cc: Start using raster/eviction iterators.

cc/layers/picture_layer_impl.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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/time/time.h"
@@ skipping 68 matching lines @@
     LayerTreeImpl* tree_impl) {
   return PictureLayerImpl::Create(tree_impl, id()).PassAs<LayerImpl>();
 }
 
 void PictureLayerImpl::PushPropertiesTo(LayerImpl* base_layer) {
   // It's possible this layer was never drawn or updated (e.g. because it was
   // a descendant of an opacity 0 layer).
   DoPostCommitInitializationIfNeeded();
   PictureLayerImpl* layer_impl = static_cast<PictureLayerImpl*>(base_layer);
 
-  // We have already synced the important bits from the the active layer, and
-  // we will soon swap out its tilings and use them for recycling. However,
-  // there are now tiles in this layer's tilings that were unref'd and replaced
-  // with new tiles (due to invalidation). This resets all active priorities on
-  // the to-be-recycled tiling to ensure replaced tiles don't linger and take
-  // memory (due to a stale 'active' priority).
-  if (layer_impl->tilings_)
-    layer_impl->tilings_->DidBecomeRecycled();

[vmpstr, 2014/07/02 23:51:29]

This is no longer needed, as we can't access tiles without first updating the
priorities.

[enne (OOO), 2014/07/07 19:41:59]

\o/

-
   LayerImpl::PushPropertiesTo(base_layer);
 
   // When the pending tree pushes to the active tree, the pending twin
   // disappears.
   layer_impl->twin_layer_ = NULL;
   twin_layer_ = NULL;
 
   layer_impl->SetIsMask(is_mask_);
   layer_impl->pile_ = pile_;
 
@@ skipping 326 matching lines @@
   DCHECK(raster_source_scale_);
   DCHECK(raster_contents_scale_);
   DCHECK(low_res_raster_contents_scale_);
 
   was_screen_space_transform_animating_ =
       draw_properties().screen_space_transform_is_animating;
 
   should_update_tile_priorities_ = true;
 
   UpdateTilePriorities(occlusion_tracker);
-
-  if (layer_tree_impl()->IsPendingTree())
-    MarkVisibleResourcesAsRequired();
 }
 
 void PictureLayerImpl::UpdateTilePriorities(
     const OcclusionTracker<LayerImpl>* occlusion_tracker) {
   TRACE_EVENT0("cc", "PictureLayerImpl::UpdateTilePriorities");
 
   double current_frame_time_in_seconds =
       (layer_tree_impl()->CurrentFrameTimeTicks() -
        base::TimeTicks()).InSecondsF();
 
@@ skipping 142 matching lines @@
          layer_tree_impl()->begin_impl_frame_interval().InSecondsF() *
          layer_tree_impl()->settings().skewport_target_time_multiplier;
 }
 
 int PictureLayerImpl::GetSkewportExtrapolationLimitInContentPixels() const {
   return layer_tree_impl()
       ->settings()
       .skewport_extrapolation_limit_in_content_pixels;
 }
 
+bool PictureLayerImpl::RequiresHighResToDraw() const {
+  const PictureLayerImpl* layer = this;
+  if (GetTree() == PENDING_TREE)
+    layer = twin_layer_;
+
+  if (layer)
+    return layer->layer_tree_impl()->RequiresHighResToDraw();
+  return false;
+}
+
 gfx::Size PictureLayerImpl::CalculateTileSize(
     const gfx::Size& content_bounds) const {
   if (is_mask_) {
     int max_size = layer_tree_impl()->MaxTextureSize();
     return gfx::Size(
         std::min(max_size, content_bounds.width()),
         std::min(max_size, content_bounds.height()));
   }
 
   int max_texture_size =
@@ skipping 134 matching lines @@
 
   const ManagedTileState::TileVersion& tile_version =
       iter->GetTileVersionForDrawing();
   if (!tile_version.IsReadyToDraw() ||
       tile_version.mode() != ManagedTileState::TileVersion::RESOURCE_MODE)
     return 0;
 
   return tile_version.get_resource_id();
 }
 
-void PictureLayerImpl::MarkVisibleResourcesAsRequired() const {

[enne (OOO), 2014/07/07 19:41:59]

\o/

-  DCHECK(layer_tree_impl()->IsPendingTree());
-  DCHECK(ideal_contents_scale_);
-  DCHECK_GT(tilings_->num_tilings(), 0u);
-
-  // The goal of this function is to find the minimum set of tiles that need to
-  // be ready to draw in order to activate without flashing content from a
-  // higher res on the active tree to a lower res on the pending tree.
-
-  // First, early out for layers with no visible content.
-  if (visible_content_rect().IsEmpty())
-    return;
-
-  gfx::Rect rect(visible_content_rect());
-
-  float min_acceptable_scale =
-      std::min(raster_contents_scale_, ideal_contents_scale_);
-
-  if (PictureLayerImpl* twin = twin_layer_) {
-    float twin_min_acceptable_scale =
-        std::min(twin->ideal_contents_scale_, twin->raster_contents_scale_);
-    // Ignore 0 scale in case CalculateContentsScale() has never been
-    // called for active twin.
-    if (twin_min_acceptable_scale != 0.0f) {
-      min_acceptable_scale =
-          std::min(min_acceptable_scale, twin_min_acceptable_scale);
-    }
-  }
-
-  PictureLayerTiling* high_res = NULL;
-  PictureLayerTiling* low_res = NULL;
-
-  // First pass: ready to draw tiles in acceptable but non-ideal tilings are
-  // marked as required for activation so that their textures are not thrown
-  // away; any non-ready tiles are not marked as required.
-  Region missing_region = rect;
-  for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
-    PictureLayerTiling* tiling = tilings_->tiling_at(i);
-    DCHECK(tiling->has_ever_been_updated());
-
-    if (tiling->resolution() == LOW_RESOLUTION) {
-      DCHECK(!low_res) << "There can only be one low res tiling";
-      low_res = tiling;
-    }
-    if (tiling->contents_scale() < min_acceptable_scale)
-      continue;
-    if (tiling->resolution() == HIGH_RESOLUTION) {
-      DCHECK(!high_res) << "There can only be one high res tiling";
-      high_res = tiling;
-      continue;
-    }
-    for (PictureLayerTiling::CoverageIterator iter(tiling,
-                                                   contents_scale_x(),
-                                                   rect);
-         iter;
-         ++iter) {
-      if (!*iter || !iter->IsReadyToDraw())
-        continue;
-
-      missing_region.Subtract(iter.geometry_rect());
-      iter->MarkRequiredForActivation();
-    }
-  }
-  DCHECK(high_res) << "There must be one high res tiling";
-
-  // If these pointers are null (because no twin, no matching tiling, or the
-  // simpification just below), then high res tiles will be required to fill any
-  // holes left by the first pass above.  If the pointers are valid, then this
-  // layer is allowed to skip any tiles that are not ready on its twin.
-  const PictureLayerTiling* twin_high_res = NULL;
-  const PictureLayerTiling* twin_low_res = NULL;
-
-  if (twin_layer_) {
-    // As a simplification, only allow activating to skip twin tiles that the
-    // active layer is also missing when both this layer and its twin have
-    // "simple" sets of tilings: only 2 tilings (high and low) or only 1 high
-    // res tiling. This avoids having to iterate/track coverage of non-ideal
-    // tilings during the last draw call on the active layer.
-    if (tilings_->num_tilings() <= 2 &&
-        twin_layer_->tilings_->num_tilings() <= tilings_->num_tilings()) {
-      twin_low_res = low_res ? GetTwinTiling(low_res) : NULL;
-      twin_high_res = high_res ? GetTwinTiling(high_res) : NULL;
-    }
-
-    // If this layer and its twin have different transforms, then don't compare
-    // them and only allow activating to high res tiles, since tiles on each
-    // layer will be in different places on screen.
-    if (twin_layer_->layer_tree_impl()->RequiresHighResToDraw() ||
-        bounds() != twin_layer_->bounds() ||
-        draw_properties().screen_space_transform !=
-            twin_layer_->draw_properties().screen_space_transform) {
-      twin_high_res = NULL;
-      twin_low_res = NULL;
-    }
-  }
-
-  // As a second pass, mark as required any visible high res tiles not filled in
-  // by acceptable non-ideal tiles from the first pass.
-  if (MarkVisibleTilesAsRequired(
-      high_res, twin_high_res, contents_scale_x(), rect, missing_region)) {
-    // As an optional third pass, if a high res tile was skipped because its
-    // twin was also missing, then fall back to mark low res tiles as required
-    // in case the active twin is substituting those for missing high res
-    // content. Only suitable, when low res is enabled.
-    if (low_res) {
-      MarkVisibleTilesAsRequired(
-          low_res, twin_low_res, contents_scale_x(), rect, missing_region);
-    }
-  }
-}
-
-bool PictureLayerImpl::MarkVisibleTilesAsRequired(
-    PictureLayerTiling* tiling,
-    const PictureLayerTiling* optional_twin_tiling,
-    float contents_scale,
-    const gfx::Rect& rect,
-    const Region& missing_region) const {
-  bool twin_had_missing_tile = false;
-  for (PictureLayerTiling::CoverageIterator iter(tiling,
-                                                 contents_scale,
-                                                 rect);
-       iter;
-       ++iter) {
-    Tile* tile = *iter;
-    // A null tile (i.e. missing recording) can just be skipped.
-    if (!tile)
-      continue;
-
-    // If the tile is occluded, don't mark it as required for activation.
-    if (tile->is_occluded())
-      continue;
-
-    // If the missing region doesn't cover it, this tile is fully
-    // covered by acceptable tiles at other scales.
-    if (!missing_region.Intersects(iter.geometry_rect()))
-      continue;
-
-    // If the twin tile doesn't exist (i.e. missing recording or so far away
-    // that it is outside the visible tile rect) or this tile is shared between
-    // with the twin, then this tile isn't required to prevent flashing.
-    if (optional_twin_tiling) {
-      Tile* twin_tile = optional_twin_tiling->TileAt(iter.i(), iter.j());
-      if (!twin_tile || twin_tile == tile) {
-        twin_had_missing_tile = true;
-        continue;
-      }
-    }
-
-    tile->MarkRequiredForActivation();
-  }
-  return twin_had_missing_tile;
-}
-
 void PictureLayerImpl::DoPostCommitInitialization() {
   DCHECK(needs_post_commit_initialization_);
   DCHECK(layer_tree_impl()->IsPendingTree());
 
   if (!tilings_)
     tilings_.reset(new PictureLayerTilingSet(this, bounds()));
 
   DCHECK(!twin_layer_);
   twin_layer_ = static_cast<PictureLayerImpl*>(
       layer_tree_impl()->FindActiveTreeLayerById(id()));
@@ skipping 714 matching lines @@
   return iterator_index_ < iterators_.size();
 }
 
 bool PictureLayerImpl::LayerEvictionTileIterator::IsCorrectType(
     PictureLayerTiling::TilingEvictionTileIterator* it) const {
   return it->get_type() == iteration_stage_ &&
          (**it)->required_for_activation() == required_for_activation_;
 }
 
 }  // namespace cc