blob: f2fdce78f2f6b7881669bcb7de9445678b7ce72e [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 GrStrikeCache_DEFINED
#define GrStrikeCache_DEFINED
#include "src/codec/SkMasks.h"
#include "src/core/SkArenaAlloc.h"
#include "src/core/SkStrike.h"
#include "src/core/SkTDynamicHash.h"
#include "src/gpu/GrDrawOpAtlas.h"
#include "src/gpu/GrGlyph.h"
class GrAtlasManager;
class GrGpu;
class GrStrikeCache;
/**
* The GrTextStrike manages a pool of CPU backing memory for GrGlyphs. This backing memory
* is indexed by a PackedID and SkStrike. The SkStrike is what actually creates the mask.
* The GrTextStrike may outlive the generating SkStrike. However, it retains a copy
* of it's SkDescriptor as a key to access (or regenerate) the SkStrike. GrTextStrikes are
* created by and owned by a GrStrikeCache.
*/
class GrTextStrike : public SkNVRefCnt<GrTextStrike> {
public:
GrTextStrike(const SkDescriptor& fontScalerKey);
GrGlyph* getGlyph(const SkGlyph& skGlyph) {
GrGlyph* grGlyph = fCache.find(skGlyph.getPackedID());
if (grGlyph == nullptr) {
grGlyph = fAlloc.make<GrGlyph>(skGlyph);
fCache.add(grGlyph);
}
return grGlyph;
}
// This variant of the above function is called by GrAtlasTextOp. 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
GrGlyph* getGlyph(SkPackedGlyphID packed, SkStrike* skStrike) {
GrGlyph* grGlyph = fCache.find(packed);
if (grGlyph == nullptr) {
// 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 = skStrike->getGlyphIDMetrics(packed);
grGlyph = fAlloc.make<GrGlyph>(skGlyph);
fCache.add(grGlyph);
}
return grGlyph;
}
// 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.
GrDrawOpAtlas::ErrorCode addGlyphToAtlas(GrResourceProvider*, GrDeferredUploadTarget*,
GrStrikeCache*, GrAtlasManager*, GrGlyph*,
SkStrike*, GrMaskFormat expectedMaskFormat,
bool isScaledGlyph);
// testing
int countGlyphs() const { return fCache.count(); }
// remove any references to this plot
void removeID(GrDrawOpAtlas::AtlasID);
// If a TextStrike is abandoned by the cache, then the caller must get a new strike
bool isAbandoned() const { return fIsAbandoned; }
static const SkDescriptor& GetKey(const GrTextStrike& strike) {
return *strike.fFontScalerKey.getDesc();
}
static uint32_t Hash(const SkDescriptor& desc) { return desc.getChecksum(); }
private:
SkTDynamicHash<GrGlyph, SkPackedGlyphID> fCache;
SkAutoDescriptor fFontScalerKey;
SkArenaAlloc fAlloc{512};
int fAtlasedGlyphs{0};
bool fIsAbandoned{false};
friend class GrStrikeCache;
};
/**
* GrStrikeCache manages strikes which are indexed by a SkStrike. These strikes can then be
* used to generate individual Glyph Masks.
*/
class GrStrikeCache {
public:
GrStrikeCache(const GrCaps* caps, size_t maxTextureBytes);
~GrStrikeCache();
void setStrikeToPreserve(GrTextStrike* strike) { fPreserveStrike = strike; }
// 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 GrTextStrike::isAbandoned() if there are other
// interactions with the cache since the strike was received.
sk_sp<GrTextStrike> getStrike(const SkDescriptor& desc) {
sk_sp<GrTextStrike> strike = sk_ref_sp(fCache.find(desc));
if (!strike) {
strike = this->generateStrike(desc);
}
return strike;
}
const SkMasks& getMasks() const { return *f565Masks; }
void freeAll();
static void HandleEviction(GrDrawOpAtlas::AtlasID, void*);
private:
sk_sp<GrTextStrike> generateStrike(const SkDescriptor& desc) {
// 'fCache' get the construction ref
sk_sp<GrTextStrike> strike = sk_ref_sp(new GrTextStrike(desc));
fCache.add(strike.get());
return strike;
}
using StrikeHash = SkTDynamicHash<GrTextStrike, SkDescriptor>;
StrikeHash fCache;
GrTextStrike* fPreserveStrike;
std::unique_ptr<const SkMasks> f565Masks;
};
#endif // GrStrikeCache_DEFINED