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#ifndef SkGLTextCache_DEFINED
#define SkGLTextCache_DEFINED
#include "SkGL.h"
class SkGlyph;
class SkGLTextCache {
public:
SkGLTextCache();
~SkGLTextCache();
/** Delete all of the strikes in the cache. Pass true if the texture IDs are
still valid, in which case glDeleteTextures will be called. Pass false
if they are invalid (e.g. the gl-context has changed), in which case
they will just be abandoned.
*/
void deleteAllStrikes(bool texturesAreValid);
class Strike {
public:
int width() const { return fStrikeWidth; }
int height() const { return fStrikeHeight; }
GLuint texture() const { return fTexName; }
int widthShift() const { return fStrikeWidthShift; }
int heightShift() const { return fStrikeHeightShift; }
// call this to force us to ignore the texture name in our destructor
// only call it right before our destructor
void abandonTexture() { fTexName = 0; }
private:
// if next is non-null, its height must match our height
Strike(Strike* next, int width, int height);
~Strike();
Strike* findGlyph(const SkGlyph&, int* offset);
Strike* addGlyphAndBind(const SkGlyph&, const uint8_t*, int* offset);
enum {
kMinStrikeWidth = 1024,
kMaxGlyphCount = 256
};
Strike* fNext;
GLuint fTexName;
uint32_t fGlyphIDArray[kMaxGlyphCount]; // stores glyphIDs
uint16_t fGlyphOffsetX[kMaxGlyphCount]; // stores x-offsets
uint16_t fGlyphCount;
uint16_t fNextFreeOffsetX;
uint16_t fStrikeWidth;
uint16_t fStrikeHeight;
uint8_t fStrikeWidthShift; // pow2(fStrikeWidth)
uint8_t fStrikeHeightShift; // pow2(fStrikeHeight)
friend class SkGLTextCache;
};
/** If found, returns the exact strike containing it (there may be more than
one with a given height), and sets offset to the offset for that glyph
(if not null). Does NOT bind the texture.
If not found, returns null and ignores offset param.
*/
Strike* findGlyph(const SkGlyph&, int* offset);
/** Adds the specified glyph to this list of strikes, returning the new
head of the list. If offset is not null, it is set to the offset
for this glyph within the strike. The associated texture is bound
to the gl context.
*/
Strike* addGlyphAndBind(const SkGlyph&, const uint8_t image[], int* offset);
private:
enum {
// greater than this we won't cache
kMaxGlyphHeightShift = 9,
kMaxGlyphHeight = 1 << kMaxGlyphHeightShift,
kMaxStrikeListCount = kMaxGlyphHeightShift + 1
};
// heads of the N families, one for each pow2 height
Strike* fStrikeList[kMaxStrikeListCount];
};
#endif
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