1 /* libs/graphics/ports/SkFontHost_FreeType.cpp 2 ** 3 ** Copyright 2006, The Android Open Source Project 4 ** 5 ** Licensed under the Apache License, Version 2.0 (the "License"); 6 ** you may not use this file except in compliance with the License. 7 ** You may obtain a copy of the License at 8 ** 9 ** http://www.apache.org/licenses/LICENSE-2.0 10 ** 11 ** Unless required by applicable law or agreed to in writing, software 12 ** distributed under the License is distributed on an "AS IS" BASIS, 13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 ** See the License for the specific language governing permissions and 15 ** limitations under the License. 16 */ 17 18 #include "SkColorPriv.h" 19 #include "SkScalerContext.h" 20 #include "SkBitmap.h" 21 #include "SkCanvas.h" 22 #include "SkDescriptor.h" 23 #include "SkFDot6.h" 24 #include "SkFontHost.h" 25 #include "SkMask.h" 26 #include "SkStream.h" 27 #include "SkString.h" 28 #include "SkThread.h" 29 #include "SkTemplates.h" 30 31 #include <ft2build.h> 32 #include FT_FREETYPE_H 33 #include FT_OUTLINE_H 34 #include FT_SIZES_H 35 #include FT_TRUETYPE_TABLES_H 36 37 #if defined(SK_SUPPORT_LCDTEXT) 38 #include FT_LCD_FILTER_H 39 #endif 40 41 #ifdef FT_ADVANCES_H 42 #include FT_ADVANCES_H 43 #endif 44 45 #if 0 46 // Also include the files by name for build tools which require this. 47 #include <freetype/freetype.h> 48 #include <freetype/ftoutln.h> 49 #include <freetype/ftsizes.h> 50 #include <freetype/tttables.h> 51 #include <freetype/ftadvanc.h> 52 #include <freetype/ftlcdfil.h> 53 #endif 54 55 //#define ENABLE_GLYPH_SPEW // for tracing calls 56 //#define DUMP_STRIKE_CREATION 57 58 #ifdef SK_DEBUG 59 #define SkASSERT_CONTINUE(pred) \ 60 do { \ 61 if (!(pred)) \ 62 SkDebugf("file %s:%d: assert failed '" #pred "'\n", __FILE__, __LINE__); \ 63 } while (false) 64 #else 65 #define SkASSERT_CONTINUE(pred) 66 #endif 67 68 ////////////////////////////////////////////////////////////////////////// 69 70 struct SkFaceRec; 71 72 static SkMutex gFTMutex; 73 static int gFTCount; 74 static FT_Library gFTLibrary; 75 static SkFaceRec* gFaceRecHead; 76 static bool gLCDSupportValid; // true iff |gLCDSupport| has been set. 77 static bool gLCDSupport; // true iff LCD is supported by the runtime. 78 79 ///////////////////////////////////////////////////////////////////////// 80 81 static bool 82 InitFreetype() { 83 FT_Error err = FT_Init_FreeType(&gFTLibrary); 84 if (err) 85 return false; 86 87 #if defined(SK_SUPPORT_LCDTEXT) 88 // Setup LCD filtering. This reduces colour fringes for LCD rendered 89 // glyphs. 90 err = FT_Library_SetLcdFilter(gFTLibrary, FT_LCD_FILTER_DEFAULT); 91 gLCDSupport = err == 0; 92 #endif 93 gLCDSupportValid = true; 94 95 return true; 96 } 97 98 class SkScalerContext_FreeType : public SkScalerContext { 99 public: 100 SkScalerContext_FreeType(const SkDescriptor* desc); 101 virtual ~SkScalerContext_FreeType(); 102 103 bool success() const { 104 return fFaceRec != NULL && 105 fFTSize != NULL && 106 fFace != NULL; 107 } 108 109 protected: 110 virtual unsigned generateGlyphCount() const; 111 virtual uint16_t generateCharToGlyph(SkUnichar uni); 112 virtual void generateAdvance(SkGlyph* glyph); 113 virtual void generateMetrics(SkGlyph* glyph); 114 virtual void generateImage(const SkGlyph& glyph); 115 virtual void generatePath(const SkGlyph& glyph, SkPath* path); 116 virtual void generateFontMetrics(SkPaint::FontMetrics* mx, 117 SkPaint::FontMetrics* my); 118 virtual SkUnichar generateGlyphToChar(uint16_t glyph); 119 120 private: 121 SkFaceRec* fFaceRec; 122 FT_Face fFace; // reference to shared face in gFaceRecHead 123 FT_Size fFTSize; // our own copy 124 SkFixed fScaleX, fScaleY; 125 FT_Matrix fMatrix22; 126 uint32_t fLoadGlyphFlags; 127 128 FT_Error setupSize(); 129 void emboldenOutline(FT_Outline* outline); 130 }; 131 132 /////////////////////////////////////////////////////////////////////////// 133 /////////////////////////////////////////////////////////////////////////// 134 135 #include "SkStream.h" 136 137 struct SkFaceRec { 138 SkFaceRec* fNext; 139 FT_Face fFace; 140 FT_StreamRec fFTStream; 141 SkStream* fSkStream; 142 uint32_t fRefCnt; 143 uint32_t fFontID; 144 145 // assumes ownership of the stream, will call unref() when its done 146 SkFaceRec(SkStream* strm, uint32_t fontID); 147 ~SkFaceRec() { 148 fSkStream->unref(); 149 } 150 }; 151 152 extern "C" { 153 static unsigned long sk_stream_read(FT_Stream stream, 154 unsigned long offset, 155 unsigned char* buffer, 156 unsigned long count ) { 157 SkStream* str = (SkStream*)stream->descriptor.pointer; 158 159 if (count) { 160 if (!str->rewind()) { 161 return 0; 162 } else { 163 unsigned long ret; 164 if (offset) { 165 ret = str->read(NULL, offset); 166 if (ret != offset) { 167 return 0; 168 } 169 } 170 ret = str->read(buffer, count); 171 if (ret != count) { 172 return 0; 173 } 174 count = ret; 175 } 176 } 177 return count; 178 } 179 180 static void sk_stream_close( FT_Stream stream) {} 181 } 182 183 SkFaceRec::SkFaceRec(SkStream* strm, uint32_t fontID) 184 : fSkStream(strm), fFontID(fontID) { 185 // SkDEBUGF(("SkFaceRec: opening %s (%p)\n", key.c_str(), strm)); 186 187 sk_bzero(&fFTStream, sizeof(fFTStream)); 188 fFTStream.size = fSkStream->getLength(); 189 fFTStream.descriptor.pointer = fSkStream; 190 fFTStream.read = sk_stream_read; 191 fFTStream.close = sk_stream_close; 192 } 193 194 // Will return 0 on failure 195 static SkFaceRec* ref_ft_face(uint32_t fontID) { 196 SkFaceRec* rec = gFaceRecHead; 197 while (rec) { 198 if (rec->fFontID == fontID) { 199 SkASSERT(rec->fFace); 200 rec->fRefCnt += 1; 201 return rec; 202 } 203 rec = rec->fNext; 204 } 205 206 SkStream* strm = SkFontHost::OpenStream(fontID); 207 if (NULL == strm) { 208 SkDEBUGF(("SkFontHost::OpenStream failed opening %x\n", fontID)); 209 return 0; 210 } 211 212 // this passes ownership of strm to the rec 213 rec = SkNEW_ARGS(SkFaceRec, (strm, fontID)); 214 215 FT_Open_Args args; 216 memset(&args, 0, sizeof(args)); 217 const void* memoryBase = strm->getMemoryBase(); 218 219 if (NULL != memoryBase) { 220 //printf("mmap(%s)\n", keyString.c_str()); 221 args.flags = FT_OPEN_MEMORY; 222 args.memory_base = (const FT_Byte*)memoryBase; 223 args.memory_size = strm->getLength(); 224 } else { 225 //printf("fopen(%s)\n", keyString.c_str()); 226 args.flags = FT_OPEN_STREAM; 227 args.stream = &rec->fFTStream; 228 } 229 230 if (gFTCount == 0) { 231 if (!InitFreetype()) { 232 return 0; 233 } 234 } 235 ++gFTCount; 236 237 FT_Error err = FT_Open_Face(gFTLibrary, &args, 0, &rec->fFace); 238 239 if (err) { // bad filename, try the default font 240 fprintf(stderr, "ERROR: unable to open font '%x'\n", fontID); 241 SkDELETE(rec); 242 return 0; 243 } else { 244 SkASSERT(rec->fFace); 245 //fprintf(stderr, "Opened font '%s'\n", filename.c_str()); 246 rec->fNext = gFaceRecHead; 247 gFaceRecHead = rec; 248 rec->fRefCnt = 1; 249 return rec; 250 } 251 } 252 253 static void unref_ft_face(FT_Face face) { 254 SkFaceRec* rec = gFaceRecHead; 255 SkFaceRec* prev = NULL; 256 while (rec) { 257 SkFaceRec* next = rec->fNext; 258 if (rec->fFace == face) { 259 if (--rec->fRefCnt == 0) { 260 if (prev) { 261 prev->fNext = next; 262 } else { 263 gFaceRecHead = next; 264 } 265 FT_Done_Face(face); 266 SkDELETE(rec); 267 268 if (--gFTCount == 0) { 269 FT_Done_FreeType(gFTLibrary); 270 } 271 } 272 return; 273 } 274 prev = rec; 275 rec = next; 276 } 277 SkASSERT("shouldn't get here, face not in list"); 278 } 279 280 /////////////////////////////////////////////////////////////////////////// 281 282 void SkFontHost::FilterRec(SkScalerContext::Rec* rec) { 283 if (!gLCDSupportValid) { 284 InitFreetype(); 285 FT_Done_FreeType(gFTLibrary); 286 } 287 288 if (!gLCDSupport && rec->isLCD()) { 289 // If the runtime Freetype library doesn't support LCD mode, we disable 290 // it here. 291 rec->fMaskFormat = SkMask::kA8_Format; 292 } 293 294 SkPaint::Hinting h = rec->getHinting(); 295 if (SkPaint::kFull_Hinting == h && !rec->isLCD()) { 296 // collapse full->normal hinting if we're not doing LCD 297 h = SkPaint::kNormal_Hinting; 298 } else if (rec->fSubpixelPositioning && SkPaint::kNo_Hinting != h) { 299 // to do subpixel, we must have at most slight hinting 300 h = SkPaint::kSlight_Hinting; 301 } 302 rec->setHinting(h); 303 } 304 305 uint32_t SkFontHost::GetUnitsPerEm(SkFontID fontID) { 306 SkAutoMutexAcquire ac(gFTMutex); 307 SkFaceRec *rec = ref_ft_face(fontID); 308 uint16_t unitsPerEm = 0; 309 310 if (rec != NULL && rec->fFace != NULL) { 311 unitsPerEm = rec->fFace->units_per_EM; 312 unref_ft_face(rec->fFace); 313 } 314 315 return (uint32_t)unitsPerEm; 316 } 317 318 SkScalerContext_FreeType::SkScalerContext_FreeType(const SkDescriptor* desc) 319 : SkScalerContext(desc) { 320 SkAutoMutexAcquire ac(gFTMutex); 321 322 if (gFTCount == 0) { 323 if (!InitFreetype()) { 324 sk_throw(); 325 } 326 } 327 ++gFTCount; 328 329 // load the font file 330 fFTSize = NULL; 331 fFace = NULL; 332 fFaceRec = ref_ft_face(fRec.fFontID); 333 if (NULL == fFaceRec) { 334 return; 335 } 336 fFace = fFaceRec->fFace; 337 338 // compute our factors from the record 339 340 SkMatrix m; 341 342 fRec.getSingleMatrix(&m); 343 344 #ifdef DUMP_STRIKE_CREATION 345 SkString keyString; 346 SkFontHost::GetDescriptorKeyString(desc, &keyString); 347 printf("========== strike [%g %g %g] [%g %g %g %g] hints %d format %d %s\n", SkScalarToFloat(fRec.fTextSize), 348 SkScalarToFloat(fRec.fPreScaleX), SkScalarToFloat(fRec.fPreSkewX), 349 SkScalarToFloat(fRec.fPost2x2[0][0]), SkScalarToFloat(fRec.fPost2x2[0][1]), 350 SkScalarToFloat(fRec.fPost2x2[1][0]), SkScalarToFloat(fRec.fPost2x2[1][1]), 351 fRec.getHinting(), fRec.fMaskFormat, keyString.c_str()); 352 #endif 353 354 // now compute our scale factors 355 SkScalar sx = m.getScaleX(); 356 SkScalar sy = m.getScaleY(); 357 358 if (m.getSkewX() || m.getSkewY() || sx < 0 || sy < 0) { 359 // sort of give up on hinting 360 sx = SkMaxScalar(SkScalarAbs(sx), SkScalarAbs(m.getSkewX())); 361 sy = SkMaxScalar(SkScalarAbs(m.getSkewY()), SkScalarAbs(sy)); 362 sx = sy = SkScalarAve(sx, sy); 363 364 SkScalar inv = SkScalarInvert(sx); 365 366 // flip the skew elements to go from our Y-down system to FreeType's 367 fMatrix22.xx = SkScalarToFixed(SkScalarMul(m.getScaleX(), inv)); 368 fMatrix22.xy = -SkScalarToFixed(SkScalarMul(m.getSkewX(), inv)); 369 fMatrix22.yx = -SkScalarToFixed(SkScalarMul(m.getSkewY(), inv)); 370 fMatrix22.yy = SkScalarToFixed(SkScalarMul(m.getScaleY(), inv)); 371 } else { 372 fMatrix22.xx = fMatrix22.yy = SK_Fixed1; 373 fMatrix22.xy = fMatrix22.yx = 0; 374 } 375 376 fScaleX = SkScalarToFixed(sx); 377 fScaleY = SkScalarToFixed(sy); 378 379 // compute the flags we send to Load_Glyph 380 { 381 FT_Int32 loadFlags = FT_LOAD_DEFAULT; 382 383 switch (fRec.getHinting()) { 384 case SkPaint::kNo_Hinting: 385 loadFlags = FT_LOAD_NO_HINTING; 386 break; 387 case SkPaint::kSlight_Hinting: 388 loadFlags = FT_LOAD_TARGET_LIGHT; // This implies FORCE_AUTOHINT 389 break; 390 case SkPaint::kNormal_Hinting: 391 loadFlags = FT_LOAD_TARGET_NORMAL; 392 break; 393 case SkPaint::kFull_Hinting: 394 loadFlags = FT_LOAD_TARGET_NORMAL; 395 if (SkMask::kHorizontalLCD_Format == fRec.fMaskFormat) 396 loadFlags = FT_LOAD_TARGET_LCD; 397 else if (SkMask::kVerticalLCD_Format == fRec.fMaskFormat) 398 loadFlags = FT_LOAD_TARGET_LCD_V; 399 break; 400 default: 401 SkDebugf("---------- UNKNOWN hinting %d\n", fRec.getHinting()); 402 break; 403 } 404 405 if ((fRec.fFlags & SkScalerContext::kEmbeddedBitmapText_Flag) == 0) 406 loadFlags |= FT_LOAD_NO_BITMAP; 407 408 fLoadGlyphFlags = loadFlags; 409 } 410 411 // now create the FT_Size 412 413 { 414 FT_Error err; 415 416 err = FT_New_Size(fFace, &fFTSize); 417 if (err != 0) { 418 SkDEBUGF(("SkScalerContext_FreeType::FT_New_Size(%x): FT_Set_Char_Size(0x%x, 0x%x) returned 0x%x\n", 419 fFaceRec->fFontID, fScaleX, fScaleY, err)); 420 fFace = NULL; 421 return; 422 } 423 424 err = FT_Activate_Size(fFTSize); 425 if (err != 0) { 426 SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%x, 0x%x, 0x%x) returned 0x%x\n", 427 fFaceRec->fFontID, fScaleX, fScaleY, err)); 428 fFTSize = NULL; 429 } 430 431 err = FT_Set_Char_Size( fFace, 432 SkFixedToFDot6(fScaleX), SkFixedToFDot6(fScaleY), 433 72, 72); 434 if (err != 0) { 435 SkDEBUGF(("SkScalerContext_FreeType::FT_Set_Char_Size(%x, 0x%x, 0x%x) returned 0x%x\n", 436 fFaceRec->fFontID, fScaleX, fScaleY, err)); 437 fFace = NULL; 438 return; 439 } 440 441 FT_Set_Transform( fFace, &fMatrix22, NULL); 442 } 443 } 444 445 SkScalerContext_FreeType::~SkScalerContext_FreeType() { 446 if (fFTSize != NULL) { 447 FT_Done_Size(fFTSize); 448 } 449 450 SkAutoMutexAcquire ac(gFTMutex); 451 452 if (fFace != NULL) { 453 unref_ft_face(fFace); 454 } 455 if (--gFTCount == 0) { 456 // SkDEBUGF(("FT_Done_FreeType\n")); 457 FT_Done_FreeType(gFTLibrary); 458 SkDEBUGCODE(gFTLibrary = NULL;) 459 } 460 } 461 462 /* We call this before each use of the fFace, since we may be sharing 463 this face with other context (at different sizes). 464 */ 465 FT_Error SkScalerContext_FreeType::setupSize() { 466 /* In the off-chance that a font has been removed, we want to error out 467 right away, so call resolve just to be sure. 468 469 TODO: perhaps we can skip this, by walking the global font cache and 470 killing all of the contexts when we know that a given fontID is going 471 away... 472 */ 473 if (!SkFontHost::ValidFontID(fRec.fFontID)) { 474 return (FT_Error)-1; 475 } 476 477 FT_Error err = FT_Activate_Size(fFTSize); 478 479 if (err != 0) { 480 SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%x, 0x%x, 0x%x) returned 0x%x\n", 481 fFaceRec->fFontID, fScaleX, fScaleY, err)); 482 fFTSize = NULL; 483 } else { 484 // seems we need to reset this every time (not sure why, but without it 485 // I get random italics from some other fFTSize) 486 FT_Set_Transform( fFace, &fMatrix22, NULL); 487 } 488 return err; 489 } 490 491 void SkScalerContext_FreeType::emboldenOutline(FT_Outline* outline) { 492 FT_Pos strength; 493 strength = FT_MulFix(fFace->units_per_EM, fFace->size->metrics.y_scale) 494 / 24; 495 FT_Outline_Embolden(outline, strength); 496 } 497 498 unsigned SkScalerContext_FreeType::generateGlyphCount() const { 499 return fFace->num_glyphs; 500 } 501 502 uint16_t SkScalerContext_FreeType::generateCharToGlyph(SkUnichar uni) { 503 return SkToU16(FT_Get_Char_Index( fFace, uni )); 504 } 505 506 SkUnichar SkScalerContext_FreeType::generateGlyphToChar(uint16_t glyph) { 507 // iterate through each cmap entry, looking for matching glyph indices 508 FT_UInt glyphIndex; 509 SkUnichar charCode = FT_Get_First_Char( fFace, &glyphIndex ); 510 511 while (glyphIndex != 0) { 512 if (glyphIndex == glyph) { 513 return charCode; 514 } 515 charCode = FT_Get_Next_Char( fFace, charCode, &glyphIndex ); 516 } 517 518 return 0; 519 } 520 521 static FT_Pixel_Mode compute_pixel_mode(SkMask::Format format) { 522 switch (format) { 523 case SkMask::kHorizontalLCD_Format: 524 case SkMask::kVerticalLCD_Format: 525 SkASSERT(!"An LCD format should never be passed here"); 526 return FT_PIXEL_MODE_GRAY; 527 case SkMask::kBW_Format: 528 return FT_PIXEL_MODE_MONO; 529 case SkMask::kA8_Format: 530 default: 531 return FT_PIXEL_MODE_GRAY; 532 } 533 } 534 535 void SkScalerContext_FreeType::generateAdvance(SkGlyph* glyph) { 536 #ifdef FT_ADVANCES_H 537 /* unhinted and light hinted text have linearly scaled advances 538 * which are very cheap to compute with some font formats... 539 */ 540 { 541 SkAutoMutexAcquire ac(gFTMutex); 542 543 if (this->setupSize()) { 544 glyph->zeroMetrics(); 545 return; 546 } 547 548 FT_Error error; 549 FT_Fixed advance; 550 551 error = FT_Get_Advance( fFace, glyph->getGlyphID(fBaseGlyphCount), 552 fLoadGlyphFlags | FT_ADVANCE_FLAG_FAST_ONLY, 553 &advance ); 554 if (0 == error) { 555 glyph->fRsbDelta = 0; 556 glyph->fLsbDelta = 0; 557 glyph->fAdvanceX = advance; // advance *2/3; //DEBUG 558 glyph->fAdvanceY = 0; 559 return; 560 } 561 } 562 #endif /* FT_ADVANCES_H */ 563 /* otherwise, we need to load/hint the glyph, which is slower */ 564 this->generateMetrics(glyph); 565 return; 566 } 567 568 void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) { 569 SkAutoMutexAcquire ac(gFTMutex); 570 571 glyph->fRsbDelta = 0; 572 glyph->fLsbDelta = 0; 573 574 FT_Error err; 575 576 if (this->setupSize()) { 577 goto ERROR; 578 } 579 580 err = FT_Load_Glyph( fFace, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags ); 581 if (err != 0) { 582 SkDEBUGF(("SkScalerContext_FreeType::generateMetrics(%x): FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n", 583 fFaceRec->fFontID, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, err)); 584 ERROR: 585 glyph->zeroMetrics(); 586 return; 587 } 588 589 switch ( fFace->glyph->format ) { 590 case FT_GLYPH_FORMAT_OUTLINE: 591 FT_BBox bbox; 592 593 if (fRec.fFlags & kEmbolden_Flag) { 594 emboldenOutline(&fFace->glyph->outline); 595 } 596 FT_Outline_Get_CBox(&fFace->glyph->outline, &bbox); 597 598 if (fRec.fSubpixelPositioning) { 599 int dx = glyph->getSubXFixed() >> 10; 600 int dy = glyph->getSubYFixed() >> 10; 601 // negate dy since freetype-y-goes-up and skia-y-goes-down 602 bbox.xMin += dx; 603 bbox.yMin -= dy; 604 bbox.xMax += dx; 605 bbox.yMax -= dy; 606 } 607 608 bbox.xMin &= ~63; 609 bbox.yMin &= ~63; 610 bbox.xMax = (bbox.xMax + 63) & ~63; 611 bbox.yMax = (bbox.yMax + 63) & ~63; 612 613 glyph->fWidth = SkToU16((bbox.xMax - bbox.xMin) >> 6); 614 glyph->fHeight = SkToU16((bbox.yMax - bbox.yMin) >> 6); 615 glyph->fTop = -SkToS16(bbox.yMax >> 6); 616 glyph->fLeft = SkToS16(bbox.xMin >> 6); 617 break; 618 619 case FT_GLYPH_FORMAT_BITMAP: 620 glyph->fWidth = SkToU16(fFace->glyph->bitmap.width); 621 glyph->fHeight = SkToU16(fFace->glyph->bitmap.rows); 622 glyph->fTop = -SkToS16(fFace->glyph->bitmap_top); 623 glyph->fLeft = SkToS16(fFace->glyph->bitmap_left); 624 break; 625 626 default: 627 SkASSERT(!"unknown glyph format"); 628 goto ERROR; 629 } 630 631 if (!fRec.fSubpixelPositioning) { 632 glyph->fAdvanceX = SkFDot6ToFixed(fFace->glyph->advance.x); 633 glyph->fAdvanceY = -SkFDot6ToFixed(fFace->glyph->advance.y); 634 if (fRec.fFlags & kDevKernText_Flag) { 635 glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta); 636 glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta); 637 } 638 } else { 639 glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance); 640 glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance); 641 } 642 643 #ifdef ENABLE_GLYPH_SPEW 644 SkDEBUGF(("FT_Set_Char_Size(this:%p sx:%x sy:%x ", this, fScaleX, fScaleY)); 645 SkDEBUGF(("Metrics(glyph:%d flags:0x%x) w:%d\n", glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, glyph->fWidth)); 646 #endif 647 } 648 649 #if defined(SK_SUPPORT_LCDTEXT) 650 namespace skia_freetype_support { 651 // extern functions from SkFontHost_FreeType_Subpixel 652 extern void CopyFreetypeBitmapToLCDMask(const SkGlyph& dest, const FT_Bitmap& source); 653 extern void CopyFreetypeBitmapToVerticalLCDMask(const SkGlyph& dest, const FT_Bitmap& source); 654 } 655 656 using namespace skia_freetype_support; 657 #endif 658 659 void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { 660 SkAutoMutexAcquire ac(gFTMutex); 661 662 FT_Error err; 663 664 if (this->setupSize()) { 665 goto ERROR; 666 } 667 668 err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), fLoadGlyphFlags); 669 if (err != 0) { 670 SkDEBUGF(("SkScalerContext_FreeType::generateImage: FT_Load_Glyph(glyph:%d width:%d height:%d rb:%d flags:%d) returned 0x%x\n", 671 glyph.getGlyphID(fBaseGlyphCount), glyph.fWidth, glyph.fHeight, glyph.rowBytes(), fLoadGlyphFlags, err)); 672 ERROR: 673 memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight); 674 return; 675 } 676 677 const bool lcdRenderMode = fRec.fMaskFormat == SkMask::kHorizontalLCD_Format || 678 fRec.fMaskFormat == SkMask::kVerticalLCD_Format; 679 680 switch ( fFace->glyph->format ) { 681 case FT_GLYPH_FORMAT_OUTLINE: { 682 FT_Outline* outline = &fFace->glyph->outline; 683 FT_BBox bbox; 684 FT_Bitmap target; 685 686 if (fRec.fFlags & kEmbolden_Flag) { 687 emboldenOutline(outline); 688 } 689 690 int dx = 0, dy = 0; 691 if (fRec.fSubpixelPositioning) { 692 dx = glyph.getSubXFixed() >> 10; 693 dy = glyph.getSubYFixed() >> 10; 694 // negate dy since freetype-y-goes-up and skia-y-goes-down 695 dy = -dy; 696 } 697 FT_Outline_Get_CBox(outline, &bbox); 698 /* 699 what we really want to do for subpixel is 700 offset(dx, dy) 701 compute_bounds 702 offset(bbox & !63) 703 but that is two calls to offset, so we do the following, which 704 achieves the same thing with only one offset call. 705 */ 706 FT_Outline_Translate(outline, dx - ((bbox.xMin + dx) & ~63), 707 dy - ((bbox.yMin + dy) & ~63)); 708 709 #if defined(SK_SUPPORT_LCDTEXT) 710 if (lcdRenderMode) { 711 // FT_Outline_Get_Bitmap cannot render LCD glyphs. In this case 712 // we have to call FT_Render_Glyph and memcpy the image out. 713 const bool isVertical = fRec.fMaskFormat == SkMask::kVerticalLCD_Format; 714 FT_Render_Mode mode = isVertical ? FT_RENDER_MODE_LCD_V : FT_RENDER_MODE_LCD; 715 FT_Render_Glyph(fFace->glyph, mode); 716 717 if (isVertical) 718 CopyFreetypeBitmapToVerticalLCDMask(glyph, fFace->glyph->bitmap); 719 else 720 CopyFreetypeBitmapToLCDMask(glyph, fFace->glyph->bitmap); 721 722 break; 723 } 724 #endif 725 726 target.width = glyph.fWidth; 727 target.rows = glyph.fHeight; 728 target.pitch = glyph.rowBytes(); 729 target.buffer = reinterpret_cast<uint8_t*>(glyph.fImage); 730 target.pixel_mode = compute_pixel_mode( 731 (SkMask::Format)fRec.fMaskFormat); 732 target.num_grays = 256; 733 734 memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight); 735 FT_Outline_Get_Bitmap(gFTLibrary, outline, &target); 736 } break; 737 738 case FT_GLYPH_FORMAT_BITMAP: { 739 SkASSERT_CONTINUE(glyph.fWidth == fFace->glyph->bitmap.width); 740 SkASSERT_CONTINUE(glyph.fHeight == fFace->glyph->bitmap.rows); 741 SkASSERT_CONTINUE(glyph.fTop == -fFace->glyph->bitmap_top); 742 SkASSERT_CONTINUE(glyph.fLeft == fFace->glyph->bitmap_left); 743 744 const uint8_t* src = (const uint8_t*)fFace->glyph->bitmap.buffer; 745 uint8_t* dst = (uint8_t*)glyph.fImage; 746 747 if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_GRAY || 748 (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO && 749 glyph.fMaskFormat == SkMask::kBW_Format)) { 750 unsigned srcRowBytes = fFace->glyph->bitmap.pitch; 751 unsigned dstRowBytes = glyph.rowBytes(); 752 unsigned minRowBytes = SkMin32(srcRowBytes, dstRowBytes); 753 unsigned extraRowBytes = dstRowBytes - minRowBytes; 754 755 for (int y = fFace->glyph->bitmap.rows - 1; y >= 0; --y) { 756 memcpy(dst, src, minRowBytes); 757 memset(dst + minRowBytes, 0, extraRowBytes); 758 src += srcRowBytes; 759 dst += dstRowBytes; 760 } 761 } else if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO && 762 (glyph.fMaskFormat == SkMask::kA8_Format || 763 glyph.fMaskFormat == SkMask::kHorizontalLCD_Format || 764 glyph.fMaskFormat == SkMask::kVerticalLCD_Format)) { 765 for (int y = 0; y < fFace->glyph->bitmap.rows; ++y) { 766 uint8_t byte = 0; 767 int bits = 0; 768 const uint8_t* src_row = src; 769 uint8_t* dst_row = dst; 770 771 for (int x = 0; x < fFace->glyph->bitmap.width; ++x) { 772 if (!bits) { 773 byte = *src_row++; 774 bits = 8; 775 } 776 777 *dst_row++ = byte & 0x80 ? 0xff : 0; 778 bits--; 779 byte <<= 1; 780 } 781 782 src += fFace->glyph->bitmap.pitch; 783 dst += glyph.rowBytes(); 784 } 785 } else { 786 SkASSERT(!"unknown glyph bitmap transform needed"); 787 } 788 789 if (lcdRenderMode) 790 glyph.expandA8ToLCD(); 791 792 } break; 793 794 default: 795 SkASSERT(!"unknown glyph format"); 796 goto ERROR; 797 } 798 } 799 800 /////////////////////////////////////////////////////////////////////////////// 801 802 #define ft2sk(x) SkFixedToScalar((x) << 10) 803 804 #if FREETYPE_MAJOR >= 2 && FREETYPE_MINOR >= 2 805 #define CONST_PARAM const 806 #else // older freetype doesn't use const here 807 #define CONST_PARAM 808 #endif 809 810 static int move_proc(CONST_PARAM FT_Vector* pt, void* ctx) { 811 SkPath* path = (SkPath*)ctx; 812 path->close(); // to close the previous contour (if any) 813 path->moveTo(ft2sk(pt->x), -ft2sk(pt->y)); 814 return 0; 815 } 816 817 static int line_proc(CONST_PARAM FT_Vector* pt, void* ctx) { 818 SkPath* path = (SkPath*)ctx; 819 path->lineTo(ft2sk(pt->x), -ft2sk(pt->y)); 820 return 0; 821 } 822 823 static int quad_proc(CONST_PARAM FT_Vector* pt0, CONST_PARAM FT_Vector* pt1, 824 void* ctx) { 825 SkPath* path = (SkPath*)ctx; 826 path->quadTo(ft2sk(pt0->x), -ft2sk(pt0->y), ft2sk(pt1->x), -ft2sk(pt1->y)); 827 return 0; 828 } 829 830 static int cubic_proc(CONST_PARAM FT_Vector* pt0, CONST_PARAM FT_Vector* pt1, 831 CONST_PARAM FT_Vector* pt2, void* ctx) { 832 SkPath* path = (SkPath*)ctx; 833 path->cubicTo(ft2sk(pt0->x), -ft2sk(pt0->y), ft2sk(pt1->x), 834 -ft2sk(pt1->y), ft2sk(pt2->x), -ft2sk(pt2->y)); 835 return 0; 836 } 837 838 void SkScalerContext_FreeType::generatePath(const SkGlyph& glyph, 839 SkPath* path) { 840 SkAutoMutexAcquire ac(gFTMutex); 841 842 SkASSERT(&glyph && path); 843 844 if (this->setupSize()) { 845 path->reset(); 846 return; 847 } 848 849 uint32_t flags = fLoadGlyphFlags; 850 flags |= FT_LOAD_NO_BITMAP; // ignore embedded bitmaps so we're sure to get the outline 851 flags &= ~FT_LOAD_RENDER; // don't scan convert (we just want the outline) 852 853 FT_Error err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), flags); 854 855 if (err != 0) { 856 SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n", 857 glyph.getGlyphID(fBaseGlyphCount), flags, err)); 858 path->reset(); 859 return; 860 } 861 862 if (fRec.fFlags & kEmbolden_Flag) { 863 emboldenOutline(&fFace->glyph->outline); 864 } 865 866 FT_Outline_Funcs funcs; 867 868 funcs.move_to = move_proc; 869 funcs.line_to = line_proc; 870 funcs.conic_to = quad_proc; 871 funcs.cubic_to = cubic_proc; 872 funcs.shift = 0; 873 funcs.delta = 0; 874 875 err = FT_Outline_Decompose(&fFace->glyph->outline, &funcs, path); 876 877 if (err != 0) { 878 SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n", 879 glyph.getGlyphID(fBaseGlyphCount), flags, err)); 880 path->reset(); 881 return; 882 } 883 884 path->close(); 885 } 886 887 void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* mx, 888 SkPaint::FontMetrics* my) { 889 if (NULL == mx && NULL == my) { 890 return; 891 } 892 893 SkAutoMutexAcquire ac(gFTMutex); 894 895 if (this->setupSize()) { 896 ERROR: 897 if (mx) { 898 sk_bzero(mx, sizeof(SkPaint::FontMetrics)); 899 } 900 if (my) { 901 sk_bzero(my, sizeof(SkPaint::FontMetrics)); 902 } 903 return; 904 } 905 906 FT_Face face = fFace; 907 int upem = face->units_per_EM; 908 if (upem <= 0) { 909 goto ERROR; 910 } 911 912 SkPoint pts[6]; 913 SkFixed ys[6]; 914 SkFixed scaleY = fScaleY; 915 SkFixed mxy = fMatrix22.xy; 916 SkFixed myy = fMatrix22.yy; 917 SkScalar xmin = SkIntToScalar(face->bbox.xMin) / upem; 918 SkScalar xmax = SkIntToScalar(face->bbox.xMax) / upem; 919 920 int leading = face->height - (face->ascender + -face->descender); 921 if (leading < 0) { 922 leading = 0; 923 } 924 925 // Try to get the OS/2 table from the font. This contains the specific 926 // average font width metrics which Windows uses. 927 TT_OS2* os2 = (TT_OS2*) FT_Get_Sfnt_Table(face, ft_sfnt_os2); 928 929 ys[0] = -face->bbox.yMax; 930 ys[1] = -face->ascender; 931 ys[2] = -face->descender; 932 ys[3] = -face->bbox.yMin; 933 ys[4] = leading; 934 ys[5] = os2 ? os2->xAvgCharWidth : 0; 935 936 SkScalar x_height; 937 if (os2 && os2->sxHeight) { 938 x_height = SkFixedToScalar(SkMulDiv(fScaleX, os2->sxHeight, upem)); 939 } else { 940 const FT_UInt x_glyph = FT_Get_Char_Index(fFace, 'x'); 941 if (x_glyph) { 942 FT_BBox bbox; 943 FT_Load_Glyph(fFace, x_glyph, fLoadGlyphFlags); 944 if (fRec.fFlags & kEmbolden_Flag) { 945 emboldenOutline(&fFace->glyph->outline); 946 } 947 FT_Outline_Get_CBox(&fFace->glyph->outline, &bbox); 948 x_height = SkIntToScalar(bbox.yMax) / 64; 949 } else { 950 x_height = 0; 951 } 952 } 953 954 // convert upem-y values into scalar points 955 for (int i = 0; i < 6; i++) { 956 SkFixed y = SkMulDiv(scaleY, ys[i], upem); 957 SkFixed x = SkFixedMul(mxy, y); 958 y = SkFixedMul(myy, y); 959 pts[i].set(SkFixedToScalar(x), SkFixedToScalar(y)); 960 } 961 962 if (mx) { 963 mx->fTop = pts[0].fX; 964 mx->fAscent = pts[1].fX; 965 mx->fDescent = pts[2].fX; 966 mx->fBottom = pts[3].fX; 967 mx->fLeading = pts[4].fX; 968 mx->fAvgCharWidth = pts[5].fX; 969 mx->fXMin = xmin; 970 mx->fXMax = xmax; 971 mx->fXHeight = x_height; 972 } 973 if (my) { 974 my->fTop = pts[0].fY; 975 my->fAscent = pts[1].fY; 976 my->fDescent = pts[2].fY; 977 my->fBottom = pts[3].fY; 978 my->fLeading = pts[4].fY; 979 my->fAvgCharWidth = pts[5].fY; 980 my->fXMin = xmin; 981 my->fXMax = xmax; 982 my->fXHeight = x_height; 983 } 984 } 985 986 //////////////////////////////////////////////////////////////////////// 987 //////////////////////////////////////////////////////////////////////// 988 989 SkScalerContext* SkFontHost::CreateScalerContext(const SkDescriptor* desc) { 990 SkScalerContext_FreeType* c = SkNEW_ARGS(SkScalerContext_FreeType, (desc)); 991 if (!c->success()) { 992 SkDELETE(c); 993 c = NULL; 994 } 995 return c; 996 } 997 998 /////////////////////////////////////////////////////////////////////////////// 999 1000 /* Export this so that other parts of our FonttHost port can make use of our 1001 ability to extract the name+style from a stream, using FreeType's api. 1002 */ 1003 bool find_name_and_style(SkStream* stream, SkString* name, SkTypeface::Style* style) { 1004 FT_Library library; 1005 if (FT_Init_FreeType(&library)) { 1006 name->set(NULL); 1007 return false; 1008 } 1009 1010 FT_Open_Args args; 1011 memset(&args, 0, sizeof(args)); 1012 1013 const void* memoryBase = stream->getMemoryBase(); 1014 FT_StreamRec streamRec; 1015 1016 if (NULL != memoryBase) { 1017 args.flags = FT_OPEN_MEMORY; 1018 args.memory_base = (const FT_Byte*)memoryBase; 1019 args.memory_size = stream->getLength(); 1020 } else { 1021 memset(&streamRec, 0, sizeof(streamRec)); 1022 streamRec.size = stream->read(NULL, 0); 1023 streamRec.descriptor.pointer = stream; 1024 streamRec.read = sk_stream_read; 1025 streamRec.close = sk_stream_close; 1026 1027 args.flags = FT_OPEN_STREAM; 1028 args.stream = &streamRec; 1029 } 1030 1031 FT_Face face; 1032 if (FT_Open_Face(library, &args, 0, &face)) { 1033 FT_Done_FreeType(library); 1034 name->set(NULL); 1035 return false; 1036 } 1037 1038 name->set(face->family_name); 1039 int tempStyle = SkTypeface::kNormal; 1040 1041 if (face->style_flags & FT_STYLE_FLAG_BOLD) { 1042 tempStyle |= SkTypeface::kBold; 1043 } 1044 if (face->style_flags & FT_STYLE_FLAG_ITALIC) { 1045 tempStyle |= SkTypeface::kItalic; 1046 } 1047 1048 *style = (SkTypeface::Style)tempStyle; 1049 FT_Done_Face(face); 1050 FT_Done_FreeType(library); 1051 return true; 1052 } 1053
