TestSVGTypeface.h

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/*
 * Copyright 2014 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
#ifndef TestSVGTypeface_DEFINED
#define TestSVGTypeface_DEFINED
 
#include "include/core/SkFontArguments.h"
#include "include/core/SkFontMetrics.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSpan.h"
#include "include/core/SkStream.h"
#include "include/core/SkString.h"
#include "include/core/SkTypeface.h"
#include "include/core/SkTypes.h"
#include "include/pathops/SkPathOps.h"
#include "include/private/base/SkMutex.h"
#include "include/private/base/SkTArray.h"
#include "src/core/SkTHash.h"
 
#include <memory>
 
class SkCanvas;
class SkDescriptor;
class SkFontDescriptor;
class SkFontStyle;
class SkGlyph;
class SkPath;
class SkScalerContext;
class SkSVGDOM;
class SkWStream;
struct SkAdvancedTypefaceMetrics;
struct SkScalerContextEffects;
struct SkScalerContextRec;
 
#ifdef SK_ENABLE_SVG
 
struct SkSVGTestTypefaceGlyphData {
    const char* fSvgResourcePath;
    SkPoint     fOrigin;  // y-down
    SkScalar    fAdvance;
    SkUnichar   fUnicode;  // TODO: this limits to 1:1
};
 
class TestSVGTypeface : public SkTypeface {
public:
    ~TestSVGTypeface() override;
    SkVector getAdvance(SkGlyphID) const;
    void getFontMetrics(SkFontMetrics* metrics) const;
 
    static sk_sp<TestSVGTypeface> Default();
    static sk_sp<TestSVGTypeface> Planets();
    void                          exportTtxCbdt(SkWStream*, SkSpan<unsigned> strikeSizes) const;
    void                          exportTtxSbix(SkWStream*, SkSpan<unsigned> strikeSizes) const;
    void                          exportTtxColr(SkWStream*) const;
    virtual bool                  getPathOp(SkColor, SkPathOp*) const = 0;
 
    struct GlyfLayerInfo {
        GlyfLayerInfo(int layerColorIndex, SkIRect bounds)
                : fLayerColorIndex(layerColorIndex), fBounds(bounds) {}
        int     fLayerColorIndex;
        SkIRect fBounds;
    };
    struct GlyfInfo {
        GlyfInfo() : fBounds(SkIRect::MakeEmpty()) {}
        SkIRect                             fBounds;
        skia_private::TArray<GlyfLayerInfo> fLayers;
    };
 
protected:
    void exportTtxCommon(
            SkWStream*, const char* type, const skia_private::TArray<GlyfInfo>* = nullptr) const;
 
    std::unique_ptr<SkScalerContext> onCreateScalerContext(const SkScalerContextEffects&,
                                                           const SkDescriptor* desc) const override;
    void onFilterRec(SkScalerContextRec* rec) const override;
    void getGlyphToUnicodeMap(SkUnichar*) const override;
    std::unique_ptr<SkAdvancedTypefaceMetrics> onGetAdvancedMetrics() const override;
 
    sk_sp<SkTypeface> onMakeClone(const SkFontArguments& args) const override {
        return sk_ref_sp(this);
    }
 
    void onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocal) const override = 0;
 
    void onCharsToGlyphs(const SkUnichar* chars, int count, SkGlyphID glyphs[]) const override;
 
    void getPostScriptGlyphNames(SkString*) const override {}
 
    int onCountGlyphs() const override { return fGlyphCount; }
 
    int onGetUPEM() const override { return fUpem; }
 
    void onGetFamilyName(SkString* familyName) const override;
    bool onGetPostScriptName(SkString*) const override;
    SkTypeface::LocalizedStrings* onCreateFamilyNameIterator() const override;
 
    bool onGlyphMaskNeedsCurrentColor() const override { return false; }
 
    int onGetVariationDesignPosition(SkFontArguments::VariationPosition::Coordinate coordinates[],
                                     int coordinateCount) const override {
        return 0;
    }
 
    int onGetVariationDesignParameters(SkFontParameters::Variation::Axis parameters[],
                                       int parameterCount) const override {
        return 0;
    }
 
    int onGetTableTags(SkFontTableTag tags[]) const override { return 0; }
 
    size_t onGetTableData(SkFontTableTag tag,
                          size_t         offset,
                          size_t         length,
                          void*          data) const override {
        return 0;
    }
 
private:
    TestSVGTypeface(const char* name, const SkFontStyle& style,
                    int upem, const SkFontMetrics& metrics,
                    SkSpan<const SkSVGTestTypefaceGlyphData> data);
    struct Glyph {
        Glyph();
        ~Glyph();
        SkPoint     fOrigin;
        SkScalar    fAdvance;
        const char* fResourcePath;
 
        SkSize size() const;
        void render(SkCanvas*) const;
 
    private:
        // Lazily parses the SVG from fResourcePath, and manages mutex locking.
        template <typename Fn> void withSVG(Fn&&) const;
 
        // The mutex guards lazy parsing of the SVG, but also predates that.
        // Must be SkSVGDOM::render() is not thread safe?
        // If not, an SkOnce is enough here.
        mutable SkMutex         fSvgMutex;
        mutable bool            fParsedSvg = false;
        mutable sk_sp<SkSVGDOM> fSvg;
    };
 
    const SkString fName;
    const int fUpem;
    const SkFontMetrics fFontMetrics;
    const std::unique_ptr<Glyph[]> fGlyphs;
    const int fGlyphCount;
    skia_private::THashMap<SkUnichar, SkGlyphID> fCMap;
    friend class SkTestSVGScalerContext;
};
 
#endif // SK_ENABLE_SVG
 
#endif // TestSVGTypeface_DEFINED