/* -*- 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_HARFBUZZSHAPER_H #define GFX_HARFBUZZSHAPER_H #include "gfxFont.h" #include "harfbuzz/hb.h" #include "nsUnicodeProperties.h" class gfxHarfBuzzShaper : public gfxFontShaper { public: explicit gfxHarfBuzzShaper(gfxFont *aFont); virtual ~gfxHarfBuzzShaper(); /* * For HarfBuzz font callback functions, font_data is a ptr to a * FontCallbackData struct */ struct FontCallbackData { gfxHarfBuzzShaper *mShaper; gfxContext *mContext; }; bool Initialize(); virtual bool ShapeText(gfxContext *aContext, const char16_t *aText, uint32_t aOffset, uint32_t aLength, int32_t aScript, bool aVertical, gfxShapedText *aShapedText); // get a given font table in harfbuzz blob form hb_blob_t * GetFontTable(hb_tag_t aTag) const; // map unicode character to glyph ID hb_codepoint_t GetGlyph(hb_codepoint_t unicode, hb_codepoint_t variation_selector) const; // get harfbuzz glyph advance, in font design units hb_position_t GetGlyphHAdvance(hb_codepoint_t glyph) const; hb_position_t GetGlyphVAdvance(hb_codepoint_t glyph) const; void GetGlyphVOrigin(hb_codepoint_t aGlyph, hb_position_t *aX, hb_position_t *aY) const; // get harfbuzz horizontal advance in 16.16 fixed point format. static hb_position_t HBGetGlyphHAdvance(hb_font_t *font, void *font_data, hb_codepoint_t glyph, void *user_data); // get harfbuzz vertical advance in 16.16 fixed point format. static hb_position_t HBGetGlyphVAdvance(hb_font_t *font, void *font_data, hb_codepoint_t glyph, void *user_data); static hb_bool_t HBGetGlyphHOrigin(hb_font_t *font, void *font_data, hb_codepoint_t glyph, hb_position_t *x, hb_position_t *y, void *user_data); static hb_bool_t HBGetGlyphVOrigin(hb_font_t *font, void *font_data, hb_codepoint_t glyph, hb_position_t *x, hb_position_t *y, void *user_data); hb_position_t GetHKerning(uint16_t aFirstGlyph, uint16_t aSecondGlyph) const; hb_bool_t GetGlyphExtents(hb_codepoint_t aGlyph, hb_glyph_extents_t *aExtents) const; bool UseVerticalPresentationForms() const { return mUseVerticalPresentationForms; } static hb_script_t GetHBScriptUsedForShaping(int32_t aScript) { // Decide what harfbuzz script code will be used for shaping hb_script_t hbScript; if (aScript <= MOZ_SCRIPT_INHERITED) { // For unresolved "common" or "inherited" runs, // default to Latin for now. hbScript = HB_SCRIPT_LATIN; } else { hbScript = hb_script_t(mozilla::unicode::GetScriptTagForCode(aScript)); } return hbScript; } protected: nsresult SetGlyphsFromRun(gfxContext *aContext, gfxShapedText *aShapedText, uint32_t aOffset, uint32_t aLength, const char16_t *aText, hb_buffer_t *aBuffer, bool aVertical); // retrieve glyph positions, applying advance adjustments and attachments // returns results in appUnits nscoord GetGlyphPositions(gfxContext *aContext, hb_buffer_t *aBuffer, nsTArray& aPositions, uint32_t aAppUnitsPerDevUnit); bool InitializeVertical(); bool LoadHmtxTable(); struct Glyf { // we only need the bounding-box at the beginning // of the glyph record, not the actual outline data AutoSwap_PRInt16 numberOfContours; AutoSwap_PRInt16 xMin; AutoSwap_PRInt16 yMin; AutoSwap_PRInt16 xMax; AutoSwap_PRInt16 yMax; }; const Glyf *FindGlyf(hb_codepoint_t aGlyph, bool *aEmptyGlyf) const; // harfbuzz face object: we acquire a reference from the font entry // on shaper creation, and release it in our destructor hb_face_t *mHBFace; // size-specific font object, owned by the gfxHarfBuzzShaper hb_font_t *mHBFont; FontCallbackData mCallbackData; // Following table references etc are declared "mutable" because the // harfbuzz callback functions take a const ptr to the shaper, but // wish to cache tables here to avoid repeatedly looking them up // in the font. // Old-style TrueType kern table, if we're not doing GPOS kerning mutable hb_blob_t *mKernTable; // Cached copy of the hmtx table. mutable hb_blob_t *mHmtxTable; // For vertical fonts, cached vmtx and VORG table, if present. mutable hb_blob_t *mVmtxTable; mutable hb_blob_t *mVORGTable; // And for vertical TrueType (not CFF) fonts that have vmtx, // we also use loca and glyf to get glyph bounding boxes. mutable hb_blob_t *mLocaTable; mutable hb_blob_t *mGlyfTable; // Cached pointer to cmap subtable to be used for char-to-glyph mapping. // This comes from GetFontTablePtr; if it is non-null, our destructor // must call ReleaseFontTablePtr to avoid permanently caching the table. mutable hb_blob_t *mCmapTable; mutable int32_t mCmapFormat; mutable uint32_t mSubtableOffset; mutable uint32_t mUVSTableOffset; // Cached copy of numLongMetrics field from the hhea table, // for use when looking up glyph metrics; initialized to 0 by the // constructor so we can tell it hasn't been set yet. // This is a signed value so that we can use -1 to indicate // an error (if the hhea table was not available). mutable int32_t mNumLongHMetrics; // Similarly for vhea if it's a vertical font. mutable int32_t mNumLongVMetrics; // Whether the font implements GetGlyph, or we should read tables // directly bool mUseFontGetGlyph; // Whether the font implements GetGlyphWidth, or we should read tables // directly to get ideal widths bool mUseFontGlyphWidths; bool mInitialized; bool mVerticalInitialized; // Whether to use vertical presentation forms for CJK characters // when available (only set if the 'vert' feature is not available). bool mUseVerticalPresentationForms; // these are set from the FindGlyf callback on first use of the glyf data mutable bool mLoadedLocaGlyf; mutable bool mLocaLongOffsets; }; #endif /* GFX_HARFBUZZSHAPER_H */