| |
| /* |
| * 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 "SkComposeShader.h" |
| #include "SkColorFilter.h" |
| #include "SkColorPriv.h" |
| #include "SkColorShader.h" |
| #include "SkReadBuffer.h" |
| #include "SkWriteBuffer.h" |
| #include "SkXfermode.h" |
| #include "SkString.h" |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| SkComposeShader::SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode) { |
| fShaderA = sA; sA->ref(); |
| fShaderB = sB; sB->ref(); |
| // mode may be null |
| fMode = mode; |
| SkSafeRef(mode); |
| } |
| |
| SkComposeShader::~SkComposeShader() { |
| SkSafeUnref(fMode); |
| fShaderB->unref(); |
| fShaderA->unref(); |
| } |
| |
| size_t SkComposeShader::contextSize() const { |
| return sizeof(ComposeShaderContext) + fShaderA->contextSize() + fShaderB->contextSize(); |
| } |
| |
| 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) |
| |
| SkFlattenable* SkComposeShader::CreateProc(SkReadBuffer& buffer) { |
| SkAutoTUnref<SkShader> shaderA(buffer.readShader()); |
| SkAutoTUnref<SkShader> shaderB(buffer.readShader()); |
| SkAutoTUnref<SkXfermode> mode(buffer.readXfermode()); |
| if (!shaderA.get() || !shaderB.get()) { |
| return NULL; |
| } |
| return SkNEW_ARGS(SkComposeShader, (shaderA, shaderB, mode)); |
| } |
| |
| void SkComposeShader::flatten(SkWriteBuffer& buffer) const { |
| buffer.writeFlattenable(fShaderA); |
| buffer.writeFlattenable(fShaderB); |
| buffer.writeFlattenable(fMode); |
| } |
| |
| template <typename T> void safe_call_destructor(T* obj) { |
| if (obj) { |
| obj->~T(); |
| } |
| } |
| |
| SkShader::Context* SkComposeShader::onCreateContext(const ContextRec& rec, void* storage) const { |
| char* aStorage = (char*) storage + sizeof(ComposeShaderContext); |
| char* bStorage = aStorage + fShaderA->contextSize(); |
| |
| // 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->createContext(newRec, aStorage); |
| SkShader::Context* contextB = fShaderB->createContext(newRec, bStorage); |
| if (!contextA || !contextB) { |
| safe_call_destructor(contextA); |
| safe_call_destructor(contextB); |
| return NULL; |
| } |
| |
| return SkNEW_PLACEMENT_ARGS(storage, 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) {} |
| |
| SkComposeShader::ComposeShaderContext::~ComposeShaderContext() { |
| fShaderContextA->~Context(); |
| fShaderContextB->~Context(); |
| } |
| |
| bool SkComposeShader::asACompose(ComposeRec* rec) const { |
| if (rec) { |
| rec->fShaderA = fShaderA; |
| rec->fShaderB = fShaderB; |
| rec->fMode = 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; |
| SkXfermode* mode = static_cast<const SkComposeShader&>(fShader).fMode; |
| unsigned scale = SkAlpha255To256(this->getPaintAlpha()); |
| |
| #ifdef SK_BUILD_FOR_ANDROID |
| scale = 256; // ugh -- maintain old bug/behavior for now |
| #endif |
| |
| SkPMColor tmp[TMP_COLOR_COUNT]; |
| |
| if (NULL == mode) { // 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); |
| mode->xfer32(result, tmp, n, NULL); |
| |
| 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); |
| } |
| } |
| |
| #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); |
| str->append(" Xfermode: "); |
| fMode->toString(str); |
| |
| this->INHERITED::toString(str); |
| |
| str->append(")"); |
| } |
| #endif |