| |
| /* |
| * Copyright 2012 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkTileGrid_DEFINED |
| #define SkTileGrid_DEFINED |
| |
| #include "SkBBoxHierarchy.h" |
| #include "SkPictureStateTree.h" |
| #include "SkTileGridPicture.h" // for TileGridInfo |
| |
| /** |
| * Subclass of SkBBoxHierarchy that stores elements in buckets that correspond |
| * to tile regions, disposed in a regular grid. This is useful when the tile |
| * structure that will be use in search() calls is known prior to insertion. |
| * Calls to search will return in constant time. |
| * |
| * Note: Current implementation of search() only supports looking-up regions |
| * that are an exact match to a single tile. Implementation could be augmented |
| * to support arbitrary rectangles, but performance would be sub-optimal. |
| */ |
| class SkTileGrid : public SkBBoxHierarchy { |
| public: |
| typedef void* (*SkTileGridNextDatumFunctionPtr)(SkTDArray<void*>** tileData, SkTDArray<int>& tileIndices); |
| |
| SkTileGrid(int xTileCount, int yTileCount, const SkTileGridPicture::TileGridInfo& info, |
| SkTileGridNextDatumFunctionPtr nextDatumFunction); |
| |
| virtual ~SkTileGrid(); |
| |
| /** |
| * Insert a data pointer and corresponding bounding box |
| * @param data The data pointer, may be NULL |
| * @param bounds The bounding box, should not be empty |
| * @param defer Ignored, TileArray does not defer insertions |
| */ |
| virtual void insert(void* data, const SkIRect& bounds, bool) SK_OVERRIDE; |
| |
| virtual void flushDeferredInserts() SK_OVERRIDE {}; |
| |
| /** |
| * Populate 'results' with data pointers corresponding to bounding boxes that intersect 'query' |
| * The query argument is expected to be an exact match to a tile of the grid |
| */ |
| virtual void search(const SkIRect& query, SkTDArray<void*>* results) SK_OVERRIDE; |
| |
| virtual void clear() SK_OVERRIDE; |
| |
| /** |
| * Gets the number of insertions |
| */ |
| virtual int getCount() const SK_OVERRIDE; |
| |
| // Used by search() and in SkTileGridHelper implementations |
| enum { |
| kTileFinished = -1, |
| }; |
| private: |
| SkTDArray<void*>& tile(int x, int y); |
| |
| int fXTileCount, fYTileCount, fTileCount; |
| SkTileGridPicture::TileGridInfo fInfo; |
| SkTDArray<void*>* fTileData; |
| int fInsertionCount; |
| SkIRect fGridBounds; |
| SkTileGridNextDatumFunctionPtr fNextDatumFunction; |
| |
| friend class TileGridTest; |
| typedef SkBBoxHierarchy INHERITED; |
| }; |
| |
| /** |
| * Generic implementation for SkTileGridNextDatumFunctionPtr. user code may instantiate |
| * this template to get a valid SkTileGridNextDatumFunction implementation |
| * |
| * Returns the next element of tileData[i][tileIndices[i]] for all i and advances |
| * tileIndices[] past them. The order in which data are returned by successive |
| * calls to this method must reflect the order in which the were originally |
| * recorded into the tile grid. |
| * |
| * \param tileData array of pointers to arrays of tile data |
| * \param tileIndices per-tile data indices, indices are incremented for tiles that contain |
| * the next datum. |
| * \tparam T a type to which it is safe to cast a datum and that has an operator < |
| * such that 'a < b' is true if 'a' was inserted into the tile grid before 'b'. |
| */ |
| template <typename T> |
| void* SkTileGridNextDatum(SkTDArray<void*>** tileData, SkTDArray<int>& tileIndices) { |
| T* minVal = NULL; |
| int tileCount = tileIndices.count(); |
| // Find the next Datum |
| for (int tile = 0; tile < tileCount; ++tile) { |
| int pos = tileIndices[tile]; |
| if (pos != SkTileGrid::kTileFinished) { |
| T* candidate = (T*)(*tileData[tile])[pos]; |
| if (NULL == minVal || (*candidate) < (*minVal)) { |
| minVal = candidate; |
| } |
| } |
| } |
| // Increment indices past the next datum |
| if (minVal != NULL) { |
| for (int tile = 0; tile < tileCount; ++tile) { |
| int pos = tileIndices[tile]; |
| if (pos != SkTileGrid::kTileFinished && (*tileData[tile])[pos] == minVal) { |
| if (++(tileIndices[tile]) >= tileData[tile]->count()) { |
| tileIndices[tile] = SkTileGrid::kTileFinished; |
| } |
| } |
| } |
| return minVal; |
| } |
| return NULL; |
| } |
| |
| #endif |