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 "SkBitmap.h" 19 #include "SkCanvas.h" 20 #include "SkColorPriv.h" 21 #include "SkDescriptor.h" 22 #include "SkFDot6.h" 23 #include "SkFontHost.h" 24 #include "SkMask.h" 25 #include "SkAdvancedTypefaceMetrics.h" 26 #include "SkScalerContext.h" 27 #include "SkStream.h" 28 #include "SkString.h" 29 #include "SkTemplates.h" 30 #include "SkThread.h" 31 32 #include <ft2build.h> 33 #include FT_FREETYPE_H 34 #include FT_OUTLINE_H 35 #include FT_SIZES_H 36 #include FT_TRUETYPE_TABLES_H 37 #include FT_TYPE1_TABLES_H 38 #include FT_BITMAP_H 39 // In the past, FT_GlyphSlot_Own_Bitmap was defined in this header file. 40 #include FT_SYNTHESIS_H 41 #include FT_XFREE86_H 42 #include FT_LCD_FILTER_H 43 44 #ifdef FT_ADVANCES_H 45 #include FT_ADVANCES_H 46 #endif 47 48 #if 0 49 // Also include the files by name for build tools which require this. 50 #include <freetype/freetype.h> 51 #include <freetype/ftoutln.h> 52 #include <freetype/ftsizes.h> 53 #include <freetype/tttables.h> 54 #include <freetype/ftadvanc.h> 55 #include <freetype/ftlcdfil.h> 56 #include <freetype/ftbitmap.h> 57 #include <freetype/ftsynth.h> 58 #endif 59 60 //#define ENABLE_GLYPH_SPEW // for tracing calls 61 //#define DUMP_STRIKE_CREATION 62 63 #ifdef SK_DEBUG 64 #define SkASSERT_CONTINUE(pred) \ 65 do { \ 66 if (!(pred)) \ 67 SkDebugf("file %s:%d: assert failed '" #pred "'\n", __FILE__, __LINE__); \ 68 } while (false) 69 #else 70 #define SkASSERT_CONTINUE(pred) 71 #endif 72 73 using namespace skia_advanced_typeface_metrics_utils; 74 75 // SK_FREETYPE_LCD_LERP should be 0...256 76 // 0 means no color reduction (e.g. just as returned from FreeType) 77 // 256 means 100% color reduction (e.g. gray) 78 // 79 #ifndef SK_FREETYPE_LCD_LERP 80 #define SK_FREETYPE_LCD_LERP 96 81 #endif 82 83 ////////////////////////////////////////////////////////////////////////// 84 85 struct SkFaceRec; 86 87 static SkMutex gFTMutex; 88 static int gFTCount; 89 static FT_Library gFTLibrary; 90 static SkFaceRec* gFaceRecHead; 91 static bool gLCDSupportValid; // true iff |gLCDSupport| has been set. 92 static bool gLCDSupport; // true iff LCD is supported by the runtime. 93 94 ///////////////////////////////////////////////////////////////////////// 95 96 // See http://freetype.sourceforge.net/freetype2/docs/reference/ft2-bitmap_handling.html#FT_Bitmap_Embolden 97 // This value was chosen by eyeballing the result in Firefox and trying to match it. 98 static const FT_Pos kBitmapEmboldenStrength = 1 << 6; 99 100 static bool 101 InitFreetype() { 102 FT_Error err = FT_Init_FreeType(&gFTLibrary); 103 if (err) { 104 return false; 105 } 106 107 // Setup LCD filtering. This reduces colour fringes for LCD rendered 108 // glyphs. 109 err = FT_Library_SetLcdFilter(gFTLibrary, FT_LCD_FILTER_DEFAULT); 110 gLCDSupport = err == 0; 111 gLCDSupportValid = true; 112 113 return true; 114 } 115 116 class SkScalerContext_FreeType : public SkScalerContext { 117 public: 118 SkScalerContext_FreeType(const SkDescriptor* desc); 119 virtual ~SkScalerContext_FreeType(); 120 121 bool success() const { 122 return fFaceRec != NULL && 123 fFTSize != NULL && 124 fFace != NULL; 125 } 126 127 protected: 128 virtual unsigned generateGlyphCount(); 129 virtual uint16_t generateCharToGlyph(SkUnichar uni); 130 virtual void generateAdvance(SkGlyph* glyph); 131 virtual void generateMetrics(SkGlyph* glyph); 132 virtual void generateImage(const SkGlyph& glyph); 133 virtual void generatePath(const SkGlyph& glyph, SkPath* path); 134 virtual void generateFontMetrics(SkPaint::FontMetrics* mx, 135 SkPaint::FontMetrics* my); 136 virtual SkUnichar generateGlyphToChar(uint16_t glyph); 137 138 private: 139 SkFaceRec* fFaceRec; 140 FT_Face fFace; // reference to shared face in gFaceRecHead 141 FT_Size fFTSize; // our own copy 142 SkFixed fScaleX, fScaleY; 143 FT_Matrix fMatrix22; 144 uint32_t fLoadGlyphFlags; 145 146 FT_Error setupSize(); 147 void emboldenOutline(FT_Outline* outline); 148 }; 149 150 /////////////////////////////////////////////////////////////////////////// 151 /////////////////////////////////////////////////////////////////////////// 152 153 #include "SkStream.h" 154 155 struct SkFaceRec { 156 SkFaceRec* fNext; 157 FT_Face fFace; 158 FT_StreamRec fFTStream; 159 SkStream* fSkStream; 160 uint32_t fRefCnt; 161 uint32_t fFontID; 162 163 // assumes ownership of the stream, will call unref() when its done 164 SkFaceRec(SkStream* strm, uint32_t fontID); 165 ~SkFaceRec() { 166 fSkStream->unref(); 167 } 168 }; 169 170 extern "C" { 171 static unsigned long sk_stream_read(FT_Stream stream, 172 unsigned long offset, 173 unsigned char* buffer, 174 unsigned long count ) { 175 SkStream* str = (SkStream*)stream->descriptor.pointer; 176 177 if (count) { 178 if (!str->rewind()) { 179 return 0; 180 } else { 181 unsigned long ret; 182 if (offset) { 183 ret = str->read(NULL, offset); 184 if (ret != offset) { 185 return 0; 186 } 187 } 188 ret = str->read(buffer, count); 189 if (ret != count) { 190 return 0; 191 } 192 count = ret; 193 } 194 } 195 return count; 196 } 197 198 static void sk_stream_close( FT_Stream stream) {} 199 } 200 201 SkFaceRec::SkFaceRec(SkStream* strm, uint32_t fontID) 202 : fSkStream(strm), fFontID(fontID) { 203 // SkDEBUGF(("SkFaceRec: opening %s (%p)\n", key.c_str(), strm)); 204 205 sk_bzero(&fFTStream, sizeof(fFTStream)); 206 fFTStream.size = fSkStream->getLength(); 207 fFTStream.descriptor.pointer = fSkStream; 208 fFTStream.read = sk_stream_read; 209 fFTStream.close = sk_stream_close; 210 } 211 212 // Will return 0 on failure 213 static SkFaceRec* ref_ft_face(uint32_t fontID) { 214 SkFaceRec* rec = gFaceRecHead; 215 while (rec) { 216 if (rec->fFontID == fontID) { 217 SkASSERT(rec->fFace); 218 rec->fRefCnt += 1; 219 return rec; 220 } 221 rec = rec->fNext; 222 } 223 224 SkStream* strm = SkFontHost::OpenStream(fontID); 225 if (NULL == strm) { 226 SkDEBUGF(("SkFontHost::OpenStream failed opening %x\n", fontID)); 227 return 0; 228 } 229 230 // this passes ownership of strm to the rec 231 rec = SkNEW_ARGS(SkFaceRec, (strm, fontID)); 232 233 FT_Open_Args args; 234 memset(&args, 0, sizeof(args)); 235 const void* memoryBase = strm->getMemoryBase(); 236 237 if (NULL != memoryBase) { 238 //printf("mmap(%s)\n", keyString.c_str()); 239 args.flags = FT_OPEN_MEMORY; 240 args.memory_base = (const FT_Byte*)memoryBase; 241 args.memory_size = strm->getLength(); 242 } else { 243 //printf("fopen(%s)\n", keyString.c_str()); 244 args.flags = FT_OPEN_STREAM; 245 args.stream = &rec->fFTStream; 246 } 247 248 int face_index; 249 int length = SkFontHost::GetFileName(fontID, NULL, 0, &face_index); 250 FT_Error err = FT_Open_Face(gFTLibrary, &args, length ? face_index : 0, 251 &rec->fFace); 252 253 if (err) { // bad filename, try the default font 254 fprintf(stderr, "ERROR: unable to open font '%x'\n", fontID); 255 SkDELETE(rec); 256 return 0; 257 } else { 258 SkASSERT(rec->fFace); 259 //fprintf(stderr, "Opened font '%s'\n", filename.c_str()); 260 rec->fNext = gFaceRecHead; 261 gFaceRecHead = rec; 262 rec->fRefCnt = 1; 263 return rec; 264 } 265 } 266 267 static void unref_ft_face(FT_Face face) { 268 SkFaceRec* rec = gFaceRecHead; 269 SkFaceRec* prev = NULL; 270 while (rec) { 271 SkFaceRec* next = rec->fNext; 272 if (rec->fFace == face) { 273 if (--rec->fRefCnt == 0) { 274 if (prev) { 275 prev->fNext = next; 276 } else { 277 gFaceRecHead = next; 278 } 279 FT_Done_Face(face); 280 SkDELETE(rec); 281 } 282 return; 283 } 284 prev = rec; 285 rec = next; 286 } 287 SkASSERT("shouldn't get here, face not in list"); 288 } 289 290 /////////////////////////////////////////////////////////////////////////// 291 292 // Work around for old versions of freetype. 293 static FT_Error getAdvances(FT_Face face, FT_UInt start, FT_UInt count, 294 FT_Int32 loadFlags, FT_Fixed* advances) { 295 #ifdef FT_ADVANCES_H 296 return FT_Get_Advances(face, start, count, loadFlags, advances); 297 #else 298 if (!face || start >= face->num_glyphs || 299 start + count > face->num_glyphs || loadFlags != FT_LOAD_NO_SCALE) { 300 return 6; // "Invalid argument." 301 } 302 if (count == 0) 303 return 0; 304 305 for (int i = 0; i < count; i++) { 306 FT_Error err = FT_Load_Glyph(face, start + i, FT_LOAD_NO_SCALE); 307 if (err) 308 return err; 309 advances[i] = face->glyph->advance.x; 310 } 311 312 return 0; 313 #endif 314 } 315 316 static bool canEmbed(FT_Face face) { 317 #ifdef FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING 318 FT_UShort fsType = FT_Get_FSType_Flags(face); 319 return (fsType & (FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING | 320 FT_FSTYPE_BITMAP_EMBEDDING_ONLY)) == 0; 321 #else 322 // No embedding is 0x2 and bitmap embedding only is 0x200. 323 TT_OS2* os2_table; 324 if ((os2_table = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != NULL) { 325 return (os2_table->fsType & 0x202) == 0; 326 } 327 return false; // We tried, fail safe. 328 #endif 329 } 330 331 static bool GetLetterCBox(FT_Face face, char letter, FT_BBox* bbox) { 332 const FT_UInt glyph_id = FT_Get_Char_Index(face, letter); 333 if (!glyph_id) 334 return false; 335 FT_Load_Glyph(face, glyph_id, FT_LOAD_NO_SCALE); 336 FT_Outline_Get_CBox(&face->glyph->outline, bbox); 337 return true; 338 } 339 340 static bool getWidthAdvance(FT_Face face, int gId, int16_t* data) { 341 FT_Fixed advance = 0; 342 if (getAdvances(face, gId, 1, FT_LOAD_NO_SCALE, &advance)) { 343 return false; 344 } 345 SkASSERT(data); 346 *data = advance; 347 return true; 348 } 349 350 static void populate_glyph_to_unicode(FT_Face& face, 351 SkTDArray<SkUnichar>* glyphToUnicode) { 352 // Check and see if we have Unicode cmaps. 353 for (int i = 0; i < face->num_charmaps; ++i) { 354 // CMaps known to support Unicode: 355 // Platform ID Encoding ID Name 356 // ----------- ----------- ----------------------------------- 357 // 0 0,1 Apple Unicode 358 // 0 3 Apple Unicode 2.0 (preferred) 359 // 3 1 Microsoft Unicode UCS-2 360 // 3 10 Microsoft Unicode UCS-4 (preferred) 361 // 362 // See Apple TrueType Reference Manual 363 // http://developer.apple.com/fonts/TTRefMan/RM06/Chap6cmap.html 364 // http://developer.apple.com/fonts/TTRefMan/RM06/Chap6name.html#ID 365 // Microsoft OpenType Specification 366 // http://www.microsoft.com/typography/otspec/cmap.htm 367 368 FT_UShort platformId = face->charmaps[i]->platform_id; 369 FT_UShort encodingId = face->charmaps[i]->encoding_id; 370 371 if (platformId != 0 && platformId != 3) { 372 continue; 373 } 374 if (platformId == 3 && encodingId != 1 && encodingId != 10) { 375 continue; 376 } 377 bool preferredMap = ((platformId == 3 && encodingId == 10) || 378 (platformId == 0 && encodingId == 3)); 379 380 FT_Set_Charmap(face, face->charmaps[i]); 381 if (glyphToUnicode->isEmpty()) { 382 glyphToUnicode->setCount(face->num_glyphs); 383 memset(glyphToUnicode->begin(), 0, 384 sizeof(SkUnichar) * face->num_glyphs); 385 } 386 387 // Iterate through each cmap entry. 388 FT_UInt glyphIndex; 389 for (SkUnichar charCode = FT_Get_First_Char(face, &glyphIndex); 390 glyphIndex != 0; 391 charCode = FT_Get_Next_Char(face, charCode, &glyphIndex)) { 392 if (charCode && 393 ((*glyphToUnicode)[glyphIndex] == 0 || preferredMap)) { 394 (*glyphToUnicode)[glyphIndex] = charCode; 395 } 396 } 397 } 398 } 399 400 // static 401 SkAdvancedTypefaceMetrics* SkFontHost::GetAdvancedTypefaceMetrics( 402 uint32_t fontID, 403 SkAdvancedTypefaceMetrics::PerGlyphInfo perGlyphInfo) { 404 #if defined(SK_BUILD_FOR_MAC) || defined(ANDROID) 405 return NULL; 406 #else 407 SkAutoMutexAcquire ac(gFTMutex); 408 FT_Library libInit = NULL; 409 if (gFTCount == 0) { 410 if (!InitFreetype()) 411 sk_throw(); 412 libInit = gFTLibrary; 413 } 414 SkAutoTCallIProc<struct FT_LibraryRec_, FT_Done_FreeType> ftLib(libInit); 415 SkFaceRec* rec = ref_ft_face(fontID); 416 if (NULL == rec) 417 return NULL; 418 FT_Face face = rec->fFace; 419 420 SkAdvancedTypefaceMetrics* info = new SkAdvancedTypefaceMetrics; 421 info->fFontName.set(FT_Get_Postscript_Name(face)); 422 info->fMultiMaster = FT_HAS_MULTIPLE_MASTERS(face); 423 info->fLastGlyphID = face->num_glyphs - 1; 424 info->fEmSize = 1000; 425 426 bool cid = false; 427 const char* fontType = FT_Get_X11_Font_Format(face); 428 if (strcmp(fontType, "Type 1") == 0) { 429 info->fType = SkAdvancedTypefaceMetrics::kType1_Font; 430 } else if (strcmp(fontType, "CID Type 1") == 0) { 431 info->fType = SkAdvancedTypefaceMetrics::kType1CID_Font; 432 cid = true; 433 } else if (strcmp(fontType, "CFF") == 0) { 434 info->fType = SkAdvancedTypefaceMetrics::kCFF_Font; 435 } else if (strcmp(fontType, "TrueType") == 0) { 436 info->fType = SkAdvancedTypefaceMetrics::kTrueType_Font; 437 cid = true; 438 TT_Header* ttHeader; 439 if ((ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face, 440 ft_sfnt_head)) != NULL) { 441 info->fEmSize = ttHeader->Units_Per_EM; 442 } 443 } 444 445 info->fStyle = 0; 446 if (FT_IS_FIXED_WIDTH(face)) 447 info->fStyle |= SkAdvancedTypefaceMetrics::kFixedPitch_Style; 448 if (face->style_flags & FT_STYLE_FLAG_ITALIC) 449 info->fStyle |= SkAdvancedTypefaceMetrics::kItalic_Style; 450 // We should set either Symbolic or Nonsymbolic; Nonsymbolic if the font's 451 // character set is a subset of 'Adobe standard Latin.' 452 info->fStyle |= SkAdvancedTypefaceMetrics::kSymbolic_Style; 453 454 PS_FontInfoRec ps_info; 455 TT_Postscript* tt_info; 456 if (FT_Get_PS_Font_Info(face, &ps_info) == 0) { 457 info->fItalicAngle = ps_info.italic_angle; 458 } else if ((tt_info = 459 (TT_Postscript*)FT_Get_Sfnt_Table(face, 460 ft_sfnt_post)) != NULL) { 461 info->fItalicAngle = SkFixedToScalar(tt_info->italicAngle); 462 } else { 463 info->fItalicAngle = 0; 464 } 465 466 info->fAscent = face->ascender; 467 info->fDescent = face->descender; 468 469 // Figure out a good guess for StemV - Min width of i, I, !, 1. 470 // This probably isn't very good with an italic font. 471 int16_t min_width = SHRT_MAX; 472 info->fStemV = 0; 473 char stem_chars[] = {'i', 'I', '!', '1'}; 474 for (size_t i = 0; i < SK_ARRAY_COUNT(stem_chars); i++) { 475 FT_BBox bbox; 476 if (GetLetterCBox(face, stem_chars[i], &bbox)) { 477 int16_t width = bbox.xMax - bbox.xMin; 478 if (width > 0 && width < min_width) { 479 min_width = width; 480 info->fStemV = min_width; 481 } 482 } 483 } 484 485 TT_PCLT* pclt_info; 486 TT_OS2* os2_table; 487 if ((pclt_info = (TT_PCLT*)FT_Get_Sfnt_Table(face, ft_sfnt_pclt)) != NULL) { 488 info->fCapHeight = pclt_info->CapHeight; 489 uint8_t serif_style = pclt_info->SerifStyle & 0x3F; 490 if (serif_style >= 2 && serif_style <= 6) 491 info->fStyle |= SkAdvancedTypefaceMetrics::kSerif_Style; 492 else if (serif_style >= 9 && serif_style <= 12) 493 info->fStyle |= SkAdvancedTypefaceMetrics::kScript_Style; 494 } else if ((os2_table = 495 (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != NULL) { 496 info->fCapHeight = os2_table->sCapHeight; 497 } else { 498 // Figure out a good guess for CapHeight: average the height of M and X. 499 FT_BBox m_bbox, x_bbox; 500 bool got_m, got_x; 501 got_m = GetLetterCBox(face, 'M', &m_bbox); 502 got_x = GetLetterCBox(face, 'X', &x_bbox); 503 if (got_m && got_x) { 504 info->fCapHeight = (m_bbox.yMax - m_bbox.yMin + x_bbox.yMax - 505 x_bbox.yMin) / 2; 506 } else if (got_m && !got_x) { 507 info->fCapHeight = m_bbox.yMax - m_bbox.yMin; 508 } else if (!got_m && got_x) { 509 info->fCapHeight = x_bbox.yMax - x_bbox.yMin; 510 } 511 } 512 513 info->fBBox = SkIRect::MakeLTRB(face->bbox.xMin, face->bbox.yMax, 514 face->bbox.xMax, face->bbox.yMin); 515 516 if (!canEmbed(face) || !FT_IS_SCALABLE(face) || 517 info->fType == SkAdvancedTypefaceMetrics::kOther_Font) { 518 perGlyphInfo = SkAdvancedTypefaceMetrics::kNo_PerGlyphInfo; 519 } 520 521 if (perGlyphInfo & SkAdvancedTypefaceMetrics::kHAdvance_PerGlyphInfo) { 522 if (FT_IS_FIXED_WIDTH(face)) { 523 appendRange(&info->fGlyphWidths, 0); 524 int16_t advance = face->max_advance_width; 525 info->fGlyphWidths->fAdvance.append(1, &advance); 526 finishRange(info->fGlyphWidths.get(), 0, 527 SkAdvancedTypefaceMetrics::WidthRange::kDefault); 528 } else if (!cid) { 529 appendRange(&info->fGlyphWidths, 0); 530 // So as to not blow out the stack, get advances in batches. 531 for (int gID = 0; gID < face->num_glyphs; gID += 128) { 532 FT_Fixed advances[128]; 533 int advanceCount = 128; 534 if (gID + advanceCount > face->num_glyphs) 535 advanceCount = face->num_glyphs - gID + 1; 536 getAdvances(face, gID, advanceCount, FT_LOAD_NO_SCALE, 537 advances); 538 for (int i = 0; i < advanceCount; i++) { 539 int16_t advance = advances[gID + i]; 540 info->fGlyphWidths->fAdvance.append(1, &advance); 541 } 542 } 543 finishRange(info->fGlyphWidths.get(), face->num_glyphs - 1, 544 SkAdvancedTypefaceMetrics::WidthRange::kRange); 545 } else { 546 info->fGlyphWidths.reset( 547 getAdvanceData(face, face->num_glyphs, &getWidthAdvance)); 548 } 549 } 550 551 if (perGlyphInfo & SkAdvancedTypefaceMetrics::kVAdvance_PerGlyphInfo && 552 FT_HAS_VERTICAL(face)) { 553 SkASSERT(false); // Not implemented yet. 554 } 555 556 if (perGlyphInfo & SkAdvancedTypefaceMetrics::kGlyphNames_PerGlyphInfo && 557 info->fType == SkAdvancedTypefaceMetrics::kType1_Font) { 558 // Postscript fonts may contain more than 255 glyphs, so we end up 559 // using multiple font descriptions with a glyph ordering. Record 560 // the name of each glyph. 561 info->fGlyphNames.reset( 562 new SkAutoTArray<SkString>(face->num_glyphs)); 563 for (int gID = 0; gID < face->num_glyphs; gID++) { 564 char glyphName[128]; // PS limit for names is 127 bytes. 565 FT_Get_Glyph_Name(face, gID, glyphName, 128); 566 info->fGlyphNames->get()[gID].set(glyphName); 567 } 568 } 569 570 if (perGlyphInfo & SkAdvancedTypefaceMetrics::kToUnicode_PerGlyphInfo && 571 info->fType != SkAdvancedTypefaceMetrics::kType1_Font && 572 face->num_charmaps) { 573 populate_glyph_to_unicode(face, &(info->fGlyphToUnicode)); 574 } 575 576 if (!canEmbed(face)) 577 info->fType = SkAdvancedTypefaceMetrics::kNotEmbeddable_Font; 578 579 unref_ft_face(face); 580 return info; 581 #endif 582 } 583 /////////////////////////////////////////////////////////////////////////// 584 585 void SkFontHost::FilterRec(SkScalerContext::Rec* rec) { 586 if (!gLCDSupportValid) { 587 InitFreetype(); 588 FT_Done_FreeType(gFTLibrary); 589 } 590 591 if (!gLCDSupport && (rec->isLCD() || SkMask::kLCD16_Format == rec->fMaskFormat)) { 592 // If the runtime Freetype library doesn't support LCD mode, we disable 593 // it here. 594 rec->fMaskFormat = SkMask::kA8_Format; 595 } 596 597 SkPaint::Hinting h = rec->getHinting(); 598 if (SkPaint::kFull_Hinting == h && !rec->isLCD()) { 599 // collapse full->normal hinting if we're not doing LCD 600 h = SkPaint::kNormal_Hinting; 601 } else if ((rec->fFlags & SkScalerContext::kSubpixelPositioning_Flag) && 602 SkPaint::kNo_Hinting != h) { 603 // to do subpixel, we must have at most slight hinting 604 h = SkPaint::kSlight_Hinting; 605 } 606 rec->setHinting(h); 607 } 608 609 #ifdef ANDROID 610 uint32_t SkFontHost::GetUnitsPerEm(SkFontID fontID) { 611 SkAutoMutexAcquire ac(gFTMutex); 612 SkFaceRec *rec = ref_ft_face(fontID); 613 uint16_t unitsPerEm = 0; 614 615 if (rec != NULL && rec->fFace != NULL) { 616 unitsPerEm = rec->fFace->units_per_EM; 617 unref_ft_face(rec->fFace); 618 } 619 620 return (uint32_t)unitsPerEm; 621 } 622 #endif 623 624 SkScalerContext_FreeType::SkScalerContext_FreeType(const SkDescriptor* desc) 625 : SkScalerContext(desc) { 626 SkAutoMutexAcquire ac(gFTMutex); 627 628 if (gFTCount == 0) { 629 if (!InitFreetype()) { 630 sk_throw(); 631 } 632 } 633 ++gFTCount; 634 635 // load the font file 636 fFTSize = NULL; 637 fFace = NULL; 638 fFaceRec = ref_ft_face(fRec.fFontID); 639 if (NULL == fFaceRec) { 640 return; 641 } 642 fFace = fFaceRec->fFace; 643 644 // compute our factors from the record 645 646 SkMatrix m; 647 648 fRec.getSingleMatrix(&m); 649 650 #ifdef DUMP_STRIKE_CREATION 651 SkString keyString; 652 SkFontHost::GetDescriptorKeyString(desc, &keyString); 653 printf("========== strike [%g %g %g] [%g %g %g %g] hints %d format %d %s\n", SkScalarToFloat(fRec.fTextSize), 654 SkScalarToFloat(fRec.fPreScaleX), SkScalarToFloat(fRec.fPreSkewX), 655 SkScalarToFloat(fRec.fPost2x2[0][0]), SkScalarToFloat(fRec.fPost2x2[0][1]), 656 SkScalarToFloat(fRec.fPost2x2[1][0]), SkScalarToFloat(fRec.fPost2x2[1][1]), 657 fRec.getHinting(), fRec.fMaskFormat, keyString.c_str()); 658 #endif 659 660 // now compute our scale factors 661 SkScalar sx = m.getScaleX(); 662 SkScalar sy = m.getScaleY(); 663 664 if (m.getSkewX() || m.getSkewY() || sx < 0 || sy < 0) { 665 // sort of give up on hinting 666 sx = SkMaxScalar(SkScalarAbs(sx), SkScalarAbs(m.getSkewX())); 667 sy = SkMaxScalar(SkScalarAbs(m.getSkewY()), SkScalarAbs(sy)); 668 sx = sy = SkScalarAve(sx, sy); 669 670 SkScalar inv = SkScalarInvert(sx); 671 672 // flip the skew elements to go from our Y-down system to FreeType's 673 fMatrix22.xx = SkScalarToFixed(SkScalarMul(m.getScaleX(), inv)); 674 fMatrix22.xy = -SkScalarToFixed(SkScalarMul(m.getSkewX(), inv)); 675 fMatrix22.yx = -SkScalarToFixed(SkScalarMul(m.getSkewY(), inv)); 676 fMatrix22.yy = SkScalarToFixed(SkScalarMul(m.getScaleY(), inv)); 677 } else { 678 fMatrix22.xx = fMatrix22.yy = SK_Fixed1; 679 fMatrix22.xy = fMatrix22.yx = 0; 680 } 681 682 fScaleX = SkScalarToFixed(sx); 683 fScaleY = SkScalarToFixed(sy); 684 685 // compute the flags we send to Load_Glyph 686 { 687 FT_Int32 loadFlags = FT_LOAD_DEFAULT; 688 689 if (SkMask::kBW_Format == fRec.fMaskFormat) { 690 // See http://code.google.com/p/chromium/issues/detail?id=43252#c24 691 loadFlags = FT_LOAD_TARGET_MONO; 692 if (fRec.getHinting() == SkPaint::kNo_Hinting) 693 loadFlags = FT_LOAD_NO_HINTING; 694 } else { 695 switch (fRec.getHinting()) { 696 case SkPaint::kNo_Hinting: 697 loadFlags = FT_LOAD_NO_HINTING; 698 break; 699 case SkPaint::kSlight_Hinting: 700 loadFlags = FT_LOAD_TARGET_LIGHT; // This implies FORCE_AUTOHINT 701 break; 702 case SkPaint::kNormal_Hinting: 703 if (fRec.fFlags & SkScalerContext::kAutohinting_Flag) 704 loadFlags = FT_LOAD_FORCE_AUTOHINT; 705 else 706 loadFlags = FT_LOAD_NO_AUTOHINT; 707 break; 708 case SkPaint::kFull_Hinting: 709 if (fRec.fFlags & SkScalerContext::kAutohinting_Flag) { 710 loadFlags = FT_LOAD_FORCE_AUTOHINT; 711 break; 712 } 713 loadFlags = FT_LOAD_TARGET_NORMAL; 714 if (SkMask::kHorizontalLCD_Format == fRec.fMaskFormat || 715 SkMask::kLCD16_Format == fRec.fMaskFormat) { 716 loadFlags = FT_LOAD_TARGET_LCD; 717 } else if (SkMask::kVerticalLCD_Format == fRec.fMaskFormat) { 718 loadFlags = FT_LOAD_TARGET_LCD_V; 719 } 720 break; 721 default: 722 SkDebugf("---------- UNKNOWN hinting %d\n", fRec.getHinting()); 723 break; 724 } 725 } 726 727 if ((fRec.fFlags & SkScalerContext::kEmbeddedBitmapText_Flag) == 0) 728 loadFlags |= FT_LOAD_NO_BITMAP; 729 730 // Always using FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH to get correct 731 // advances, as fontconfig and cairo do. 732 // See http://code.google.com/p/skia/issues/detail?id=222. 733 loadFlags |= FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH; 734 735 fLoadGlyphFlags = loadFlags; 736 } 737 738 // now create the FT_Size 739 740 { 741 FT_Error err; 742 743 err = FT_New_Size(fFace, &fFTSize); 744 if (err != 0) { 745 SkDEBUGF(("SkScalerContext_FreeType::FT_New_Size(%x): FT_Set_Char_Size(0x%x, 0x%x) returned 0x%x\n", 746 fFaceRec->fFontID, fScaleX, fScaleY, err)); 747 fFace = NULL; 748 return; 749 } 750 751 err = FT_Activate_Size(fFTSize); 752 if (err != 0) { 753 SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%x, 0x%x, 0x%x) returned 0x%x\n", 754 fFaceRec->fFontID, fScaleX, fScaleY, err)); 755 fFTSize = NULL; 756 } 757 758 err = FT_Set_Char_Size( fFace, 759 SkFixedToFDot6(fScaleX), SkFixedToFDot6(fScaleY), 760 72, 72); 761 if (err != 0) { 762 SkDEBUGF(("SkScalerContext_FreeType::FT_Set_Char_Size(%x, 0x%x, 0x%x) returned 0x%x\n", 763 fFaceRec->fFontID, fScaleX, fScaleY, err)); 764 fFace = NULL; 765 return; 766 } 767 768 FT_Set_Transform( fFace, &fMatrix22, NULL); 769 } 770 } 771 772 SkScalerContext_FreeType::~SkScalerContext_FreeType() { 773 if (fFTSize != NULL) { 774 FT_Done_Size(fFTSize); 775 } 776 777 SkAutoMutexAcquire ac(gFTMutex); 778 779 if (fFace != NULL) { 780 unref_ft_face(fFace); 781 } 782 if (--gFTCount == 0) { 783 // SkDEBUGF(("FT_Done_FreeType\n")); 784 FT_Done_FreeType(gFTLibrary); 785 SkDEBUGCODE(gFTLibrary = NULL;) 786 } 787 } 788 789 /* We call this before each use of the fFace, since we may be sharing 790 this face with other context (at different sizes). 791 */ 792 FT_Error SkScalerContext_FreeType::setupSize() { 793 /* In the off-chance that a font has been removed, we want to error out 794 right away, so call resolve just to be sure. 795 796 TODO: perhaps we can skip this, by walking the global font cache and 797 killing all of the contexts when we know that a given fontID is going 798 away... 799 */ 800 if (!SkFontHost::ValidFontID(fRec.fFontID)) { 801 return (FT_Error)-1; 802 } 803 804 FT_Error err = FT_Activate_Size(fFTSize); 805 806 if (err != 0) { 807 SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%x, 0x%x, 0x%x) returned 0x%x\n", 808 fFaceRec->fFontID, fScaleX, fScaleY, err)); 809 fFTSize = NULL; 810 } else { 811 // seems we need to reset this every time (not sure why, but without it 812 // I get random italics from some other fFTSize) 813 FT_Set_Transform( fFace, &fMatrix22, NULL); 814 } 815 return err; 816 } 817 818 void SkScalerContext_FreeType::emboldenOutline(FT_Outline* outline) { 819 FT_Pos strength; 820 strength = FT_MulFix(fFace->units_per_EM, fFace->size->metrics.y_scale) 821 / 24; 822 FT_Outline_Embolden(outline, strength); 823 } 824 825 unsigned SkScalerContext_FreeType::generateGlyphCount() { 826 return fFace->num_glyphs; 827 } 828 829 uint16_t SkScalerContext_FreeType::generateCharToGlyph(SkUnichar uni) { 830 return SkToU16(FT_Get_Char_Index( fFace, uni )); 831 } 832 833 SkUnichar SkScalerContext_FreeType::generateGlyphToChar(uint16_t glyph) { 834 // iterate through each cmap entry, looking for matching glyph indices 835 FT_UInt glyphIndex; 836 SkUnichar charCode = FT_Get_First_Char( fFace, &glyphIndex ); 837 838 while (glyphIndex != 0) { 839 if (glyphIndex == glyph) { 840 return charCode; 841 } 842 charCode = FT_Get_Next_Char( fFace, charCode, &glyphIndex ); 843 } 844 845 return 0; 846 } 847 848 static FT_Pixel_Mode compute_pixel_mode(SkMask::Format format) { 849 switch (format) { 850 case SkMask::kHorizontalLCD_Format: 851 case SkMask::kVerticalLCD_Format: 852 SkASSERT(!"An LCD format should never be passed here"); 853 return FT_PIXEL_MODE_GRAY; 854 case SkMask::kBW_Format: 855 return FT_PIXEL_MODE_MONO; 856 case SkMask::kA8_Format: 857 default: 858 return FT_PIXEL_MODE_GRAY; 859 } 860 } 861 862 void SkScalerContext_FreeType::generateAdvance(SkGlyph* glyph) { 863 #ifdef FT_ADVANCES_H 864 /* unhinted and light hinted text have linearly scaled advances 865 * which are very cheap to compute with some font formats... 866 */ 867 { 868 SkAutoMutexAcquire ac(gFTMutex); 869 870 if (this->setupSize()) { 871 glyph->zeroMetrics(); 872 return; 873 } 874 875 FT_Error error; 876 FT_Fixed advance; 877 878 error = FT_Get_Advance( fFace, glyph->getGlyphID(fBaseGlyphCount), 879 fLoadGlyphFlags | FT_ADVANCE_FLAG_FAST_ONLY, 880 &advance ); 881 if (0 == error) { 882 glyph->fRsbDelta = 0; 883 glyph->fLsbDelta = 0; 884 glyph->fAdvanceX = advance; // advance *2/3; //DEBUG 885 glyph->fAdvanceY = 0; 886 return; 887 } 888 } 889 #endif /* FT_ADVANCES_H */ 890 /* otherwise, we need to load/hint the glyph, which is slower */ 891 this->generateMetrics(glyph); 892 return; 893 } 894 895 void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) { 896 SkAutoMutexAcquire ac(gFTMutex); 897 898 glyph->fRsbDelta = 0; 899 glyph->fLsbDelta = 0; 900 901 FT_Error err; 902 903 if (this->setupSize()) { 904 goto ERROR; 905 } 906 907 err = FT_Load_Glyph( fFace, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags ); 908 if (err != 0) { 909 SkDEBUGF(("SkScalerContext_FreeType::generateMetrics(%x): FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n", 910 fFaceRec->fFontID, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, err)); 911 ERROR: 912 glyph->zeroMetrics(); 913 return; 914 } 915 916 switch ( fFace->glyph->format ) { 917 case FT_GLYPH_FORMAT_OUTLINE: { 918 FT_BBox bbox; 919 920 if (fRec.fFlags & kEmbolden_Flag) { 921 emboldenOutline(&fFace->glyph->outline); 922 } 923 FT_Outline_Get_CBox(&fFace->glyph->outline, &bbox); 924 925 if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) { 926 int dx = glyph->getSubXFixed() >> 10; 927 int dy = glyph->getSubYFixed() >> 10; 928 // negate dy since freetype-y-goes-up and skia-y-goes-down 929 bbox.xMin += dx; 930 bbox.yMin -= dy; 931 bbox.xMax += dx; 932 bbox.yMax -= dy; 933 } 934 935 bbox.xMin &= ~63; 936 bbox.yMin &= ~63; 937 bbox.xMax = (bbox.xMax + 63) & ~63; 938 bbox.yMax = (bbox.yMax + 63) & ~63; 939 940 glyph->fWidth = SkToU16((bbox.xMax - bbox.xMin) >> 6); 941 glyph->fHeight = SkToU16((bbox.yMax - bbox.yMin) >> 6); 942 glyph->fTop = -SkToS16(bbox.yMax >> 6); 943 glyph->fLeft = SkToS16(bbox.xMin >> 6); 944 break; 945 } 946 947 case FT_GLYPH_FORMAT_BITMAP: 948 if (fRec.fFlags & kEmbolden_Flag) { 949 FT_GlyphSlot_Own_Bitmap(fFace->glyph); 950 FT_Bitmap_Embolden(gFTLibrary, &fFace->glyph->bitmap, kBitmapEmboldenStrength, 0); 951 } 952 glyph->fWidth = SkToU16(fFace->glyph->bitmap.width); 953 glyph->fHeight = SkToU16(fFace->glyph->bitmap.rows); 954 glyph->fTop = -SkToS16(fFace->glyph->bitmap_top); 955 glyph->fLeft = SkToS16(fFace->glyph->bitmap_left); 956 break; 957 958 default: 959 SkASSERT(!"unknown glyph format"); 960 goto ERROR; 961 } 962 963 if ((fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) == 0) { 964 glyph->fAdvanceX = SkFDot6ToFixed(fFace->glyph->advance.x); 965 glyph->fAdvanceY = -SkFDot6ToFixed(fFace->glyph->advance.y); 966 if (fRec.fFlags & kDevKernText_Flag) { 967 glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta); 968 glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta); 969 } 970 } else { 971 glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance); 972 glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance); 973 } 974 975 #ifdef ENABLE_GLYPH_SPEW 976 SkDEBUGF(("FT_Set_Char_Size(this:%p sx:%x sy:%x ", this, fScaleX, fScaleY)); 977 SkDEBUGF(("Metrics(glyph:%d flags:0x%x) w:%d\n", glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, glyph->fWidth)); 978 #endif 979 } 980 981 #if defined(SK_SUPPORT_LCDTEXT) 982 namespace skia_freetype_support { 983 // extern functions from SkFontHost_FreeType_Subpixel 984 extern void CopyFreetypeBitmapToLCDMask(const SkGlyph& dest, const FT_Bitmap& source); 985 extern void CopyFreetypeBitmapToVerticalLCDMask(const SkGlyph& dest, const FT_Bitmap& source); 986 } 987 988 using namespace skia_freetype_support; 989 #endif 990 991 static int lerp(int start, int end) { 992 SkASSERT((unsigned)SK_FREETYPE_LCD_LERP <= 256); 993 return start + ((end - start) * (SK_FREETYPE_LCD_LERP) >> 8); 994 } 995 996 static uint16_t packTriple(unsigned r, unsigned g, unsigned b) { 997 if (SK_FREETYPE_LCD_LERP) { 998 // want (a+b+c)/3, but we approx to avoid the divide 999 unsigned ave = (5 * (r + g + b) + b) >> 4; 1000 r = lerp(r, ave); 1001 g = lerp(g, ave); 1002 b = lerp(b, ave); 1003 } 1004 return SkPackRGB16(r >> 3, g >> 2, b >> 3); 1005 } 1006 1007 static void copyFT2LCD16(const SkGlyph& glyph, const FT_Bitmap& bitmap) { 1008 SkASSERT(glyph.fWidth * 3 == bitmap.width - 6); 1009 SkASSERT(glyph.fHeight == bitmap.rows); 1010 1011 const uint8_t* src = bitmap.buffer + 3; 1012 uint16_t* dst = reinterpret_cast<uint16_t*>(glyph.fImage); 1013 size_t dstRB = glyph.rowBytes(); 1014 int width = glyph.fWidth; 1015 1016 for (int y = 0; y < glyph.fHeight; y++) { 1017 const uint8_t* triple = src; 1018 for (int x = 0; x < width; x++) { 1019 dst[x] = packTriple(triple[0], triple[1], triple[2]); 1020 triple += 3; 1021 } 1022 src += bitmap.pitch; 1023 dst = (uint16_t*)((char*)dst + dstRB); 1024 } 1025 } 1026 1027 void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { 1028 SkAutoMutexAcquire ac(gFTMutex); 1029 1030 FT_Error err; 1031 1032 if (this->setupSize()) { 1033 goto ERROR; 1034 } 1035 1036 err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), fLoadGlyphFlags); 1037 if (err != 0) { 1038 SkDEBUGF(("SkScalerContext_FreeType::generateImage: FT_Load_Glyph(glyph:%d width:%d height:%d rb:%d flags:%d) returned 0x%x\n", 1039 glyph.getGlyphID(fBaseGlyphCount), glyph.fWidth, glyph.fHeight, glyph.rowBytes(), fLoadGlyphFlags, err)); 1040 ERROR: 1041 memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight); 1042 return; 1043 } 1044 1045 const bool lcdRenderMode = fRec.fMaskFormat == SkMask::kHorizontalLCD_Format || 1046 fRec.fMaskFormat == SkMask::kVerticalLCD_Format; 1047 1048 switch ( fFace->glyph->format ) { 1049 case FT_GLYPH_FORMAT_OUTLINE: { 1050 FT_Outline* outline = &fFace->glyph->outline; 1051 FT_BBox bbox; 1052 FT_Bitmap target; 1053 1054 if (fRec.fFlags & kEmbolden_Flag) { 1055 emboldenOutline(outline); 1056 } 1057 1058 int dx = 0, dy = 0; 1059 if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) { 1060 dx = glyph.getSubXFixed() >> 10; 1061 dy = glyph.getSubYFixed() >> 10; 1062 // negate dy since freetype-y-goes-up and skia-y-goes-down 1063 dy = -dy; 1064 } 1065 FT_Outline_Get_CBox(outline, &bbox); 1066 /* 1067 what we really want to do for subpixel is 1068 offset(dx, dy) 1069 compute_bounds 1070 offset(bbox & !63) 1071 but that is two calls to offset, so we do the following, which 1072 achieves the same thing with only one offset call. 1073 */ 1074 FT_Outline_Translate(outline, dx - ((bbox.xMin + dx) & ~63), 1075 dy - ((bbox.yMin + dy) & ~63)); 1076 1077 #if defined(SK_SUPPORT_LCDTEXT) 1078 if (lcdRenderMode) { 1079 // FT_Outline_Get_Bitmap cannot render LCD glyphs. In this case 1080 // we have to call FT_Render_Glyph and memcpy the image out. 1081 const bool isVertical = fRec.fMaskFormat == SkMask::kVerticalLCD_Format; 1082 FT_Render_Mode mode = isVertical ? FT_RENDER_MODE_LCD_V : FT_RENDER_MODE_LCD; 1083 FT_Render_Glyph(fFace->glyph, mode); 1084 1085 if (isVertical) 1086 CopyFreetypeBitmapToVerticalLCDMask(glyph, fFace->glyph->bitmap); 1087 else 1088 CopyFreetypeBitmapToLCDMask(glyph, fFace->glyph->bitmap); 1089 1090 break; 1091 } 1092 #endif 1093 1094 if (SkMask::kLCD16_Format == glyph.fMaskFormat) { 1095 FT_Render_Glyph(fFace->glyph, FT_RENDER_MODE_LCD); 1096 copyFT2LCD16(glyph, fFace->glyph->bitmap); 1097 } else { 1098 target.width = glyph.fWidth; 1099 target.rows = glyph.fHeight; 1100 target.pitch = glyph.rowBytes(); 1101 target.buffer = reinterpret_cast<uint8_t*>(glyph.fImage); 1102 target.pixel_mode = compute_pixel_mode( 1103 (SkMask::Format)fRec.fMaskFormat); 1104 target.num_grays = 256; 1105 1106 memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight); 1107 FT_Outline_Get_Bitmap(gFTLibrary, outline, &target); 1108 } 1109 } break; 1110 1111 case FT_GLYPH_FORMAT_BITMAP: { 1112 if (fRec.fFlags & kEmbolden_Flag) { 1113 FT_GlyphSlot_Own_Bitmap(fFace->glyph); 1114 FT_Bitmap_Embolden(gFTLibrary, &fFace->glyph->bitmap, kBitmapEmboldenStrength, 0); 1115 } 1116 SkASSERT_CONTINUE(glyph.fWidth == fFace->glyph->bitmap.width); 1117 SkASSERT_CONTINUE(glyph.fHeight == fFace->glyph->bitmap.rows); 1118 SkASSERT_CONTINUE(glyph.fTop == -fFace->glyph->bitmap_top); 1119 SkASSERT_CONTINUE(glyph.fLeft == fFace->glyph->bitmap_left); 1120 1121 const uint8_t* src = (const uint8_t*)fFace->glyph->bitmap.buffer; 1122 uint8_t* dst = (uint8_t*)glyph.fImage; 1123 1124 if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_GRAY || 1125 (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO && 1126 glyph.fMaskFormat == SkMask::kBW_Format)) { 1127 unsigned srcRowBytes = fFace->glyph->bitmap.pitch; 1128 unsigned dstRowBytes = glyph.rowBytes(); 1129 unsigned minRowBytes = SkMin32(srcRowBytes, dstRowBytes); 1130 unsigned extraRowBytes = dstRowBytes - minRowBytes; 1131 1132 for (int y = fFace->glyph->bitmap.rows - 1; y >= 0; --y) { 1133 memcpy(dst, src, minRowBytes); 1134 memset(dst + minRowBytes, 0, extraRowBytes); 1135 src += srcRowBytes; 1136 dst += dstRowBytes; 1137 } 1138 } else if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO && 1139 (glyph.fMaskFormat == SkMask::kA8_Format || 1140 glyph.fMaskFormat == SkMask::kHorizontalLCD_Format || 1141 glyph.fMaskFormat == SkMask::kVerticalLCD_Format)) { 1142 for (int y = 0; y < fFace->glyph->bitmap.rows; ++y) { 1143 uint8_t byte = 0; 1144 int bits = 0; 1145 const uint8_t* src_row = src; 1146 uint8_t* dst_row = dst; 1147 1148 for (int x = 0; x < fFace->glyph->bitmap.width; ++x) { 1149 if (!bits) { 1150 byte = *src_row++; 1151 bits = 8; 1152 } 1153 1154 *dst_row++ = byte & 0x80 ? 0xff : 0; 1155 bits--; 1156 byte <<= 1; 1157 } 1158 1159 src += fFace->glyph->bitmap.pitch; 1160 dst += glyph.rowBytes(); 1161 } 1162 } else { 1163 SkASSERT(!"unknown glyph bitmap transform needed"); 1164 } 1165 1166 if (lcdRenderMode) 1167 glyph.expandA8ToLCD(); 1168 1169 } break; 1170 1171 default: 1172 SkASSERT(!"unknown glyph format"); 1173 goto ERROR; 1174 } 1175 } 1176 1177 /////////////////////////////////////////////////////////////////////////////// 1178 1179 #define ft2sk(x) SkFixedToScalar((x) << 10) 1180 1181 #if FREETYPE_MAJOR >= 2 && FREETYPE_MINOR >= 2 1182 #define CONST_PARAM const 1183 #else // older freetype doesn't use const here 1184 #define CONST_PARAM 1185 #endif 1186 1187 static int move_proc(CONST_PARAM FT_Vector* pt, void* ctx) { 1188 SkPath* path = (SkPath*)ctx; 1189 path->close(); // to close the previous contour (if any) 1190 path->moveTo(ft2sk(pt->x), -ft2sk(pt->y)); 1191 return 0; 1192 } 1193 1194 static int line_proc(CONST_PARAM FT_Vector* pt, void* ctx) { 1195 SkPath* path = (SkPath*)ctx; 1196 path->lineTo(ft2sk(pt->x), -ft2sk(pt->y)); 1197 return 0; 1198 } 1199 1200 static int quad_proc(CONST_PARAM FT_Vector* pt0, CONST_PARAM FT_Vector* pt1, 1201 void* ctx) { 1202 SkPath* path = (SkPath*)ctx; 1203 path->quadTo(ft2sk(pt0->x), -ft2sk(pt0->y), ft2sk(pt1->x), -ft2sk(pt1->y)); 1204 return 0; 1205 } 1206 1207 static int cubic_proc(CONST_PARAM FT_Vector* pt0, CONST_PARAM FT_Vector* pt1, 1208 CONST_PARAM FT_Vector* pt2, void* ctx) { 1209 SkPath* path = (SkPath*)ctx; 1210 path->cubicTo(ft2sk(pt0->x), -ft2sk(pt0->y), ft2sk(pt1->x), 1211 -ft2sk(pt1->y), ft2sk(pt2->x), -ft2sk(pt2->y)); 1212 return 0; 1213 } 1214 1215 void SkScalerContext_FreeType::generatePath(const SkGlyph& glyph, 1216 SkPath* path) { 1217 SkAutoMutexAcquire ac(gFTMutex); 1218 1219 SkASSERT(&glyph && path); 1220 1221 if (this->setupSize()) { 1222 path->reset(); 1223 return; 1224 } 1225 1226 uint32_t flags = fLoadGlyphFlags; 1227 flags |= FT_LOAD_NO_BITMAP; // ignore embedded bitmaps so we're sure to get the outline 1228 flags &= ~FT_LOAD_RENDER; // don't scan convert (we just want the outline) 1229 1230 FT_Error err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), flags); 1231 1232 if (err != 0) { 1233 SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n", 1234 glyph.getGlyphID(fBaseGlyphCount), flags, err)); 1235 path->reset(); 1236 return; 1237 } 1238 1239 if (fRec.fFlags & kEmbolden_Flag) { 1240 emboldenOutline(&fFace->glyph->outline); 1241 } 1242 1243 FT_Outline_Funcs funcs; 1244 1245 funcs.move_to = move_proc; 1246 funcs.line_to = line_proc; 1247 funcs.conic_to = quad_proc; 1248 funcs.cubic_to = cubic_proc; 1249 funcs.shift = 0; 1250 funcs.delta = 0; 1251 1252 err = FT_Outline_Decompose(&fFace->glyph->outline, &funcs, path); 1253 1254 if (err != 0) { 1255 SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n", 1256 glyph.getGlyphID(fBaseGlyphCount), flags, err)); 1257 path->reset(); 1258 return; 1259 } 1260 1261 path->close(); 1262 } 1263 1264 void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* mx, 1265 SkPaint::FontMetrics* my) { 1266 if (NULL == mx && NULL == my) { 1267 return; 1268 } 1269 1270 SkAutoMutexAcquire ac(gFTMutex); 1271 1272 if (this->setupSize()) { 1273 ERROR: 1274 if (mx) { 1275 sk_bzero(mx, sizeof(SkPaint::FontMetrics)); 1276 } 1277 if (my) { 1278 sk_bzero(my, sizeof(SkPaint::FontMetrics)); 1279 } 1280 return; 1281 } 1282 1283 FT_Face face = fFace; 1284 int upem = face->units_per_EM; 1285 if (upem <= 0) { 1286 goto ERROR; 1287 } 1288 1289 SkPoint pts[6]; 1290 SkFixed ys[6]; 1291 SkFixed scaleY = fScaleY; 1292 SkFixed mxy = fMatrix22.xy; 1293 SkFixed myy = fMatrix22.yy; 1294 SkScalar xmin = SkIntToScalar(face->bbox.xMin) / upem; 1295 SkScalar xmax = SkIntToScalar(face->bbox.xMax) / upem; 1296 1297 int leading = face->height - (face->ascender + -face->descender); 1298 if (leading < 0) { 1299 leading = 0; 1300 } 1301 1302 // Try to get the OS/2 table from the font. This contains the specific 1303 // average font width metrics which Windows uses. 1304 TT_OS2* os2 = (TT_OS2*) FT_Get_Sfnt_Table(face, ft_sfnt_os2); 1305 1306 ys[0] = -face->bbox.yMax; 1307 ys[1] = -face->ascender; 1308 ys[2] = -face->descender; 1309 ys[3] = -face->bbox.yMin; 1310 ys[4] = leading; 1311 ys[5] = os2 ? os2->xAvgCharWidth : 0; 1312 1313 SkScalar x_height; 1314 if (os2 && os2->sxHeight) { 1315 x_height = SkFixedToScalar(SkMulDiv(fScaleX, os2->sxHeight, upem)); 1316 } else { 1317 const FT_UInt x_glyph = FT_Get_Char_Index(fFace, 'x'); 1318 if (x_glyph) { 1319 FT_BBox bbox; 1320 FT_Load_Glyph(fFace, x_glyph, fLoadGlyphFlags); 1321 if (fRec.fFlags & kEmbolden_Flag) { 1322 emboldenOutline(&fFace->glyph->outline); 1323 } 1324 FT_Outline_Get_CBox(&fFace->glyph->outline, &bbox); 1325 x_height = SkIntToScalar(bbox.yMax) / 64; 1326 } else { 1327 x_height = 0; 1328 } 1329 } 1330 1331 // convert upem-y values into scalar points 1332 for (int i = 0; i < 6; i++) { 1333 SkFixed y = SkMulDiv(scaleY, ys[i], upem); 1334 SkFixed x = SkFixedMul(mxy, y); 1335 y = SkFixedMul(myy, y); 1336 pts[i].set(SkFixedToScalar(x), SkFixedToScalar(y)); 1337 } 1338 1339 if (mx) { 1340 mx->fTop = pts[0].fX; 1341 mx->fAscent = pts[1].fX; 1342 mx->fDescent = pts[2].fX; 1343 mx->fBottom = pts[3].fX; 1344 mx->fLeading = pts[4].fX; 1345 mx->fAvgCharWidth = pts[5].fX; 1346 mx->fXMin = xmin; 1347 mx->fXMax = xmax; 1348 mx->fXHeight = x_height; 1349 } 1350 if (my) { 1351 my->fTop = pts[0].fY; 1352 my->fAscent = pts[1].fY; 1353 my->fDescent = pts[2].fY; 1354 my->fBottom = pts[3].fY; 1355 my->fLeading = pts[4].fY; 1356 my->fAvgCharWidth = pts[5].fY; 1357 my->fXMin = xmin; 1358 my->fXMax = xmax; 1359 my->fXHeight = x_height; 1360 } 1361 } 1362 1363 //////////////////////////////////////////////////////////////////////// 1364 //////////////////////////////////////////////////////////////////////// 1365 1366 SkScalerContext* SkFontHost::CreateScalerContext(const SkDescriptor* desc) { 1367 SkScalerContext_FreeType* c = SkNEW_ARGS(SkScalerContext_FreeType, (desc)); 1368 if (!c->success()) { 1369 SkDELETE(c); 1370 c = NULL; 1371 } 1372 return c; 1373 } 1374 1375 /////////////////////////////////////////////////////////////////////////////// 1376 1377 /* Export this so that other parts of our FonttHost port can make use of our 1378 ability to extract the name+style from a stream, using FreeType's api. 1379 */ 1380 SkTypeface::Style find_name_and_attributes(SkStream* stream, SkString* name, 1381 bool* isFixedWidth) { 1382 FT_Library library; 1383 if (FT_Init_FreeType(&library)) { 1384 name->reset(); 1385 return SkTypeface::kNormal; 1386 } 1387 1388 FT_Open_Args args; 1389 memset(&args, 0, sizeof(args)); 1390 1391 const void* memoryBase = stream->getMemoryBase(); 1392 FT_StreamRec streamRec; 1393 1394 if (NULL != memoryBase) { 1395 args.flags = FT_OPEN_MEMORY; 1396 args.memory_base = (const FT_Byte*)memoryBase; 1397 args.memory_size = stream->getLength(); 1398 } else { 1399 memset(&streamRec, 0, sizeof(streamRec)); 1400 streamRec.size = stream->read(NULL, 0); 1401 streamRec.descriptor.pointer = stream; 1402 streamRec.read = sk_stream_read; 1403 streamRec.close = sk_stream_close; 1404 1405 args.flags = FT_OPEN_STREAM; 1406 args.stream = &streamRec; 1407 } 1408 1409 FT_Face face; 1410 if (FT_Open_Face(library, &args, 0, &face)) { 1411 FT_Done_FreeType(library); 1412 name->reset(); 1413 return SkTypeface::kNormal; 1414 } 1415 1416 name->set(face->family_name); 1417 int style = SkTypeface::kNormal; 1418 1419 if (face->style_flags & FT_STYLE_FLAG_BOLD) { 1420 style |= SkTypeface::kBold; 1421 } 1422 if (face->style_flags & FT_STYLE_FLAG_ITALIC) { 1423 style |= SkTypeface::kItalic; 1424 } 1425 if (isFixedWidth) { 1426 *isFixedWidth = FT_IS_FIXED_WIDTH(face); 1427 } 1428 1429 FT_Done_Face(face); 1430 FT_Done_FreeType(library); 1431 return (SkTypeface::Style)style; 1432 } 1433
