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
 165   // Iterate over all tiles to fill content_rect.  Even if tiles are invalid
 166   // (i.e. no valid resource) this tiling should still iterate over them.
 167   // The union of all geometry_rect calls for each element iterated over should
 168   // exactly equal content_rect and no two geometry_rects should intersect.
 169   class CC_EXPORT CoverageIterator {
 170    public:
 171     CoverageIterator();
 172     CoverageIterator(const PictureLayerTiling* tiling,
 173         float dest_scale,
 174         const gfx::Rect& rect);
 175     ~CoverageIterator();
 176
 177     // Visible rect (no borders), always in the space of content_rect,
 178     // regardless of the contents scale of the tiling.
 179     gfx::Rect geometry_rect() const;
 180     // Texture rect (in texels) for geometry_rect
 181     gfx::RectF texture_rect() const;
 182
 183     Tile* operator->() const { return current_tile_; }
 184     Tile* operator*() const { return current_tile_; }
 185
 186     CoverageIterator& operator++();
 187     operator bool() const { return tile_j_ <= bottom_; }
 188
 189     int i() const { return tile_i_; }
 190     int j() const { return tile_j_; }
 191
 192    private:
 193     const PictureLayerTiling* tiling_;
 194     gfx::Rect dest_rect_;
 195     float dest_to_content_scale_;
 196
 197     Tile* current_tile_;
 198     gfx::Rect current_geometry_rect_;
 199     int tile_i_;
 200     int tile_j_;
 201     int left_;
 202     int top_;
 203     int right_;
 204     int bottom_;
 205
 206     friend class PictureLayerTiling;
 207   };
 208
 209   void Reset();
 210
 211   bool ComputeTilePriorityRects(const gfx::Rect& viewport_in_layer_space,
 212                                 float ideal_contents_scale,
 213                                 double current_frame_time_in_seconds,
 214                                 const Occlusion& occlusion_in_layer_space);
 215
 216   void GetAllTilesAndPrioritiesForTracing(
 217       std::map<const Tile*, TilePriority>* tile_map) const;
 218   void AsValueInto(base::trace_event::TracedValue* array) const;
 219   size_t GPUMemoryUsageInBytes() const;
 220
 221   struct RectExpansionCache {
 222     RectExpansionCache();
 223
 224     gfx::Rect previous_start;
 225     gfx::Rect previous_bounds;
 226     gfx::Rect previous_result;
 227     int64 previous_target;
 228   };
 229
 230   static
 231   gfx::Rect ExpandRectEquallyToAreaBoundedBy(
 232       const gfx::Rect& starting_rect,
 233       int64 target_area,
 234       const gfx::Rect& bounding_rect,
 235       RectExpansionCache* cache);
 236
 237   bool has_ever_been_updated() const {
 238     return visible_rect_history_[0].frame_time_in_seconds != 0.0;
 239   }
 240
 241  protected:
 242   friend class CoverageIterator;
 243   friend class TilingSetRasterQueueAll;
 244   friend class TilingSetRasterQueueRequired;
 245   friend class TilingSetEvictionQueue;
 246
 247   typedef std::pair<int, int> TileMapKey;
 248   typedef base::hash_map<TileMapKey, scoped_refptr<Tile>> TileMap;
 249
 250   struct FrameVisibleRect {
 251     gfx::Rect visible_rect_in_content_space;
 252     double frame_time_in_seconds = 0.0;
 253   };
 254
 255   PictureLayerTiling(float contents_scale,
 256                      scoped_refptr<RasterSource> raster_source,
 257                      PictureLayerTilingClient* client,
 258                      size_t max_tiles_for_interest_area,
 259                      float skewport_target_time_in_seconds,
 260                      int skewport_extrapolation_limit_in_content_pixels);
 261   void SetLiveTilesRect(const gfx::Rect& live_tiles_rect);
 262   void VerifyLiveTilesRect(bool is_on_recycle_tree) const;
 263   Tile* CreateTile(int i,
 264                    int j,
 265                    const PictureLayerTiling* twin_tiling,
 266                    PictureLayerTiling* recycled_twin);
 267   // Returns true if the Tile existed and was removed from the tiling.
 268   bool RemoveTileAt(int i, int j, PictureLayerTiling* recycled_twin);
 269
 270   // Computes a skewport. The calculation extrapolates the last visible
 271   // rect and the current visible rect to expand the skewport to where it
 272   // would be in |skewport_target_time| seconds. Note that the skewport
 273   // is guaranteed to contain the current visible rect.
 274   gfx::Rect ComputeSkewport(double current_frame_time_in_seconds,
 275                             const gfx::Rect& visible_rect_in_content_space)
 276       const;
 277
 278   // Save the required data for computing tile priorities later.
 279   void UpdateTilePriorityRects(float content_to_screen_scale_,
 280                                const gfx::Rect& visible_rect_in_content_space,
 281                                const gfx::Rect& skewport,
 282                                const gfx::Rect& soon_border_rect,
 283                                const gfx::Rect& eventually_rect,
 284                                const Occlusion& occlusion_in_layer_space);
 285
 286   void UpdateTilePriorityForTree(Tile* tile, WhichTree tree) const;
 287   bool NeedsUpdateForFrameAtTimeAndViewport(
 288       double frame_time_in_seconds,
 289       const gfx::Rect& viewport_in_layer_space) {
 290     return frame_time_in_seconds !=
 291                visible_rect_history_[0].frame_time_in_seconds ||
 292            viewport_in_layer_space != last_viewport_in_layer_space_;
 293   }
 294   void UpdateVisibleRectHistory(
 295       double frame_time_in_seconds,
 296       const gfx::Rect& visible_rect_in_content_space) {
 297     visible_rect_history_[1] = visible_rect_history_[0];
 298     visible_rect_history_[0].frame_time_in_seconds = frame_time_in_seconds;
 299     visible_rect_history_[0].visible_rect_in_content_space =
 300         visible_rect_in_content_space;
 301     // If we don't have a second history item, set it to the most recent one.
 302     if (visible_rect_history_[1].frame_time_in_seconds == 0.0)
 303       visible_rect_history_[1] = visible_rect_history_[0];
 304   }
 305
 306   const size_t max_tiles_for_interest_area_;
 307   const float skewport_target_time_in_seconds_;
 308   const int skewport_extrapolation_limit_in_content_pixels_;
 309
 310   // Given properties.
 311   const float contents_scale_;
 312   PictureLayerTilingClient* const client_;
 313   scoped_refptr<RasterSource> raster_source_;
 314   TileResolution resolution_;
 315
 316   // Internal data.
 317   TilingData tiling_data_;
 318   TileMap tiles_;  // It is not legal to have a NULL tile in the tiles_ map.
 319   gfx::Rect live_tiles_rect_;
 320
 321   gfx::Rect last_viewport_in_layer_space_;
 322   // State saved for computing velocities based upon finite differences.
 323   FrameVisibleRect visible_rect_history_[2];
 324
 325   bool can_require_tiles_for_activation_;
 326
 327   // Iteration rects in content space.
 328   gfx::Rect current_visible_rect_;
 329   gfx::Rect current_skewport_rect_;
 330   gfx::Rect current_soon_border_rect_;
 331   gfx::Rect current_eventually_rect_;
 332   // Other properties used for tile iteration and prioritization.
 333   float current_content_to_screen_scale_;
 334   Occlusion current_occlusion_in_layer_space_;
 335
 336   bool has_visible_rect_tiles_;
 337   bool has_skewport_rect_tiles_;
 338   bool has_soon_border_rect_tiles_;
 339   bool has_eventually_rect_tiles_;
 340
 341  private:
 342   DISALLOW_ASSIGN(PictureLayerTiling);
 343
 344   RectExpansionCache expansion_cache_;
 345 };
 346
 347 }  // namespace cc
 348
 349 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_