blob: 9804750f17ab3a054c4a31ee7df2fb1a94d47d63 [file] [log] [blame]
* Copyright 2015 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef GrBatchFontCache_DEFINED
#define GrBatchFontCache_DEFINED
#include "GrBatchAtlas.h"
#include "GrFontScaler.h"
#include "GrGlyph.h"
#include "SkTDynamicHash.h"
#include "SkVarAlloc.h"
class GrBatchFontCache;
class GrBatchTarget;
class GrGpu;
* The GrBatchTextStrike manages a pool of CPU backing memory for Glyph Masks. This backing memory
* is abstracted by GrGlyph, and indexed by a PackedID and GrFontScaler. The GrFontScaler is what
* actually creates the mask.
class GrBatchTextStrike : public SkNVRefCnt<GrBatchTextStrike> {
GrBatchTextStrike(GrBatchFontCache*, const GrFontDescKey* fontScalerKey);
const GrFontDescKey* getFontScalerKey() const { return fFontScalerKey; }
GrBatchFontCache* getBatchFontCache() const { return fBatchFontCache; }
inline GrGlyph* getGlyph(GrGlyph::PackedID packed, GrFontScaler* scaler) {
GrGlyph* glyph = fCache.find(packed);
if (NULL == glyph) {
glyph = this->generateGlyph(packed, scaler);
return glyph;
// returns true if glyph successfully added to texture atlas, false otherwise
bool addGlyphToAtlas(GrBatchTarget*, GrGlyph*, GrFontScaler*);
// testing
int countGlyphs() const { return fCache.count(); }
// remove any references to this plot
void removeID(GrBatchAtlas::AtlasID);
// If a TextStrike is abandoned by the cache, then the caller must get a new strike
bool isAbandoned() const { return fIsAbandoned; }
static const GrFontDescKey& GetKey(const GrBatchTextStrike& ts) {
return *(ts.fFontScalerKey);
static uint32_t Hash(const GrFontDescKey& key) {
return key.getHash();
SkTDynamicHash<GrGlyph, GrGlyph::PackedID> fCache;
SkAutoTUnref<const GrFontDescKey> fFontScalerKey;
SkVarAlloc fPool;
GrBatchFontCache* fBatchFontCache;
int fAtlasedGlyphs;
bool fIsAbandoned;
GrGlyph* generateGlyph(GrGlyph::PackedID packed, GrFontScaler* scaler);
friend class GrBatchFontCache;
* GrBatchFontCache manages strikes which are indexed by a GrFontScaler. These strikes can then be
* used to individual Glyph Masks. The GrBatchFontCache also manages GrBatchAtlases, though this is
* more or less transparent to the client(aside from atlasGeneration, described below).
* Note - we used to initialize the backing atlas for the GrBatchFontCache at initialization time.
* However, this caused a regression, even when the GrBatchFontCache was unused. We now initialize
* the backing atlases lazily. Its not immediately clear why this improves the situation.
class GrBatchFontCache {
// The user of the cache may hold a long-lived ref to the returned strike. However, actions by
// another client of the cache may cause the strike to be purged while it is still reffed.
// Therefore, the caller must check GrBatchTextStrike::isAbandoned() if there are other
// interactions with the cache since the strike was received.
inline GrBatchTextStrike* getStrike(GrFontScaler* scaler) {
GrBatchTextStrike* strike = fCache.find(*(scaler->getKey()));
if (NULL == strike) {
strike = this->generateStrike(scaler);
return strike;
void freeAll();
// if getTexture returns NULL, the client must not try to use other functions on the
// GrBatchFontCache which use the atlas. This function *must* be called first, before other
// functions which use the atlas.
GrTexture* getTexture(GrMaskFormat format) {
if (this->initAtlas(format)) {
return this->getAtlas(format)->getTexture();
return NULL;
bool hasGlyph(GrGlyph* glyph) {
return this->getAtlas(glyph->fMaskFormat)->hasID(glyph->fID);
// To ensure the GrBatchAtlas does not evict the Glyph Mask from its texture backing store,
// the client must pass in the currentToken from the GrBatchTarget along with the GrGlyph.
// A BulkUseTokenUpdater is used to manage bulk last use token updating in the Atlas.
// For convenience, this function will also set the use token for the current glyph if required
// NOTE: the bulk uploader is only valid if the subrun has a valid atlasGeneration
void addGlyphToBulkAndSetUseToken(GrBatchAtlas::BulkUseTokenUpdater* updater,
GrGlyph* glyph, GrBatchAtlas::BatchToken token) {
this->getAtlas(glyph->fMaskFormat)->setLastUseToken(glyph->fID, token);
void setUseTokenBulk(const GrBatchAtlas::BulkUseTokenUpdater& updater,
GrBatchAtlas::BatchToken token,
GrMaskFormat format) {
this->getAtlas(format)->setLastUseTokenBulk(updater, token);
// add to texture atlas that matches this format
bool addToAtlas(GrBatchTextStrike* strike, GrBatchAtlas::AtlasID* id,
GrBatchTarget* batchTarget,
GrMaskFormat format, int width, int height, const void* image,
SkIPoint16* loc) {
fPreserveStrike = strike;
return this->getAtlas(format)->addToAtlas(id, batchTarget, width, height, image, loc);
// Some clients may wish to verify the integrity of the texture backing store of the
// GrBatchAtlas. The atlasGeneration returned below is a monitonically increasing number which
// changes everytime something is removed from the texture backing store.
uint64_t atlasGeneration(GrMaskFormat format) const {
return this->getAtlas(format)->atlasGeneration();
GrPixelConfig getPixelConfig(GrMaskFormat) const;
void dump() const;
// There is a 1:1 mapping between GrMaskFormats and atlas indices
static int MaskFormatToAtlasIndex(GrMaskFormat format) {
static const int sAtlasIndices[] = {
SK_COMPILE_ASSERT(SK_ARRAY_COUNT(sAtlasIndices) == kMaskFormatCount, array_size_mismatch);
SkASSERT(sAtlasIndices[format] < kMaskFormatCount);
return sAtlasIndices[format];
bool initAtlas(GrMaskFormat);
GrBatchTextStrike* generateStrike(GrFontScaler* scaler) {
GrBatchTextStrike* strike = SkNEW_ARGS(GrBatchTextStrike, (this, scaler->getKey()));
return strike;
GrBatchAtlas* getAtlas(GrMaskFormat format) const {
int atlasIndex = MaskFormatToAtlasIndex(format);
return fAtlases[atlasIndex];
static void HandleEviction(GrBatchAtlas::AtlasID, void*);
GrContext* fContext;
SkTDynamicHash<GrBatchTextStrike, GrFontDescKey> fCache;
GrBatchAtlas* fAtlases[kMaskFormatCount];
GrBatchTextStrike* fPreserveStrike;