cc/tiles/tiles_with_resource_iterator.h

   1 // Copyright 2022 The Chromium Authors
   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_TILES_TILES_WITH_RESOURCE_ITERATOR_H_
   6 #define CC_TILES_TILES_WITH_RESOURCE_ITERATOR_H_
   7
   8 #include <set>
   9 #include <vector>
  10
  11 #include "base/memory/raw_ptr.h"
  12 #include "cc/cc_export.h"
  13 #include "cc/tiles/picture_layer_tiling.h"
  14 #include "cc/tiles/prioritized_tile.h"
  15 #include "third_party/abseil-cpp/absl/types/optional.h"
  16
  17 namespace cc {
  18
  19 class PictureLayerImpl;
  20 class PictureLayerTilingSet;
  21
  22 // Iterates over all tiles that have a resource. The order of iteration is not
  23 // defined.
  24 class CC_EXPORT TilesWithResourceIterator {
  25  public:
  26   TilesWithResourceIterator(
  27       const std::vector<PictureLayerImpl*>* picture_layers,
  28       const std::vector<PictureLayerImpl*>* secondary_picture_layers);
  29   TilesWithResourceIterator(const TilesWithResourceIterator&) = delete;
  30   TilesWithResourceIterator& operator=(const TilesWithResourceIterator&) =
  31       delete;
  32   ~TilesWithResourceIterator();
  33
  34   bool AtEnd() const;
  35   void Next();
  36   Tile* GetCurrent();
  37
  38   // Returns the PrioritizedTile for the current tile, null if at the end.
  39   PrioritizedTile* GetCurrentAsPrioritizedTile();
  40
  41   // Returns true if the current tile is occluded, false if at the end.
  42   bool IsCurrentTileOccluded();
  43
  44  private:
  45   // The following functions start iterating at the *current* location.
  46   // Each function returns true if a match is found, false indicates there
  47   // are no more items to iterate through.
  48   bool FindNextInPictureLayers();
  49   bool FindNextInActiveLayers();
  50   bool FindNextInPictureLayerTilingSet();
  51   bool FindNextInTileIterator();
  52
  53   PictureLayerTilingSet* CurrentPictureLayerTilingSet();
  54   PictureLayerTiling* CurrentPictureLayerTiling();
  55
  56   // Iteration occurs over this vector first.
  57   const raw_ptr<const std::vector<PictureLayerImpl*>> picture_layers_;
  58
  59   // The secondary set of layers to iterate through, may be null.
  60   const raw_ptr<const std::vector<PictureLayerImpl*>> secondary_picture_layers_;
  61
  62   // Indicates whether `active_layers_` is referencing `picture_layers_` or
  63   // `secondary_picture_layers_`.
  64   bool is_active_layers_secondary_layers_ = false;
  65
  66   raw_ptr<const std::vector<PictureLayerImpl*>> active_layers_;
  67
  68   // Index into `active_layers_` the current tile comes from.
  69   size_t current_picture_layer_index_ = 0;
  70
  71   // Index into the current PictureLayerTilingSet the current tile comes from.
  72   size_t current_picture_layer_tiling_index_ = 0;
  73
  74   // Iterates over the tiles from the current PictureLayerTiling. If this is
  75   // not set, the end has been reached.
  76   absl::optional<PictureLayerTiling::TileIterator> tile_iterator_;
  77
  78   // Set of tiles that have been visited. Used to ensure the same tile isn't
  79   // visited more than once.
  80   std::set<Tile*> visited_;
  81
  82   // Created when GetCurrentAsPrioritizedTile() is called.
  83   absl::optional<PrioritizedTile> prioritized_tile_;
  84 };
  85
  86 }  // namespace cc
  87
  88 #endif  // CC_TILES_TILES_WITH_RESOURCE_ITERATOR_H_