/*

 * Copyright 2006-2012 The Android Open Source Project

 * Copyright 2012 Mozilla Foundation

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#ifndef SKFONTHOST_FREETYPE_COMMON_H_

#define SKFONTHOST_FREETYPE_COMMON_H_

#include "include/core/SkTypeface.h"

#include "include/core/SkTypes.h"

#include "src/core/SkGlyph.h"

#include "src/core/SkScalerContext.h"

#include "src/core/SkSharedMutex.h"

#include "src/utils/SkCharToGlyphCache.h"

#include "include/core/SkFontMgr.h"

// These are forward declared to avoid pimpl but also hide the FreeType implementation.

typedef struct FT_LibraryRec_* FT_Library;

typedef struct FT_FaceRec_* FT_Face;

typedef struct FT_StreamRec_* FT_Stream;

typedef signed long FT_Pos;

typedef struct FT_BBox_ FT_BBox;

#ifdef SK_DEBUG

const char* SkTraceFtrGetError(int);

#define SK_TRACEFTR(ERR, MSG, ...) \

    SkDebugf("%s:%d:1: error: 0x%x '%s' " MSG "\n", __FILE__, __LINE__, ERR, \

            SkTraceFtrGetError((int)(ERR)), __VA_ARGS__)

#else

#define SK_TRACEFTR(ERR, ...) do { sk_ignore_unused_variable(ERR); } while (false)

#endif

class SkScalerContext_FreeType_Base : public SkScalerContext {

protected:

    // See http://freetype.sourceforge.net/freetype2/docs/reference/ft2-bitmap_handling.html#FT_Bitmap_Embolden

    // This value was chosen by eyeballing the result in Firefox and trying to match it.

    static const FT_Pos kBitmapEmboldenStrength = 1 << 6;

    SkScalerContext_FreeType_Base(sk_sp<SkTypeface> typeface, const SkScalerContextEffects& effects,

                                  const SkDescriptor *desc)

        : INHERITED(std::move(typeface), effects, desc)

    {}

    void generateGlyphImage(FT_Face face, const SkGlyph& glyph, const SkMatrix& bitmapTransform);

    bool generateGlyphPath(FT_Face face, SkPath* path);

    bool generateFacePath(FT_Face face, SkGlyphID glyphID, SkPath* path);

    // Computes a bounding box for a COLRv1 glyph id in FT_BBox 26.6 format and FreeType's y-up

    // coordinate space.

    // Needed to call into COLRv1 from generateMetrics().

    //

    // Note : This method may change the configured size and transforms on FT_Face. Make sure to

    // configure size, matrix and load glyphs as needed after using this function to restore the

    // state of FT_Face.

    bool computeColrV1GlyphBoundingBox(FT_Face face, SkGlyphID glyphID, FT_BBox* boundingBox);

private:

    using INHERITED = SkScalerContext;

};

class SkTypeface_FreeType : public SkTypeface {

public:

    /** For SkFontMgrs to make use of our ability to extract

     *  name and style from a stream, using FreeType's API.

     */

    class Scanner : ::SkNoncopyable {

    public:

        Scanner();

        ~Scanner();

        struct AxisDefinition {

            SkFourByteTag fTag;

            SkFixed fMinimum;

            SkFixed fDefault;

            SkFixed fMaximum;

        };

        using AxisDefinitions = SkSTArray<4, AxisDefinition, true>;

        bool recognizedFont(SkStreamAsset* stream, int* numFonts) const;

        bool scanFont(SkStreamAsset* stream, int ttcIndex,

                      SkString* name, SkFontStyle* style, bool* isFixedPitch,

                      AxisDefinitions* axes) const;

        static void computeAxisValues(

            AxisDefinitions axisDefinitions,

            const SkFontArguments::VariationPosition position,

            SkFixed* axisValues,

            const SkString& name,

            const SkFontArguments::VariationPosition::Coordinate* currentPosition = nullptr);

        static bool GetAxes(FT_Face face, AxisDefinitions* axes);

    private:

        FT_Face openFace(SkStreamAsset* stream, int ttcIndex, FT_Stream ftStream) const;

        FT_Library fLibrary;

        mutable SkMutex fLibraryMutex;

    };

    /** Fetch units/EM from "head" table if needed (ie for bitmap fonts) */

    static int GetUnitsPerEm(FT_Face face);

    /**

     *  Return the font data, or nullptr on failure.

     */

    std::unique_ptr<SkFontData> makeFontData() const;

    class FaceRec;

    FaceRec* getFaceRec() const;

protected:

    SkTypeface_FreeType(const SkFontStyle& style, bool isFixedPitch);

    ~SkTypeface_FreeType() override;

    std::unique_ptr<SkFontData> cloneFontData(const SkFontArguments&) const;

    std::unique_ptr<SkScalerContext> onCreateScalerContext(const SkScalerContextEffects&,

                                                           const SkDescriptor*) const override;

    void onFilterRec(SkScalerContextRec*) const override;

    void getGlyphToUnicodeMap(SkUnichar*) const override;

    std::unique_ptr<SkAdvancedTypefaceMetrics> onGetAdvancedMetrics() const override;

    void getPostScriptGlyphNames(SkString* dstArray) const override;

    bool onGetPostScriptName(SkString*) const override;

    int onGetUPEM() const override;

    bool onGetKerningPairAdjustments(const uint16_t glyphs[], int count,

                                     int32_t adjustments[]) const override;

    void onCharsToGlyphs(const SkUnichar uni[], int count, SkGlyphID glyphs[]) const override;

    int onCountGlyphs() const override;

    LocalizedStrings* onCreateFamilyNameIterator() const override;

    int onGetVariationDesignPosition(SkFontArguments::VariationPosition::Coordinate coordinates[],

                                     int coordinateCount) const override;

    int onGetVariationDesignParameters(SkFontParameters::Variation::Axis parameters[],

                                       int parameterCount) const override;

    int onGetTableTags(SkFontTableTag tags[]) const override;

    size_t onGetTableData(SkFontTableTag, size_t offset,

                          size_t length, void* data) const override;

    sk_sp<SkData> onCopyTableData(SkFontTableTag) const override;

    virtual std::unique_ptr<SkFontData> onMakeFontData() const = 0;

private:

    mutable SkOnce fFTFaceOnce;

    mutable std::unique_ptr<FaceRec> fFaceRec;

    mutable SkSharedMutex fC2GCacheMutex;

    mutable SkCharToGlyphCache fC2GCache;

    using INHERITED = SkTypeface;

};

#endif // SKFONTHOST_FREETYPE_COMMON_H_