cc: Add tiling raster tile iterators.

cc/resources/picture_layer_tiling.h

 // 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.
 
 #ifndef CC_RESOURCES_PICTURE_LAYER_TILING_H_
 #define CC_RESOURCES_PICTURE_LAYER_TILING_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 27 matching lines @@
   virtual size_t GetMaxTilesForInterestArea() const = 0;
   virtual float GetSkewportTargetTimeInSeconds() const = 0;
   virtual int GetSkewportExtrapolationLimitInContentPixels() const = 0;
 
  protected:
   virtual ~PictureLayerTilingClient() {}
 };
 
 class CC_EXPORT PictureLayerTiling {
  public:
+  class CC_EXPORT TilingRasterTileIterator {

[epennerAtGoogle, 2014/03/05 00:16:03]

Cool. One thing I didn't see in here is whether we filter already-rastered
tiles. Seems like we should only return tiles that haven't yet been rastered.

[vmpstr, 2014/03/05 00:37:21]

Not really... See my comment in the unittests. I think I can rework this a bit.

+   public:
+    enum Type { VISIBLE, SKEWPORT, EVENTUALLY };
+
+    TilingRasterTileIterator();
+    explicit TilingRasterTileIterator(PictureLayerTiling* tiling);
+    ~TilingRasterTileIterator();
+
+    operator bool() const { return !!current_tile_; }
+    Tile* operator*() { return current_tile_; }
+    Type get_type() const { return type_; }
+
+    TilingRasterTileIterator& operator++();
+
+    bool HasVisibleTiles() const { return type_ == VISIBLE; }
+
+    gfx::Rect TileBounds() const {
+      DCHECK(*this);
+      if (type_ == VISIBLE) {
+        return tiling_->tiling_data_.TileBounds(visible_iterator_.index_x(),
+                                                visible_iterator_.index_y());
+      }
+      return tiling_->tiling_data_.TileBounds(spiral_iterator_.index_x(),
+                                              spiral_iterator_.index_y());
+    }
+
+   private:
+    void AdvancePhase();
+
+    PictureLayerTiling* tiling_;
+
+    Type type_;
+
+    Tile* current_tile_;
+    TilingData::Iterator visible_iterator_;
+    TilingData::SpiralDifferenceIterator spiral_iterator_;
+  };
+
   ~PictureLayerTiling();
 
   // Create a tiling with no tiles.  CreateTiles must be called to add some.
   static scoped_ptr<PictureLayerTiling> Create(
       float contents_scale,
       const gfx::Size& layer_bounds,
       PictureLayerTilingClient* client);
   gfx::Size layer_bounds() const { return layer_bounds_; }
   void SetLayerBounds(const gfx::Size& layer_bounds);
   void Invalidate(const Region& layer_region);
   void CreateMissingTilesInLiveTilesRect();
 
   void SetCanUseLCDText(bool can_use_lcd_text);
 
   void SetClient(PictureLayerTilingClient* client);
   void set_resolution(TileResolution resolution) { resolution_ = resolution; }
   TileResolution resolution() const { return resolution_; }
 
   gfx::Rect ContentRect() const;
   gfx::SizeF ContentSizeF() const;
   gfx::Rect live_tiles_rect() const { return live_tiles_rect_; }
   gfx::Size tile_size() const { return tiling_data_.max_texture_size(); }
   float contents_scale() const { return contents_scale_; }
 
+  Tile* TileAt(int i, int j) const {
+    TileMap::const_iterator iter = tiles_.find(TileMapKey(i, j));
+    return (iter == tiles_.end()) ? NULL : iter->second.get();
+  }
+
   void CreateAllTilesForTesting() {
     SetLiveTilesRect(gfx::Rect(tiling_data_.total_size()));
   }
 
   std::vector<Tile*> AllTilesForTesting() const {
     std::vector<Tile*> all_tiles;
     for (TileMap::const_iterator it = tiles_.begin();
          it != tiles_.end(); ++it)
       all_tiles.push_back(it->second.get());
     return all_tiles;
   }
 
-  Tile* TileAt(int i, int j) const;
-
   // Iterate over all tiles to fill content_rect.  Even if tiles are invalid
   // (i.e. no valid resource) this tiling should still iterate over them.
   // The union of all geometry_rect calls for each element iterated over should
   // exactly equal content_rect and no two geometry_rects should intersect.
   class CC_EXPORT CoverageIterator {
    public:
     CoverageIterator();
     CoverageIterator(const PictureLayerTiling* tiling,
         float dest_scale,
         const gfx::Rect& rect);
@@ skipping 56 matching lines @@
   // be called before DidBecomeActive, as it resets the active priority
   // while DidBecomeActive promotes pending priority on a similar set of tiles.
   void DidBecomeRecycled();
 
   void UpdateTilesToCurrentPile();
 
   bool NeedsUpdateForFrameAtTime(double frame_time_in_seconds) {
     return frame_time_in_seconds != last_impl_frame_time_in_seconds_;
   }
 
+  size_t RequiredGPUMemoryInBytes() const;
+
   scoped_ptr<base::Value> AsValue() const;
   size_t GPUMemoryUsageInBytes() const;
 
   struct RectExpansionCache {
     RectExpansionCache();
 
     gfx::Rect previous_start;
     gfx::Rect previous_bounds;
     gfx::Rect previous_result;
     int64 previous_target;
   };
 
   static
   gfx::Rect ExpandRectEquallyToAreaBoundedBy(
       const gfx::Rect& starting_rect,
       int64 target_area,
       const gfx::Rect& bounding_rect,
       RectExpansionCache* cache);
 
   bool has_ever_been_updated() const {
     return last_impl_frame_time_in_seconds_ != 0.0;
   }
 
  protected:
+  friend class TilingRasterTileIterator;
+  friend class TilingEvictionTileIterator;
+
   typedef std::pair<int, int> TileMapKey;
   typedef base::hash_map<TileMapKey, scoped_refptr<Tile> > TileMap;
 
   PictureLayerTiling(float contents_scale,
                      const gfx::Size& layer_bounds,
                      PictureLayerTilingClient* client);
   void SetLiveTilesRect(const gfx::Rect& live_tiles_rect);
   void CreateTile(int i, int j, const PictureLayerTiling* twin_tiling);
 
   // Computes a skewport. The calculation extrapolates the last visible
@@ skipping 10 matching lines @@
   TileResolution resolution_;
   PictureLayerTilingClient* client_;
 
   // Internal data.
   TilingData tiling_data_;
   TileMap tiles_;  // It is not legal to have a NULL tile in the tiles_ map.
   gfx::Rect live_tiles_rect_;
 
   // State saved for computing velocities based upon finite differences.
   double last_impl_frame_time_in_seconds_;
-  gfx::RectF last_visible_rect_in_content_space_;
+  gfx::Rect last_visible_rect_in_content_space_;
+
+  gfx::Rect current_visible_rect_in_content_space_;
+  gfx::Rect current_skewport_;
+  gfx::Rect current_eventually_rect_;
+
+  WhichTree last_update_tree_;
 
   friend class CoverageIterator;
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 
   RectExpansionCache expansion_cache_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_