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comparison: gfx/thebes/gfxFT2Utils.h
gfx/thebes/gfxFT2Utils.h
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- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:25734a7d5254 |
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| 1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- | |
| 2 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 | |
| 6 #ifndef GFX_FT2UTILS_H | |
| 7 #define GFX_FT2UTILS_H | |
| 8 | |
| 9 #include "cairo-ft.h" | |
| 10 #include "gfxFT2FontBase.h" | |
| 11 #include "mozilla/Likely.h" | |
| 12 | |
| 13 // Rounding and truncation functions for a FreeType fixed point number | |
| 14 // (FT26Dot6) stored in a 32bit integer with high 26 bits for the integer | |
| 15 // part and low 6 bits for the fractional part. | |
| 16 #define FLOAT_FROM_26_6(x) ((x) / 64.0) | |
| 17 #define FLOAT_FROM_16_16(x) ((x) / 65536.0) | |
| 18 #define ROUND_26_6_TO_INT(x) ((x) >= 0 ? ((32 + (x)) >> 6) \ | |
| 19 : -((32 - (x)) >> 6)) | |
| 20 | |
| 21 typedef struct FT_FaceRec_* FT_Face; | |
| 22 | |
| 23 class gfxFT2LockedFace { | |
| 24 public: | |
| 25 gfxFT2LockedFace(gfxFT2FontBase *aFont) : | |
| 26 mGfxFont(aFont), | |
| 27 mFace(cairo_ft_scaled_font_lock_face(aFont->CairoScaledFont())) | |
| 28 { } | |
| 29 ~gfxFT2LockedFace() | |
| 30 { | |
| 31 if (mFace) { | |
| 32 cairo_ft_scaled_font_unlock_face(mGfxFont->CairoScaledFont()); | |
| 33 } | |
| 34 } | |
| 35 | |
| 36 FT_Face get() { return mFace; }; | |
| 37 | |
| 38 /** | |
| 39 * Get the glyph id for a Unicode character representable by a single | |
| 40 * glyph, or return zero if there is no such glyph. This does no caching, | |
| 41 * so you probably want gfxFcFont::GetGlyph. | |
| 42 */ | |
| 43 uint32_t GetGlyph(uint32_t aCharCode); | |
| 44 /** | |
| 45 * Returns 0 if there is no variation selector cmap subtable. | |
| 46 */ | |
| 47 uint32_t GetUVSGlyph(uint32_t aCharCode, uint32_t aVariantSelector); | |
| 48 | |
| 49 void GetMetrics(gfxFont::Metrics* aMetrics, uint32_t* aSpaceGlyph); | |
| 50 | |
| 51 // A scale factor for use in converting horizontal metrics from font units | |
| 52 // to pixels. | |
| 53 gfxFloat XScale() | |
| 54 { | |
| 55 if (MOZ_UNLIKELY(!mFace)) | |
| 56 return 0.0; | |
| 57 | |
| 58 const FT_Size_Metrics& ftMetrics = mFace->size->metrics; | |
| 59 | |
| 60 if (FT_IS_SCALABLE(mFace)) { | |
| 61 // Prefer FT_Size_Metrics::x_scale to x_ppem as x_ppem does not | |
| 62 // have subpixel accuracy. | |
| 63 // | |
| 64 // FT_Size_Metrics::x_scale is in 16.16 fixed point format. Its | |
| 65 // (fractional) value is a factor that converts vertical metrics | |
| 66 // from design units to units of 1/64 pixels, so that the result | |
| 67 // may be interpreted as pixels in 26.6 fixed point format. | |
| 68 return FLOAT_FROM_26_6(FLOAT_FROM_16_16(ftMetrics.x_scale)); | |
| 69 } | |
| 70 | |
| 71 // Not scalable. | |
| 72 // FT_Size_Metrics doc says x_scale is "only relevant for scalable | |
| 73 // font formats". | |
| 74 return gfxFloat(ftMetrics.x_ppem) / gfxFloat(mFace->units_per_EM); | |
| 75 } | |
| 76 | |
| 77 protected: | |
| 78 /** | |
| 79 * Get extents for a simple character representable by a single glyph. | |
| 80 * The return value is the glyph id of that glyph or zero if no such glyph | |
| 81 * exists. aExtents is only set when this returns a non-zero glyph id. | |
| 82 */ | |
| 83 uint32_t GetCharExtents(char aChar, cairo_text_extents_t* aExtents); | |
| 84 | |
| 85 typedef FT_UInt (*CharVariantFunction)(FT_Face face, | |
| 86 FT_ULong charcode, | |
| 87 FT_ULong variantSelector); | |
| 88 CharVariantFunction FindCharVariantFunction(); | |
| 89 | |
| 90 nsRefPtr<gfxFT2FontBase> mGfxFont; | |
| 91 FT_Face mFace; | |
| 92 }; | |
| 93 | |
| 94 #endif /* GFX_FT2UTILS_H */ |
