gecko-dev/gfx/thebes/gfxGraphiteShaper.h

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef GFX_GRAPHITESHAPER_H
#define GFX_GRAPHITESHAPER_H

#include "gfxFont.h"

#include "mozilla/gfx/2D.h"

struct gr_face;
struct gr_font;
struct gr_segment;

class gfxGraphiteShaper : public gfxFontShaper {
public:
    explicit gfxGraphiteShaper(gfxFont *aFont);
    virtual ~gfxGraphiteShaper();

    bool ShapeText(DrawTarget      *aDrawTarget,
                   const char16_t *aText,
                   uint32_t         aOffset,
                   uint32_t         aLength,
                   Script           aScript,
                   bool             aVertical,
                   RoundingFlags    aRounding,
                   gfxShapedText   *aShapedText) override;

    static void Shutdown();

protected:
    nsresult SetGlyphsFromSegment(gfxShapedText   *aShapedText,
                                  uint32_t         aOffset,
                                  uint32_t         aLength,
                                  const char16_t *aText,
                                  gr_segment      *aSegment,
                                  RoundingFlags    aRounding);

    static float GrGetAdvance(const void* appFontHandle, uint16_t glyphid);

    gr_face *mGrFace; // owned by the font entry; shaper must call
                      // gfxFontEntry::ReleaseGrFace when finished with it
    gr_font *mGrFont; // owned by the shaper itself

    struct CallbackData {
        // mFont is a pointer to the font that owns this shaper, so it will
        // remain valid throughout our lifetime
        gfxFont* MOZ_NON_OWNING_REF mFont;
        // initialized to a DrawTarget owned by our caller on every call to
        // ShapeText
        mozilla::gfx::DrawTarget* MOZ_NON_OWNING_REF mDrawTarget;
    };

    CallbackData mCallbackData;
    bool mFallbackToSmallCaps; // special fallback for the petite-caps case

    // Convert HTML 'lang' (BCP47) to Graphite language code
    static uint32_t GetGraphiteTagForLang(const nsCString& aLang);
    static nsTHashtable<nsUint32HashKey> *sLanguageTags;
};

#endif /* GFX_GRAPHITESHAPER_H */