SkSVGFilterContext.h

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/*
 * Copyright 2020 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
#ifndef SkSVGFilterContext_DEFINED
#define SkSVGFilterContext_DEFINED
 
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkString.h"
#include "modules/svg/include/SkSVGTypes.h"
#include "src/core/SkTHash.h"
 
class SkImageFilter;
class SkSVGFeInputType;
class SkSVGRenderContext;
 
class SkSVGFilterContext {
public:
    SkSVGFilterContext(const SkRect& filterEffectsRegion,
                       const SkSVGObjectBoundingBoxUnits& primitiveUnits)
            : fFilterEffectsRegion(filterEffectsRegion)
            , fPrimitiveUnits(primitiveUnits)
            , fPreviousResult({nullptr, filterEffectsRegion, SkSVGColorspace::kSRGB}) {}
 
    const SkRect& filterEffectsRegion() const { return fFilterEffectsRegion; }
 
    const SkRect& filterPrimitiveSubregion(const SkSVGFeInputType&) const;
 
    const SkSVGObjectBoundingBoxUnits& primitiveUnits() const { return fPrimitiveUnits; }
 
    void registerResult(const SkSVGStringType&, const sk_sp<SkImageFilter>&, const SkRect&, SkSVGColorspace);
 
    void setPreviousResult(const sk_sp<SkImageFilter>&, const SkRect&, SkSVGColorspace);
 
    bool previousResultIsSourceGraphic() const;
 
    SkSVGColorspace resolveInputColorspace(const SkSVGRenderContext&,
                                           const SkSVGFeInputType&) const;
 
    sk_sp<SkImageFilter> resolveInput(const SkSVGRenderContext&, const SkSVGFeInputType&) const;
 
    sk_sp<SkImageFilter> resolveInput(const SkSVGRenderContext&, const SkSVGFeInputType&, SkSVGColorspace) const;
 
private:
    struct Result {
        sk_sp<SkImageFilter> fImageFilter;
        SkRect fFilterSubregion;
        SkSVGColorspace fColorspace;
    };
 
    const Result* findResultById(const SkSVGStringType&) const;
 
    std::tuple<sk_sp<SkImageFilter>, SkSVGColorspace> getInput(const SkSVGRenderContext&,
                                                               const SkSVGFeInputType&) const;
 
    SkRect fFilterEffectsRegion;
 
    SkSVGObjectBoundingBoxUnits fPrimitiveUnits;
 
    skia_private::THashMap<SkSVGStringType, Result> fResults;
 
    Result fPreviousResult;
};
 
#endif  // SkSVGFilterContext_DEFINED