blob: 310aa0b897ed4acb186413ab577dc58f61f87cb4 [file] [log] [blame]
/*
* Copyright 2020 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "include/core/SkColorFilter.h"
#include "include/effects/SkColorMatrix.h"
#include "include/effects/SkImageFilters.h"
#include "modules/svg/include/SkSVGFilterContext.h"
#include "modules/svg/include/SkSVGNode.h"
#include "modules/svg/include/SkSVGRenderContext.h"
#include "modules/svg/include/SkSVGTypes.h"
namespace {
sk_sp<SkImageFilter> ConvertFilterColorspace(sk_sp<SkImageFilter>&& input,
SkSVGColorspace src,
SkSVGColorspace dst) {
if (src == dst) {
return std::move(input);
} else if (src == SkSVGColorspace::kSRGB && dst == SkSVGColorspace::kLinearRGB) {
return SkImageFilters::ColorFilter(SkColorFilters::SRGBToLinearGamma(), input);
} else {
SkASSERT(src == SkSVGColorspace::kLinearRGB && dst == SkSVGColorspace::kSRGB);
return SkImageFilters::ColorFilter(SkColorFilters::LinearToSRGBGamma(), input);
}
}
} // namespace
const SkSVGFilterContext::Result* SkSVGFilterContext::findResultById(
const SkSVGStringType& id) const {
return fResults.find(id);
}
const SkRect& SkSVGFilterContext::filterPrimitiveSubregion(const SkSVGFeInputType& input) const {
const Result* res = nullptr;
if (input.type() == SkSVGFeInputType::Type::kFilterPrimitiveReference) {
res = fResults.find(input.id());
} else if (input.type() == SkSVGFeInputType::Type::kUnspecified) {
res = &fPreviousResult;
}
return res ? res->fFilterSubregion : fFilterEffectsRegion;
}
void SkSVGFilterContext::registerResult(const SkSVGStringType& id,
const sk_sp<SkImageFilter>& result,
const SkRect& subregion,
SkSVGColorspace resultColorspace) {
SkASSERT(!id.isEmpty());
fResults[id] = {result, subregion, resultColorspace};
}
void SkSVGFilterContext::setPreviousResult(const sk_sp<SkImageFilter>& result,
const SkRect& subregion,
SkSVGColorspace resultColorspace) {
fPreviousResult = {result, subregion, resultColorspace};
}
bool SkSVGFilterContext::previousResultIsSourceGraphic() const {
return fPreviousResult.fImageFilter == nullptr;
}
// https://www.w3.org/TR/SVG11/filters.html#FilterPrimitiveInAttribute
std::tuple<sk_sp<SkImageFilter>, SkSVGColorspace> SkSVGFilterContext::getInput(
const SkSVGRenderContext& ctx, const SkSVGFeInputType& inputType) const {
SkSVGColorspace inputCS = SkSVGColorspace::kSRGB;
sk_sp<SkImageFilter> result;
switch (inputType.type()) {
case SkSVGFeInputType::Type::kSourceAlpha: {
SkColorMatrix m;
m.setScale(0, 0, 0, 1.0f);
result = SkImageFilters::ColorFilter(SkColorFilters::Matrix(m), nullptr);
break;
}
case SkSVGFeInputType::Type::kSourceGraphic:
// Do nothing.
break;
case SkSVGFeInputType::Type::kFillPaint: {
const auto& fillPaint = ctx.fillPaint();
if (fillPaint.isValid()) {
result = SkImageFilters::Paint(*fillPaint);
}
break;
}
case SkSVGFeInputType::Type::kStrokePaint: {
// The paint filter doesn't handle stroke paints properly, so convert to fill for
// simplicity.
// TODO: Paint filter is deprecated, but the replacement (SkShaders::*())
// requires some extra work to handle all paint features (gradients, etc).
const auto& strokePaint = ctx.strokePaint();
if (strokePaint.isValid()) {
SkPaint p = *strokePaint;
p.setStyle(SkPaint::kFill_Style);
result = SkImageFilters::Paint(p);
}
break;
}
case SkSVGFeInputType::Type::kFilterPrimitiveReference: {
const Result* res = findResultById(inputType.id());
if (res) {
result = res->fImageFilter;
inputCS = res->fColorspace;
}
break;
}
case SkSVGFeInputType::Type::kUnspecified: {
result = fPreviousResult.fImageFilter;
inputCS = fPreviousResult.fColorspace;
break;
}
default:
SkDebugf("unhandled filter input type %d\n", (int)inputType.type());
break;
}
return {result, inputCS};
}
SkSVGColorspace SkSVGFilterContext::resolveInputColorspace(
const SkSVGRenderContext& ctx, const SkSVGFeInputType& inputType) const {
return std::get<1>(this->getInput(ctx, inputType));
}
sk_sp<SkImageFilter> SkSVGFilterContext::resolveInput(const SkSVGRenderContext& ctx,
const SkSVGFeInputType& inputType) const {
return std::get<0>(this->getInput(ctx, inputType));
}
sk_sp<SkImageFilter> SkSVGFilterContext::resolveInput(const SkSVGRenderContext& ctx,
const SkSVGFeInputType& inputType,
SkSVGColorspace colorspace) const {
auto [result, inputCS] = this->getInput(ctx, inputType);
return ConvertFilterColorspace(std::move(result), inputCS, colorspace);
}