gfx/thebes/gfxHarfBuzzShaper.h@b8a032363ba2 (annotated)
gfx/thebes/gfxHarfBuzzShaper.h
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- |
| michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | #ifndef GFX_HARFBUZZSHAPER_H |
| michael@0 | 7 | #define GFX_HARFBUZZSHAPER_H |
| michael@0 | 8 | |
| michael@0 | 9 | #include "gfxFont.h" |
| michael@0 | 10 | |
| michael@0 | 11 | #include "harfbuzz/hb.h" |
| michael@0 | 12 | |
| michael@0 | 13 | class gfxHarfBuzzShaper : public gfxFontShaper { |
| michael@0 | 14 | public: |
| michael@0 | 15 | gfxHarfBuzzShaper(gfxFont *aFont); |
| michael@0 | 16 | virtual ~gfxHarfBuzzShaper(); |
| michael@0 | 17 | |
| michael@0 | 18 | /* |
| michael@0 | 19 | * For HarfBuzz font callback functions, font_data is a ptr to a |
| michael@0 | 20 | * FontCallbackData struct |
| michael@0 | 21 | */ |
| michael@0 | 22 | struct FontCallbackData { |
| michael@0 | 23 | gfxHarfBuzzShaper *mShaper; |
| michael@0 | 24 | gfxContext *mContext; |
| michael@0 | 25 | }; |
| michael@0 | 26 | |
| michael@0 | 27 | bool Initialize(); |
| michael@0 | 28 | virtual bool ShapeText(gfxContext *aContext, |
| michael@0 | 29 | const char16_t *aText, |
| michael@0 | 30 | uint32_t aOffset, |
| michael@0 | 31 | uint32_t aLength, |
| michael@0 | 32 | int32_t aScript, |
| michael@0 | 33 | gfxShapedText *aShapedText); |
| michael@0 | 34 | |
| michael@0 | 35 | // get a given font table in harfbuzz blob form |
| michael@0 | 36 | hb_blob_t * GetFontTable(hb_tag_t aTag) const; |
| michael@0 | 37 | |
| michael@0 | 38 | // map unicode character to glyph ID |
| michael@0 | 39 | hb_codepoint_t GetGlyph(hb_codepoint_t unicode, |
| michael@0 | 40 | hb_codepoint_t variation_selector) const; |
| michael@0 | 41 | |
| michael@0 | 42 | // get harfbuzz glyph advance, in font design units |
| michael@0 | 43 | hb_position_t GetGlyphHAdvance(gfxContext *aContext, |
| michael@0 | 44 | hb_codepoint_t glyph) const; |
| michael@0 | 45 | |
| michael@0 | 46 | // get harfbuzz horizontal advance in 16.16 fixed point format. |
| michael@0 | 47 | static hb_position_t |
| michael@0 | 48 | HBGetGlyphHAdvance(hb_font_t *font, void *font_data, |
| michael@0 | 49 | hb_codepoint_t glyph, void *user_data); |
| michael@0 | 50 | |
| michael@0 | 51 | hb_position_t GetHKerning(uint16_t aFirstGlyph, |
| michael@0 | 52 | uint16_t aSecondGlyph) const; |
| michael@0 | 53 | |
| michael@0 | 54 | protected: |
| michael@0 | 55 | nsresult SetGlyphsFromRun(gfxContext *aContext, |
| michael@0 | 56 | gfxShapedText *aShapedText, |
| michael@0 | 57 | uint32_t aOffset, |
| michael@0 | 58 | uint32_t aLength, |
| michael@0 | 59 | const char16_t *aText, |
| michael@0 | 60 | hb_buffer_t *aBuffer); |
| michael@0 | 61 | |
| michael@0 | 62 | // retrieve glyph positions, applying advance adjustments and attachments |
| michael@0 | 63 | // returns results in appUnits |
| michael@0 | 64 | nscoord GetGlyphPositions(gfxContext *aContext, |
| michael@0 | 65 | hb_buffer_t *aBuffer, |
| michael@0 | 66 | nsTArray<nsPoint>& aPositions, |
| michael@0 | 67 | uint32_t aAppUnitsPerDevUnit); |
| michael@0 | 68 | |
| michael@0 | 69 | // harfbuzz face object: we acquire a reference from the font entry |
| michael@0 | 70 | // on shaper creation, and release it in our destructor |
| michael@0 | 71 | hb_face_t *mHBFace; |
| michael@0 | 72 | |
| michael@0 | 73 | // size-specific font object, owned by the gfxHarfBuzzShaper |
| michael@0 | 74 | hb_font_t *mHBFont; |
| michael@0 | 75 | |
| michael@0 | 76 | FontCallbackData mCallbackData; |
| michael@0 | 77 | |
| michael@0 | 78 | // Following table references etc are declared "mutable" because the |
| michael@0 | 79 | // harfbuzz callback functions take a const ptr to the shaper, but |
| michael@0 | 80 | // wish to cache tables here to avoid repeatedly looking them up |
| michael@0 | 81 | // in the font. |
| michael@0 | 82 | |
| michael@0 | 83 | // Old-style TrueType kern table, if we're not doing GPOS kerning |
| michael@0 | 84 | mutable hb_blob_t *mKernTable; |
| michael@0 | 85 | |
| michael@0 | 86 | // Cached copy of the hmtx table and numLongMetrics field from hhea, |
| michael@0 | 87 | // for use when looking up glyph metrics; initialized to 0 by the |
| michael@0 | 88 | // constructor so we can tell it hasn't been set yet. |
| michael@0 | 89 | // This is a signed value so that we can use -1 to indicate |
| michael@0 | 90 | // an error (if the hhea table was not available). |
| michael@0 | 91 | mutable hb_blob_t *mHmtxTable; |
| michael@0 | 92 | mutable int32_t mNumLongMetrics; |
| michael@0 | 93 | |
| michael@0 | 94 | // Cached pointer to cmap subtable to be used for char-to-glyph mapping. |
| michael@0 | 95 | // This comes from GetFontTablePtr; if it is non-null, our destructor |
| michael@0 | 96 | // must call ReleaseFontTablePtr to avoid permanently caching the table. |
| michael@0 | 97 | mutable hb_blob_t *mCmapTable; |
| michael@0 | 98 | mutable int32_t mCmapFormat; |
| michael@0 | 99 | mutable uint32_t mSubtableOffset; |
| michael@0 | 100 | mutable uint32_t mUVSTableOffset; |
| michael@0 | 101 | |
| michael@0 | 102 | // Whether the font implements GetGlyph, or we should read tables |
| michael@0 | 103 | // directly |
| michael@0 | 104 | bool mUseFontGetGlyph; |
| michael@0 | 105 | // Whether the font implements GetGlyphWidth, or we should read tables |
| michael@0 | 106 | // directly to get ideal widths |
| michael@0 | 107 | bool mUseFontGlyphWidths; |
| michael@0 | 108 | |
| michael@0 | 109 | bool mInitialized; |
| michael@0 | 110 | }; |
| michael@0 | 111 | |
| michael@0 | 112 | #endif /* GFX_HARFBUZZSHAPER_H */ |
