| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkArenaAlloc.h" |
| #include "SkComposeShader.h" |
| #include "SkColorFilter.h" |
| #include "SkColorPriv.h" |
| #include "SkColorShader.h" |
| #include "SkReadBuffer.h" |
| #include "SkWriteBuffer.h" |
| #include "SkString.h" |
| |
| sk_sp<SkShader> SkShader::MakeComposeShader(sk_sp<SkShader> dst, sk_sp<SkShader> src, |
| SkBlendMode mode) { |
| if (!src || !dst) { |
| return nullptr; |
| } |
| if (SkBlendMode::kSrc == mode) { |
| return src; |
| } |
| if (SkBlendMode::kDst == mode) { |
| return dst; |
| } |
| return sk_sp<SkShader>(new SkComposeShader(std::move(dst), std::move(src), mode)); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| class SkAutoAlphaRestore { |
| public: |
| SkAutoAlphaRestore(SkPaint* paint, uint8_t newAlpha) { |
| fAlpha = paint->getAlpha(); |
| fPaint = paint; |
| paint->setAlpha(newAlpha); |
| } |
| |
| ~SkAutoAlphaRestore() { |
| fPaint->setAlpha(fAlpha); |
| } |
| private: |
| SkPaint* fPaint; |
| uint8_t fAlpha; |
| }; |
| #define SkAutoAlphaRestore(...) SK_REQUIRE_LOCAL_VAR(SkAutoAlphaRestore) |
| |
| sk_sp<SkFlattenable> SkComposeShader::CreateProc(SkReadBuffer& buffer) { |
| sk_sp<SkShader> shaderA(buffer.readShader()); |
| sk_sp<SkShader> shaderB(buffer.readShader()); |
| SkBlendMode mode; |
| if (buffer.isVersionLT(SkReadBuffer::kXfermodeToBlendMode2_Version)) { |
| sk_sp<SkXfermode> xfer = buffer.readXfermode(); |
| mode = xfer ? xfer->blend() : SkBlendMode::kSrcOver; |
| } else { |
| mode = (SkBlendMode)buffer.read32(); |
| } |
| if (!shaderA || !shaderB) { |
| return nullptr; |
| } |
| return sk_make_sp<SkComposeShader>(std::move(shaderA), std::move(shaderB), mode); |
| } |
| |
| void SkComposeShader::flatten(SkWriteBuffer& buffer) const { |
| buffer.writeFlattenable(fShaderA.get()); |
| buffer.writeFlattenable(fShaderB.get()); |
| buffer.write32((int)fMode); |
| } |
| |
| SkShader::Context* SkComposeShader::onMakeContext( |
| const ContextRec& rec, SkArenaAlloc* alloc) const |
| { |
| // we preconcat our localMatrix (if any) with the device matrix |
| // before calling our sub-shaders |
| SkMatrix tmpM; |
| tmpM.setConcat(*rec.fMatrix, this->getLocalMatrix()); |
| |
| // Our sub-shaders need to see opaque, so by combining them we don't double-alphatize the |
| // result. ComposeShader itself will respect the alpha, and post-apply it after calling the |
| // sub-shaders. |
| SkPaint opaquePaint(*rec.fPaint); |
| opaquePaint.setAlpha(0xFF); |
| |
| ContextRec newRec(rec); |
| newRec.fMatrix = &tmpM; |
| newRec.fPaint = &opaquePaint; |
| |
| SkShader::Context* contextA = fShaderA->makeContext(newRec, alloc); |
| SkShader::Context* contextB = fShaderB->makeContext(newRec, alloc); |
| if (!contextA || !contextB) { |
| return nullptr; |
| } |
| |
| return alloc->make<ComposeShaderContext>(*this, rec, contextA, contextB); |
| } |
| |
| SkComposeShader::ComposeShaderContext::ComposeShaderContext( |
| const SkComposeShader& shader, const ContextRec& rec, |
| SkShader::Context* contextA, SkShader::Context* contextB) |
| : INHERITED(shader, rec) |
| , fShaderContextA(contextA) |
| , fShaderContextB(contextB) {} |
| |
| bool SkComposeShader::asACompose(ComposeRec* rec) const { |
| if (rec) { |
| rec->fShaderA = fShaderA.get(); |
| rec->fShaderB = fShaderB.get(); |
| rec->fBlendMode = fMode; |
| } |
| return true; |
| } |
| |
| |
| // larger is better (fewer times we have to loop), but we shouldn't |
| // take up too much stack-space (each element is 4 bytes) |
| #define TMP_COLOR_COUNT 64 |
| |
| void SkComposeShader::ComposeShaderContext::shadeSpan(int x, int y, SkPMColor result[], int count) { |
| SkShader::Context* shaderContextA = fShaderContextA; |
| SkShader::Context* shaderContextB = fShaderContextB; |
| SkBlendMode mode = static_cast<const SkComposeShader&>(fShader).fMode; |
| unsigned scale = SkAlpha255To256(this->getPaintAlpha()); |
| |
| SkPMColor tmp[TMP_COLOR_COUNT]; |
| |
| SkXfermode* xfer = SkXfermode::Peek(mode); |
| if (nullptr == xfer) { // implied SRC_OVER |
| // TODO: when we have a good test-case, should use SkBlitRow::Proc32 |
| // for these loops |
| do { |
| int n = count; |
| if (n > TMP_COLOR_COUNT) { |
| n = TMP_COLOR_COUNT; |
| } |
| |
| shaderContextA->shadeSpan(x, y, result, n); |
| shaderContextB->shadeSpan(x, y, tmp, n); |
| |
| if (256 == scale) { |
| for (int i = 0; i < n; i++) { |
| result[i] = SkPMSrcOver(tmp[i], result[i]); |
| } |
| } else { |
| for (int i = 0; i < n; i++) { |
| result[i] = SkAlphaMulQ(SkPMSrcOver(tmp[i], result[i]), |
| scale); |
| } |
| } |
| |
| result += n; |
| x += n; |
| count -= n; |
| } while (count > 0); |
| } else { // use mode for the composition |
| do { |
| int n = count; |
| if (n > TMP_COLOR_COUNT) { |
| n = TMP_COLOR_COUNT; |
| } |
| |
| shaderContextA->shadeSpan(x, y, result, n); |
| shaderContextB->shadeSpan(x, y, tmp, n); |
| xfer->xfer32(result, tmp, n, nullptr); |
| |
| if (256 != scale) { |
| for (int i = 0; i < n; i++) { |
| result[i] = SkAlphaMulQ(result[i], scale); |
| } |
| } |
| |
| result += n; |
| x += n; |
| count -= n; |
| } while (count > 0); |
| } |
| } |
| |
| #if SK_SUPPORT_GPU |
| |
| #include "effects/GrConstColorProcessor.h" |
| #include "effects/GrXfermodeFragmentProcessor.h" |
| |
| ///////////////////////////////////////////////////////////////////// |
| |
| sk_sp<GrFragmentProcessor> SkComposeShader::asFragmentProcessor(const AsFPArgs& args) const { |
| switch (fMode) { |
| case SkBlendMode::kClear: |
| return GrConstColorProcessor::Make(GrColor4f::TransparentBlack(), |
| GrConstColorProcessor::kIgnore_InputMode); |
| break; |
| case SkBlendMode::kSrc: |
| return fShaderB->asFragmentProcessor(args); |
| break; |
| case SkBlendMode::kDst: |
| return fShaderA->asFragmentProcessor(args); |
| break; |
| default: |
| sk_sp<GrFragmentProcessor> fpA(fShaderA->asFragmentProcessor(args)); |
| if (!fpA) { |
| return nullptr; |
| } |
| sk_sp<GrFragmentProcessor> fpB(fShaderB->asFragmentProcessor(args)); |
| if (!fpB) { |
| return nullptr; |
| } |
| return GrXfermodeFragmentProcessor::MakeFromTwoProcessors(std::move(fpB), |
| std::move(fpA), fMode); |
| } |
| } |
| #endif |
| |
| #ifndef SK_IGNORE_TO_STRING |
| void SkComposeShader::toString(SkString* str) const { |
| str->append("SkComposeShader: ("); |
| |
| str->append("ShaderA: "); |
| fShaderA->toString(str); |
| str->append(" ShaderB: "); |
| fShaderB->toString(str); |
| if (SkBlendMode::kSrcOver != fMode) { |
| str->appendf(" Xfermode: %s", SkXfermode::ModeName(fMode)); |
| } |
| |
| this->INHERITED::toString(str); |
| |
| str->append(")"); |
| } |
| #endif |