture_->willPlayBackBitmaps())
 224     return;
 225
 226   pixel_refs_->GatherPixelRefsFromPicture(picture_.get());
 227 }
 228 }  // namespace cc