The Tor Browser / file comparison
comparison: gfx/skia/trunk/src/ports/SkHarfBuzzFont.cpp
gfx/skia/trunk/src/ports/SkHarfBuzzFont.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:defb04e278ee |
|---|---|
| 1 | |
| 2 /* | |
| 3 * Copyright 2009 The Android Open Source Project | |
| 4 * | |
| 5 * Use of this source code is governed by a BSD-style license that can be | |
| 6 * found in the LICENSE file. | |
| 7 */ | |
| 8 | |
| 9 | |
| 10 #include "SkHarfBuzzFont.h" | |
| 11 #include "SkFontHost.h" | |
| 12 #include "SkPaint.h" | |
| 13 #include "SkPath.h" | |
| 14 | |
| 15 // HB_Fixed is a 26.6 fixed point format. | |
| 16 static inline HB_Fixed SkScalarToHarfbuzzFixed(SkScalar value) { | |
| 17 return static_cast<HB_Fixed>(value * 64); | |
| 18 } | |
| 19 | |
| 20 static HB_Bool stringToGlyphs(HB_Font hbFont, const HB_UChar16* characters, | |
| 21 hb_uint32 length, HB_Glyph* glyphs, | |
| 22 hb_uint32* glyphsSize, HB_Bool isRTL) { | |
| 23 SkHarfBuzzFont* font = reinterpret_cast<SkHarfBuzzFont*>(hbFont->userData); | |
| 24 SkPaint paint; | |
| 25 | |
| 26 paint.setTypeface(font->getTypeface()); | |
| 27 paint.setTextEncoding(SkPaint::kUTF16_TextEncoding); | |
| 28 int numGlyphs = paint.textToGlyphs(characters, length * sizeof(uint16_t), | |
| 29 reinterpret_cast<uint16_t*>(glyphs)); | |
| 30 | |
| 31 // HB_Glyph is 32-bit, but Skia outputs only 16-bit numbers. So our | |
| 32 // |glyphs| array needs to be converted. | |
| 33 for (int i = numGlyphs - 1; i >= 0; --i) { | |
| 34 uint16_t value; | |
| 35 // We use a memcpy to avoid breaking strict aliasing rules. | |
| 36 memcpy(&value, reinterpret_cast<char*>(glyphs) + sizeof(uint16_t) * i, sizeof(uint16_t)); | |
| 37 glyphs[i] = value; | |
| 38 } | |
| 39 | |
| 40 *glyphsSize = numGlyphs; | |
| 41 return 1; | |
| 42 } | |
| 43 | |
| 44 static void glyphsToAdvances(HB_Font hbFont, const HB_Glyph* glyphs, | |
| 45 hb_uint32 numGlyphs, HB_Fixed* advances, int flags) { | |
| 46 SkHarfBuzzFont* font = reinterpret_cast<SkHarfBuzzFont*>(hbFont->userData); | |
| 47 SkPaint paint; | |
| 48 | |
| 49 font->setupPaint(&paint); | |
| 50 paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding); | |
| 51 | |
| 52 SkAutoMalloc storage(numGlyphs * (sizeof(SkScalar) + sizeof(uint16_t))); | |
| 53 SkScalar* scalarWidths = reinterpret_cast<SkScalar*>(storage.get()); | |
| 54 uint16_t* glyphs16 = reinterpret_cast<uint16_t*>(scalarWidths + numGlyphs); | |
| 55 | |
| 56 // convert HB 32bit glyphs to skia's 16bit | |
| 57 for (hb_uint32 i = 0; i < numGlyphs; ++i) { | |
| 58 glyphs16[i] = SkToU16(glyphs[i]); | |
| 59 } | |
| 60 paint.getTextWidths(glyphs16, numGlyphs * sizeof(uint16_t), scalarWidths); | |
| 61 | |
| 62 for (hb_uint32 i = 0; i < numGlyphs; ++i) { | |
| 63 advances[i] = SkScalarToHarfbuzzFixed(scalarWidths[i]); | |
| 64 } | |
| 65 } | |
| 66 | |
| 67 static HB_Bool canRender(HB_Font hbFont, const HB_UChar16* characters, | |
| 68 hb_uint32 length) { | |
| 69 SkHarfBuzzFont* font = reinterpret_cast<SkHarfBuzzFont*>(hbFont->userData); | |
| 70 SkPaint paint; | |
| 71 | |
| 72 paint.setTypeface(font->getTypeface()); | |
| 73 paint.setTextEncoding(SkPaint::kUTF16_TextEncoding); | |
| 74 return paint.containsText(characters, length * sizeof(uint16_t)); | |
| 75 } | |
| 76 | |
| 77 static HB_Error getOutlinePoint(HB_Font hbFont, HB_Glyph glyph, int flags, | |
| 78 hb_uint32 index, HB_Fixed* xPos, HB_Fixed* yPos, | |
| 79 hb_uint32* resultingNumPoints) { | |
| 80 SkHarfBuzzFont* font = reinterpret_cast<SkHarfBuzzFont*>(hbFont->userData); | |
| 81 SkPaint paint; | |
| 82 | |
| 83 font->setupPaint(&paint); | |
| 84 paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding); | |
| 85 if (flags & HB_ShaperFlag_UseDesignMetrics) { | |
| 86 paint.setHinting(SkPaint::kNo_Hinting); | |
| 87 } | |
| 88 | |
| 89 SkPath path; | |
| 90 uint16_t glyph16 = SkToU16(glyph); | |
| 91 paint.getTextPath(&glyph16, sizeof(glyph16), 0, 0, &path); | |
| 92 int numPoints = path.countPoints(); | |
| 93 if (index >= numPoints) { | |
| 94 return HB_Err_Invalid_SubTable; | |
| 95 } | |
| 96 | |
| 97 SkPoint pt = path.getPoint(index); | |
| 98 *xPos = SkScalarToHarfbuzzFixed(pt.fX); | |
| 99 *yPos = SkScalarToHarfbuzzFixed(pt.fY); | |
| 100 *resultingNumPoints = numPoints; | |
| 101 | |
| 102 return HB_Err_Ok; | |
| 103 } | |
| 104 | |
| 105 static void getGlyphMetrics(HB_Font hbFont, HB_Glyph glyph, | |
| 106 HB_GlyphMetrics* metrics) { | |
| 107 SkHarfBuzzFont* font = reinterpret_cast<SkHarfBuzzFont*>(hbFont->userData); | |
| 108 SkPaint paint; | |
| 109 | |
| 110 font->setupPaint(&paint); | |
| 111 paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding); | |
| 112 | |
| 113 SkScalar width; | |
| 114 SkRect bounds; | |
| 115 uint16_t glyph16 = SkToU16(glyph); | |
| 116 paint.getTextWidths(&glyph16, sizeof(glyph16), &width, &bounds); | |
| 117 | |
| 118 metrics->x = SkScalarToHarfbuzzFixed(bounds.fLeft); | |
| 119 metrics->y = SkScalarToHarfbuzzFixed(bounds.fTop); | |
| 120 metrics->width = SkScalarToHarfbuzzFixed(bounds.width()); | |
| 121 metrics->height = SkScalarToHarfbuzzFixed(bounds.height()); | |
| 122 | |
| 123 metrics->xOffset = SkScalarToHarfbuzzFixed(width); | |
| 124 // We can't actually get the |y| correct because Skia doesn't export | |
| 125 // the vertical advance. However, nor we do ever render vertical text at | |
| 126 // the moment so it's unimportant. | |
| 127 metrics->yOffset = 0; | |
| 128 } | |
| 129 | |
| 130 static HB_Fixed getFontMetric(HB_Font hbFont, HB_FontMetric metric) | |
| 131 { | |
| 132 SkHarfBuzzFont* font = reinterpret_cast<SkHarfBuzzFont*>(hbFont->userData); | |
| 133 SkPaint paint; | |
| 134 SkPaint::FontMetrics skiaMetrics; | |
| 135 | |
| 136 font->setupPaint(&paint); | |
| 137 paint.getFontMetrics(&skiaMetrics); | |
| 138 | |
| 139 switch (metric) { | |
| 140 case HB_FontAscent: | |
| 141 return SkScalarToHarfbuzzFixed(-skiaMetrics.fAscent); | |
| 142 default: | |
| 143 SkDebugf("--- unknown harfbuzz metric enum %d\n", metric); | |
| 144 return 0; | |
| 145 } | |
| 146 } | |
| 147 | |
| 148 static HB_FontClass gSkHarfBuzzFontClass = { | |
| 149 stringToGlyphs, | |
| 150 glyphsToAdvances, | |
| 151 canRender, | |
| 152 getOutlinePoint, | |
| 153 getGlyphMetrics, | |
| 154 getFontMetric, | |
| 155 }; | |
| 156 | |
| 157 const HB_FontClass& SkHarfBuzzFont::GetFontClass() { | |
| 158 return gSkHarfBuzzFontClass; | |
| 159 } | |
| 160 | |
| 161 HB_Error SkHarfBuzzFont::GetFontTableFunc(void* voidface, const HB_Tag tag, | |
| 162 HB_Byte* buffer, HB_UInt* len) { | |
| 163 SkHarfBuzzFont* font = reinterpret_cast<SkHarfBuzzFont*>(voidface); | |
| 164 SkTypeface* typeface = font->getTypeface(); | |
| 165 | |
| 166 const size_t tableSize = typeface->getTableSize(tag); | |
| 167 if (!tableSize) { | |
| 168 return HB_Err_Invalid_Argument; | |
| 169 } | |
| 170 // If Harfbuzz specified a NULL buffer then it's asking for the size. | |
| 171 if (!buffer) { | |
| 172 *len = tableSize; | |
| 173 return HB_Err_Ok; | |
| 174 } | |
| 175 | |
| 176 if (*len < tableSize) { | |
| 177 // is this right, or should we just copy less than the full table? | |
| 178 return HB_Err_Invalid_Argument; | |
| 179 } | |
| 180 typeface->getTableData(tag, 0, tableSize, buffer); | |
| 181 return HB_Err_Ok; | |
| 182 } |
