cc/resources/picture_layer_tiling.h

   1 // Copyright 2012 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 #ifndef CC_RESOURCES_PICTURE_LAYER_TILING_H_
   6 #define CC_RESOURCES_PICTURE_LAYER_TILING_H_
   7
   8 #include <map>
   9 #include <utility>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/containers/hash_tables.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "cc/base/cc_export.h"
  16 #include "cc/base/region.h"
  17 #include "cc/base/tiling_data.h"
  18 #include "cc/resources/tile.h"
  19 #include "cc/resources/tile_priority.h"
  20 #include "cc/trees/occlusion.h"
  21 #include "ui/gfx/geometry/rect.h"
  22
  23 namespace base {
  24 namespace trace_event {
  25 class TracedValue;
  26 }
  27 }
  28
  29 namespace cc {
  30
  31 class PictureLayerTiling;
  32 class RasterSource;
  33
  34 class CC_EXPORT PictureLayerTilingClient {
  35  public:
  36   // Create a tile at the given content_rect (in the contents scale of the
  37   // tiling) This might return null if the client cannot create such a tile.
  38   virtual scoped_refptr<Tile> CreateTile(float contents_scale,
  39                                          const gfx::Rect& content_rect) = 0;
  40   virtual gfx::Size CalculateTileSize(
  41     const gfx::Size& content_bounds) const = 0;
  42   // This invalidation region defines the area (if any, it can by null) that
  43   // tiles can not be shared between pending and active trees.
  44   virtual const Region* GetPendingInvalidation() = 0;
  45   virtual const PictureLayerTiling* GetPendingOrActiveTwinTiling(
  46       const PictureLayerTiling* tiling) const = 0;
  47   virtual PictureLayerTiling* GetRecycledTwinTiling(
  48       const PictureLayerTiling* tiling) = 0;
  49   virtual TilePriority::PriorityBin GetMaxTilePriorityBin() const = 0;
  50   virtual WhichTree GetTree() const = 0;
  51   virtual bool RequiresHighResToDraw() const = 0;
  52
  53  protected:
  54   virtual ~PictureLayerTilingClient() {}
  55 };
  56
  57 class CC_EXPORT PictureLayerTiling {
  58  public:
  59   static const int kBorderTexels = 1;
  60
  61   ~PictureLayerTiling();
  62
  63   static float CalculateSoonBorderDistance(
  64       const gfx::Rect& visible_rect_in_content_space,
  65       float content_to_screen_scale);
  66
  67   // Create a tiling with no tiles. CreateTile() must be called to add some.
  68   static scoped_ptr<PictureLayerTiling> Create(
  69       float contents_scale,
  70       scoped_refptr<RasterSource> raster_source,
  71       PictureLayerTilingClient* client,
  72       size_t max_tiles_for_interest_area,
  73       float skewport_target_time_in_seconds,
  74       int skewport_extrapolation_limit_in_content_pixels);
  75
  76   void SetRasterSourceAndResize(scoped_refptr<RasterSource> raster_source);
  77   void Invalidate(const Region& layer_invalidation);
  78   void SetRasterSourceOnTiles();
  79   void CreateMissingTilesInLiveTilesRect();
  80
  81   void CloneTilesAndPropertiesFrom(const PictureLayerTiling& twin_tiling);
  82
  83   void set_resolution(TileResolution resolution) { resolution_ = resolution; }
  84   TileResolution resolution() const { return resolution_; }
  85   void set_can_require_tiles_for_activation(bool can_require_tiles) {
  86     can_require_tiles_for_activation_ = can_require_tiles;
  87   }
  88
  89   RasterSource* raster_source() const { return raster_source_.get(); }
  90   gfx::Size tiling_size() const { return tiling_data_.tiling_size(); }
  91   gfx::Rect live_tiles_rect() const { return live_tiles_rect_; }
  92   gfx::Size tile_size() const { return tiling_data_.max_texture_size(); }
  93   float contents_scale() const { return contents_scale_; }
  94
  95   Tile* TileAt(int i, int j) const {
  96     TileMap::const_iterator iter = tiles_.find(TileMapKey(i, j));
  97     return (iter == tiles_.end()) ? NULL : iter->second.get();
  98   }
  99
 100   void CreateAllTilesForTesting() {
 101     SetLiveTilesRect(gfx::Rect(tiling_data_.tiling_size()));
 102   }
 103
 104   const TilingData& TilingDataForTesting() const { return tiling_data_; }
 105
 106   std::vector<Tile*> AllTilesForTesting() const {
 107     std::vector<Tile*> all_tiles;
 108     for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it)
 109       all_tiles.push_back(it->second.get());
 110     return all_tiles;
 111   }
 112
 113   void UpdateAllTilePrioritiesForTesting() {
 114     for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it)
 115       UpdateTileAndTwinPriority(it->second.get());
 116   }
 117
 118   std::vector<scoped_refptr<Tile>> AllRefTilesForTesting() const {
 119     std::vector<scoped_refptr<Tile>> all_tiles;
 120     for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it)
 121       all_tiles.push_back(it->second);
 122     return all_tiles;
 123   }
 124
 125   void SetAllTilesOccludedForTesting() {
 126     gfx::Rect viewport_in_layer_space =
 127         ScaleToEnclosingRect(current_visible_rect_, 1.0f / contents_scale_);
 128     current_occlusion_in_layer_space_ =
 129         Occlusion(gfx::Transform(),
 130                   SimpleEnclosedRegion(viewport_in_layer_space),
 131                   SimpleEnclosedRegion(viewport_in_layer_space));
 132   }
 133
 134   const gfx::Rect& GetCurrentVisibleRectForTesting() const {
 135     return current_visible_rect_;
 136   }
 137
 138   bool IsTileOccluded(const Tile* tile) const;
 139   bool IsTileRequiredForActivationIfVisible(const Tile* tile) const;
 140   bool IsTileRequiredForDrawIfVisible(const Tile* tile) const;
 141
 142   void UpdateTileAndTwinPriority(Tile* tile) const;
 143   TilePriority ComputePriorityForTile(const Tile* tile) const;
 144   void UpdateRequiredStateForTile(Tile* tile, WhichTree tree) const;
 145   bool has_visible_rect_tiles() const { return has_visible_rect_tiles_; }
 146   bool has_skewport_rect_tiles() const { return has_skewport_rect_tiles_; }
 147   bool has_soon_border_rect_tiles() const {
 148     return has_soon_border_rect_tiles_;
 149   }
 150   bool has_eventually_rect_tiles() const { return has_eventually_rect_tiles_; }
 151
 152   const gfx::Rect& current_visible_rect() const {
 153     return current_visible_rect_;
 154   }
 155   const gfx::Rect& current_skewport_rect() const {
 156     return current_skewport_rect_;
 157   }
 158   const gfx::Rect& current_soon_border_rect() const {
 159     return current_soon_border_rect_;
 160   }
 161   const gfx::Rect& current_eventually_rect() const {
 162     return current_eventually_rect_;
 163   }
 164   void VerifyAllTilesHaveCurrentRasterSource() const;
 165
 166   // Iterate over all tiles to fill content_rect.  Even if tiles are invalid
 167   // (i.e. no valid resource) this tiling should still iterate over them.
 168   // The union of all geometry_rect calls for each element iterated over should
 169   // exactly equal content_rect and no two geometry_rects should intersect.
 170   class CC_EXPORT CoverageIterator {
 171    public:
 172     CoverageIterator();
 173     CoverageIterator(const PictureLayerTiling* tiling,
 174         float dest_scale,
 175         const gfx::Rect& rect);
 176     ~CoverageIterator();
 177
 178     // Visible rect (no borders), always in the space of content_rect,
 179     // regardless of the contents scale of the tiling.
 180     gfx::Rect geometry_rect() const;
 181     // Texture rect (in texels) for geometry_rect
 182     gfx::RectF texture_rect() const;
 183
 184     Tile* operator->() const { return current_tile_; }
 185     Tile* operator*() const { return current_tile_; }
 186
 187     CoverageIterator& operator++();
 188     operator bool() const { return tile_j_ <= bottom_; }
 189
 190     int i() const { return tile_i_; }
 191     int j() const { return tile_j_; }
 192
 193    private:
 194     const PictureLayerTiling* tiling_;
 195     gfx::Rect dest_rect_;
 196     float dest_to_content_scale_;
 197
 198     Tile* current_tile_;
 199     gfx::Rect current_geometry_rect_;
 200     int tile_i_;
 201     int tile_j_;
 202     int left_;
 203     int top_;
 204     int right_;
 205     int bottom_;
 206
 207     friend class PictureLayerTiling;
 208   };
 209
 210   void Reset();
 211
 212   bool ComputeTilePriorityRects(const gfx::Rect& viewport_in_layer_space,
 213                                 float ideal_contents_scale,
 214                                 double current_frame_time_in_seconds,
 215                                 const Occlusion& occlusion_in_layer_space);
 216
 217   void GetAllTilesAndPrioritiesForTracing(
 218       std::map<const Tile*, TilePriority>* tile_map) const;
 219   void AsValueInto(base::trace_event::TracedValue* array) const;
 220   size_t GPUMemoryUsageInBytes() const;
 221
 222   struct RectExpansionCache {
 223     RectExpansionCache();
 224
 225     gfx::Rect previous_start;
 226     gfx::Rect previous_bounds;
 227     gfx::Rect previous_result;
 228     int64 previous_target;
 229   };
 230
 231   static
 232   gfx::Rect ExpandRectEquallyToAreaBoundedBy(
 233       const gfx::Rect& starting_rect,
 234       int64 target_area,
 235       const gfx::Rect& bounding_rect,
 236       RectExpansionCache* cache);
 237
 238   bool has_ever_been_updated() const {
 239     return visible_rect_history_[0].frame_time_in_seconds != 0.0;
 240   }
 241
 242  protected:
 243   friend class CoverageIterator;
 244   friend class TilingSetRasterQueueAll;
 245   friend class TilingSetRasterQueueRequired;
 246   friend class TilingSetEvictionQueue;
 247
 248   typedef std::pair<int, int> TileMapKey;
 249   typedef base::hash_map<TileMapKey, scoped_refptr<Tile>> TileMap;
 250
 251   struct FrameVisibleRect {
 252     gfx::Rect visible_rect_in_content_space;
 253     double frame_time_in_seconds = 0.0;
 254   };
 255
 256   PictureLayerTiling(float contents_scale,
 257                      scoped_refptr<RasterSource> raster_source,
 258                      PictureLayerTilingClient* client,
 259                      size_t max_tiles_for_interest_area,
 260                      float skewport_target_time_in_seconds,
 261                      int skewport_extrapolation_limit_in_content_pixels);
 262   void SetLiveTilesRect(const gfx::Rect& live_tiles_rect);
 263   void VerifyLiveTilesRect(bool is_on_recycle_tree) const;
 264   Tile* CreateTile(int i,
 265                    int j,
 266                    const PictureLayerTiling* twin_tiling,
 267                    PictureLayerTiling* recycled_twin);
 268   // Returns true if the Tile existed and was removed from the tiling.
 269   bool RemoveTileAt(int i, int j, PictureLayerTiling* recycled_twin);
 270
 271   // Computes a skewport. The calculation extrapolates the last visible
 272   // rect and the current visible rect to expand the skewport to where it
 273   // would be in |skewport_target_time| seconds. Note that the skewport
 274   // is guaranteed to contain the current visible rect.
 275   gfx::Rect ComputeSkewport(double current_frame_time_in_seconds,
 276                             const gfx::Rect& visible_rect_in_content_space)
 277       const;
 278
 279   // Save the required data for computing tile priorities later.
 280   void UpdateTilePriorityRects(float content_to_screen_scale_,
 281                                const gfx::Rect& visible_rect_in_content_space,
 282                                const gfx::Rect& skewport,
 283                                const gfx::Rect& soon_border_rect,
 284                                const gfx::Rect& eventually_rect,
 285                                const Occlusion& occlusion_in_layer_space);
 286
 287   void UpdateTilePriorityForTree(Tile* tile, WhichTree tree) const;
 288   bool NeedsUpdateForFrameAtTimeAndViewport(
 289       double frame_time_in_seconds,
 290       const gfx::Rect& viewport_in_layer_space) {
 291     return frame_time_in_seconds !=
 292                visible_rect_history_[0].frame_time_in_seconds ||
 293            viewport_in_layer_space != last_viewport_in_layer_space_;
 294   }
 295   void UpdateVisibleRectHistory(
 296       double frame_time_in_seconds,
 297       const gfx::Rect& visible_rect_in_content_space) {
 298     visible_rect_history_[1] = visible_rect_history_[0];
 299     visible_rect_history_[0].frame_time_in_seconds = frame_time_in_seconds;
 300     visible_rect_history_[0].visible_rect_in_content_space =
 301         visible_rect_in_content_space;
 302     // If we don't have a second history item, set it to the most recent one.
 303     if (visible_rect_history_[1].frame_time_in_seconds == 0.0)
 304       visible_rect_history_[1] = visible_rect_history_[0];
 305   }
 306
 307   const size_t max_tiles_for_interest_area_;
 308   const float skewport_target_time_in_seconds_;
 309   const int skewport_extrapolation_limit_in_content_pixels_;
 310
 311   // Given properties.
 312   const float contents_scale_;
 313   PictureLayerTilingClient* const client_;
 314   scoped_refptr<RasterSource> raster_source_;
 315   TileResolution resolution_;
 316
 317   // Internal data.
 318   TilingData tiling_data_;
 319   TileMap tiles_;  // It is not legal to have a NULL tile in the tiles_ map.
 320   gfx::Rect live_tiles_rect_;
 321
 322   gfx::Rect last_viewport_in_layer_space_;
 323   // State saved for computing velocities based upon finite differences.
 324   FrameVisibleRect visible_rect_history_[2];
 325
 326   bool can_require_tiles_for_activation_;
 327
 328   // Iteration rects in content space.
 329   gfx::Rect current_visible_rect_;
 330   gfx::Rect current_skewport_rect_;
 331   gfx::Rect current_soon_border_rect_;
 332   gfx::Rect current_eventually_rect_;
 333   // Other properties used for tile iteration and prioritization.
 334   float current_content_to_screen_scale_;
 335   Occlusion current_occlusion_in_layer_space_;
 336
 337   bool has_visible_rect_tiles_;
 338   bool has_skewport_rect_tiles_;
 339   bool has_soon_border_rect_tiles_;
 340   bool has_eventually_rect_tiles_;
 341
 342  private:
 343   DISALLOW_ASSIGN(PictureLayerTiling);
 344
 345   RectExpansionCache expansion_cache_;
 346 };
 347
 348 }  // namespace cc
 349
 350 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_