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comparison: gfx/thebes/gfxHarfBuzzShaper.cpp
gfx/thebes/gfxHarfBuzzShaper.cpp
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| -1:000000000000 | 0:16b5ec5e1d52 |
|---|---|
| 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 #include "nsString.h" | |
| 7 #include "gfxContext.h" | |
| 8 #include "gfxHarfBuzzShaper.h" | |
| 9 #include "gfxFontUtils.h" | |
| 10 #include "nsUnicodeProperties.h" | |
| 11 #include "nsUnicodeScriptCodes.h" | |
| 12 #include "nsUnicodeNormalizer.h" | |
| 13 | |
| 14 #include "harfbuzz/hb.h" | |
| 15 #include "harfbuzz/hb-ot.h" | |
| 16 | |
| 17 #include <algorithm> | |
| 18 | |
| 19 #define FloatToFixed(f) (65536 * (f)) | |
| 20 #define FixedToFloat(f) ((f) * (1.0 / 65536.0)) | |
| 21 // Right shifts of negative (signed) integers are undefined, as are overflows | |
| 22 // when converting unsigned to negative signed integers. | |
| 23 // (If speed were an issue we could make some 2's complement assumptions.) | |
| 24 #define FixedToIntRound(f) ((f) > 0 ? ((32768 + (f)) >> 16) \ | |
| 25 : -((32767 - (f)) >> 16)) | |
| 26 | |
| 27 using namespace mozilla; // for AutoSwap_* types | |
| 28 using namespace mozilla::unicode; // for Unicode property lookup | |
| 29 | |
| 30 /* | |
| 31 * Creation and destruction; on deletion, release any font tables we're holding | |
| 32 */ | |
| 33 | |
| 34 gfxHarfBuzzShaper::gfxHarfBuzzShaper(gfxFont *aFont) | |
| 35 : gfxFontShaper(aFont), | |
| 36 mHBFace(aFont->GetFontEntry()->GetHBFace()), | |
| 37 mHBFont(nullptr), | |
| 38 mKernTable(nullptr), | |
| 39 mHmtxTable(nullptr), | |
| 40 mNumLongMetrics(0), | |
| 41 mCmapTable(nullptr), | |
| 42 mCmapFormat(-1), | |
| 43 mSubtableOffset(0), | |
| 44 mUVSTableOffset(0), | |
| 45 mUseFontGetGlyph(aFont->ProvidesGetGlyph()), | |
| 46 mUseFontGlyphWidths(false), | |
| 47 mInitialized(false) | |
| 48 { | |
| 49 } | |
| 50 | |
| 51 gfxHarfBuzzShaper::~gfxHarfBuzzShaper() | |
| 52 { | |
| 53 if (mCmapTable) { | |
| 54 hb_blob_destroy(mCmapTable); | |
| 55 } | |
| 56 if (mHmtxTable) { | |
| 57 hb_blob_destroy(mHmtxTable); | |
| 58 } | |
| 59 if (mKernTable) { | |
| 60 hb_blob_destroy(mKernTable); | |
| 61 } | |
| 62 if (mHBFont) { | |
| 63 hb_font_destroy(mHBFont); | |
| 64 } | |
| 65 if (mHBFace) { | |
| 66 hb_face_destroy(mHBFace); | |
| 67 } | |
| 68 } | |
| 69 | |
| 70 #define UNICODE_BMP_LIMIT 0x10000 | |
| 71 | |
| 72 hb_codepoint_t | |
| 73 gfxHarfBuzzShaper::GetGlyph(hb_codepoint_t unicode, | |
| 74 hb_codepoint_t variation_selector) const | |
| 75 { | |
| 76 hb_codepoint_t gid = 0; | |
| 77 | |
| 78 if (mUseFontGetGlyph) { | |
| 79 gid = mFont->GetGlyph(unicode, variation_selector); | |
| 80 } else { | |
| 81 // we only instantiate a harfbuzz shaper if there's a cmap available | |
| 82 NS_ASSERTION(mFont->GetFontEntry()->HasCmapTable(), | |
| 83 "we cannot be using this font!"); | |
| 84 | |
| 85 NS_ASSERTION(mCmapTable && (mCmapFormat > 0) && (mSubtableOffset > 0), | |
| 86 "cmap data not correctly set up, expect disaster"); | |
| 87 | |
| 88 const uint8_t* data = | |
| 89 (const uint8_t*)hb_blob_get_data(mCmapTable, nullptr); | |
| 90 | |
| 91 if (variation_selector) { | |
| 92 if (mUVSTableOffset) { | |
| 93 gid = | |
| 94 gfxFontUtils::MapUVSToGlyphFormat14(data + mUVSTableOffset, | |
| 95 unicode, | |
| 96 variation_selector); | |
| 97 } | |
| 98 if (!gid) { | |
| 99 uint32_t compat = | |
| 100 gfxFontUtils::GetUVSFallback(unicode, variation_selector); | |
| 101 if (compat) { | |
| 102 switch (mCmapFormat) { | |
| 103 case 4: | |
| 104 if (compat < UNICODE_BMP_LIMIT) { | |
| 105 gid = gfxFontUtils::MapCharToGlyphFormat4(data + mSubtableOffset, | |
| 106 compat); | |
| 107 } | |
| 108 break; | |
| 109 case 12: | |
| 110 gid = gfxFontUtils::MapCharToGlyphFormat12(data + mSubtableOffset, | |
| 111 compat); | |
| 112 break; | |
| 113 } | |
| 114 } | |
| 115 } | |
| 116 // If the variation sequence was not supported, return zero here; | |
| 117 // harfbuzz will call us again for the base character alone | |
| 118 return gid; | |
| 119 } | |
| 120 | |
| 121 switch (mCmapFormat) { | |
| 122 case 4: | |
| 123 gid = unicode < UNICODE_BMP_LIMIT ? | |
| 124 gfxFontUtils::MapCharToGlyphFormat4(data + mSubtableOffset, | |
| 125 unicode) : 0; | |
| 126 break; | |
| 127 case 12: | |
| 128 gid = gfxFontUtils::MapCharToGlyphFormat12(data + mSubtableOffset, | |
| 129 unicode); | |
| 130 break; | |
| 131 default: | |
| 132 NS_WARNING("unsupported cmap format, glyphs will be missing"); | |
| 133 break; | |
| 134 } | |
| 135 } | |
| 136 | |
| 137 if (!gid) { | |
| 138 // if there's no glyph for , just use the space glyph instead | |
| 139 if (unicode == 0xA0) { | |
| 140 gid = mFont->GetSpaceGlyph(); | |
| 141 } | |
| 142 } | |
| 143 | |
| 144 return gid; | |
| 145 } | |
| 146 | |
| 147 static hb_bool_t | |
| 148 HBGetGlyph(hb_font_t *font, void *font_data, | |
| 149 hb_codepoint_t unicode, hb_codepoint_t variation_selector, | |
| 150 hb_codepoint_t *glyph, | |
| 151 void *user_data) | |
| 152 { | |
| 153 const gfxHarfBuzzShaper::FontCallbackData *fcd = | |
| 154 static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data); | |
| 155 *glyph = fcd->mShaper->GetGlyph(unicode, variation_selector); | |
| 156 return *glyph != 0; | |
| 157 } | |
| 158 | |
| 159 struct HMetricsHeader { | |
| 160 AutoSwap_PRUint32 tableVersionNumber; | |
| 161 AutoSwap_PRInt16 ascender; | |
| 162 AutoSwap_PRInt16 descender; | |
| 163 AutoSwap_PRInt16 lineGap; | |
| 164 AutoSwap_PRUint16 advanceWidthMax; | |
| 165 AutoSwap_PRInt16 minLeftSideBearing; | |
| 166 AutoSwap_PRInt16 minRightSideBearing; | |
| 167 AutoSwap_PRInt16 xMaxExtent; | |
| 168 AutoSwap_PRInt16 caretSlopeRise; | |
| 169 AutoSwap_PRInt16 caretSlopeRun; | |
| 170 AutoSwap_PRInt16 caretOffset; | |
| 171 AutoSwap_PRInt16 reserved[4]; | |
| 172 AutoSwap_PRInt16 metricDataFormat; | |
| 173 AutoSwap_PRUint16 numberOfHMetrics; | |
| 174 }; | |
| 175 | |
| 176 struct HLongMetric { | |
| 177 AutoSwap_PRUint16 advanceWidth; | |
| 178 AutoSwap_PRInt16 lsb; | |
| 179 }; | |
| 180 | |
| 181 struct HMetrics { | |
| 182 HLongMetric metrics[1]; // actually numberOfHMetrics | |
| 183 // the variable-length metrics[] array is immediately followed by: | |
| 184 // AutoSwap_PRUint16 leftSideBearing[]; | |
| 185 }; | |
| 186 | |
| 187 hb_position_t | |
| 188 gfxHarfBuzzShaper::GetGlyphHAdvance(gfxContext *aContext, | |
| 189 hb_codepoint_t glyph) const | |
| 190 { | |
| 191 // font did not implement GetHintedGlyphWidth, so get an unhinted value | |
| 192 // directly from the font tables | |
| 193 | |
| 194 NS_ASSERTION((mNumLongMetrics > 0) && mHmtxTable != nullptr, | |
| 195 "font is lacking metrics, we shouldn't be here"); | |
| 196 | |
| 197 if (glyph >= uint32_t(mNumLongMetrics)) { | |
| 198 glyph = mNumLongMetrics - 1; | |
| 199 } | |
| 200 | |
| 201 // glyph must be valid now, because we checked during initialization | |
| 202 // that mNumLongMetrics is > 0, and that the hmtx table is large enough | |
| 203 // to contain mNumLongMetrics records | |
| 204 const HMetrics* hmtx = | |
| 205 reinterpret_cast<const HMetrics*>(hb_blob_get_data(mHmtxTable, nullptr)); | |
| 206 return FloatToFixed(mFont->FUnitsToDevUnitsFactor() * | |
| 207 uint16_t(hmtx->metrics[glyph].advanceWidth)); | |
| 208 } | |
| 209 | |
| 210 /* static */ | |
| 211 hb_position_t | |
| 212 gfxHarfBuzzShaper::HBGetGlyphHAdvance(hb_font_t *font, void *font_data, | |
| 213 hb_codepoint_t glyph, void *user_data) | |
| 214 { | |
| 215 const gfxHarfBuzzShaper::FontCallbackData *fcd = | |
| 216 static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data); | |
| 217 gfxFont *gfxfont = fcd->mShaper->GetFont(); | |
| 218 if (gfxfont->ProvidesGlyphWidths()) { | |
| 219 return gfxfont->GetGlyphWidth(fcd->mContext, glyph); | |
| 220 } else { | |
| 221 return fcd->mShaper->GetGlyphHAdvance(fcd->mContext, glyph); | |
| 222 } | |
| 223 } | |
| 224 | |
| 225 static hb_bool_t | |
| 226 HBGetContourPoint(hb_font_t *font, void *font_data, | |
| 227 unsigned int point_index, hb_codepoint_t glyph, | |
| 228 hb_position_t *x, hb_position_t *y, | |
| 229 void *user_data) | |
| 230 { | |
| 231 /* not yet implemented - no support for used of hinted contour points | |
| 232 to fine-tune anchor positions in GPOS AnchorFormat2 */ | |
| 233 return false; | |
| 234 } | |
| 235 | |
| 236 struct KernHeaderFmt0 { | |
| 237 AutoSwap_PRUint16 nPairs; | |
| 238 AutoSwap_PRUint16 searchRange; | |
| 239 AutoSwap_PRUint16 entrySelector; | |
| 240 AutoSwap_PRUint16 rangeShift; | |
| 241 }; | |
| 242 | |
| 243 struct KernPair { | |
| 244 AutoSwap_PRUint16 left; | |
| 245 AutoSwap_PRUint16 right; | |
| 246 AutoSwap_PRInt16 value; | |
| 247 }; | |
| 248 | |
| 249 // Find a kern pair in a Format 0 subtable. | |
| 250 // The aSubtable parameter points to the subtable itself, NOT its header, | |
| 251 // as the header structure differs between Windows and Mac (v0 and v1.0) | |
| 252 // versions of the 'kern' table. | |
| 253 // aSubtableLen is the length of the subtable EXCLUDING its header. | |
| 254 // If the pair <aFirstGlyph,aSecondGlyph> is found, the kerning value is | |
| 255 // added to aValue, so that multiple subtables can accumulate a total | |
| 256 // kerning value for a given pair. | |
| 257 static void | |
| 258 GetKernValueFmt0(const void* aSubtable, | |
| 259 uint32_t aSubtableLen, | |
| 260 uint16_t aFirstGlyph, | |
| 261 uint16_t aSecondGlyph, | |
| 262 int32_t& aValue, | |
| 263 bool aIsOverride = false, | |
| 264 bool aIsMinimum = false) | |
| 265 { | |
| 266 const KernHeaderFmt0* hdr = | |
| 267 reinterpret_cast<const KernHeaderFmt0*>(aSubtable); | |
| 268 | |
| 269 const KernPair *lo = reinterpret_cast<const KernPair*>(hdr + 1); | |
| 270 const KernPair *hi = lo + uint16_t(hdr->nPairs); | |
| 271 const KernPair *limit = hi; | |
| 272 | |
| 273 if (reinterpret_cast<const char*>(aSubtable) + aSubtableLen < | |
| 274 reinterpret_cast<const char*>(hi)) { | |
| 275 // subtable is not large enough to contain the claimed number | |
| 276 // of kern pairs, so just ignore it | |
| 277 return; | |
| 278 } | |
| 279 | |
| 280 #define KERN_PAIR_KEY(l,r) (uint32_t((uint16_t(l) << 16) + uint16_t(r))) | |
| 281 | |
| 282 uint32_t key = KERN_PAIR_KEY(aFirstGlyph, aSecondGlyph); | |
| 283 while (lo < hi) { | |
| 284 const KernPair *mid = lo + (hi - lo) / 2; | |
| 285 if (KERN_PAIR_KEY(mid->left, mid->right) < key) { | |
| 286 lo = mid + 1; | |
| 287 } else { | |
| 288 hi = mid; | |
| 289 } | |
| 290 } | |
| 291 | |
| 292 if (lo < limit && KERN_PAIR_KEY(lo->left, lo->right) == key) { | |
| 293 if (aIsOverride) { | |
| 294 aValue = int16_t(lo->value); | |
| 295 } else if (aIsMinimum) { | |
| 296 aValue = std::max(aValue, int32_t(lo->value)); | |
| 297 } else { | |
| 298 aValue += int16_t(lo->value); | |
| 299 } | |
| 300 } | |
| 301 } | |
| 302 | |
| 303 // Get kerning value from Apple (version 1.0) kern table, | |
| 304 // subtable format 2 (simple N x M array of kerning values) | |
| 305 | |
| 306 // See http://developer.apple.com/fonts/TTRefMan/RM06/Chap6kern.html | |
| 307 // for details of version 1.0 format 2 subtable. | |
| 308 | |
| 309 struct KernHeaderVersion1Fmt2 { | |
| 310 KernTableSubtableHeaderVersion1 header; | |
| 311 AutoSwap_PRUint16 rowWidth; | |
| 312 AutoSwap_PRUint16 leftOffsetTable; | |
| 313 AutoSwap_PRUint16 rightOffsetTable; | |
| 314 AutoSwap_PRUint16 array; | |
| 315 }; | |
| 316 | |
| 317 struct KernClassTableHdr { | |
| 318 AutoSwap_PRUint16 firstGlyph; | |
| 319 AutoSwap_PRUint16 nGlyphs; | |
| 320 AutoSwap_PRUint16 offsets[1]; // actually an array of nGlyphs entries | |
| 321 }; | |
| 322 | |
| 323 static int16_t | |
| 324 GetKernValueVersion1Fmt2(const void* aSubtable, | |
| 325 uint32_t aSubtableLen, | |
| 326 uint16_t aFirstGlyph, | |
| 327 uint16_t aSecondGlyph) | |
| 328 { | |
| 329 if (aSubtableLen < sizeof(KernHeaderVersion1Fmt2)) { | |
| 330 return 0; | |
| 331 } | |
| 332 | |
| 333 const char* base = reinterpret_cast<const char*>(aSubtable); | |
| 334 const char* subtableEnd = base + aSubtableLen; | |
| 335 | |
| 336 const KernHeaderVersion1Fmt2* h = | |
| 337 reinterpret_cast<const KernHeaderVersion1Fmt2*>(aSubtable); | |
| 338 uint32_t offset = h->array; | |
| 339 | |
| 340 const KernClassTableHdr* leftClassTable = | |
| 341 reinterpret_cast<const KernClassTableHdr*>(base + | |
| 342 uint16_t(h->leftOffsetTable)); | |
| 343 if (reinterpret_cast<const char*>(leftClassTable) + | |
| 344 sizeof(KernClassTableHdr) > subtableEnd) { | |
| 345 return 0; | |
| 346 } | |
| 347 if (aFirstGlyph >= uint16_t(leftClassTable->firstGlyph)) { | |
| 348 aFirstGlyph -= uint16_t(leftClassTable->firstGlyph); | |
| 349 if (aFirstGlyph < uint16_t(leftClassTable->nGlyphs)) { | |
| 350 if (reinterpret_cast<const char*>(leftClassTable) + | |
| 351 sizeof(KernClassTableHdr) + | |
| 352 aFirstGlyph * sizeof(uint16_t) >= subtableEnd) { | |
| 353 return 0; | |
| 354 } | |
| 355 offset = uint16_t(leftClassTable->offsets[aFirstGlyph]); | |
| 356 } | |
| 357 } | |
| 358 | |
| 359 const KernClassTableHdr* rightClassTable = | |
| 360 reinterpret_cast<const KernClassTableHdr*>(base + | |
| 361 uint16_t(h->rightOffsetTable)); | |
| 362 if (reinterpret_cast<const char*>(rightClassTable) + | |
| 363 sizeof(KernClassTableHdr) > subtableEnd) { | |
| 364 return 0; | |
| 365 } | |
| 366 if (aSecondGlyph >= uint16_t(rightClassTable->firstGlyph)) { | |
| 367 aSecondGlyph -= uint16_t(rightClassTable->firstGlyph); | |
| 368 if (aSecondGlyph < uint16_t(rightClassTable->nGlyphs)) { | |
| 369 if (reinterpret_cast<const char*>(rightClassTable) + | |
| 370 sizeof(KernClassTableHdr) + | |
| 371 aSecondGlyph * sizeof(uint16_t) >= subtableEnd) { | |
| 372 return 0; | |
| 373 } | |
| 374 offset += uint16_t(rightClassTable->offsets[aSecondGlyph]); | |
| 375 } | |
| 376 } | |
| 377 | |
| 378 const AutoSwap_PRInt16* pval = | |
| 379 reinterpret_cast<const AutoSwap_PRInt16*>(base + offset); | |
| 380 if (reinterpret_cast<const char*>(pval + 1) >= subtableEnd) { | |
| 381 return 0; | |
| 382 } | |
| 383 return *pval; | |
| 384 } | |
| 385 | |
| 386 // Get kerning value from Apple (version 1.0) kern table, | |
| 387 // subtable format 3 (simple N x M array of kerning values) | |
| 388 | |
| 389 // See http://developer.apple.com/fonts/TTRefMan/RM06/Chap6kern.html | |
| 390 // for details of version 1.0 format 3 subtable. | |
| 391 | |
| 392 struct KernHeaderVersion1Fmt3 { | |
| 393 KernTableSubtableHeaderVersion1 header; | |
| 394 AutoSwap_PRUint16 glyphCount; | |
| 395 uint8_t kernValueCount; | |
| 396 uint8_t leftClassCount; | |
| 397 uint8_t rightClassCount; | |
| 398 uint8_t flags; | |
| 399 }; | |
| 400 | |
| 401 static int16_t | |
| 402 GetKernValueVersion1Fmt3(const void* aSubtable, | |
| 403 uint32_t aSubtableLen, | |
| 404 uint16_t aFirstGlyph, | |
| 405 uint16_t aSecondGlyph) | |
| 406 { | |
| 407 // check that we can safely read the header fields | |
| 408 if (aSubtableLen < sizeof(KernHeaderVersion1Fmt3)) { | |
| 409 return 0; | |
| 410 } | |
| 411 | |
| 412 const KernHeaderVersion1Fmt3* hdr = | |
| 413 reinterpret_cast<const KernHeaderVersion1Fmt3*>(aSubtable); | |
| 414 if (hdr->flags != 0) { | |
| 415 return 0; | |
| 416 } | |
| 417 | |
| 418 uint16_t glyphCount = hdr->glyphCount; | |
| 419 | |
| 420 // check that table is large enough for the arrays | |
| 421 if (sizeof(KernHeaderVersion1Fmt3) + | |
| 422 hdr->kernValueCount * sizeof(int16_t) + | |
| 423 glyphCount + glyphCount + | |
| 424 hdr->leftClassCount * hdr->rightClassCount > aSubtableLen) { | |
| 425 return 0; | |
| 426 } | |
| 427 | |
| 428 if (aFirstGlyph >= glyphCount || aSecondGlyph >= glyphCount) { | |
| 429 // glyphs are out of range for the class tables | |
| 430 return 0; | |
| 431 } | |
| 432 | |
| 433 // get pointers to the four arrays within the subtable | |
| 434 const AutoSwap_PRInt16* kernValue = | |
| 435 reinterpret_cast<const AutoSwap_PRInt16*>(hdr + 1); | |
| 436 const uint8_t* leftClass = | |
| 437 reinterpret_cast<const uint8_t*>(kernValue + hdr->kernValueCount); | |
| 438 const uint8_t* rightClass = leftClass + glyphCount; | |
| 439 const uint8_t* kernIndex = rightClass + glyphCount; | |
| 440 | |
| 441 uint8_t lc = leftClass[aFirstGlyph]; | |
| 442 uint8_t rc = rightClass[aSecondGlyph]; | |
| 443 if (lc >= hdr->leftClassCount || rc >= hdr->rightClassCount) { | |
| 444 return 0; | |
| 445 } | |
| 446 | |
| 447 uint8_t ki = kernIndex[leftClass[aFirstGlyph] * hdr->rightClassCount + | |
| 448 rightClass[aSecondGlyph]]; | |
| 449 if (ki >= hdr->kernValueCount) { | |
| 450 return 0; | |
| 451 } | |
| 452 | |
| 453 return kernValue[ki]; | |
| 454 } | |
| 455 | |
| 456 #define KERN0_COVERAGE_HORIZONTAL 0x0001 | |
| 457 #define KERN0_COVERAGE_MINIMUM 0x0002 | |
| 458 #define KERN0_COVERAGE_CROSS_STREAM 0x0004 | |
| 459 #define KERN0_COVERAGE_OVERRIDE 0x0008 | |
| 460 #define KERN0_COVERAGE_RESERVED 0x00F0 | |
| 461 | |
| 462 #define KERN1_COVERAGE_VERTICAL 0x8000 | |
| 463 #define KERN1_COVERAGE_CROSS_STREAM 0x4000 | |
| 464 #define KERN1_COVERAGE_VARIATION 0x2000 | |
| 465 #define KERN1_COVERAGE_RESERVED 0x1F00 | |
| 466 | |
| 467 hb_position_t | |
| 468 gfxHarfBuzzShaper::GetHKerning(uint16_t aFirstGlyph, | |
| 469 uint16_t aSecondGlyph) const | |
| 470 { | |
| 471 // We want to ignore any kern pairs involving <space>, because we are | |
| 472 // handling words in isolation, the only space characters seen here are | |
| 473 // the ones artificially added by the textRun code. | |
| 474 uint32_t spaceGlyph = mFont->GetSpaceGlyph(); | |
| 475 if (aFirstGlyph == spaceGlyph || aSecondGlyph == spaceGlyph) { | |
| 476 return 0; | |
| 477 } | |
| 478 | |
| 479 if (!mKernTable) { | |
| 480 mKernTable = mFont->GetFontEntry()->GetFontTable(TRUETYPE_TAG('k','e','r','n')); | |
| 481 if (!mKernTable) { | |
| 482 mKernTable = hb_blob_get_empty(); | |
| 483 } | |
| 484 } | |
| 485 | |
| 486 uint32_t len; | |
| 487 const char* base = hb_blob_get_data(mKernTable, &len); | |
| 488 if (len < sizeof(KernTableVersion0)) { | |
| 489 return 0; | |
| 490 } | |
| 491 int32_t value = 0; | |
| 492 | |
| 493 // First try to interpret as "version 0" kern table | |
| 494 // (see http://www.microsoft.com/typography/otspec/kern.htm) | |
| 495 const KernTableVersion0* kern0 = | |
| 496 reinterpret_cast<const KernTableVersion0*>(base); | |
| 497 if (uint16_t(kern0->version) == 0) { | |
| 498 uint16_t nTables = kern0->nTables; | |
| 499 uint32_t offs = sizeof(KernTableVersion0); | |
| 500 for (uint16_t i = 0; i < nTables; ++i) { | |
| 501 if (offs + sizeof(KernTableSubtableHeaderVersion0) > len) { | |
| 502 break; | |
| 503 } | |
| 504 const KernTableSubtableHeaderVersion0* st0 = | |
| 505 reinterpret_cast<const KernTableSubtableHeaderVersion0*> | |
| 506 (base + offs); | |
| 507 uint16_t subtableLen = uint16_t(st0->length); | |
| 508 if (offs + subtableLen > len) { | |
| 509 break; | |
| 510 } | |
| 511 offs += subtableLen; | |
| 512 uint16_t coverage = st0->coverage; | |
| 513 if (!(coverage & KERN0_COVERAGE_HORIZONTAL)) { | |
| 514 // we only care about horizontal kerning (for now) | |
| 515 continue; | |
| 516 } | |
| 517 if (coverage & | |
| 518 (KERN0_COVERAGE_CROSS_STREAM | KERN0_COVERAGE_RESERVED)) { | |
| 519 // we don't support cross-stream kerning, and | |
| 520 // reserved bits should be zero; | |
| 521 // ignore the subtable if not | |
| 522 continue; | |
| 523 } | |
| 524 uint8_t format = (coverage >> 8); | |
| 525 switch (format) { | |
| 526 case 0: | |
| 527 GetKernValueFmt0(st0 + 1, subtableLen - sizeof(*st0), | |
| 528 aFirstGlyph, aSecondGlyph, value, | |
| 529 (coverage & KERN0_COVERAGE_OVERRIDE) != 0, | |
| 530 (coverage & KERN0_COVERAGE_MINIMUM) != 0); | |
| 531 break; | |
| 532 default: | |
| 533 // TODO: implement support for other formats, | |
| 534 // if they're ever used in practice | |
| 535 #if DEBUG | |
| 536 { | |
| 537 char buf[1024]; | |
| 538 sprintf(buf, "unknown kern subtable in %s: " | |
| 539 "ver 0 format %d\n", | |
| 540 NS_ConvertUTF16toUTF8(mFont->GetName()).get(), | |
| 541 format); | |
| 542 NS_WARNING(buf); | |
| 543 } | |
| 544 #endif | |
| 545 break; | |
| 546 } | |
| 547 } | |
| 548 } else { | |
| 549 // It wasn't a "version 0" table; check if it is Apple version 1.0 | |
| 550 // (see http://developer.apple.com/fonts/TTRefMan/RM06/Chap6kern.html) | |
| 551 const KernTableVersion1* kern1 = | |
| 552 reinterpret_cast<const KernTableVersion1*>(base); | |
| 553 if (uint32_t(kern1->version) == 0x00010000) { | |
| 554 uint32_t nTables = kern1->nTables; | |
| 555 uint32_t offs = sizeof(KernTableVersion1); | |
| 556 for (uint32_t i = 0; i < nTables; ++i) { | |
| 557 if (offs + sizeof(KernTableSubtableHeaderVersion1) > len) { | |
| 558 break; | |
| 559 } | |
| 560 const KernTableSubtableHeaderVersion1* st1 = | |
| 561 reinterpret_cast<const KernTableSubtableHeaderVersion1*> | |
| 562 (base + offs); | |
| 563 uint32_t subtableLen = uint32_t(st1->length); | |
| 564 offs += subtableLen; | |
| 565 uint16_t coverage = st1->coverage; | |
| 566 if (coverage & | |
| 567 (KERN1_COVERAGE_VERTICAL | | |
| 568 KERN1_COVERAGE_CROSS_STREAM | | |
| 569 KERN1_COVERAGE_VARIATION | | |
| 570 KERN1_COVERAGE_RESERVED)) { | |
| 571 // we only care about horizontal kerning (for now), | |
| 572 // we don't support cross-stream kerning, | |
| 573 // we don't support variations, | |
| 574 // reserved bits should be zero; | |
| 575 // ignore the subtable if not | |
| 576 continue; | |
| 577 } | |
| 578 uint8_t format = (coverage & 0xff); | |
| 579 switch (format) { | |
| 580 case 0: | |
| 581 GetKernValueFmt0(st1 + 1, subtableLen - sizeof(*st1), | |
| 582 aFirstGlyph, aSecondGlyph, value); | |
| 583 break; | |
| 584 case 2: | |
| 585 value = GetKernValueVersion1Fmt2(st1, subtableLen, | |
| 586 aFirstGlyph, aSecondGlyph); | |
| 587 break; | |
| 588 case 3: | |
| 589 value = GetKernValueVersion1Fmt3(st1, subtableLen, | |
| 590 aFirstGlyph, aSecondGlyph); | |
| 591 break; | |
| 592 default: | |
| 593 // TODO: implement support for other formats. | |
| 594 // Note that format 1 cannot be supported here, | |
| 595 // as it requires the full glyph array to run the FSM, | |
| 596 // not just the current glyph pair. | |
| 597 #if DEBUG | |
| 598 { | |
| 599 char buf[1024]; | |
| 600 sprintf(buf, "unknown kern subtable in %s: " | |
| 601 "ver 0 format %d\n", | |
| 602 NS_ConvertUTF16toUTF8(mFont->GetName()).get(), | |
| 603 format); | |
| 604 NS_WARNING(buf); | |
| 605 } | |
| 606 #endif | |
| 607 break; | |
| 608 } | |
| 609 } | |
| 610 } | |
| 611 } | |
| 612 | |
| 613 if (value != 0) { | |
| 614 return FloatToFixed(mFont->FUnitsToDevUnitsFactor() * value); | |
| 615 } | |
| 616 return 0; | |
| 617 } | |
| 618 | |
| 619 static hb_position_t | |
| 620 HBGetHKerning(hb_font_t *font, void *font_data, | |
| 621 hb_codepoint_t first_glyph, hb_codepoint_t second_glyph, | |
| 622 void *user_data) | |
| 623 { | |
| 624 const gfxHarfBuzzShaper::FontCallbackData *fcd = | |
| 625 static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data); | |
| 626 return fcd->mShaper->GetHKerning(first_glyph, second_glyph); | |
| 627 } | |
| 628 | |
| 629 /* | |
| 630 * HarfBuzz unicode property callbacks | |
| 631 */ | |
| 632 | |
| 633 static hb_codepoint_t | |
| 634 HBGetMirroring(hb_unicode_funcs_t *ufuncs, hb_codepoint_t aCh, | |
| 635 void *user_data) | |
| 636 { | |
| 637 return GetMirroredChar(aCh); | |
| 638 } | |
| 639 | |
| 640 static hb_unicode_general_category_t | |
| 641 HBGetGeneralCategory(hb_unicode_funcs_t *ufuncs, hb_codepoint_t aCh, | |
| 642 void *user_data) | |
| 643 { | |
| 644 return hb_unicode_general_category_t(GetGeneralCategory(aCh)); | |
| 645 } | |
| 646 | |
| 647 static hb_script_t | |
| 648 HBGetScript(hb_unicode_funcs_t *ufuncs, hb_codepoint_t aCh, void *user_data) | |
| 649 { | |
| 650 return hb_script_t(GetScriptTagForCode(GetScriptCode(aCh))); | |
| 651 } | |
| 652 | |
| 653 static hb_unicode_combining_class_t | |
| 654 HBGetCombiningClass(hb_unicode_funcs_t *ufuncs, hb_codepoint_t aCh, | |
| 655 void *user_data) | |
| 656 { | |
| 657 return hb_unicode_combining_class_t(GetCombiningClass(aCh)); | |
| 658 } | |
| 659 | |
| 660 static unsigned int | |
| 661 HBGetEastAsianWidth(hb_unicode_funcs_t *ufuncs, hb_codepoint_t aCh, | |
| 662 void *user_data) | |
| 663 { | |
| 664 return GetEastAsianWidth(aCh); | |
| 665 } | |
| 666 | |
| 667 // Hebrew presentation forms with dagesh, for characters 0x05D0..0x05EA; | |
| 668 // note that some letters do not have a dagesh presForm encoded | |
| 669 static const char16_t sDageshForms[0x05EA - 0x05D0 + 1] = { | |
| 670 0xFB30, // ALEF | |
| 671 0xFB31, // BET | |
| 672 0xFB32, // GIMEL | |
| 673 0xFB33, // DALET | |
| 674 0xFB34, // HE | |
| 675 0xFB35, // VAV | |
| 676 0xFB36, // ZAYIN | |
| 677 0, // HET | |
| 678 0xFB38, // TET | |
| 679 0xFB39, // YOD | |
| 680 0xFB3A, // FINAL KAF | |
| 681 0xFB3B, // KAF | |
| 682 0xFB3C, // LAMED | |
| 683 0, // FINAL MEM | |
| 684 0xFB3E, // MEM | |
| 685 0, // FINAL NUN | |
| 686 0xFB40, // NUN | |
| 687 0xFB41, // SAMEKH | |
| 688 0, // AYIN | |
| 689 0xFB43, // FINAL PE | |
| 690 0xFB44, // PE | |
| 691 0, // FINAL TSADI | |
| 692 0xFB46, // TSADI | |
| 693 0xFB47, // QOF | |
| 694 0xFB48, // RESH | |
| 695 0xFB49, // SHIN | |
| 696 0xFB4A // TAV | |
| 697 }; | |
| 698 | |
| 699 static hb_bool_t | |
| 700 HBUnicodeCompose(hb_unicode_funcs_t *ufuncs, | |
| 701 hb_codepoint_t a, | |
| 702 hb_codepoint_t b, | |
| 703 hb_codepoint_t *ab, | |
| 704 void *user_data) | |
| 705 { | |
| 706 hb_bool_t found = nsUnicodeNormalizer::Compose(a, b, ab); | |
| 707 | |
| 708 if (!found && (b & 0x1fff80) == 0x0580) { | |
| 709 // special-case Hebrew presentation forms that are excluded from | |
| 710 // standard normalization, but wanted for old fonts | |
| 711 switch (b) { | |
| 712 case 0x05B4: // HIRIQ | |
| 713 if (a == 0x05D9) { // YOD | |
| 714 *ab = 0xFB1D; | |
| 715 found = true; | |
| 716 } | |
| 717 break; | |
| 718 case 0x05B7: // patah | |
| 719 if (a == 0x05F2) { // YIDDISH YOD YOD | |
| 720 *ab = 0xFB1F; | |
| 721 found = true; | |
| 722 } else if (a == 0x05D0) { // ALEF | |
| 723 *ab = 0xFB2E; | |
| 724 found = true; | |
| 725 } | |
| 726 break; | |
| 727 case 0x05B8: // QAMATS | |
| 728 if (a == 0x05D0) { // ALEF | |
| 729 *ab = 0xFB2F; | |
| 730 found = true; | |
| 731 } | |
| 732 break; | |
| 733 case 0x05B9: // HOLAM | |
| 734 if (a == 0x05D5) { // VAV | |
| 735 *ab = 0xFB4B; | |
| 736 found = true; | |
| 737 } | |
| 738 break; | |
| 739 case 0x05BC: // DAGESH | |
| 740 if (a >= 0x05D0 && a <= 0x05EA) { | |
| 741 *ab = sDageshForms[a - 0x05D0]; | |
| 742 found = (*ab != 0); | |
| 743 } else if (a == 0xFB2A) { // SHIN WITH SHIN DOT | |
| 744 *ab = 0xFB2C; | |
| 745 found = true; | |
| 746 } else if (a == 0xFB2B) { // SHIN WITH SIN DOT | |
| 747 *ab = 0xFB2D; | |
| 748 found = true; | |
| 749 } | |
| 750 break; | |
| 751 case 0x05BF: // RAFE | |
| 752 switch (a) { | |
| 753 case 0x05D1: // BET | |
| 754 *ab = 0xFB4C; | |
| 755 found = true; | |
| 756 break; | |
| 757 case 0x05DB: // KAF | |
| 758 *ab = 0xFB4D; | |
| 759 found = true; | |
| 760 break; | |
| 761 case 0x05E4: // PE | |
| 762 *ab = 0xFB4E; | |
| 763 found = true; | |
| 764 break; | |
| 765 } | |
| 766 break; | |
| 767 case 0x05C1: // SHIN DOT | |
| 768 if (a == 0x05E9) { // SHIN | |
| 769 *ab = 0xFB2A; | |
| 770 found = true; | |
| 771 } else if (a == 0xFB49) { // SHIN WITH DAGESH | |
| 772 *ab = 0xFB2C; | |
| 773 found = true; | |
| 774 } | |
| 775 break; | |
| 776 case 0x05C2: // SIN DOT | |
| 777 if (a == 0x05E9) { // SHIN | |
| 778 *ab = 0xFB2B; | |
| 779 found = true; | |
| 780 } else if (a == 0xFB49) { // SHIN WITH DAGESH | |
| 781 *ab = 0xFB2D; | |
| 782 found = true; | |
| 783 } | |
| 784 break; | |
| 785 } | |
| 786 } | |
| 787 | |
| 788 return found; | |
| 789 } | |
| 790 | |
| 791 static hb_bool_t | |
| 792 HBUnicodeDecompose(hb_unicode_funcs_t *ufuncs, | |
| 793 hb_codepoint_t ab, | |
| 794 hb_codepoint_t *a, | |
| 795 hb_codepoint_t *b, | |
| 796 void *user_data) | |
| 797 { | |
| 798 #ifdef MOZ_WIDGET_ANDROID | |
| 799 // Hack for the SamsungDevanagari font, bug 1012365: | |
| 800 // support U+0972 by decomposing it. | |
| 801 if (ab == 0x0972) { | |
| 802 *a = 0x0905; | |
| 803 *b = 0x0945; | |
| 804 return true; | |
| 805 } | |
| 806 #endif | |
| 807 return nsUnicodeNormalizer::DecomposeNonRecursively(ab, a, b); | |
| 808 } | |
| 809 | |
| 810 static PLDHashOperator | |
| 811 AddOpenTypeFeature(const uint32_t& aTag, uint32_t& aValue, void *aUserArg) | |
| 812 { | |
| 813 nsTArray<hb_feature_t>* features = static_cast<nsTArray<hb_feature_t>*> (aUserArg); | |
| 814 | |
| 815 hb_feature_t feat = { 0, 0, 0, UINT_MAX }; | |
| 816 feat.tag = aTag; | |
| 817 feat.value = aValue; | |
| 818 features->AppendElement(feat); | |
| 819 return PL_DHASH_NEXT; | |
| 820 } | |
| 821 | |
| 822 /* | |
| 823 * gfxFontShaper override to initialize the text run using HarfBuzz | |
| 824 */ | |
| 825 | |
| 826 static hb_font_funcs_t * sHBFontFuncs = nullptr; | |
| 827 static hb_unicode_funcs_t * sHBUnicodeFuncs = nullptr; | |
| 828 static const hb_script_t sMathScript = | |
| 829 hb_ot_tag_to_script(HB_TAG('m','a','t','h')); | |
| 830 | |
| 831 bool | |
| 832 gfxHarfBuzzShaper::Initialize() | |
| 833 { | |
| 834 if (mInitialized) { | |
| 835 return mHBFont != nullptr; | |
| 836 } | |
| 837 mInitialized = true; | |
| 838 mCallbackData.mShaper = this; | |
| 839 | |
| 840 mUseFontGlyphWidths = mFont->ProvidesGlyphWidths(); | |
| 841 | |
| 842 if (!sHBFontFuncs) { | |
| 843 // static function callback pointers, initialized by the first | |
| 844 // harfbuzz shaper used | |
| 845 sHBFontFuncs = hb_font_funcs_create(); | |
| 846 hb_font_funcs_set_glyph_func(sHBFontFuncs, HBGetGlyph, | |
| 847 nullptr, nullptr); | |
| 848 hb_font_funcs_set_glyph_h_advance_func(sHBFontFuncs, | |
| 849 HBGetGlyphHAdvance, | |
| 850 nullptr, nullptr); | |
| 851 hb_font_funcs_set_glyph_contour_point_func(sHBFontFuncs, | |
| 852 HBGetContourPoint, | |
| 853 nullptr, nullptr); | |
| 854 hb_font_funcs_set_glyph_h_kerning_func(sHBFontFuncs, | |
| 855 HBGetHKerning, | |
| 856 nullptr, nullptr); | |
| 857 | |
| 858 sHBUnicodeFuncs = | |
| 859 hb_unicode_funcs_create(hb_unicode_funcs_get_empty()); | |
| 860 hb_unicode_funcs_set_mirroring_func(sHBUnicodeFuncs, | |
| 861 HBGetMirroring, | |
| 862 nullptr, nullptr); | |
| 863 hb_unicode_funcs_set_script_func(sHBUnicodeFuncs, HBGetScript, | |
| 864 nullptr, nullptr); | |
| 865 hb_unicode_funcs_set_general_category_func(sHBUnicodeFuncs, | |
| 866 HBGetGeneralCategory, | |
| 867 nullptr, nullptr); | |
| 868 hb_unicode_funcs_set_combining_class_func(sHBUnicodeFuncs, | |
| 869 HBGetCombiningClass, | |
| 870 nullptr, nullptr); | |
| 871 hb_unicode_funcs_set_eastasian_width_func(sHBUnicodeFuncs, | |
| 872 HBGetEastAsianWidth, | |
| 873 nullptr, nullptr); | |
| 874 hb_unicode_funcs_set_compose_func(sHBUnicodeFuncs, | |
| 875 HBUnicodeCompose, | |
| 876 nullptr, nullptr); | |
| 877 hb_unicode_funcs_set_decompose_func(sHBUnicodeFuncs, | |
| 878 HBUnicodeDecompose, | |
| 879 nullptr, nullptr); | |
| 880 } | |
| 881 | |
| 882 gfxFontEntry *entry = mFont->GetFontEntry(); | |
| 883 if (!mUseFontGetGlyph) { | |
| 884 // get the cmap table and find offset to our subtable | |
| 885 mCmapTable = entry->GetFontTable(TRUETYPE_TAG('c','m','a','p')); | |
| 886 if (!mCmapTable) { | |
| 887 NS_WARNING("failed to load cmap, glyphs will be missing"); | |
| 888 return false; | |
| 889 } | |
| 890 uint32_t len; | |
| 891 const uint8_t* data = (const uint8_t*)hb_blob_get_data(mCmapTable, &len); | |
| 892 bool symbol; | |
| 893 mCmapFormat = gfxFontUtils:: | |
| 894 FindPreferredSubtable(data, len, | |
| 895 &mSubtableOffset, &mUVSTableOffset, | |
| 896 &symbol); | |
| 897 if (mCmapFormat <= 0) { | |
| 898 return false; | |
| 899 } | |
| 900 } | |
| 901 | |
| 902 if (!mUseFontGlyphWidths) { | |
| 903 // if font doesn't implement GetGlyphWidth, we will be reading | |
| 904 // the hmtx table directly; | |
| 905 // read mNumLongMetrics from hhea table without caching its blob, | |
| 906 // and preload/cache the hmtx table | |
| 907 gfxFontEntry::AutoTable hheaTable(entry, TRUETYPE_TAG('h','h','e','a')); | |
| 908 if (hheaTable) { | |
| 909 uint32_t len; | |
| 910 const HMetricsHeader* hhea = | |
| 911 reinterpret_cast<const HMetricsHeader*> | |
| 912 (hb_blob_get_data(hheaTable, &len)); | |
| 913 if (len >= sizeof(HMetricsHeader)) { | |
| 914 mNumLongMetrics = hhea->numberOfHMetrics; | |
| 915 if (mNumLongMetrics > 0 && | |
| 916 int16_t(hhea->metricDataFormat) == 0) { | |
| 917 // no point reading hmtx if number of entries is zero! | |
| 918 // in that case, we won't be able to use this font | |
| 919 // (this method will return FALSE below if mHmtx is null) | |
| 920 mHmtxTable = | |
| 921 entry->GetFontTable(TRUETYPE_TAG('h','m','t','x')); | |
| 922 if (hb_blob_get_length(mHmtxTable) < | |
| 923 mNumLongMetrics * sizeof(HLongMetric)) { | |
| 924 // hmtx table is not large enough for the claimed | |
| 925 // number of entries: invalid, do not use. | |
| 926 hb_blob_destroy(mHmtxTable); | |
| 927 mHmtxTable = nullptr; | |
| 928 } | |
| 929 } | |
| 930 } | |
| 931 } | |
| 932 if (!mHmtxTable) { | |
| 933 return false; | |
| 934 } | |
| 935 } | |
| 936 | |
| 937 mHBFont = hb_font_create(mHBFace); | |
| 938 hb_font_set_funcs(mHBFont, sHBFontFuncs, &mCallbackData, nullptr); | |
| 939 hb_font_set_ppem(mHBFont, mFont->GetAdjustedSize(), mFont->GetAdjustedSize()); | |
| 940 uint32_t scale = FloatToFixed(mFont->GetAdjustedSize()); // 16.16 fixed-point | |
| 941 hb_font_set_scale(mHBFont, scale, scale); | |
| 942 | |
| 943 return true; | |
| 944 } | |
| 945 | |
| 946 bool | |
| 947 gfxHarfBuzzShaper::ShapeText(gfxContext *aContext, | |
| 948 const char16_t *aText, | |
| 949 uint32_t aOffset, | |
| 950 uint32_t aLength, | |
| 951 int32_t aScript, | |
| 952 gfxShapedText *aShapedText) | |
| 953 { | |
| 954 // some font back-ends require this in order to get proper hinted metrics | |
| 955 if (!mFont->SetupCairoFont(aContext)) { | |
| 956 return false; | |
| 957 } | |
| 958 | |
| 959 mCallbackData.mContext = aContext; | |
| 960 | |
| 961 if (!Initialize()) { | |
| 962 return false; | |
| 963 } | |
| 964 | |
| 965 const gfxFontStyle *style = mFont->GetStyle(); | |
| 966 | |
| 967 nsAutoTArray<hb_feature_t,20> features; | |
| 968 nsDataHashtable<nsUint32HashKey,uint32_t> mergedFeatures; | |
| 969 | |
| 970 gfxFontEntry *entry = mFont->GetFontEntry(); | |
| 971 if (MergeFontFeatures(style, | |
| 972 entry->mFeatureSettings, | |
| 973 aShapedText->DisableLigatures(), | |
| 974 entry->FamilyName(), | |
| 975 mergedFeatures)) | |
| 976 { | |
| 977 // enumerate result and insert into hb_feature array | |
| 978 mergedFeatures.Enumerate(AddOpenTypeFeature, &features); | |
| 979 } | |
| 980 | |
| 981 bool isRightToLeft = aShapedText->IsRightToLeft(); | |
| 982 hb_buffer_t *buffer = hb_buffer_create(); | |
| 983 hb_buffer_set_unicode_funcs(buffer, sHBUnicodeFuncs); | |
| 984 hb_buffer_set_direction(buffer, isRightToLeft ? HB_DIRECTION_RTL : | |
| 985 HB_DIRECTION_LTR); | |
| 986 hb_script_t scriptTag; | |
| 987 if (aShapedText->Flags() & gfxTextRunFactory::TEXT_USE_MATH_SCRIPT) { | |
| 988 scriptTag = sMathScript; | |
| 989 } else if (aScript <= MOZ_SCRIPT_INHERITED) { | |
| 990 // For unresolved "common" or "inherited" runs, default to Latin for | |
| 991 // now. (Should we somehow use the language or locale to try and infer | |
| 992 // a better default?) | |
| 993 scriptTag = HB_SCRIPT_LATIN; | |
| 994 } else { | |
| 995 scriptTag = hb_script_t(GetScriptTagForCode(aScript)); | |
| 996 } | |
| 997 hb_buffer_set_script(buffer, scriptTag); | |
| 998 | |
| 999 hb_language_t language; | |
| 1000 if (style->languageOverride) { | |
| 1001 language = hb_ot_tag_to_language(style->languageOverride); | |
| 1002 } else if (entry->mLanguageOverride) { | |
| 1003 language = hb_ot_tag_to_language(entry->mLanguageOverride); | |
| 1004 } else { | |
| 1005 nsCString langString; | |
| 1006 style->language->ToUTF8String(langString); | |
| 1007 language = | |
| 1008 hb_language_from_string(langString.get(), langString.Length()); | |
| 1009 } | |
| 1010 hb_buffer_set_language(buffer, language); | |
| 1011 | |
| 1012 uint32_t length = aLength; | |
| 1013 hb_buffer_add_utf16(buffer, | |
| 1014 reinterpret_cast<const uint16_t*>(aText), | |
| 1015 length, 0, length); | |
| 1016 | |
| 1017 hb_shape(mHBFont, buffer, features.Elements(), features.Length()); | |
| 1018 | |
| 1019 if (isRightToLeft) { | |
| 1020 hb_buffer_reverse(buffer); | |
| 1021 } | |
| 1022 | |
| 1023 nsresult rv = SetGlyphsFromRun(aContext, aShapedText, aOffset, aLength, | |
| 1024 aText, buffer); | |
| 1025 | |
| 1026 NS_WARN_IF_FALSE(NS_SUCCEEDED(rv), "failed to store glyphs into gfxShapedWord"); | |
| 1027 hb_buffer_destroy(buffer); | |
| 1028 | |
| 1029 return NS_SUCCEEDED(rv); | |
| 1030 } | |
| 1031 | |
| 1032 #define SMALL_GLYPH_RUN 128 // some testing indicates that 90%+ of text runs | |
| 1033 // will fit without requiring separate allocation | |
| 1034 // for charToGlyphArray | |
| 1035 | |
| 1036 nsresult | |
| 1037 gfxHarfBuzzShaper::SetGlyphsFromRun(gfxContext *aContext, | |
| 1038 gfxShapedText *aShapedText, | |
| 1039 uint32_t aOffset, | |
| 1040 uint32_t aLength, | |
| 1041 const char16_t *aText, | |
| 1042 hb_buffer_t *aBuffer) | |
| 1043 { | |
| 1044 uint32_t numGlyphs; | |
| 1045 const hb_glyph_info_t *ginfo = hb_buffer_get_glyph_infos(aBuffer, &numGlyphs); | |
| 1046 if (numGlyphs == 0) { | |
| 1047 return NS_OK; | |
| 1048 } | |
| 1049 | |
| 1050 nsAutoTArray<gfxTextRun::DetailedGlyph,1> detailedGlyphs; | |
| 1051 | |
| 1052 uint32_t wordLength = aLength; | |
| 1053 static const int32_t NO_GLYPH = -1; | |
| 1054 AutoFallibleTArray<int32_t,SMALL_GLYPH_RUN> charToGlyphArray; | |
| 1055 if (!charToGlyphArray.SetLength(wordLength)) { | |
| 1056 return NS_ERROR_OUT_OF_MEMORY; | |
| 1057 } | |
| 1058 | |
| 1059 int32_t *charToGlyph = charToGlyphArray.Elements(); | |
| 1060 for (uint32_t offset = 0; offset < wordLength; ++offset) { | |
| 1061 charToGlyph[offset] = NO_GLYPH; | |
| 1062 } | |
| 1063 | |
| 1064 for (uint32_t i = 0; i < numGlyphs; ++i) { | |
| 1065 uint32_t loc = ginfo[i].cluster; | |
| 1066 if (loc < wordLength) { | |
| 1067 charToGlyph[loc] = i; | |
| 1068 } | |
| 1069 } | |
| 1070 | |
| 1071 int32_t glyphStart = 0; // looking for a clump that starts at this glyph | |
| 1072 int32_t charStart = 0; // and this char index within the range of the run | |
| 1073 | |
| 1074 bool roundX; | |
| 1075 bool roundY; | |
| 1076 aContext->GetRoundOffsetsToPixels(&roundX, &roundY); | |
| 1077 | |
| 1078 int32_t appUnitsPerDevUnit = aShapedText->GetAppUnitsPerDevUnit(); | |
| 1079 gfxShapedText::CompressedGlyph *charGlyphs = | |
| 1080 aShapedText->GetCharacterGlyphs() + aOffset; | |
| 1081 | |
| 1082 // factor to convert 16.16 fixed-point pixels to app units | |
| 1083 // (only used if not rounding) | |
| 1084 double hb2appUnits = FixedToFloat(aShapedText->GetAppUnitsPerDevUnit()); | |
| 1085 | |
| 1086 // Residual from rounding of previous advance, for use in rounding the | |
| 1087 // subsequent offset or advance appropriately. 16.16 fixed-point | |
| 1088 // | |
| 1089 // When rounding, the goal is to make the distance between glyphs and | |
| 1090 // their base glyph equal to the integral number of pixels closest to that | |
| 1091 // suggested by that shaper. | |
| 1092 // i.e. posInfo[n].x_advance - posInfo[n].x_offset + posInfo[n+1].x_offset | |
| 1093 // | |
| 1094 // The value of the residual is the part of the desired distance that has | |
| 1095 // not been included in integer offsets. | |
| 1096 hb_position_t x_residual = 0; | |
| 1097 | |
| 1098 // keep track of y-position to set glyph offsets if needed | |
| 1099 nscoord yPos = 0; | |
| 1100 | |
| 1101 const hb_glyph_position_t *posInfo = | |
| 1102 hb_buffer_get_glyph_positions(aBuffer, nullptr); | |
| 1103 | |
| 1104 while (glyphStart < int32_t(numGlyphs)) { | |
| 1105 | |
| 1106 int32_t charEnd = ginfo[glyphStart].cluster; | |
| 1107 int32_t glyphEnd = glyphStart; | |
| 1108 int32_t charLimit = wordLength; | |
| 1109 while (charEnd < charLimit) { | |
| 1110 // This is normally executed once for each iteration of the outer loop, | |
| 1111 // but in unusual cases where the character/glyph association is complex, | |
| 1112 // the initial character range might correspond to a non-contiguous | |
| 1113 // glyph range with "holes" in it. If so, we will repeat this loop to | |
| 1114 // extend the character range until we have a contiguous glyph sequence. | |
| 1115 charEnd += 1; | |
| 1116 while (charEnd != charLimit && charToGlyph[charEnd] == NO_GLYPH) { | |
| 1117 charEnd += 1; | |
| 1118 } | |
| 1119 | |
| 1120 // find the maximum glyph index covered by the clump so far | |
| 1121 for (int32_t i = charStart; i < charEnd; ++i) { | |
| 1122 if (charToGlyph[i] != NO_GLYPH) { | |
| 1123 glyphEnd = std::max(glyphEnd, charToGlyph[i] + 1); | |
| 1124 // update extent of glyph range | |
| 1125 } | |
| 1126 } | |
| 1127 | |
| 1128 if (glyphEnd == glyphStart + 1) { | |
| 1129 // for the common case of a single-glyph clump, | |
| 1130 // we can skip the following checks | |
| 1131 break; | |
| 1132 } | |
| 1133 | |
| 1134 if (glyphEnd == glyphStart) { | |
| 1135 // no glyphs, try to extend the clump | |
| 1136 continue; | |
| 1137 } | |
| 1138 | |
| 1139 // check whether all glyphs in the range are associated with the characters | |
| 1140 // in our clump; if not, we have a discontinuous range, and should extend it | |
| 1141 // unless we've reached the end of the text | |
| 1142 bool allGlyphsAreWithinCluster = true; | |
| 1143 for (int32_t i = glyphStart; i < glyphEnd; ++i) { | |
| 1144 int32_t glyphCharIndex = ginfo[i].cluster; | |
| 1145 if (glyphCharIndex < charStart || glyphCharIndex >= charEnd) { | |
| 1146 allGlyphsAreWithinCluster = false; | |
| 1147 break; | |
| 1148 } | |
| 1149 } | |
| 1150 if (allGlyphsAreWithinCluster) { | |
| 1151 break; | |
| 1152 } | |
| 1153 } | |
| 1154 | |
| 1155 NS_ASSERTION(glyphStart < glyphEnd, | |
| 1156 "character/glyph clump contains no glyphs!"); | |
| 1157 NS_ASSERTION(charStart != charEnd, | |
| 1158 "character/glyph clump contains no characters!"); | |
| 1159 | |
| 1160 // Now charStart..charEnd is a ligature clump, corresponding to glyphStart..glyphEnd; | |
| 1161 // Set baseCharIndex to the char we'll actually attach the glyphs to (1st of ligature), | |
| 1162 // and endCharIndex to the limit (position beyond the last char), | |
| 1163 // adjusting for the offset of the stringRange relative to the textRun. | |
| 1164 int32_t baseCharIndex, endCharIndex; | |
| 1165 while (charEnd < int32_t(wordLength) && charToGlyph[charEnd] == NO_GLYPH) | |
| 1166 charEnd++; | |
| 1167 baseCharIndex = charStart; | |
| 1168 endCharIndex = charEnd; | |
| 1169 | |
| 1170 // Then we check if the clump falls outside our actual string range; | |
| 1171 // if so, just go to the next. | |
| 1172 if (baseCharIndex >= int32_t(wordLength)) { | |
| 1173 glyphStart = glyphEnd; | |
| 1174 charStart = charEnd; | |
| 1175 continue; | |
| 1176 } | |
| 1177 // Ensure we won't try to go beyond the valid length of the textRun's text | |
| 1178 endCharIndex = std::min<int32_t>(endCharIndex, wordLength); | |
| 1179 | |
| 1180 // Now we're ready to set the glyph info in the textRun | |
| 1181 int32_t glyphsInClump = glyphEnd - glyphStart; | |
| 1182 | |
| 1183 // Check for default-ignorable char that didn't get filtered, combined, | |
| 1184 // etc by the shaping process, and remove from the run. | |
| 1185 // (This may be done within harfbuzz eventually.) | |
| 1186 if (glyphsInClump == 1 && baseCharIndex + 1 == endCharIndex && | |
| 1187 aShapedText->FilterIfIgnorable(aOffset + baseCharIndex, | |
| 1188 aText[baseCharIndex])) { | |
| 1189 glyphStart = glyphEnd; | |
| 1190 charStart = charEnd; | |
| 1191 continue; | |
| 1192 } | |
| 1193 | |
| 1194 hb_position_t x_offset = posInfo[glyphStart].x_offset; | |
| 1195 hb_position_t x_advance = posInfo[glyphStart].x_advance; | |
| 1196 nscoord xOffset, advance; | |
| 1197 if (roundX) { | |
| 1198 xOffset = | |
| 1199 appUnitsPerDevUnit * FixedToIntRound(x_offset + x_residual); | |
| 1200 // Desired distance from the base glyph to the next reference point. | |
| 1201 hb_position_t width = x_advance - x_offset; | |
| 1202 int intWidth = FixedToIntRound(width); | |
| 1203 x_residual = width - FloatToFixed(intWidth); | |
| 1204 advance = appUnitsPerDevUnit * intWidth + xOffset; | |
| 1205 } else { | |
| 1206 xOffset = floor(hb2appUnits * x_offset + 0.5); | |
| 1207 advance = floor(hb2appUnits * x_advance + 0.5); | |
| 1208 } | |
| 1209 // Check if it's a simple one-to-one mapping | |
| 1210 if (glyphsInClump == 1 && | |
| 1211 gfxTextRun::CompressedGlyph::IsSimpleGlyphID(ginfo[glyphStart].codepoint) && | |
| 1212 gfxTextRun::CompressedGlyph::IsSimpleAdvance(advance) && | |
| 1213 charGlyphs[baseCharIndex].IsClusterStart() && | |
| 1214 xOffset == 0 && | |
| 1215 posInfo[glyphStart].y_offset == 0 && yPos == 0) | |
| 1216 { | |
| 1217 charGlyphs[baseCharIndex].SetSimpleGlyph(advance, | |
| 1218 ginfo[glyphStart].codepoint); | |
| 1219 } else { | |
| 1220 // collect all glyphs in a list to be assigned to the first char; | |
| 1221 // there must be at least one in the clump, and we already measured | |
| 1222 // its advance, hence the placement of the loop-exit test and the | |
| 1223 // measurement of the next glyph | |
| 1224 while (1) { | |
| 1225 gfxTextRun::DetailedGlyph* details = | |
| 1226 detailedGlyphs.AppendElement(); | |
| 1227 details->mGlyphID = ginfo[glyphStart].codepoint; | |
| 1228 | |
| 1229 details->mXOffset = xOffset; | |
| 1230 details->mAdvance = advance; | |
| 1231 | |
| 1232 hb_position_t y_offset = posInfo[glyphStart].y_offset; | |
| 1233 details->mYOffset = yPos - | |
| 1234 (roundY ? appUnitsPerDevUnit * FixedToIntRound(y_offset) | |
| 1235 : floor(hb2appUnits * y_offset + 0.5)); | |
| 1236 | |
| 1237 hb_position_t y_advance = posInfo[glyphStart].y_advance; | |
| 1238 if (y_advance != 0) { | |
| 1239 yPos -= | |
| 1240 roundY ? appUnitsPerDevUnit * FixedToIntRound(y_advance) | |
| 1241 : floor(hb2appUnits * y_advance + 0.5); | |
| 1242 } | |
| 1243 if (++glyphStart >= glyphEnd) { | |
| 1244 break; | |
| 1245 } | |
| 1246 | |
| 1247 x_offset = posInfo[glyphStart].x_offset; | |
| 1248 x_advance = posInfo[glyphStart].x_advance; | |
| 1249 if (roundX) { | |
| 1250 xOffset = appUnitsPerDevUnit * | |
| 1251 FixedToIntRound(x_offset + x_residual); | |
| 1252 // Desired distance to the next reference point. The | |
| 1253 // residual is considered here, and includes the residual | |
| 1254 // from the base glyph offset and subsequent advances, so | |
| 1255 // that the distance from the base glyph is optimized | |
| 1256 // rather than the distance from combining marks. | |
| 1257 x_advance += x_residual; | |
| 1258 int intAdvance = FixedToIntRound(x_advance); | |
| 1259 x_residual = x_advance - FloatToFixed(intAdvance); | |
| 1260 advance = appUnitsPerDevUnit * intAdvance; | |
| 1261 } else { | |
| 1262 xOffset = floor(hb2appUnits * x_offset + 0.5); | |
| 1263 advance = floor(hb2appUnits * x_advance + 0.5); | |
| 1264 } | |
| 1265 } | |
| 1266 | |
| 1267 gfxShapedText::CompressedGlyph g; | |
| 1268 g.SetComplex(charGlyphs[baseCharIndex].IsClusterStart(), | |
| 1269 true, detailedGlyphs.Length()); | |
| 1270 aShapedText->SetGlyphs(aOffset + baseCharIndex, | |
| 1271 g, detailedGlyphs.Elements()); | |
| 1272 | |
| 1273 detailedGlyphs.Clear(); | |
| 1274 } | |
| 1275 | |
| 1276 // the rest of the chars in the group are ligature continuations, | |
| 1277 // no associated glyphs | |
| 1278 while (++baseCharIndex != endCharIndex && | |
| 1279 baseCharIndex < int32_t(wordLength)) { | |
| 1280 gfxShapedText::CompressedGlyph &g = charGlyphs[baseCharIndex]; | |
| 1281 NS_ASSERTION(!g.IsSimpleGlyph(), "overwriting a simple glyph"); | |
| 1282 g.SetComplex(g.IsClusterStart(), false, 0); | |
| 1283 } | |
| 1284 | |
| 1285 glyphStart = glyphEnd; | |
| 1286 charStart = charEnd; | |
| 1287 } | |
| 1288 | |
| 1289 return NS_OK; | |
| 1290 } |
