1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/thebes/gfxHarfBuzzShaper.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,112 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef GFX_HARFBUZZSHAPER_H
1.10 +#define GFX_HARFBUZZSHAPER_H
1.11 +
1.12 +#include "gfxFont.h"
1.13 +
1.14 +#include "harfbuzz/hb.h"
1.15 +
1.16 +class gfxHarfBuzzShaper : public gfxFontShaper {
1.17 +public:
1.18 + gfxHarfBuzzShaper(gfxFont *aFont);
1.19 + virtual ~gfxHarfBuzzShaper();
1.20 +
1.21 + /*
1.22 + * For HarfBuzz font callback functions, font_data is a ptr to a
1.23 + * FontCallbackData struct
1.24 + */
1.25 + struct FontCallbackData {
1.26 + gfxHarfBuzzShaper *mShaper;
1.27 + gfxContext *mContext;
1.28 + };
1.29 +
1.30 + bool Initialize();
1.31 + virtual bool ShapeText(gfxContext *aContext,
1.32 + const char16_t *aText,
1.33 + uint32_t aOffset,
1.34 + uint32_t aLength,
1.35 + int32_t aScript,
1.36 + gfxShapedText *aShapedText);
1.37 +
1.38 + // get a given font table in harfbuzz blob form
1.39 + hb_blob_t * GetFontTable(hb_tag_t aTag) const;
1.40 +
1.41 + // map unicode character to glyph ID
1.42 + hb_codepoint_t GetGlyph(hb_codepoint_t unicode,
1.43 + hb_codepoint_t variation_selector) const;
1.44 +
1.45 + // get harfbuzz glyph advance, in font design units
1.46 + hb_position_t GetGlyphHAdvance(gfxContext *aContext,
1.47 + hb_codepoint_t glyph) const;
1.48 +
1.49 + // get harfbuzz horizontal advance in 16.16 fixed point format.
1.50 + static hb_position_t
1.51 + HBGetGlyphHAdvance(hb_font_t *font, void *font_data,
1.52 + hb_codepoint_t glyph, void *user_data);
1.53 +
1.54 + hb_position_t GetHKerning(uint16_t aFirstGlyph,
1.55 + uint16_t aSecondGlyph) const;
1.56 +
1.57 +protected:
1.58 + nsresult SetGlyphsFromRun(gfxContext *aContext,
1.59 + gfxShapedText *aShapedText,
1.60 + uint32_t aOffset,
1.61 + uint32_t aLength,
1.62 + const char16_t *aText,
1.63 + hb_buffer_t *aBuffer);
1.64 +
1.65 + // retrieve glyph positions, applying advance adjustments and attachments
1.66 + // returns results in appUnits
1.67 + nscoord GetGlyphPositions(gfxContext *aContext,
1.68 + hb_buffer_t *aBuffer,
1.69 + nsTArray<nsPoint>& aPositions,
1.70 + uint32_t aAppUnitsPerDevUnit);
1.71 +
1.72 + // harfbuzz face object: we acquire a reference from the font entry
1.73 + // on shaper creation, and release it in our destructor
1.74 + hb_face_t *mHBFace;
1.75 +
1.76 + // size-specific font object, owned by the gfxHarfBuzzShaper
1.77 + hb_font_t *mHBFont;
1.78 +
1.79 + FontCallbackData mCallbackData;
1.80 +
1.81 + // Following table references etc are declared "mutable" because the
1.82 + // harfbuzz callback functions take a const ptr to the shaper, but
1.83 + // wish to cache tables here to avoid repeatedly looking them up
1.84 + // in the font.
1.85 +
1.86 + // Old-style TrueType kern table, if we're not doing GPOS kerning
1.87 + mutable hb_blob_t *mKernTable;
1.88 +
1.89 + // Cached copy of the hmtx table and numLongMetrics field from hhea,
1.90 + // for use when looking up glyph metrics; initialized to 0 by the
1.91 + // constructor so we can tell it hasn't been set yet.
1.92 + // This is a signed value so that we can use -1 to indicate
1.93 + // an error (if the hhea table was not available).
1.94 + mutable hb_blob_t *mHmtxTable;
1.95 + mutable int32_t mNumLongMetrics;
1.96 +
1.97 + // Cached pointer to cmap subtable to be used for char-to-glyph mapping.
1.98 + // This comes from GetFontTablePtr; if it is non-null, our destructor
1.99 + // must call ReleaseFontTablePtr to avoid permanently caching the table.
1.100 + mutable hb_blob_t *mCmapTable;
1.101 + mutable int32_t mCmapFormat;
1.102 + mutable uint32_t mSubtableOffset;
1.103 + mutable uint32_t mUVSTableOffset;
1.104 +
1.105 + // Whether the font implements GetGlyph, or we should read tables
1.106 + // directly
1.107 + bool mUseFontGetGlyph;
1.108 + // Whether the font implements GetGlyphWidth, or we should read tables
1.109 + // directly to get ideal widths
1.110 + bool mUseFontGlyphWidths;
1.111 +
1.112 + bool mInitialized;
1.113 +};
1.114 +
1.115 +#endif /* GFX_HARFBUZZSHAPER_H */
