1 #ifndef SkGLTextCache_DEFINED 2 #define SkGLTextCache_DEFINED 3 4 #include "SkGL.h" 5 6 class SkGlyph; 7 8 class SkGLTextCache { 9 public: 10 SkGLTextCache(); 11 ~SkGLTextCache(); 12 13 /** Delete all of the strikes in the cache. Pass true if the texture IDs are 14 still valid, in which case glDeleteTextures will be called. Pass false 15 if they are invalid (e.g. the gl-context has changed), in which case 16 they will just be abandoned. 17 */ 18 void deleteAllStrikes(bool texturesAreValid); 19 20 class Strike { 21 public: width()22 int width() const { return fStrikeWidth; } height()23 int height() const { return fStrikeHeight; } texture()24 GLuint texture() const { return fTexName; } widthShift()25 int widthShift() const { return fStrikeWidthShift; } heightShift()26 int heightShift() const { return fStrikeHeightShift; } 27 28 // call this to force us to ignore the texture name in our destructor 29 // only call it right before our destructor abandonTexture()30 void abandonTexture() { fTexName = 0; } 31 32 private: 33 // if next is non-null, its height must match our height 34 Strike(Strike* next, int width, int height); 35 ~Strike(); 36 37 Strike* findGlyph(const SkGlyph&, int* offset); 38 Strike* addGlyphAndBind(const SkGlyph&, const uint8_t*, int* offset); 39 40 enum { 41 kMinStrikeWidth = 1024, 42 kMaxGlyphCount = 256 43 }; 44 45 Strike* fNext; 46 GLuint fTexName; 47 uint32_t fGlyphIDArray[kMaxGlyphCount]; // stores glyphIDs 48 uint16_t fGlyphOffsetX[kMaxGlyphCount]; // stores x-offsets 49 uint16_t fGlyphCount; 50 uint16_t fNextFreeOffsetX; 51 uint16_t fStrikeWidth; 52 uint16_t fStrikeHeight; 53 uint8_t fStrikeWidthShift; // pow2(fStrikeWidth) 54 uint8_t fStrikeHeightShift; // pow2(fStrikeHeight) 55 56 friend class SkGLTextCache; 57 }; 58 59 /** If found, returns the exact strike containing it (there may be more than 60 one with a given height), and sets offset to the offset for that glyph 61 (if not null). Does NOT bind the texture. 62 If not found, returns null and ignores offset param. 63 */ 64 Strike* findGlyph(const SkGlyph&, int* offset); 65 66 /** Adds the specified glyph to this list of strikes, returning the new 67 head of the list. If offset is not null, it is set to the offset 68 for this glyph within the strike. The associated texture is bound 69 to the gl context. 70 */ 71 Strike* addGlyphAndBind(const SkGlyph&, const uint8_t image[], int* offset); 72 73 private: 74 enum { 75 // greater than this we won't cache 76 kMaxGlyphHeightShift = 9, 77 78 kMaxGlyphHeight = 1 << kMaxGlyphHeightShift, 79 kMaxStrikeListCount = kMaxGlyphHeightShift + 1 80 }; 81 82 // heads of the N families, one for each pow2 height 83 Strike* fStrikeList[kMaxStrikeListCount]; 84 }; 85 86 #endif 87