cc: Low quality support for low res tiles

cc/resources/tile_manager.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/tile_manager.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "cc/debug/devtools_instrumentation.h"
 #include "cc/debug/traced_value.h"
 #include "cc/resources/image_raster_worker_pool.h"
 #include "cc/resources/pixel_buffer_raster_worker_pool.h"
 #include "cc/resources/tile.h"
+#include "skia/ext/paint_simplifier.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/rect_conversions.h"
 
 namespace cc {
 
 namespace {
 
+class DisableLCDTextFilter : public SkDrawFilter {
+ public:
+  // SkDrawFilter interface.
+  virtual bool filter(SkPaint* paint, SkDrawFilter::Type type) OVERRIDE {
+    if (type != SkDrawFilter::kText_Type)
+      return true;
+
+    paint->setLCDRenderText(false);
+    return true;
+  }
+};
+
 // Determine bin based on three categories of tiles: things we need now,
 // things we need soon, and eventually.
 inline TileManagerBin BinFromTilePriority(const TilePriority& prio) {
   // The amount of time for which we want to have prepainting coverage.
   const float kPrepaintingWindowTimeSeconds = 1.0f;
   const float kBackflingGuardDistancePixels = 314.0f;
 
   if (prio.time_to_visible_in_seconds == 0)
     return NOW_BIN;
 
@@ skipping 350 matching lines @@
 }
 
 void TileManager::AddRequiredTileForActivation(Tile* tile) {
   DCHECK(std::find(tiles_that_need_to_be_initialized_for_activation_.begin(),
                    tiles_that_need_to_be_initialized_for_activation_.end(),
                    tile) ==
          tiles_that_need_to_be_initialized_for_activation_.end());
   tiles_that_need_to_be_initialized_for_activation_.insert(tile);
 }
 
+unsigned TileManager::DetermineRasterFlags(const Tile* tile) const {
+  DCHECK(tile);
+  DCHECK(tile->picture_pile());
+
+  unsigned raster_flags = 0;
+  if (tile->picture_pile()->can_use_lcd_text())
+    raster_flags |= USE_LCD_TEXT;
+
+  if (tile->managed_state().resolution != LOW_RESOLUTION)
+    raster_flags |= USE_HIGH_QUALITY;
+  return raster_flags;
+}
+
 void TileManager::AssignGpuMemoryToTiles() {
   TRACE_EVENT0("cc", "TileManager::AssignGpuMemoryToTiles");
 
   // Now give memory out to the tiles until we're out, and build
   // the needs-to-be-rasterized queue.
   tiles_that_need_to_be_rasterized_.clear();
   tiles_that_need_to_be_initialized_for_activation_.clear();
 
   size_t bytes_releasable = 0;
   for (TileVector::const_iterator it = tiles_.begin();
@@ skipping 33 matching lines @@
       FreeResourcesForTile(tile);
       continue;
     }
 
     size_t tile_bytes = 0;
 
     // It costs to maintain a resource.
     if (tile_version.resource_)
       tile_bytes += tile->bytes_consumed_if_allocated();
 
+    unsigned current_raster_flags = tile_version.raster_flags_;
+    unsigned required_raster_flags = DetermineRasterFlags(tile);
+
     // It will cost to allocate a resource.
-    // Note that this is separate from the above condition,
-    // so that it's clear why we're adding memory.
-    if (!tile_version.resource_ && mts.raster_task.is_null())
+    if (mts.raster_task.is_null() &&
+        (!tile_version.resource_ ||
+         (current_raster_flags != required_raster_flags))) {
       tile_bytes += tile->bytes_consumed_if_allocated();
+    }
 
     // Tile is OOM.
     if (tile_bytes > bytes_left) {
       tile->tile_version().set_rasterize_on_demand();
       if (mts.tree_bin[PENDING_TREE] == NOW_BIN) {
         tiles_requiring_memory_but_oomed.push_back(tile);
         bytes_oom_in_now_bin_on_pending_tree += tile_bytes;
       }
       FreeResourcesForTile(tile);
       higher_priority_tile_oomed = true;
       continue;
     }
 
     tile_version.set_use_resource();
     bytes_left -= tile_bytes;
 
     // Tile shouldn't be rasterized if we've failed to assign
     // gpu memory to a higher priority tile. This is important for
     // two reasons:
     // 1. Tile size should not impact raster priority.
     // 2. Tile with unreleasable memory could otherwise incorrectly
     //    be added as it's not affected by |bytes_allocatable|.
     if (higher_priority_tile_oomed)
       continue;
 
-    if (!tile_version.resource_)
+    if (!tile_version.resource_ ||
+        (current_raster_flags != required_raster_flags)) {
       tiles_that_need_to_be_rasterized_.push_back(tile);
+    }
 
     if (!tile_version.resource_ && tile->required_for_activation())
       AddRequiredTileForActivation(tile);
   }
 
   // In OOM situation, we iterate tiles_, remove the memory for active tree
   // and not the now bin. And give them to bytes_oom_in_now_bin_on_pending_tree
   if (!tiles_requiring_memory_but_oomed.empty()) {
     size_t bytes_freed = 0;
     for (TileVector::iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
@@ skipping 63 matching lines @@
 
   // Build a new task queue containing all task currently needed. Tasks
   // are added in order of priority, highest priority task first.
   for (TileVector::iterator it = tiles_that_need_to_be_rasterized_.begin();
        it != tiles_that_need_to_be_rasterized_.end();
        ++it) {
     Tile* tile = *it;
     ManagedTileState& mts = tile->managed_state();
 
     DCHECK(tile->tile_version().requires_resource());
-    DCHECK(!tile->tile_version().resource_);
+    DCHECK(!tile->tile_version().resource_ ||
+           (tile->tile_version().raster_flags_ != DetermineRasterFlags(tile)));
 
     // Create raster task for this tile if necessary.
     if (mts.raster_task.is_null())
       mts.raster_task = CreateRasterTask(tile);
 
     // Finally append raster task.
     tasks.Append(mts.raster_task);
   }
 
   // Schedule running of |tasks|. This replaces any previously
@@ skipping 28 matching lines @@
 TileManager::RasterTaskMetadata TileManager::GetRasterTaskMetadata(
     const Tile& tile) const {
   RasterTaskMetadata metadata;
   const ManagedTileState& mts = tile.managed_state();
   metadata.is_tile_in_pending_tree_now_bin =
       mts.tree_bin[PENDING_TREE] == NOW_BIN;
   metadata.tile_resolution = mts.resolution;
   metadata.layer_id = tile.layer_id();
   metadata.tile_id = &tile;
   metadata.source_frame_number = tile.source_frame_number();
+  metadata.raster_flags = DetermineRasterFlags(&tile);
   return metadata;
 }
 
 RasterWorkerPool::RasterTask TileManager::CreateRasterTask(Tile* tile) {
   TRACE_EVENT0("cc", "TileManager::CreateRasterTask");
 
   scoped_ptr<ResourcePool::Resource> resource =
       resource_pool_->AcquireResource(
           tile->tile_size_.size(),
           tile->tile_version().resource_format_);
@@ skipping 25 matching lines @@
       continue;
     }
 
     // Create and append new image decode task for this pixel ref.
     RasterWorkerPool::Task decode_task = CreateImageDecodeTask(
         tile, pixel_ref);
     decode_tasks.Insert(decode_task);
     pending_decode_tasks_[id] = decode_task;
   }
 
+  RasterTaskMetadata metadata = GetRasterTaskMetadata(*tile);
   return RasterWorkerPool::RasterTask(
       tile->picture_pile(),
       const_resource,
       base::Bind(&TileManager::RunAnalyzeAndRasterTask,
                  base::Bind(&TileManager::RunAnalyzeTask,
                             analysis,
                             tile->content_rect(),
                             tile->contents_scale(),
                             use_color_estimator_,
-                            GetRasterTaskMetadata(*tile),
+                            metadata,
                             rendering_stats_instrumentation_),
                  base::Bind(&TileManager::RunRasterTask,
                             analysis,
                             tile->content_rect(),
                             tile->contents_scale(),
-                            GetRasterTaskMetadata(*tile),
+                            metadata,
                             rendering_stats_instrumentation_)),
       base::Bind(&TileManager::OnRasterTaskCompleted,
                  base::Unretained(this),
                  make_scoped_refptr(tile),
                  base::Passed(&resource),
-                 base::Owned(analysis)),
+                 base::Owned(analysis),
+                 metadata.raster_flags),
       &decode_tasks);
 }
 
 void TileManager::OnRasterTaskCompleted(
     scoped_refptr<Tile> tile,
     scoped_ptr<ResourcePool::Resource> resource,
     PicturePileImpl::Analysis* analysis,
+    unsigned raster_flags,
     bool was_canceled) {
   TRACE_EVENT1("cc", "TileManager::OnRasterTaskCompleted",
                "was_canceled", was_canceled);
 
   ManagedTileState& mts = tile->managed_state();
   DCHECK(!mts.raster_task.is_null());
   mts.raster_task.Reset();
 
   if (was_canceled) {
     resource_pool_->ReleaseResource(resource.Pass());
     return;
   }
 
+  if (tile->tile_version().resource_) {
+    resource_pool_->ReleaseResource(tile->tile_version().resource_.Pass());
+    DCHECK(tile->tile_version().raster_flags_ != raster_flags);
+    tile->tile_version().raster_flags_ = 0;
+  }
+
   mts.picture_pile_analysis = *analysis;
   mts.picture_pile_analyzed = true;
 
   if (analysis->is_solid_color) {
     tile->tile_version().set_solid_color(analysis->solid_color);
     resource_pool_->ReleaseResource(resource.Pass());
   } else {
     tile->tile_version().resource_ = resource.Pass();
+    tile->tile_version().raster_flags_ = raster_flags;
   }
 
   DidFinishTileInitialization(tile.get());
 }
 
 void TileManager::DidFinishTileInitialization(Tile* tile) {
   if (tile->priority(ACTIVE_TREE).distance_to_visible_in_pixels == 0)
     did_initialize_visible_tile_ = true;
   if (tile->required_for_activation()) {
     // It's possible that a tile required for activation is not in this list
@@ skipping 65 matching lines @@
   analysis->is_solid_color &= use_color_estimator;
 }
 
 scoped_ptr<base::Value> TileManager::RasterTaskMetadata::AsValue() const {
   scoped_ptr<base::DictionaryValue> res(new base::DictionaryValue());
   res->Set("tile_id", TracedValue::CreateIDRef(tile_id).release());
   res->SetBoolean("is_tile_in_pending_tree_now_bin",
                   is_tile_in_pending_tree_now_bin);
   res->Set("resolution", TileResolutionAsValue(tile_resolution).release());
   res->SetInteger("source_frame_number", source_frame_number);
+  res->SetInteger("raster_flags", raster_flags);
   return res.PassAs<base::Value>();
 }
 
 // static
 bool TileManager::RunRasterTask(
     PicturePileImpl::Analysis* analysis,
     gfx::Rect rect,
     float contents_scale,
     const RasterTaskMetadata& metadata,
     RenderingStatsInstrumentation* stats_instrumentation,
     SkDevice* device,
     PicturePileImpl* picture_pile) {
   TRACE_EVENT1(
       "cc", "TileManager::RunRasterTask",
       "metadata", TracedValue::FromValue(metadata.AsValue().release()));
   devtools_instrumentation::ScopedLayerTask raster_task(
       devtools_instrumentation::kRasterTask, metadata.layer_id);
 
   DCHECK(picture_pile);
   DCHECK(analysis);
   DCHECK(device);
 
   if (analysis->is_solid_color)
     return false;
 
   SkCanvas canvas(device);
 
+  skia::RefPtr<SkDrawFilter> draw_filter;
+  if ((metadata.raster_flags & USE_HIGH_QUALITY) == 0)
+    draw_filter = skia::AdoptRef(new skia::PaintSimplifier);
+  else if ((metadata.raster_flags & USE_LCD_TEXT) == 0)
+    draw_filter = skia::AdoptRef(new DisableLCDTextFilter);
+
+  canvas.setDrawFilter(draw_filter.get());
+
   if (stats_instrumentation->record_rendering_stats()) {
     PicturePileImpl::RasterStats raster_stats;
     picture_pile->RasterToBitmap(&canvas, rect, contents_scale, &raster_stats);
     stats_instrumentation->AddRaster(
         raster_stats.total_rasterize_time,
         raster_stats.best_rasterize_time,
         raster_stats.total_pixels_rasterized,
         metadata.is_tile_in_pending_tree_now_bin);
 
     HISTOGRAM_CUSTOM_COUNTS(
         "Renderer4.PictureRasterTimeUS",
         raster_stats.total_rasterize_time.InMicroseconds(),
         0,
         100000,
         100);
   } else {
     picture_pile->RasterToBitmap(&canvas, rect, contents_scale, NULL);
   }
 
   return true;
 }
 
 }  // namespace cc