/*
* 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 "SkGlyph.h"
#include "SkTDynamicHash.h"
#include "SkVarAlloc.h"
class GrBatchFontCache;
class GrGpu;
/**
* The GrBatchTextStrike manages a pool of CPU backing memory for GrGlyphs. This backing memory
* is indexed by a PackedID and GrFontScaler. The GrFontScaler is what actually creates the mask.
*/
class GrBatchTextStrike : public SkNVRefCnt<GrBatchTextStrike> {
public:
GrBatchTextStrike(GrBatchFontCache*, const GrFontDescKey* fontScalerKey);
~GrBatchTextStrike();
const GrFontDescKey* getFontScalerKey() const { return fFontScalerKey; }
GrBatchFontCache* getBatchFontCache() const { return fBatchFontCache; }
inline GrGlyph* getGlyph(const SkGlyph& skGlyph, GrGlyph::PackedID packed,
GrFontScaler* scaler) {
GrGlyph* glyph = fCache.find(packed);
if (nullptr == glyph) {
glyph = this->generateGlyph(skGlyph, packed, scaler);
}
return glyph;
}
// This variant of the above function is called by TextBatch. At this point, it is possible
// that the maskformat of the glyph differs from what we expect. In these cases we will just
// draw a clear square.
// skbug:4143 crbug:510931
inline GrGlyph* getGlyph(GrGlyph::PackedID packed,
GrMaskFormat expectedMaskFormat,
GrFontScaler* scaler) {
GrGlyph* glyph = fCache.find(packed);
if (nullptr == glyph) {
// We could return this to the caller, but in practice it adds code complexity for
// potentially little benefit(ie, if the glyph is not in our font cache, then its not
// in the atlas and we're going to be doing a texture upload anyways).
const SkGlyph& skGlyph = scaler->grToSkGlyph(packed);
glyph = this->generateGlyph(skGlyph, packed, scaler);
glyph->fMaskFormat = expectedMaskFormat;
}
return glyph;
}
// returns true if glyph successfully added to texture atlas, false otherwise. If the glyph's
// mask format has changed, then addGlyphToAtlas will draw a clear box. This will almost never
// happen.
// TODO we can handle some of these cases if we really want to, but the long term solution is to
// get the actual glyph image itself when we get the glyph metrics.
bool addGlyphToAtlas(GrDrawBatch::Target*, GrGlyph*, GrFontScaler*,
GrMaskFormat expectedMaskFormat);
// 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();
}
private:
SkTDynamicHash<GrGlyph, GrGlyph::PackedID> fCache;
SkAutoTUnref<const GrFontDescKey> fFontScalerKey;
SkVarAlloc fPool;
GrBatchFontCache* fBatchFontCache;
int fAtlasedGlyphs;
bool fIsAbandoned;
GrGlyph* generateGlyph(const SkGlyph&, GrGlyph::PackedID, GrFontScaler*);
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 {
public:
GrBatchFontCache(GrContext*);
~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 (nullptr == strike) {
strike = this->generateStrike(scaler);
}
return strike;
}
void freeAll();
// if getTexture returns nullptr, 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 nullptr;
}
bool hasGlyph(GrGlyph* glyph) {
SkASSERT(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 current batch token 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, GrBatchToken token) {
SkASSERT(glyph);
updater->add(glyph->fID);
this->getAtlas(glyph->fMaskFormat)->setLastUseToken(glyph->fID, token);
}
void setUseTokenBulk(const GrBatchAtlas::BulkUseTokenUpdater& updater,
GrBatchToken token,
GrMaskFormat format) {
this->getAtlas(format)->setLastUseTokenBulk(updater, token);
}
// add to texture atlas that matches this format
bool addToAtlas(GrBatchTextStrike* strike, GrBatchAtlas::AtlasID* id,
GrDrawBatch::Target* target,
GrMaskFormat format, int width, int height, const void* image,
SkIPoint16* loc) {
fPreserveStrike = strike;
return this->getAtlas(format)->addToAtlas(id, target, 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();
}
int log2Width(GrMaskFormat format) { return fAtlasConfigs[format].fLog2Width; }
int log2Height(GrMaskFormat format) { return fAtlasConfigs[format].fLog2Height; }
///////////////////////////////////////////////////////////////////////////
// Functions intended debug only
void dump() const;
void setAtlasSizes_ForTesting(const GrBatchAtlasConfig configs[3]);
private:
static GrPixelConfig MaskFormatToPixelConfig(GrMaskFormat format) {
static const GrPixelConfig kPixelConfigs[] = {
kAlpha_8_GrPixelConfig,
kRGB_565_GrPixelConfig,
kSkia8888_GrPixelConfig
};
static_assert(SK_ARRAY_COUNT(kPixelConfigs) == kMaskFormatCount, "array_size_mismatch");
return kPixelConfigs[format];
}
// There is a 1:1 mapping between GrMaskFormats and atlas indices
static int MaskFormatToAtlasIndex(GrMaskFormat format) {
static const int sAtlasIndices[] = {
kA8_GrMaskFormat,
kA565_GrMaskFormat,
kARGB_GrMaskFormat,
};
static_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 = new GrBatchTextStrike(this, scaler->getKey());
fCache.add(strike);
return strike;
}
GrBatchAtlas* getAtlas(GrMaskFormat format) const {
int atlasIndex = MaskFormatToAtlasIndex(format);
SkASSERT(fAtlases[atlasIndex]);
return fAtlases[atlasIndex];
}
static void HandleEviction(GrBatchAtlas::AtlasID, void*);
GrContext* fContext;
SkTDynamicHash<GrBatchTextStrike, GrFontDescKey> fCache;
GrBatchAtlas* fAtlases[kMaskFormatCount];
GrBatchTextStrike* fPreserveStrike;
GrBatchAtlasConfig fAtlasConfigs[kMaskFormatCount];
};
#endif