-
/*
* Copyright 2012 Google Inc.
*
#include "SkBBHFactory.h"
#include "SkBBoxHierarchy.h"
-#include "SkPictureStateTree.h"
/**
* 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:
- enum {
- // Number of tiles for which data is allocated on the stack in
- // SkTileGrid::search. If malloc becomes a bottleneck, we may consider
- // increasing this number. Typical large web page, say 2k x 16k, would
- // require 512 tiles of size 256 x 256 pixels.
- kStackAllocationTileCount = 1024
- };
-
- typedef void* (*SkTileGridNextDatumFunctionPtr)(SkTDArray<void*>** tileData, SkAutoSTArray<kStackAllocationTileCount, int>& tileIndices);
-
- SkTileGrid(int xTileCount, int yTileCount, const SkTileGridFactory::TileGridInfo& info,
- SkTileGridNextDatumFunctionPtr nextDatumFunction);
+ SkTileGrid(int xTiles, int yTiles, const SkTileGridFactory::TileGridInfo& info);
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
+ * @param data An arbitrary data pointer, may be NULL.
+ * @param bounds The bounding box, should not be empty.
+ * @param defer Ignored; SkTileGrid 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
+ * Populate 'results' with data pointers corresponding to bounding boxes that intersect 'query'.
+ * This will be fastest if the query is an exact match to a single grid tile.
*/
- virtual void search(const SkIRect& query, SkTDArray<void*>* results) SK_OVERRIDE;
+ virtual void search(const SkIRect& query, SkTDArray<void*>* results) const SK_OVERRIDE;
virtual void clear() SK_OVERRIDE;
- /**
- * Gets the number of insertions
- */
- virtual int getCount() const SK_OVERRIDE;
+ virtual int getCount() const SK_OVERRIDE { return fCount; }
virtual int getDepth() const SK_OVERRIDE { return -1; }
virtual void rewindInserts() SK_OVERRIDE;
- // Used by search() and in SkTileGridHelper implementations
- enum {
- kTileFinished = -1,
- };
-
- int tileCount(int x, int y); // For testing only.
+ // For testing.
+ int tileCount(int x, int y) { return fTiles[y * fXTiles + x].count(); }
private:
- SkTDArray<void*>& tile(int x, int y);
+ struct Entry {
+ size_t order; // Insertion order. Used to preserve order when merging multiple tiles.
+ void* data;
+ };
- int fXTileCount, fYTileCount, fTileCount;
+ const int fXTiles, fYTiles;
SkTileGridFactory::TileGridInfo fInfo;
- SkTDArray<void*>* fTileData;
- int fInsertionCount;
- SkIRect fGridBounds;
- SkTileGridNextDatumFunctionPtr fNextDatumFunction;
+ size_t fCount;
+
+ // (fXTiles * fYTiles) SkTDArrays, each listing data overlapping that tile in insertion order.
+ SkTDArray<Entry>* fTiles;
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, SkAutoSTArray<SkTileGrid::kStackAllocationTileCount, int>& tileIndices) {
- T* minVal = NULL;
- int tileCount = tileIndices.count();
- int minIndex = tileCount;
- int maxIndex = 0;
- // Find the next Datum; track where it's found so we reduce the size of the second loop.
- 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;
- minIndex = tile;
- maxIndex = tile;
- } else if (!((*minVal) < (*candidate))) {
- // We don't require operator==; if !(candidate<minVal) && !(minVal<candidate),
- // candidate==minVal and we have to add this tile to the range searched.
- maxIndex = tile;
- }
- }
- }
- // Increment indices past the next datum
- if (minVal != NULL) {
- for (int tile = minIndex; tile <= maxIndex; ++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
projects / platform / framework / web / crosswalk.git / blobdiff