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/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkPictureShader.h"
#include "SkArenaAlloc.h"
#include "SkBitmap.h"
#include "SkBitmapProcShader.h"
#include "SkCanvas.h"
#include "SkColorSpaceXformCanvas.h"
#include "SkImage.h"
#include "SkImageShader.h"
#include "SkMatrixUtils.h"
#include "SkPicture.h"
#include "SkPictureImageGenerator.h"
#include "SkReadBuffer.h"
#include "SkResourceCache.h"
#if SK_SUPPORT_GPU
#include "GrCaps.h"
#include "GrColorSpaceInfo.h"
#include "GrContext.h"
#include "GrContextPriv.h"
#include "GrFragmentProcessor.h"
#endif
namespace {
static unsigned gBitmapSkaderKeyNamespaceLabel;
struct BitmapShaderKey : public SkResourceCache::Key {
public:
BitmapShaderKey(sk_sp<SkColorSpace> colorSpace,
uint32_t shaderID,
const SkRect& tile,
SkShader::TileMode tmx,
SkShader::TileMode tmy,
const SkSize& scale,
SkTransferFunctionBehavior blendBehavior)
: fColorSpace(std::move(colorSpace))
, fTile(tile)
, fTmx(tmx)
, fTmy(tmy)
, fScale(scale)
, fBlendBehavior(blendBehavior) {
static const size_t keySize = sizeof(fColorSpace) +
sizeof(fTile) +
sizeof(fTmx) + sizeof(fTmy) +
sizeof(fScale) +
sizeof(fBlendBehavior);
// This better be packed.
SkASSERT(sizeof(uint32_t) * (&fEndOfStruct - (uint32_t*)&fColorSpace) == keySize);
this->init(&gBitmapSkaderKeyNamespaceLabel, MakeSharedID(shaderID), keySize);
}
static uint64_t MakeSharedID(uint32_t shaderID) {
uint64_t sharedID = SkSetFourByteTag('p', 's', 'd', 'r');
return (sharedID << 32) | shaderID;
}
private:
// TODO: there are some fishy things about using CS sk_sps in the key:
// - false negatives: keys are memcmp'ed, so we don't detect equivalent CSs
// (SkColorspace::Equals)
// - we're keeping the CS alive, even when the client releases it
//
// Ideally we'd be using unique IDs or some other weak ref + purge mechanism
// when the CS is deleted.
sk_sp<SkColorSpace> fColorSpace;
SkRect fTile;
SkShader::TileMode fTmx, fTmy;
SkSize fScale;
SkTransferFunctionBehavior fBlendBehavior;
SkDEBUGCODE(uint32_t fEndOfStruct;)
};
struct BitmapShaderRec : public SkResourceCache::Rec {
BitmapShaderRec(const BitmapShaderKey& key, SkShader* tileShader)
: fKey(key)
, fShader(SkRef(tileShader)) {}
BitmapShaderKey fKey;
sk_sp<SkShader> fShader;
const Key& getKey() const override { return fKey; }
size_t bytesUsed() const override {
// Just the record overhead -- the actual pixels are accounted by SkImageCacherator.
return sizeof(fKey) + sizeof(SkImageShader);
}
const char* getCategory() const override { return "bitmap-shader"; }
SkDiscardableMemory* diagnostic_only_getDiscardable() const override { return nullptr; }
static bool Visitor(const SkResourceCache::Rec& baseRec, void* contextShader) {
const BitmapShaderRec& rec = static_cast<const BitmapShaderRec&>(baseRec);
sk_sp<SkShader>* result = reinterpret_cast<sk_sp<SkShader>*>(contextShader);
*result = rec.fShader;
// The bitmap shader is backed by an image generator, thus it can always re-generate its
// pixels if discarded.
return true;
}
};
static int32_t gNextID = 1;
uint32_t next_id() {
int32_t id;
do {
id = sk_atomic_inc(&gNextID);
} while (id == SK_InvalidGenID);
return static_cast<uint32_t>(id);
}
} // namespace
SkPictureShader::SkPictureShader(sk_sp<SkPicture> picture, TileMode tmx, TileMode tmy,
const SkMatrix* localMatrix, const SkRect* tile,
sk_sp<SkColorSpace> colorSpace)
: INHERITED(localMatrix)
, fPicture(std::move(picture))
, fTile(tile ? *tile : fPicture->cullRect())
, fTmx(tmx)
, fTmy(tmy)
, fColorSpace(std::move(colorSpace))
, fUniqueID(next_id())
, fAddedToCache(false) {}
SkPictureShader::~SkPictureShader() {
if (fAddedToCache.load()) {
SkResourceCache::PostPurgeSharedID(BitmapShaderKey::MakeSharedID(fUniqueID));
}
}
sk_sp<SkShader> SkPictureShader::Make(sk_sp<SkPicture> picture, TileMode tmx, TileMode tmy,
const SkMatrix* localMatrix, const SkRect* tile) {
if (!picture || picture->cullRect().isEmpty() || (tile && tile->isEmpty())) {
return SkShader::MakeEmptyShader();
}
return sk_sp<SkShader>(new SkPictureShader(std::move(picture), tmx, tmy, localMatrix, tile,
nullptr));
}
sk_sp<SkFlattenable> SkPictureShader::CreateProc(SkReadBuffer& buffer) {
SkMatrix lm;
buffer.readMatrix(&lm);
TileMode mx = (TileMode)buffer.read32();
TileMode my = (TileMode)buffer.read32();
SkRect tile;
buffer.readRect(&tile);
sk_sp<SkPicture> picture;
bool didSerialize = buffer.readBool();
if (didSerialize) {
picture = SkPicture::MakeFromBuffer(buffer);
}
return SkPictureShader::Make(picture, mx, my, &lm, &tile);
}
void SkPictureShader::flatten(SkWriteBuffer& buffer) const {
buffer.writeMatrix(this->getLocalMatrix());
buffer.write32(fTmx);
buffer.write32(fTmy);
buffer.writeRect(fTile);
buffer.writeBool(true);
fPicture->flatten(buffer);
}
// Returns a cached image shader, which wraps a single picture tile at the given
// CTM/local matrix. Also adjusts the local matrix for tile scaling.
sk_sp<SkShader> SkPictureShader::refBitmapShader(const SkMatrix& viewMatrix,
SkTCopyOnFirstWrite<SkMatrix>* localMatrix,
SkColorSpace* dstColorSpace,
const int maxTextureSize) const {
SkASSERT(fPicture && !fPicture->cullRect().isEmpty());
const SkMatrix m = SkMatrix::Concat(viewMatrix, **localMatrix);
// Use a rotation-invariant scale
SkPoint scale;
//
// TODO: replace this with decomposeScale() -- but beware LayoutTest rebaselines!
//
if (!SkDecomposeUpper2x2(m, nullptr, &scale, nullptr)) {
// Decomposition failed, use an approximation.
scale.set(SkScalarSqrt(m.getScaleX() * m.getScaleX() + m.getSkewX() * m.getSkewX()),
SkScalarSqrt(m.getScaleY() * m.getScaleY() + m.getSkewY() * m.getSkewY()));
}
SkSize scaledSize = SkSize::Make(SkScalarAbs(scale.x() * fTile.width()),
SkScalarAbs(scale.y() * fTile.height()));
// Clamp the tile size to about 4M pixels
static const SkScalar kMaxTileArea = 2048 * 2048;
SkScalar tileArea = scaledSize.width() * scaledSize.height();
if (tileArea > kMaxTileArea) {
SkScalar clampScale = SkScalarSqrt(kMaxTileArea / tileArea);
scaledSize.set(scaledSize.width() * clampScale,
scaledSize.height() * clampScale);
}
#if SK_SUPPORT_GPU
// Scale down the tile size if larger than maxTextureSize for GPU Path or it should fail on create texture
if (maxTextureSize) {
if (scaledSize.width() > maxTextureSize || scaledSize.height() > maxTextureSize) {
SkScalar downScale = maxTextureSize / SkMaxScalar(scaledSize.width(), scaledSize.height());
scaledSize.set(SkScalarFloorToScalar(scaledSize.width() * downScale),
SkScalarFloorToScalar(scaledSize.height() * downScale));
}
}
#endif
const SkISize tileSize = scaledSize.toCeil();
if (tileSize.isEmpty()) {
return SkShader::MakeEmptyShader();
}
// The actual scale, compensating for rounding & clamping.
const SkSize tileScale = SkSize::Make(SkIntToScalar(tileSize.width()) / fTile.width(),
SkIntToScalar(tileSize.height()) / fTile.height());
// |fColorSpace| will only be set when using an SkColorSpaceXformCanvas to do pre-draw xforms.
// This canvas is strictly for legacy mode. A non-null |dstColorSpace| indicates that we
// should perform color correct rendering and xform at draw time.
SkASSERT(!fColorSpace || !dstColorSpace);
sk_sp<SkColorSpace> keyCS = dstColorSpace ? sk_ref_sp(dstColorSpace) : fColorSpace;
SkTransferFunctionBehavior blendBehavior = dstColorSpace ? SkTransferFunctionBehavior::kRespect
: SkTransferFunctionBehavior::kIgnore;
sk_sp<SkShader> tileShader;
BitmapShaderKey key(std::move(keyCS),
fUniqueID,
fTile,
fTmx,
fTmy,
tileScale,
blendBehavior);
if (!SkResourceCache::Find(key, BitmapShaderRec::Visitor, &tileShader)) {
SkMatrix tileMatrix;
tileMatrix.setRectToRect(fTile, SkRect::MakeIWH(tileSize.width(), tileSize.height()),
SkMatrix::kFill_ScaleToFit);
sk_sp<SkImage> tileImage = SkImage::MakeFromGenerator(
SkPictureImageGenerator::Make(tileSize, fPicture, &tileMatrix, nullptr,
SkImage::BitDepth::kU8, sk_ref_sp(dstColorSpace)));
if (!tileImage) {
return nullptr;
}
if (fColorSpace) {
tileImage = tileImage->makeColorSpace(fColorSpace, SkTransferFunctionBehavior::kIgnore);
}
tileShader = tileImage->makeShader(fTmx, fTmy);
SkResourceCache::Add(new BitmapShaderRec(key, tileShader.get()));
fAddedToCache.store(true);
}
if (tileScale.width() != 1 || tileScale.height() != 1) {
localMatrix->writable()->preScale(1 / tileScale.width(), 1 / tileScale.height());
}
return tileShader;
}
bool SkPictureShader::onAppendStages(const StageRec& rec) const {
auto lm = this->totalLocalMatrix(rec.fLocalM);
// Keep bitmapShader alive by using alloc instead of stack memory
auto& bitmapShader = *rec.fAlloc->make<sk_sp<SkShader>>();
bitmapShader = this->refBitmapShader(rec.fCTM, &lm, rec.fDstCS);
if (!bitmapShader) {
return false;
}
StageRec localRec = rec;
localRec.fLocalM = lm->isIdentity() ? nullptr : lm.get();
return as_SB(bitmapShader)->appendStages(localRec);
}
/////////////////////////////////////////////////////////////////////////////////////////
SkShaderBase::Context* SkPictureShader::onMakeContext(const ContextRec& rec, SkArenaAlloc* alloc)
const {
auto lm = this->totalLocalMatrix(rec.fLocalMatrix);
sk_sp<SkShader> bitmapShader = this->refBitmapShader(*rec.fMatrix, &lm, rec.fDstColorSpace);
if (!bitmapShader) {
return nullptr;
}
ContextRec localRec = rec;
localRec.fLocalMatrix = lm->isIdentity() ? nullptr : lm.get();
PictureShaderContext* ctx =
alloc->make<PictureShaderContext>(*this, localRec, std::move(bitmapShader), alloc);
if (nullptr == ctx->fBitmapShaderContext) {
ctx = nullptr;
}
return ctx;
}
sk_sp<SkShader> SkPictureShader::onMakeColorSpace(SkColorSpaceXformer* xformer) const {
sk_sp<SkColorSpace> dstCS = xformer->dst();
if (SkColorSpace::Equals(dstCS.get(), fColorSpace.get())) {
return sk_ref_sp(const_cast<SkPictureShader*>(this));
}
return sk_sp<SkPictureShader>(new SkPictureShader(fPicture, fTmx, fTmy, &this->getLocalMatrix(),
&fTile, std::move(dstCS)));
}
/////////////////////////////////////////////////////////////////////////////////////////
SkPictureShader::PictureShaderContext::PictureShaderContext(
const SkPictureShader& shader, const ContextRec& rec, sk_sp<SkShader> bitmapShader,
SkArenaAlloc* alloc)
: INHERITED(shader, rec)
, fBitmapShader(std::move(bitmapShader))
{
fBitmapShaderContext = as_SB(fBitmapShader)->makeContext(rec, alloc);
//if fBitmapShaderContext is null, we are invalid
}
uint32_t SkPictureShader::PictureShaderContext::getFlags() const {
SkASSERT(fBitmapShaderContext);
return fBitmapShaderContext->getFlags();
}
void SkPictureShader::PictureShaderContext::shadeSpan(int x, int y, SkPMColor dstC[], int count) {
SkASSERT(fBitmapShaderContext);
fBitmapShaderContext->shadeSpan(x, y, dstC, count);
}
void SkPictureShader::toString(SkString* str) const {
static const char* gTileModeName[SkShader::kTileModeCount] = {
"clamp", "repeat", "mirror"
};
str->appendf("PictureShader: [%f:%f:%f:%f] ",
fPicture->cullRect().fLeft,
fPicture->cullRect().fTop,
fPicture->cullRect().fRight,
fPicture->cullRect().fBottom);
str->appendf("(%s, %s)", gTileModeName[fTmx], gTileModeName[fTmy]);
this->INHERITED::toString(str);
}
#if SK_SUPPORT_GPU
std::unique_ptr<GrFragmentProcessor> SkPictureShader::asFragmentProcessor(
const GrFPArgs& args) const {
int maxTextureSize = 0;
if (args.fContext) {
maxTextureSize = args.fContext->contextPriv().caps()->maxTextureSize();
}
auto lm = this->totalLocalMatrix(args.fPreLocalMatrix, args.fPostLocalMatrix);
sk_sp<SkShader> bitmapShader(this->refBitmapShader(*args.fViewMatrix, &lm,
args.fDstColorSpaceInfo->colorSpace(),
maxTextureSize));
if (!bitmapShader) {
return nullptr;
}
// We want to *reset* args.fPreLocalMatrix, not compose it.
GrFPArgs newArgs(args.fContext, args.fViewMatrix, args.fFilterQuality, args.fDstColorSpaceInfo);
newArgs.fPreLocalMatrix = lm.get();
return as_SB(bitmapShader)->asFragmentProcessor(newArgs);
}
#endif