static SkPDFIndirectReference make_alpha_function_shader(SkPDFDocument* doc,
const SkPDFGradientShader::Key& state) {
SkASSERT(state.fType != SkShader::kNone_GradientType);
SkPDFGradientShader::Key opaqueState = clone_key(state);
for (int i = 0; i < opaqueState.fInfo.fColorCount; i++) {
opaqueState.fInfo.fColors[i] = SkColorSetA(opaqueState.fInfo.fColors[i], SK_AlphaOPAQUE);
}
opaqueState.fHash = hash(opaqueState);
SkASSERT(!gradient_has_alpha(opaqueState));
SkRect bbox = SkRect::Make(state.fBBox);
SkPDFIndirectReference colorShader = find_pdf_shader(doc, std::move(opaqueState), false);
if (!colorShader) {
return SkPDFIndirectReference();
}
// Create resource dict with alpha graphics state as G0 and
// pattern shader as P0, then write content stream.
SkPDFIndirectReference alphaGsRef = create_smask_graphic_state(doc, state);
std::unique_ptr<SkPDFDict> resourceDict = get_gradient_resource_dict(colorShader, alphaGsRef);
std::unique_ptr<SkStreamAsset> colorStream =
create_pattern_fill_content(alphaGsRef.fValue, colorShader.fValue, bbox);
std::unique_ptr<SkPDFDict> alphaFunctionShader = SkPDFMakeDict();
SkPDFUtils::PopulateTilingPatternDict(alphaFunctionShader.get(), bbox,
std::move(resourceDict), SkMatrix::I());
return SkPDFStreamOut(std::move(alphaFunctionShader), std::move(colorStream), doc);
}
SkPDFAlphaFunctionShader* SkPDFAlphaFunctionShader::Create(
SkPDFCanon* canon,
SkScalar dpi,
SkAutoTDelete<SkPDFShader::State>* autoState) {
const SkPDFShader::State& state = **autoState;
SkRect bbox;
bbox.set(state.fBBox);
SkAutoTDelete<SkPDFShader::State> opaqueState(state.CreateOpaqueState());
SkAutoTUnref<SkPDFObject> colorShader(
get_pdf_shader_by_state(canon, dpi, &opaqueState));
if (!colorShader) {
return NULL;
}
// Create resource dict with alpha graphics state as G0 and
// pattern shader as P0, then write content stream.
SkAutoTUnref<SkPDFObject> alphaGs(
create_smask_graphic_state(canon, dpi, state));
SkPDFAlphaFunctionShader* alphaFunctionShader =
SkNEW_ARGS(SkPDFAlphaFunctionShader, (autoState->detach()));
SkAutoTUnref<SkPDFDict> resourceDict(
get_gradient_resource_dict(colorShader.get(), alphaGs.get()));
SkAutoTDelete<SkStream> colorStream(
create_pattern_fill_content(0, bbox));
alphaFunctionShader->setData(colorStream.get());
populate_tiling_pattern_dict(alphaFunctionShader, bbox, resourceDict.get(),
SkMatrix::I());
canon->addAlphaShader(alphaFunctionShader);
return alphaFunctionShader;
}