1 /*
2 * Copyright 2006 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkAdvancedTypefaceMetrics.h"
9 #include "SkBitmap.h"
10 #include "SkCanvas.h"
11 #include "SkColorPriv.h"
12 #include "SkDescriptor.h"
13 #include "SkFDot6.h"
14 #include "SkFontDescriptor.h"
15 #include "SkFontHost_FreeType_common.h"
16 #include "SkGlyph.h"
17 #include "SkMask.h"
18 #include "SkMaskGamma.h"
19 #include "SkMatrix22.h"
20 #include "SkMutex.h"
21 #include "SkOTUtils.h"
22 #include "SkPath.h"
23 #include "SkScalerContext.h"
24 #include "SkStream.h"
25 #include "SkString.h"
26 #include "SkTemplates.h"
27 #include "SkTypes.h"
28 #include "SkUniquePtr.h"
29
30 #if defined(SK_CAN_USE_DLOPEN)
31 #include <dlfcn.h>
32 #endif
33 #include <ft2build.h>
34 #include FT_ADVANCES_H
35 #include FT_BITMAP_H
36 #include FT_FREETYPE_H
37 #include FT_LCD_FILTER_H
38 #include FT_MODULE_H
39 #include FT_MULTIPLE_MASTERS_H
40 #include FT_OUTLINE_H
41 #include FT_SIZES_H
42 #include FT_SYSTEM_H
43 #include FT_TRUETYPE_TABLES_H
44 #include FT_TYPE1_TABLES_H
45 #include FT_XFREE86_H
46
47 // FT_LOAD_COLOR and the corresponding FT_Pixel_Mode::FT_PIXEL_MODE_BGRA
48 // were introduced in FreeType 2.5.0.
49 // The following may be removed once FreeType 2.5.0 is required to build.
50 #ifndef FT_LOAD_COLOR
51 # define FT_LOAD_COLOR ( 1L << 20 )
52 # define FT_PIXEL_MODE_BGRA 7
53 #endif
54
55 //#define ENABLE_GLYPH_SPEW // for tracing calls
56 //#define DUMP_STRIKE_CREATION
57 //#define SK_FONTHOST_FREETYPE_USE_NORMAL_LCD_FILTER
58 //#define SK_FONTHOST_FREETYPE_RUNTIME_VERSION
59 //#define SK_GAMMA_APPLY_TO_A8
60
61 using namespace skia_advanced_typeface_metrics_utils;
62
isLCD(const SkScalerContext::Rec & rec)63 static bool isLCD(const SkScalerContext::Rec& rec) {
64 return SkMask::kLCD16_Format == rec.fMaskFormat;
65 }
66
67 //////////////////////////////////////////////////////////////////////////
68
69 extern "C" {
sk_ft_alloc(FT_Memory,long size)70 static void* sk_ft_alloc(FT_Memory, long size) {
71 return sk_malloc_throw(size);
72 }
sk_ft_free(FT_Memory,void * block)73 static void sk_ft_free(FT_Memory, void* block) {
74 sk_free(block);
75 }
sk_ft_realloc(FT_Memory,long cur_size,long new_size,void * block)76 static void* sk_ft_realloc(FT_Memory, long cur_size, long new_size, void* block) {
77 return sk_realloc_throw(block, new_size);
78 }
79 };
80 FT_MemoryRec_ gFTMemory = { nullptr, sk_ft_alloc, sk_ft_free, sk_ft_realloc };
81
82 class FreeTypeLibrary : SkNoncopyable {
83 public:
FreeTypeLibrary()84 FreeTypeLibrary() : fLibrary(nullptr), fIsLCDSupported(false), fLCDExtra(0) {
85 if (FT_New_Library(&gFTMemory, &fLibrary)) {
86 return;
87 }
88 FT_Add_Default_Modules(fLibrary);
89
90 // Setup LCD filtering. This reduces color fringes for LCD smoothed glyphs.
91 // Default { 0x10, 0x40, 0x70, 0x40, 0x10 } adds up to 0x110, simulating ink spread.
92 // SetLcdFilter must be called before SetLcdFilterWeights.
93 if (FT_Library_SetLcdFilter(fLibrary, FT_LCD_FILTER_DEFAULT) == 0) {
94 fIsLCDSupported = true;
95 fLCDExtra = 2; //Using a filter adds one full pixel to each side.
96
97 #ifdef SK_FONTHOST_FREETYPE_USE_NORMAL_LCD_FILTER
98 // Adds to 0x110 simulating ink spread, but provides better results than default.
99 static unsigned char gGaussianLikeHeavyWeights[] = { 0x1A, 0x43, 0x56, 0x43, 0x1A, };
100
101 # if SK_FONTHOST_FREETYPE_RUNTIME_VERSION > 0x020400
102 FT_Library_SetLcdFilterWeights(fLibrary, gGaussianLikeHeavyWeights);
103 # elif SK_CAN_USE_DLOPEN == 1
104 //The FreeType library is already loaded, so symbols are available in process.
105 void* self = dlopen(nullptr, RTLD_LAZY);
106 if (self) {
107 FT_Library_SetLcdFilterWeightsProc setLcdFilterWeights;
108 //The following cast is non-standard, but safe for POSIX.
109 *reinterpret_cast<void**>(&setLcdFilterWeights) =
110 dlsym(self, "FT_Library_SetLcdFilterWeights");
111 dlclose(self);
112
113 if (setLcdFilterWeights) {
114 setLcdFilterWeights(fLibrary, gGaussianLikeHeavyWeights);
115 }
116 }
117 # endif
118 #endif
119 }
120 }
~FreeTypeLibrary()121 ~FreeTypeLibrary() {
122 if (fLibrary) {
123 FT_Done_Library(fLibrary);
124 }
125 }
126
library()127 FT_Library library() { return fLibrary; }
isLCDSupported()128 bool isLCDSupported() { return fIsLCDSupported; }
lcdExtra()129 int lcdExtra() { return fLCDExtra; }
130
131 private:
132 FT_Library fLibrary;
133 bool fIsLCDSupported;
134 int fLCDExtra;
135
136 // FT_Library_SetLcdFilterWeights was introduced in FreeType 2.4.0.
137 // The following platforms provide FreeType of at least 2.4.0.
138 // Ubuntu >= 11.04 (previous deprecated April 2013)
139 // Debian >= 6.0 (good)
140 // OpenSuse >= 11.4 (previous deprecated January 2012 / Nov 2013 for Evergreen 11.2)
141 // Fedora >= 14 (good)
142 // Android >= Gingerbread (good)
143 typedef FT_Error (*FT_Library_SetLcdFilterWeightsProc)(FT_Library, unsigned char*);
144 };
145
146 struct SkFaceRec;
147
148 SK_DECLARE_STATIC_MUTEX(gFTMutex);
149 static FreeTypeLibrary* gFTLibrary;
150 static SkFaceRec* gFaceRecHead;
151
152 // Private to ref_ft_library and unref_ft_library
153 static int gFTCount;
154
155 // Caller must lock gFTMutex before calling this function.
ref_ft_library()156 static bool ref_ft_library() {
157 gFTMutex.assertHeld();
158 SkASSERT(gFTCount >= 0);
159
160 if (0 == gFTCount) {
161 SkASSERT(nullptr == gFTLibrary);
162 gFTLibrary = new FreeTypeLibrary;
163 }
164 ++gFTCount;
165 return gFTLibrary->library();
166 }
167
168 // Caller must lock gFTMutex before calling this function.
unref_ft_library()169 static void unref_ft_library() {
170 gFTMutex.assertHeld();
171 SkASSERT(gFTCount > 0);
172
173 --gFTCount;
174 if (0 == gFTCount) {
175 SkASSERT(nullptr == gFaceRecHead);
176 SkASSERT(nullptr != gFTLibrary);
177 delete gFTLibrary;
178 SkDEBUGCODE(gFTLibrary = nullptr;)
179 }
180 }
181
182 class SkScalerContext_FreeType : public SkScalerContext_FreeType_Base {
183 public:
184 SkScalerContext_FreeType(SkTypeface*, const SkDescriptor* desc);
185 virtual ~SkScalerContext_FreeType();
186
success() const187 bool success() const {
188 return fFTSize != nullptr && fFace != nullptr;
189 }
190
191 protected:
192 unsigned generateGlyphCount() override;
193 uint16_t generateCharToGlyph(SkUnichar uni) override;
194 void generateAdvance(SkGlyph* glyph) override;
195 void generateMetrics(SkGlyph* glyph) override;
196 void generateImage(const SkGlyph& glyph) override;
197 void generatePath(const SkGlyph& glyph, SkPath* path) override;
198 void generateFontMetrics(SkPaint::FontMetrics*) override;
199 SkUnichar generateGlyphToChar(uint16_t glyph) override;
200
201 private:
202 FT_Face fFace; // reference to shared face in gFaceRecHead
203 FT_Size fFTSize; // our own copy
204 FT_Int fStrikeIndex;
205 FT_F26Dot6 fScaleX, fScaleY;
206 FT_Matrix fMatrix22;
207 uint32_t fLoadGlyphFlags;
208 bool fDoLinearMetrics;
209 bool fLCDIsVert;
210
211 // Need scalar versions for generateFontMetrics
212 SkVector fScale;
213 SkMatrix fMatrix22Scalar;
214
215 FT_Error setupSize();
216 void getBBoxForCurrentGlyph(SkGlyph* glyph, FT_BBox* bbox,
217 bool snapToPixelBoundary = false);
218 bool getCBoxForLetter(char letter, FT_BBox* bbox);
219 // Caller must lock gFTMutex before calling this function.
220 void updateGlyphIfLCD(SkGlyph* glyph);
221 // Caller must lock gFTMutex before calling this function.
222 // update FreeType2 glyph slot with glyph emboldened
223 void emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph);
224 };
225
226 ///////////////////////////////////////////////////////////////////////////
227 ///////////////////////////////////////////////////////////////////////////
228
229 struct SkFaceRec {
230 SkFaceRec* fNext;
231 FT_Face fFace;
232 FT_StreamRec fFTStream;
233 SkAutoTDelete<SkStreamAsset> fSkStream;
234 uint32_t fRefCnt;
235 uint32_t fFontID;
236
237 // assumes ownership of the stream, will delete when its done
238 SkFaceRec(SkStreamAsset* strm, uint32_t fontID);
239 };
240
241 extern "C" {
sk_ft_stream_io(FT_Stream ftStream,unsigned long offset,unsigned char * buffer,unsigned long count)242 static unsigned long sk_ft_stream_io(FT_Stream ftStream,
243 unsigned long offset,
244 unsigned char* buffer,
245 unsigned long count)
246 {
247 SkStreamAsset* stream = static_cast<SkStreamAsset*>(ftStream->descriptor.pointer);
248
249 if (count) {
250 if (!stream->seek(offset)) {
251 return 0;
252 }
253 count = stream->read(buffer, count);
254 }
255 return count;
256 }
257
sk_ft_stream_close(FT_Stream)258 static void sk_ft_stream_close(FT_Stream) {}
259 }
260
SkFaceRec(SkStreamAsset * stream,uint32_t fontID)261 SkFaceRec::SkFaceRec(SkStreamAsset* stream, uint32_t fontID)
262 : fNext(nullptr), fSkStream(stream), fRefCnt(1), fFontID(fontID)
263 {
264 sk_bzero(&fFTStream, sizeof(fFTStream));
265 fFTStream.size = fSkStream->getLength();
266 fFTStream.descriptor.pointer = fSkStream;
267 fFTStream.read = sk_ft_stream_io;
268 fFTStream.close = sk_ft_stream_close;
269 }
270
ft_face_setup_axes(FT_Face face,const SkFontData & data)271 static void ft_face_setup_axes(FT_Face face, const SkFontData& data) {
272 if (!(face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS)) {
273 return;
274 }
275
276 SkDEBUGCODE(
277 FT_MM_Var* variations = nullptr;
278 if (FT_Get_MM_Var(face, &variations)) {
279 SkDEBUGF(("INFO: font %s claims variations, but none found.\n", face->family_name));
280 return;
281 }
282 SkAutoFree autoFreeVariations(variations);
283
284 if (static_cast<FT_UInt>(data.getAxisCount()) != variations->num_axis) {
285 SkDEBUGF(("INFO: font %s has %d variations, but %d were specified.\n",
286 face->family_name, variations->num_axis, data.getAxisCount()));
287 return;
288 }
289 )
290
291 SkAutoSTMalloc<4, FT_Fixed> coords(data.getAxisCount());
292 for (int i = 0; i < data.getAxisCount(); ++i) {
293 coords[i] = data.getAxis()[i];
294 }
295 if (FT_Set_Var_Design_Coordinates(face, data.getAxisCount(), coords.get())) {
296 SkDEBUGF(("INFO: font %s has variations, but specified variations could not be set.\n",
297 face->family_name));
298 return;
299 }
300 }
301
302 // Will return 0 on failure
303 // Caller must lock gFTMutex before calling this function.
ref_ft_face(const SkTypeface * typeface)304 static FT_Face ref_ft_face(const SkTypeface* typeface) {
305 gFTMutex.assertHeld();
306
307 const SkFontID fontID = typeface->uniqueID();
308 SkFaceRec* rec = gFaceRecHead;
309 while (rec) {
310 if (rec->fFontID == fontID) {
311 SkASSERT(rec->fFace);
312 rec->fRefCnt += 1;
313 return rec->fFace;
314 }
315 rec = rec->fNext;
316 }
317
318 SkAutoTDelete<SkFontData> data(typeface->createFontData());
319 if (nullptr == data || !data->hasStream()) {
320 return nullptr;
321 }
322
323 // this passes ownership of stream to the rec
324 rec = new SkFaceRec(data->detachStream(), fontID);
325
326 FT_Open_Args args;
327 memset(&args, 0, sizeof(args));
328 const void* memoryBase = rec->fSkStream->getMemoryBase();
329 if (memoryBase) {
330 args.flags = FT_OPEN_MEMORY;
331 args.memory_base = (const FT_Byte*)memoryBase;
332 args.memory_size = rec->fSkStream->getLength();
333 } else {
334 args.flags = FT_OPEN_STREAM;
335 args.stream = &rec->fFTStream;
336 }
337
338 FT_Error err = FT_Open_Face(gFTLibrary->library(), &args, data->getIndex(), &rec->fFace);
339 if (err) {
340 SkDEBUGF(("ERROR: unable to open font '%x'\n", fontID));
341 delete rec;
342 return nullptr;
343 }
344 SkASSERT(rec->fFace);
345
346 ft_face_setup_axes(rec->fFace, *data);
347
348 // FreeType will set the charmap to the "most unicode" cmap if it exists.
349 // If there are no unicode cmaps, the charmap is set to nullptr.
350 // However, "symbol" cmaps should also be considered "fallback unicode" cmaps
351 // because they are effectively private use area only (even if they aren't).
352 // This is the last on the fallback list at
353 // https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6cmap.html
354 if (!rec->fFace->charmap) {
355 FT_Select_Charmap(rec->fFace, FT_ENCODING_MS_SYMBOL);
356 }
357
358 rec->fNext = gFaceRecHead;
359 gFaceRecHead = rec;
360 return rec->fFace;
361 }
362
363 // Caller must lock gFTMutex before calling this function.
unref_ft_face(FT_Face face)364 static void unref_ft_face(FT_Face face) {
365 gFTMutex.assertHeld();
366
367 SkFaceRec* rec = gFaceRecHead;
368 SkFaceRec* prev = nullptr;
369 while (rec) {
370 SkFaceRec* next = rec->fNext;
371 if (rec->fFace == face) {
372 if (--rec->fRefCnt == 0) {
373 if (prev) {
374 prev->fNext = next;
375 } else {
376 gFaceRecHead = next;
377 }
378 FT_Done_Face(face);
379 delete rec;
380 }
381 return;
382 }
383 prev = rec;
384 rec = next;
385 }
386 SkDEBUGFAIL("shouldn't get here, face not in list");
387 }
388
389 class AutoFTAccess {
390 public:
AutoFTAccess(const SkTypeface * tf)391 AutoFTAccess(const SkTypeface* tf) : fFace(nullptr) {
392 gFTMutex.acquire();
393 if (!ref_ft_library()) {
394 sk_throw();
395 }
396 fFace = ref_ft_face(tf);
397 }
398
~AutoFTAccess()399 ~AutoFTAccess() {
400 if (fFace) {
401 unref_ft_face(fFace);
402 }
403 unref_ft_library();
404 gFTMutex.release();
405 }
406
face()407 FT_Face face() { return fFace; }
408
409 private:
410 FT_Face fFace;
411 };
412
413 ///////////////////////////////////////////////////////////////////////////
414
canEmbed(FT_Face face)415 static bool canEmbed(FT_Face face) {
416 FT_UShort fsType = FT_Get_FSType_Flags(face);
417 return (fsType & (FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING |
418 FT_FSTYPE_BITMAP_EMBEDDING_ONLY)) == 0;
419 }
420
canSubset(FT_Face face)421 static bool canSubset(FT_Face face) {
422 FT_UShort fsType = FT_Get_FSType_Flags(face);
423 return (fsType & FT_FSTYPE_NO_SUBSETTING) == 0;
424 }
425
GetLetterCBox(FT_Face face,char letter,FT_BBox * bbox)426 static bool GetLetterCBox(FT_Face face, char letter, FT_BBox* bbox) {
427 const FT_UInt glyph_id = FT_Get_Char_Index(face, letter);
428 if (!glyph_id)
429 return false;
430 if (FT_Load_Glyph(face, glyph_id, FT_LOAD_NO_SCALE) != 0)
431 return false;
432 FT_Outline_Get_CBox(&face->glyph->outline, bbox);
433 return true;
434 }
435
getWidthAdvance(FT_Face face,int gId,int16_t * data)436 static bool getWidthAdvance(FT_Face face, int gId, int16_t* data) {
437 FT_Fixed advance = 0;
438 if (FT_Get_Advances(face, gId, 1, FT_LOAD_NO_SCALE, &advance)) {
439 return false;
440 }
441 SkASSERT(data);
442 *data = advance;
443 return true;
444 }
445
populate_glyph_to_unicode(FT_Face & face,SkTDArray<SkUnichar> * glyphToUnicode)446 static void populate_glyph_to_unicode(FT_Face& face, SkTDArray<SkUnichar>* glyphToUnicode) {
447 glyphToUnicode->setCount(face->num_glyphs);
448 sk_bzero(glyphToUnicode->begin(), sizeof((*glyphToUnicode)[0]) * face->num_glyphs);
449
450 FT_UInt glyphIndex;
451 SkUnichar charCode = FT_Get_First_Char(face, &glyphIndex);
452 while (glyphIndex) {
453 (*glyphToUnicode)[glyphIndex] = charCode;
454 charCode = FT_Get_Next_Char(face, charCode, &glyphIndex);
455 }
456 }
457
onGetAdvancedTypefaceMetrics(PerGlyphInfo perGlyphInfo,const uint32_t * glyphIDs,uint32_t glyphIDsCount) const458 SkAdvancedTypefaceMetrics* SkTypeface_FreeType::onGetAdvancedTypefaceMetrics(
459 PerGlyphInfo perGlyphInfo,
460 const uint32_t* glyphIDs,
461 uint32_t glyphIDsCount) const {
462 #if defined(SK_BUILD_FOR_MAC)
463 return nullptr;
464 #else
465 AutoFTAccess fta(this);
466 FT_Face face = fta.face();
467 if (!face) {
468 return nullptr;
469 }
470
471 SkAdvancedTypefaceMetrics* info = new SkAdvancedTypefaceMetrics;
472 info->fFontName.set(FT_Get_Postscript_Name(face));
473 info->fFlags = SkAdvancedTypefaceMetrics::kEmpty_FontFlag;
474 if (FT_HAS_MULTIPLE_MASTERS(face)) {
475 info->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
476 info->fFlags, SkAdvancedTypefaceMetrics::kMultiMaster_FontFlag);
477 }
478 if (!canEmbed(face)) {
479 info->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
480 info->fFlags,
481 SkAdvancedTypefaceMetrics::kNotEmbeddable_FontFlag);
482 }
483 if (!canSubset(face)) {
484 info->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
485 info->fFlags,
486 SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag);
487 }
488 info->fLastGlyphID = face->num_glyphs - 1;
489 info->fEmSize = 1000;
490
491 bool cid = false;
492 const char* fontType = FT_Get_X11_Font_Format(face);
493 if (strcmp(fontType, "Type 1") == 0) {
494 info->fType = SkAdvancedTypefaceMetrics::kType1_Font;
495 } else if (strcmp(fontType, "CID Type 1") == 0) {
496 info->fType = SkAdvancedTypefaceMetrics::kType1CID_Font;
497 cid = true;
498 } else if (strcmp(fontType, "CFF") == 0) {
499 info->fType = SkAdvancedTypefaceMetrics::kCFF_Font;
500 } else if (strcmp(fontType, "TrueType") == 0) {
501 info->fType = SkAdvancedTypefaceMetrics::kTrueType_Font;
502 cid = true;
503 TT_Header* ttHeader;
504 if ((ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face,
505 ft_sfnt_head)) != nullptr) {
506 info->fEmSize = ttHeader->Units_Per_EM;
507 }
508 } else {
509 info->fType = SkAdvancedTypefaceMetrics::kOther_Font;
510 }
511
512 info->fStyle = 0;
513 if (FT_IS_FIXED_WIDTH(face))
514 info->fStyle |= SkAdvancedTypefaceMetrics::kFixedPitch_Style;
515 if (face->style_flags & FT_STYLE_FLAG_ITALIC)
516 info->fStyle |= SkAdvancedTypefaceMetrics::kItalic_Style;
517
518 PS_FontInfoRec ps_info;
519 TT_Postscript* tt_info;
520 if (FT_Get_PS_Font_Info(face, &ps_info) == 0) {
521 info->fItalicAngle = ps_info.italic_angle;
522 } else if ((tt_info =
523 (TT_Postscript*)FT_Get_Sfnt_Table(face,
524 ft_sfnt_post)) != nullptr) {
525 info->fItalicAngle = SkFixedToScalar(tt_info->italicAngle);
526 } else {
527 info->fItalicAngle = 0;
528 }
529
530 info->fAscent = face->ascender;
531 info->fDescent = face->descender;
532
533 // Figure out a good guess for StemV - Min width of i, I, !, 1.
534 // This probably isn't very good with an italic font.
535 int16_t min_width = SHRT_MAX;
536 info->fStemV = 0;
537 char stem_chars[] = {'i', 'I', '!', '1'};
538 for (size_t i = 0; i < SK_ARRAY_COUNT(stem_chars); i++) {
539 FT_BBox bbox;
540 if (GetLetterCBox(face, stem_chars[i], &bbox)) {
541 int16_t width = bbox.xMax - bbox.xMin;
542 if (width > 0 && width < min_width) {
543 min_width = width;
544 info->fStemV = min_width;
545 }
546 }
547 }
548
549 TT_PCLT* pclt_info;
550 TT_OS2* os2_table;
551 if ((pclt_info = (TT_PCLT*)FT_Get_Sfnt_Table(face, ft_sfnt_pclt)) != nullptr) {
552 info->fCapHeight = pclt_info->CapHeight;
553 uint8_t serif_style = pclt_info->SerifStyle & 0x3F;
554 if (serif_style >= 2 && serif_style <= 6)
555 info->fStyle |= SkAdvancedTypefaceMetrics::kSerif_Style;
556 else if (serif_style >= 9 && serif_style <= 12)
557 info->fStyle |= SkAdvancedTypefaceMetrics::kScript_Style;
558 } else if (((os2_table = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != nullptr) &&
559 // sCapHeight is available only when version 2 or later.
560 os2_table->version != 0xFFFF &&
561 os2_table->version >= 2) {
562 info->fCapHeight = os2_table->sCapHeight;
563 } else {
564 // Figure out a good guess for CapHeight: average the height of M and X.
565 FT_BBox m_bbox, x_bbox;
566 bool got_m, got_x;
567 got_m = GetLetterCBox(face, 'M', &m_bbox);
568 got_x = GetLetterCBox(face, 'X', &x_bbox);
569 if (got_m && got_x) {
570 info->fCapHeight = (m_bbox.yMax - m_bbox.yMin + x_bbox.yMax -
571 x_bbox.yMin) / 2;
572 } else if (got_m && !got_x) {
573 info->fCapHeight = m_bbox.yMax - m_bbox.yMin;
574 } else if (!got_m && got_x) {
575 info->fCapHeight = x_bbox.yMax - x_bbox.yMin;
576 } else {
577 // Last resort, use the ascent.
578 info->fCapHeight = info->fAscent;
579 }
580 }
581
582 info->fBBox = SkIRect::MakeLTRB(face->bbox.xMin, face->bbox.yMax,
583 face->bbox.xMax, face->bbox.yMin);
584
585 if (!FT_IS_SCALABLE(face)) {
586 perGlyphInfo = kNo_PerGlyphInfo;
587 }
588
589 if (perGlyphInfo & kHAdvance_PerGlyphInfo) {
590 if (FT_IS_FIXED_WIDTH(face)) {
591 appendRange(&info->fGlyphWidths, 0);
592 int16_t advance = face->max_advance_width;
593 info->fGlyphWidths->fAdvance.append(1, &advance);
594 finishRange(info->fGlyphWidths.get(), 0,
595 SkAdvancedTypefaceMetrics::WidthRange::kDefault);
596 } else if (!cid) {
597 appendRange(&info->fGlyphWidths, 0);
598 // So as to not blow out the stack, get advances in batches.
599 for (int gID = 0; gID < face->num_glyphs; gID += 128) {
600 FT_Fixed advances[128];
601 int advanceCount = 128;
602 if (gID + advanceCount > face->num_glyphs) {
603 advanceCount = face->num_glyphs - gID;
604 }
605 FT_Get_Advances(face, gID, advanceCount, FT_LOAD_NO_SCALE, advances);
606 for (int i = 0; i < advanceCount; i++) {
607 int16_t advance = advances[i];
608 info->fGlyphWidths->fAdvance.append(1, &advance);
609 }
610 }
611 finishRange(info->fGlyphWidths.get(), face->num_glyphs - 1,
612 SkAdvancedTypefaceMetrics::WidthRange::kRange);
613 } else {
614 info->fGlyphWidths.reset(
615 getAdvanceData(face,
616 face->num_glyphs,
617 glyphIDs,
618 glyphIDsCount,
619 &getWidthAdvance));
620 }
621 }
622
623 if (perGlyphInfo & kVAdvance_PerGlyphInfo &&
624 FT_HAS_VERTICAL(face)) {
625 SkASSERT(false); // Not implemented yet.
626 }
627
628 if (perGlyphInfo & kGlyphNames_PerGlyphInfo &&
629 info->fType == SkAdvancedTypefaceMetrics::kType1_Font) {
630 // Postscript fonts may contain more than 255 glyphs, so we end up
631 // using multiple font descriptions with a glyph ordering. Record
632 // the name of each glyph.
633 info->fGlyphNames.reset(
634 new SkAutoTArray<SkString>(face->num_glyphs));
635 for (int gID = 0; gID < face->num_glyphs; gID++) {
636 char glyphName[128]; // PS limit for names is 127 bytes.
637 FT_Get_Glyph_Name(face, gID, glyphName, 128);
638 info->fGlyphNames->get()[gID].set(glyphName);
639 }
640 }
641
642 if (perGlyphInfo & kToUnicode_PerGlyphInfo &&
643 info->fType != SkAdvancedTypefaceMetrics::kType1_Font &&
644 face->num_charmaps) {
645 populate_glyph_to_unicode(face, &(info->fGlyphToUnicode));
646 }
647
648 return info;
649 #endif
650 }
651
652 ///////////////////////////////////////////////////////////////////////////
653
bothZero(SkScalar a,SkScalar b)654 static bool bothZero(SkScalar a, SkScalar b) {
655 return 0 == a && 0 == b;
656 }
657
658 // returns false if there is any non-90-rotation or skew
isAxisAligned(const SkScalerContext::Rec & rec)659 static bool isAxisAligned(const SkScalerContext::Rec& rec) {
660 return 0 == rec.fPreSkewX &&
661 (bothZero(rec.fPost2x2[0][1], rec.fPost2x2[1][0]) ||
662 bothZero(rec.fPost2x2[0][0], rec.fPost2x2[1][1]));
663 }
664
onCreateScalerContext(const SkDescriptor * desc) const665 SkScalerContext* SkTypeface_FreeType::onCreateScalerContext(
666 const SkDescriptor* desc) const {
667 SkScalerContext_FreeType* c =
668 new SkScalerContext_FreeType(const_cast<SkTypeface_FreeType*>(this), desc);
669 if (!c->success()) {
670 delete c;
671 c = nullptr;
672 }
673 return c;
674 }
675
onFilterRec(SkScalerContextRec * rec) const676 void SkTypeface_FreeType::onFilterRec(SkScalerContextRec* rec) const {
677 //BOGUS: http://code.google.com/p/chromium/issues/detail?id=121119
678 //Cap the requested size as larger sizes give bogus values.
679 //Remove when http://code.google.com/p/skia/issues/detail?id=554 is fixed.
680 //Note that this also currently only protects against large text size requests,
681 //the total matrix is not taken into account here.
682 if (rec->fTextSize > SkIntToScalar(1 << 14)) {
683 rec->fTextSize = SkIntToScalar(1 << 14);
684 }
685
686 if (isLCD(*rec)) {
687 // TODO: re-work so that FreeType is set-up and selected by the SkFontMgr.
688 SkAutoMutexAcquire ama(gFTMutex);
689 ref_ft_library();
690 if (!gFTLibrary->isLCDSupported()) {
691 // If the runtime Freetype library doesn't support LCD, disable it here.
692 rec->fMaskFormat = SkMask::kA8_Format;
693 }
694 unref_ft_library();
695 }
696
697 SkPaint::Hinting h = rec->getHinting();
698 if (SkPaint::kFull_Hinting == h && !isLCD(*rec)) {
699 // collapse full->normal hinting if we're not doing LCD
700 h = SkPaint::kNormal_Hinting;
701 }
702 if ((rec->fFlags & SkScalerContext::kSubpixelPositioning_Flag)) {
703 if (SkPaint::kNo_Hinting != h) {
704 h = SkPaint::kSlight_Hinting;
705 }
706 }
707
708 // rotated text looks bad with hinting, so we disable it as needed
709 if (!isAxisAligned(*rec)) {
710 h = SkPaint::kNo_Hinting;
711 }
712 rec->setHinting(h);
713
714 #ifndef SK_GAMMA_APPLY_TO_A8
715 if (!isLCD(*rec)) {
716 rec->ignorePreBlend();
717 }
718 #endif
719 }
720
onGetUPEM() const721 int SkTypeface_FreeType::onGetUPEM() const {
722 AutoFTAccess fta(this);
723 FT_Face face = fta.face();
724 return face ? face->units_per_EM : 0;
725 }
726
onGetKerningPairAdjustments(const uint16_t glyphs[],int count,int32_t adjustments[]) const727 bool SkTypeface_FreeType::onGetKerningPairAdjustments(const uint16_t glyphs[],
728 int count, int32_t adjustments[]) const {
729 AutoFTAccess fta(this);
730 FT_Face face = fta.face();
731 if (!face || !FT_HAS_KERNING(face)) {
732 return false;
733 }
734
735 for (int i = 0; i < count - 1; ++i) {
736 FT_Vector delta;
737 FT_Error err = FT_Get_Kerning(face, glyphs[i], glyphs[i+1],
738 FT_KERNING_UNSCALED, &delta);
739 if (err) {
740 return false;
741 }
742 adjustments[i] = delta.x;
743 }
744 return true;
745 }
746
chooseBitmapStrike(FT_Face face,FT_F26Dot6 scaleY)747 static FT_Int chooseBitmapStrike(FT_Face face, FT_F26Dot6 scaleY) {
748 // early out if face is bad
749 if (face == nullptr) {
750 SkDEBUGF(("chooseBitmapStrike aborted due to nullptr face\n"));
751 return -1;
752 }
753 // determine target ppem
754 FT_Pos targetPPEM = scaleY;
755 // find a bitmap strike equal to or just larger than the requested size
756 FT_Int chosenStrikeIndex = -1;
757 FT_Pos chosenPPEM = 0;
758 for (FT_Int strikeIndex = 0; strikeIndex < face->num_fixed_sizes; ++strikeIndex) {
759 FT_Pos thisPPEM = face->available_sizes[strikeIndex].y_ppem;
760 if (thisPPEM == targetPPEM) {
761 // exact match - our search stops here
762 chosenPPEM = thisPPEM;
763 chosenStrikeIndex = strikeIndex;
764 break;
765 } else if (chosenPPEM < targetPPEM) {
766 // attempt to increase chosenPPEM
767 if (thisPPEM > chosenPPEM) {
768 chosenPPEM = thisPPEM;
769 chosenStrikeIndex = strikeIndex;
770 }
771 } else {
772 // attempt to decrease chosenPPEM, but not below targetPPEM
773 if (thisPPEM < chosenPPEM && thisPPEM > targetPPEM) {
774 chosenPPEM = thisPPEM;
775 chosenStrikeIndex = strikeIndex;
776 }
777 }
778 }
779 if (chosenStrikeIndex != -1) {
780 // use the chosen strike
781 FT_Error err = FT_Select_Size(face, chosenStrikeIndex);
782 if (err != 0) {
783 SkDEBUGF(("FT_Select_Size(%s, %d) returned 0x%x\n", face->family_name,
784 chosenStrikeIndex, err));
785 chosenStrikeIndex = -1;
786 }
787 }
788 return chosenStrikeIndex;
789 }
790
SkScalerContext_FreeType(SkTypeface * typeface,const SkDescriptor * desc)791 SkScalerContext_FreeType::SkScalerContext_FreeType(SkTypeface* typeface, const SkDescriptor* desc)
792 : SkScalerContext_FreeType_Base(typeface, desc)
793 , fFace(nullptr)
794 , fFTSize(nullptr)
795 , fStrikeIndex(-1)
796 {
797 SkAutoMutexAcquire ac(gFTMutex);
798
799 if (!ref_ft_library()) {
800 sk_throw();
801 }
802
803 // load the font file
804 using UnrefFTFace = SkFunctionWrapper<void, skstd::remove_pointer_t<FT_Face>, unref_ft_face>;
805 skstd::unique_ptr<skstd::remove_pointer_t<FT_Face>, UnrefFTFace> ftFace(ref_ft_face(typeface));
806 if (nullptr == ftFace) {
807 SkDEBUGF(("Could not create FT_Face.\n"));
808 return;
809 }
810
811 fRec.computeMatrices(SkScalerContextRec::kFull_PreMatrixScale, &fScale, &fMatrix22Scalar);
812 fMatrix22Scalar.setSkewX(-fMatrix22Scalar.getSkewX());
813 fMatrix22Scalar.setSkewY(-fMatrix22Scalar.getSkewY());
814
815 fScaleX = SkScalarToFDot6(fScale.fX);
816 fScaleY = SkScalarToFDot6(fScale.fY);
817 fMatrix22.xx = SkScalarToFixed(fMatrix22Scalar.getScaleX());
818 fMatrix22.xy = SkScalarToFixed(fMatrix22Scalar.getSkewX());
819 fMatrix22.yx = SkScalarToFixed(fMatrix22Scalar.getSkewY());
820 fMatrix22.yy = SkScalarToFixed(fMatrix22Scalar.getScaleY());
821
822 fLCDIsVert = SkToBool(fRec.fFlags & SkScalerContext::kLCD_Vertical_Flag);
823
824 // compute the flags we send to Load_Glyph
825 bool linearMetrics = SkToBool(fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag);
826 {
827 FT_Int32 loadFlags = FT_LOAD_DEFAULT;
828
829 if (SkMask::kBW_Format == fRec.fMaskFormat) {
830 // See http://code.google.com/p/chromium/issues/detail?id=43252#c24
831 loadFlags = FT_LOAD_TARGET_MONO;
832 if (fRec.getHinting() == SkPaint::kNo_Hinting) {
833 loadFlags = FT_LOAD_NO_HINTING;
834 linearMetrics = true;
835 }
836 } else {
837 switch (fRec.getHinting()) {
838 case SkPaint::kNo_Hinting:
839 loadFlags = FT_LOAD_NO_HINTING;
840 linearMetrics = true;
841 break;
842 case SkPaint::kSlight_Hinting:
843 loadFlags = FT_LOAD_TARGET_LIGHT; // This implies FORCE_AUTOHINT
844 break;
845 case SkPaint::kNormal_Hinting:
846 if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) {
847 loadFlags = FT_LOAD_FORCE_AUTOHINT;
848 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
849 } else {
850 loadFlags = FT_LOAD_NO_AUTOHINT;
851 #endif
852 }
853 break;
854 case SkPaint::kFull_Hinting:
855 if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) {
856 loadFlags = FT_LOAD_FORCE_AUTOHINT;
857 break;
858 }
859 loadFlags = FT_LOAD_TARGET_NORMAL;
860 if (isLCD(fRec)) {
861 if (fLCDIsVert) {
862 loadFlags = FT_LOAD_TARGET_LCD_V;
863 } else {
864 loadFlags = FT_LOAD_TARGET_LCD;
865 }
866 }
867 break;
868 default:
869 SkDebugf("---------- UNKNOWN hinting %d\n", fRec.getHinting());
870 break;
871 }
872 }
873
874 if ((fRec.fFlags & SkScalerContext::kEmbeddedBitmapText_Flag) == 0) {
875 loadFlags |= FT_LOAD_NO_BITMAP;
876 }
877
878 // Always using FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH to get correct
879 // advances, as fontconfig and cairo do.
880 // See http://code.google.com/p/skia/issues/detail?id=222.
881 loadFlags |= FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH;
882
883 // Use vertical layout if requested.
884 if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
885 loadFlags |= FT_LOAD_VERTICAL_LAYOUT;
886 }
887
888 loadFlags |= FT_LOAD_COLOR;
889
890 fLoadGlyphFlags = loadFlags;
891 }
892
893 using DoneFTSize = SkFunctionWrapper<FT_Error, skstd::remove_pointer_t<FT_Size>, FT_Done_Size>;
894 skstd::unique_ptr<skstd::remove_pointer_t<FT_Size>, DoneFTSize> ftSize([&ftFace]() -> FT_Size {
895 FT_Size size;
896 FT_Error err = FT_New_Size(ftFace.get(), &size);
897 if (err != 0) {
898 SkDEBUGF(("FT_New_Size returned %x for face %s\n", err, ftFace->family_name));
899 return nullptr;
900 }
901 return size;
902 }());
903 if (nullptr == ftSize) {
904 SkDEBUGF(("Could not create FT_Size.\n"));
905 return;
906 }
907
908 FT_Error err = FT_Activate_Size(ftSize.get());
909 if (err != 0) {
910 SkDEBUGF(("FT_Activate_Size(%08x, 0x%x, 0x%x) returned 0x%x\n",
911 ftFace.get(), fScaleX, fScaleY, err));
912 return;
913 }
914
915 if (FT_IS_SCALABLE(ftFace)) {
916 err = FT_Set_Char_Size(ftFace.get(), fScaleX, fScaleY, 72, 72);
917 if (err != 0) {
918 SkDEBUGF(("FT_Set_CharSize(%08x, 0x%x, 0x%x) returned 0x%x\n",
919 ftFace.get(), fScaleX, fScaleY, err));
920 return;
921 }
922 FT_Set_Transform(ftFace.get(), &fMatrix22, nullptr);
923 } else if (FT_HAS_FIXED_SIZES(ftFace)) {
924 fStrikeIndex = chooseBitmapStrike(ftFace.get(), fScaleY);
925 if (fStrikeIndex == -1) {
926 SkDEBUGF(("no glyphs for font \"%s\" size %f?\n",
927 ftFace->family_name, SkFDot6ToScalar(fScaleY)));
928 } else {
929 // FreeType does no provide linear metrics for bitmap fonts.
930 linearMetrics = false;
931
932 // FreeType documentation says:
933 // FT_LOAD_NO_BITMAP -- Ignore bitmap strikes when loading.
934 // Bitmap-only fonts ignore this flag.
935 //
936 // However, in FreeType 2.5.1 color bitmap only fonts do not ignore this flag.
937 // Force this flag off for bitmap only fonts.
938 fLoadGlyphFlags &= ~FT_LOAD_NO_BITMAP;
939 }
940 } else {
941 SkDEBUGF(("unknown kind of font \"%s\" size %f?\n",
942 fFace->family_name, SkFDot6ToScalar(fScaleY)));
943 }
944
945 fFTSize = ftSize.release();
946 fFace = ftFace.release();
947 fDoLinearMetrics = linearMetrics;
948 }
949
~SkScalerContext_FreeType()950 SkScalerContext_FreeType::~SkScalerContext_FreeType() {
951 SkAutoMutexAcquire ac(gFTMutex);
952
953 if (fFTSize != nullptr) {
954 FT_Done_Size(fFTSize);
955 }
956
957 if (fFace != nullptr) {
958 unref_ft_face(fFace);
959 }
960
961 unref_ft_library();
962 }
963
964 /* We call this before each use of the fFace, since we may be sharing
965 this face with other context (at different sizes).
966 */
setupSize()967 FT_Error SkScalerContext_FreeType::setupSize() {
968 gFTMutex.assertHeld();
969 FT_Error err = FT_Activate_Size(fFTSize);
970 if (err != 0) {
971 SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%s %s, 0x%x, 0x%x) returned 0x%x\n",
972 fFace->family_name, fFace->style_name, fScaleX, fScaleY, err));
973 fFTSize = nullptr;
974 return err;
975 }
976
977 // seems we need to reset this every time (not sure why, but without it
978 // I get random italics from some other fFTSize)
979 FT_Set_Transform(fFace, &fMatrix22, nullptr);
980 return 0;
981 }
982
generateGlyphCount()983 unsigned SkScalerContext_FreeType::generateGlyphCount() {
984 return fFace->num_glyphs;
985 }
986
generateCharToGlyph(SkUnichar uni)987 uint16_t SkScalerContext_FreeType::generateCharToGlyph(SkUnichar uni) {
988 SkAutoMutexAcquire ac(gFTMutex);
989 return SkToU16(FT_Get_Char_Index( fFace, uni ));
990 }
991
generateGlyphToChar(uint16_t glyph)992 SkUnichar SkScalerContext_FreeType::generateGlyphToChar(uint16_t glyph) {
993 SkAutoMutexAcquire ac(gFTMutex);
994 // iterate through each cmap entry, looking for matching glyph indices
995 FT_UInt glyphIndex;
996 SkUnichar charCode = FT_Get_First_Char( fFace, &glyphIndex );
997
998 while (glyphIndex != 0) {
999 if (glyphIndex == glyph) {
1000 return charCode;
1001 }
1002 charCode = FT_Get_Next_Char( fFace, charCode, &glyphIndex );
1003 }
1004
1005 return 0;
1006 }
1007
generateAdvance(SkGlyph * glyph)1008 void SkScalerContext_FreeType::generateAdvance(SkGlyph* glyph) {
1009 /* unhinted and light hinted text have linearly scaled advances
1010 * which are very cheap to compute with some font formats...
1011 */
1012 if (fDoLinearMetrics) {
1013 SkAutoMutexAcquire ac(gFTMutex);
1014
1015 if (this->setupSize()) {
1016 glyph->zeroMetrics();
1017 return;
1018 }
1019
1020 FT_Error error;
1021 FT_Fixed advance;
1022
1023 error = FT_Get_Advance( fFace, glyph->getGlyphID(),
1024 fLoadGlyphFlags | FT_ADVANCE_FLAG_FAST_ONLY,
1025 &advance );
1026 if (0 == error) {
1027 glyph->fRsbDelta = 0;
1028 glyph->fLsbDelta = 0;
1029 glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, advance);
1030 glyph->fAdvanceY = - SkFixedMul(fMatrix22.yx, advance);
1031 return;
1032 }
1033 }
1034
1035 /* otherwise, we need to load/hint the glyph, which is slower */
1036 this->generateMetrics(glyph);
1037 return;
1038 }
1039
getBBoxForCurrentGlyph(SkGlyph * glyph,FT_BBox * bbox,bool snapToPixelBoundary)1040 void SkScalerContext_FreeType::getBBoxForCurrentGlyph(SkGlyph* glyph,
1041 FT_BBox* bbox,
1042 bool snapToPixelBoundary) {
1043
1044 FT_Outline_Get_CBox(&fFace->glyph->outline, bbox);
1045
1046 if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) {
1047 int dx = SkFixedToFDot6(glyph->getSubXFixed());
1048 int dy = SkFixedToFDot6(glyph->getSubYFixed());
1049 // negate dy since freetype-y-goes-up and skia-y-goes-down
1050 bbox->xMin += dx;
1051 bbox->yMin -= dy;
1052 bbox->xMax += dx;
1053 bbox->yMax -= dy;
1054 }
1055
1056 // outset the box to integral boundaries
1057 if (snapToPixelBoundary) {
1058 bbox->xMin &= ~63;
1059 bbox->yMin &= ~63;
1060 bbox->xMax = (bbox->xMax + 63) & ~63;
1061 bbox->yMax = (bbox->yMax + 63) & ~63;
1062 }
1063
1064 // Must come after snapToPixelBoundary so that the width and height are
1065 // consistent. Otherwise asserts will fire later on when generating the
1066 // glyph image.
1067 if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
1068 FT_Vector vector;
1069 vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
1070 vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
1071 FT_Vector_Transform(&vector, &fMatrix22);
1072 bbox->xMin += vector.x;
1073 bbox->xMax += vector.x;
1074 bbox->yMin += vector.y;
1075 bbox->yMax += vector.y;
1076 }
1077 }
1078
getCBoxForLetter(char letter,FT_BBox * bbox)1079 bool SkScalerContext_FreeType::getCBoxForLetter(char letter, FT_BBox* bbox) {
1080 const FT_UInt glyph_id = FT_Get_Char_Index(fFace, letter);
1081 if (!glyph_id) {
1082 return false;
1083 }
1084 if (FT_Load_Glyph(fFace, glyph_id, fLoadGlyphFlags) != 0) {
1085 return false;
1086 }
1087 emboldenIfNeeded(fFace, fFace->glyph);
1088 FT_Outline_Get_CBox(&fFace->glyph->outline, bbox);
1089 return true;
1090 }
1091
updateGlyphIfLCD(SkGlyph * glyph)1092 void SkScalerContext_FreeType::updateGlyphIfLCD(SkGlyph* glyph) {
1093 if (isLCD(fRec)) {
1094 if (fLCDIsVert) {
1095 glyph->fHeight += gFTLibrary->lcdExtra();
1096 glyph->fTop -= gFTLibrary->lcdExtra() >> 1;
1097 } else {
1098 glyph->fWidth += gFTLibrary->lcdExtra();
1099 glyph->fLeft -= gFTLibrary->lcdExtra() >> 1;
1100 }
1101 }
1102 }
1103
scaleGlyphMetrics(SkGlyph & glyph,SkScalar scale)1104 inline void scaleGlyphMetrics(SkGlyph& glyph, SkScalar scale) {
1105 glyph.fWidth *= scale;
1106 glyph.fHeight *= scale;
1107 glyph.fTop *= scale;
1108 glyph.fLeft *= scale;
1109
1110 SkFixed fixedScale = SkScalarToFixed(scale);
1111 glyph.fAdvanceX = SkFixedMul(glyph.fAdvanceX, fixedScale);
1112 glyph.fAdvanceY = SkFixedMul(glyph.fAdvanceY, fixedScale);
1113 }
1114
generateMetrics(SkGlyph * glyph)1115 void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) {
1116 SkAutoMutexAcquire ac(gFTMutex);
1117
1118 glyph->fRsbDelta = 0;
1119 glyph->fLsbDelta = 0;
1120
1121 FT_Error err;
1122
1123 if (this->setupSize()) {
1124 glyph->zeroMetrics();
1125 return;
1126 }
1127
1128 err = FT_Load_Glyph( fFace, glyph->getGlyphID(), fLoadGlyphFlags );
1129 if (err != 0) {
1130 glyph->zeroMetrics();
1131 return;
1132 }
1133 emboldenIfNeeded(fFace, fFace->glyph);
1134
1135 switch ( fFace->glyph->format ) {
1136 case FT_GLYPH_FORMAT_OUTLINE:
1137 if (0 == fFace->glyph->outline.n_contours) {
1138 glyph->fWidth = 0;
1139 glyph->fHeight = 0;
1140 glyph->fTop = 0;
1141 glyph->fLeft = 0;
1142 } else {
1143 FT_BBox bbox;
1144 getBBoxForCurrentGlyph(glyph, &bbox, true);
1145
1146 glyph->fWidth = SkToU16(SkFDot6Floor(bbox.xMax - bbox.xMin));
1147 glyph->fHeight = SkToU16(SkFDot6Floor(bbox.yMax - bbox.yMin));
1148 glyph->fTop = -SkToS16(SkFDot6Floor(bbox.yMax));
1149 glyph->fLeft = SkToS16(SkFDot6Floor(bbox.xMin));
1150
1151 updateGlyphIfLCD(glyph);
1152 }
1153 break;
1154
1155 case FT_GLYPH_FORMAT_BITMAP:
1156 if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
1157 FT_Vector vector;
1158 vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
1159 vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
1160 FT_Vector_Transform(&vector, &fMatrix22);
1161 fFace->glyph->bitmap_left += SkFDot6Floor(vector.x);
1162 fFace->glyph->bitmap_top += SkFDot6Floor(vector.y);
1163 }
1164
1165 if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_BGRA) {
1166 glyph->fMaskFormat = SkMask::kARGB32_Format;
1167 }
1168
1169 glyph->fWidth = SkToU16(fFace->glyph->bitmap.width);
1170 glyph->fHeight = SkToU16(fFace->glyph->bitmap.rows);
1171 glyph->fTop = -SkToS16(fFace->glyph->bitmap_top);
1172 glyph->fLeft = SkToS16(fFace->glyph->bitmap_left);
1173 break;
1174
1175 default:
1176 SkDEBUGFAIL("unknown glyph format");
1177 glyph->zeroMetrics();
1178 return;
1179 }
1180
1181 if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
1182 if (fDoLinearMetrics) {
1183 glyph->fAdvanceX = -SkFixedMul(fMatrix22.xy, fFace->glyph->linearVertAdvance);
1184 glyph->fAdvanceY = SkFixedMul(fMatrix22.yy, fFace->glyph->linearVertAdvance);
1185 } else {
1186 glyph->fAdvanceX = -SkFDot6ToFixed(fFace->glyph->advance.x);
1187 glyph->fAdvanceY = SkFDot6ToFixed(fFace->glyph->advance.y);
1188 }
1189 } else {
1190 if (fDoLinearMetrics) {
1191 glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance);
1192 glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance);
1193 } else {
1194 glyph->fAdvanceX = SkFDot6ToFixed(fFace->glyph->advance.x);
1195 glyph->fAdvanceY = -SkFDot6ToFixed(fFace->glyph->advance.y);
1196
1197 if (fRec.fFlags & kDevKernText_Flag) {
1198 glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta);
1199 glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta);
1200 }
1201 }
1202 }
1203
1204 // If the font isn't scalable, scale the metrics from the non-scalable strike.
1205 // This means do not try to scale embedded bitmaps; only scale bitmaps in bitmap only fonts.
1206 if (!FT_IS_SCALABLE(fFace) && !SkScalarNearlyZero(fScale.fY) && fFace->size->metrics.y_ppem) {
1207 // NOTE: both dimensions are scaled by y_ppem. this is WAI.
1208 scaleGlyphMetrics(*glyph, fScale.fY / fFace->size->metrics.y_ppem);
1209 }
1210
1211 #ifdef ENABLE_GLYPH_SPEW
1212 SkDEBUGF(("FT_Set_Char_Size(this:%p sx:%x sy:%x ", this, fScaleX, fScaleY));
1213 SkDEBUGF(("Metrics(glyph:%d flags:0x%x) w:%d\n", glyph->getGlyphID(), fLoadGlyphFlags, glyph->fWidth));
1214 #endif
1215 }
1216
clear_glyph_image(const SkGlyph & glyph)1217 static void clear_glyph_image(const SkGlyph& glyph) {
1218 sk_bzero(glyph.fImage, glyph.rowBytes() * glyph.fHeight);
1219 }
1220
generateImage(const SkGlyph & glyph)1221 void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) {
1222 SkAutoMutexAcquire ac(gFTMutex);
1223
1224 if (this->setupSize()) {
1225 clear_glyph_image(glyph);
1226 return;
1227 }
1228
1229 FT_Error err = FT_Load_Glyph(fFace, glyph.getGlyphID(), fLoadGlyphFlags);
1230 if (err != 0) {
1231 SkDEBUGF(("SkScalerContext_FreeType::generateImage: FT_Load_Glyph(glyph:%d width:%d height:%d rb:%d flags:%d) returned 0x%x\n",
1232 glyph.getGlyphID(), glyph.fWidth, glyph.fHeight, glyph.rowBytes(), fLoadGlyphFlags, err));
1233 clear_glyph_image(glyph);
1234 return;
1235 }
1236
1237 emboldenIfNeeded(fFace, fFace->glyph);
1238 generateGlyphImage(fFace, glyph);
1239 }
1240
1241
generatePath(const SkGlyph & glyph,SkPath * path)1242 void SkScalerContext_FreeType::generatePath(const SkGlyph& glyph, SkPath* path) {
1243 SkAutoMutexAcquire ac(gFTMutex);
1244
1245 SkASSERT(path);
1246
1247 if (this->setupSize()) {
1248 path->reset();
1249 return;
1250 }
1251
1252 uint32_t flags = fLoadGlyphFlags;
1253 flags |= FT_LOAD_NO_BITMAP; // ignore embedded bitmaps so we're sure to get the outline
1254 flags &= ~FT_LOAD_RENDER; // don't scan convert (we just want the outline)
1255
1256 FT_Error err = FT_Load_Glyph( fFace, glyph.getGlyphID(), flags);
1257
1258 if (err != 0) {
1259 SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n",
1260 glyph.getGlyphID(), flags, err));
1261 path->reset();
1262 return;
1263 }
1264 emboldenIfNeeded(fFace, fFace->glyph);
1265
1266 generateGlyphPath(fFace, path);
1267
1268 // The path's origin from FreeType is always the horizontal layout origin.
1269 // Offset the path so that it is relative to the vertical origin if needed.
1270 if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
1271 FT_Vector vector;
1272 vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
1273 vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
1274 FT_Vector_Transform(&vector, &fMatrix22);
1275 path->offset(SkFDot6ToScalar(vector.x), -SkFDot6ToScalar(vector.y));
1276 }
1277 }
1278
generateFontMetrics(SkPaint::FontMetrics * metrics)1279 void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* metrics) {
1280 if (nullptr == metrics) {
1281 return;
1282 }
1283
1284 SkAutoMutexAcquire ac(gFTMutex);
1285
1286 if (this->setupSize()) {
1287 ERROR:
1288 sk_bzero(metrics, sizeof(*metrics));
1289 return;
1290 }
1291
1292 FT_Face face = fFace;
1293 SkScalar scaleX = fScale.x();
1294 SkScalar scaleY = fScale.y();
1295 SkScalar mxy = fMatrix22Scalar.getSkewX() * scaleY;
1296 SkScalar myy = fMatrix22Scalar.getScaleY() * scaleY;
1297
1298 // fetch units/EM from "head" table if needed (ie for bitmap fonts)
1299 SkScalar upem = SkIntToScalar(face->units_per_EM);
1300 if (!upem) {
1301 TT_Header* ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face, ft_sfnt_head);
1302 if (ttHeader) {
1303 upem = SkIntToScalar(ttHeader->Units_Per_EM);
1304 }
1305 }
1306
1307 // use the os/2 table as a source of reasonable defaults.
1308 SkScalar x_height = 0.0f;
1309 SkScalar avgCharWidth = 0.0f;
1310 SkScalar cap_height = 0.0f;
1311 TT_OS2* os2 = (TT_OS2*) FT_Get_Sfnt_Table(face, ft_sfnt_os2);
1312 if (os2) {
1313 x_height = scaleX * SkIntToScalar(os2->sxHeight) / upem;
1314 avgCharWidth = SkIntToScalar(os2->xAvgCharWidth) / upem;
1315 if (os2->version != 0xFFFF && os2->version >= 2) {
1316 cap_height = scaleX * SkIntToScalar(os2->sCapHeight) / upem;
1317 }
1318 }
1319
1320 // pull from format-specific metrics as needed
1321 SkScalar ascent, descent, leading, xmin, xmax, ymin, ymax;
1322 SkScalar underlineThickness, underlinePosition;
1323 if (face->face_flags & FT_FACE_FLAG_SCALABLE) { // scalable outline font
1324 // FreeType will always use HHEA metrics if they're not zero.
1325 // It completely ignores the OS/2 fsSelection::UseTypoMetrics bit.
1326 // It also ignores the VDMX tables, which are also of interest here
1327 // (and override everything else when they apply).
1328 static const int kUseTypoMetricsMask = (1 << 7);
1329 if (os2 && os2->version != 0xFFFF && (os2->fsSelection & kUseTypoMetricsMask)) {
1330 ascent = -SkIntToScalar(os2->sTypoAscender) / upem;
1331 descent = -SkIntToScalar(os2->sTypoDescender) / upem;
1332 leading = SkIntToScalar(os2->sTypoLineGap) / upem;
1333 } else {
1334 ascent = -SkIntToScalar(face->ascender) / upem;
1335 descent = -SkIntToScalar(face->descender) / upem;
1336 leading = SkIntToScalar(face->height + (face->descender - face->ascender)) / upem;
1337 }
1338 xmin = SkIntToScalar(face->bbox.xMin) / upem;
1339 xmax = SkIntToScalar(face->bbox.xMax) / upem;
1340 ymin = -SkIntToScalar(face->bbox.yMin) / upem;
1341 ymax = -SkIntToScalar(face->bbox.yMax) / upem;
1342 underlineThickness = SkIntToScalar(face->underline_thickness) / upem;
1343 underlinePosition = -SkIntToScalar(face->underline_position +
1344 face->underline_thickness / 2) / upem;
1345
1346 metrics->fFlags |= SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag;
1347 metrics->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
1348
1349 // we may be able to synthesize x_height and cap_height from outline
1350 if (!x_height) {
1351 FT_BBox bbox;
1352 if (getCBoxForLetter('x', &bbox)) {
1353 x_height = SkIntToScalar(bbox.yMax) / 64.0f;
1354 }
1355 }
1356 if (!cap_height) {
1357 FT_BBox bbox;
1358 if (getCBoxForLetter('H', &bbox)) {
1359 cap_height = SkIntToScalar(bbox.yMax) / 64.0f;
1360 }
1361 }
1362 } else if (fStrikeIndex != -1) { // bitmap strike metrics
1363 SkScalar xppem = SkIntToScalar(face->size->metrics.x_ppem);
1364 SkScalar yppem = SkIntToScalar(face->size->metrics.y_ppem);
1365 ascent = -SkIntToScalar(face->size->metrics.ascender) / (yppem * 64.0f);
1366 descent = -SkIntToScalar(face->size->metrics.descender) / (yppem * 64.0f);
1367 leading = (SkIntToScalar(face->size->metrics.height) / (yppem * 64.0f))
1368 + ascent - descent;
1369 xmin = 0.0f;
1370 xmax = SkIntToScalar(face->available_sizes[fStrikeIndex].width) / xppem;
1371 ymin = descent + leading;
1372 ymax = ascent - descent;
1373 underlineThickness = 0;
1374 underlinePosition = 0;
1375
1376 metrics->fFlags &= ~SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag;
1377 metrics->fFlags &= ~SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
1378 } else {
1379 goto ERROR;
1380 }
1381
1382 // synthesize elements that were not provided by the os/2 table or format-specific metrics
1383 if (!x_height) {
1384 x_height = -ascent;
1385 }
1386 if (!avgCharWidth) {
1387 avgCharWidth = xmax - xmin;
1388 }
1389 if (!cap_height) {
1390 cap_height = -ascent;
1391 }
1392
1393 // disallow negative linespacing
1394 if (leading < 0.0f) {
1395 leading = 0.0f;
1396 }
1397
1398 SkScalar scale = myy;
1399 if (this->isVertical()) {
1400 scale = mxy;
1401 }
1402 metrics->fTop = ymax * scale;
1403 metrics->fAscent = ascent * scale;
1404 metrics->fDescent = descent * scale;
1405 metrics->fBottom = ymin * scale;
1406 metrics->fLeading = leading * scale;
1407 metrics->fAvgCharWidth = avgCharWidth * scale;
1408 metrics->fXMin = xmin * scale;
1409 metrics->fXMax = xmax * scale;
1410 metrics->fXHeight = x_height;
1411 metrics->fCapHeight = cap_height;
1412 metrics->fUnderlineThickness = underlineThickness * scale;
1413 metrics->fUnderlinePosition = underlinePosition * scale;
1414 }
1415
1416 ///////////////////////////////////////////////////////////////////////////////
1417
1418 // hand-tuned value to reduce outline embolden strength
1419 #ifndef SK_OUTLINE_EMBOLDEN_DIVISOR
1420 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
1421 #define SK_OUTLINE_EMBOLDEN_DIVISOR 34
1422 #else
1423 #define SK_OUTLINE_EMBOLDEN_DIVISOR 24
1424 #endif
1425 #endif
1426
1427 ///////////////////////////////////////////////////////////////////////////////
1428
emboldenIfNeeded(FT_Face face,FT_GlyphSlot glyph)1429 void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph)
1430 {
1431 // check to see if the embolden bit is set
1432 if (0 == (fRec.fFlags & SkScalerContext::kEmbolden_Flag)) {
1433 return;
1434 }
1435
1436 switch (glyph->format) {
1437 case FT_GLYPH_FORMAT_OUTLINE:
1438 FT_Pos strength;
1439 strength = FT_MulFix(face->units_per_EM, face->size->metrics.y_scale)
1440 / SK_OUTLINE_EMBOLDEN_DIVISOR;
1441 FT_Outline_Embolden(&glyph->outline, strength);
1442 break;
1443 case FT_GLYPH_FORMAT_BITMAP:
1444 FT_GlyphSlot_Own_Bitmap(glyph);
1445 FT_Bitmap_Embolden(glyph->library, &glyph->bitmap, kBitmapEmboldenStrength, 0);
1446 break;
1447 default:
1448 SkDEBUGFAIL("unknown glyph format");
1449 }
1450 }
1451
1452 ///////////////////////////////////////////////////////////////////////////////
1453
1454 #include "SkUtils.h"
1455
next_utf8(const void ** chars)1456 static SkUnichar next_utf8(const void** chars) {
1457 return SkUTF8_NextUnichar((const char**)chars);
1458 }
1459
next_utf16(const void ** chars)1460 static SkUnichar next_utf16(const void** chars) {
1461 return SkUTF16_NextUnichar((const uint16_t**)chars);
1462 }
1463
next_utf32(const void ** chars)1464 static SkUnichar next_utf32(const void** chars) {
1465 const SkUnichar** uniChars = (const SkUnichar**)chars;
1466 SkUnichar uni = **uniChars;
1467 *uniChars += 1;
1468 return uni;
1469 }
1470
1471 typedef SkUnichar (*EncodingProc)(const void**);
1472
find_encoding_proc(SkTypeface::Encoding enc)1473 static EncodingProc find_encoding_proc(SkTypeface::Encoding enc) {
1474 static const EncodingProc gProcs[] = {
1475 next_utf8, next_utf16, next_utf32
1476 };
1477 SkASSERT((size_t)enc < SK_ARRAY_COUNT(gProcs));
1478 return gProcs[enc];
1479 }
1480
onCharsToGlyphs(const void * chars,Encoding encoding,uint16_t glyphs[],int glyphCount) const1481 int SkTypeface_FreeType::onCharsToGlyphs(const void* chars, Encoding encoding,
1482 uint16_t glyphs[], int glyphCount) const
1483 {
1484 AutoFTAccess fta(this);
1485 FT_Face face = fta.face();
1486 if (!face) {
1487 if (glyphs) {
1488 sk_bzero(glyphs, glyphCount * sizeof(glyphs[0]));
1489 }
1490 return 0;
1491 }
1492
1493 EncodingProc next_uni_proc = find_encoding_proc(encoding);
1494
1495 if (nullptr == glyphs) {
1496 for (int i = 0; i < glyphCount; ++i) {
1497 if (0 == FT_Get_Char_Index(face, next_uni_proc(&chars))) {
1498 return i;
1499 }
1500 }
1501 return glyphCount;
1502 } else {
1503 int first = glyphCount;
1504 for (int i = 0; i < glyphCount; ++i) {
1505 unsigned id = FT_Get_Char_Index(face, next_uni_proc(&chars));
1506 glyphs[i] = SkToU16(id);
1507 if (0 == id && i < first) {
1508 first = i;
1509 }
1510 }
1511 return first;
1512 }
1513 }
1514
onCountGlyphs() const1515 int SkTypeface_FreeType::onCountGlyphs() const {
1516 // we cache this value, using -1 as a sentinel for "not computed"
1517 if (fGlyphCount < 0) {
1518 AutoFTAccess fta(this);
1519 FT_Face face = fta.face();
1520 // if the face failed, we still assign a non-negative value
1521 fGlyphCount = face ? face->num_glyphs : 0;
1522 }
1523 return fGlyphCount;
1524 }
1525
onCreateFamilyNameIterator() const1526 SkTypeface::LocalizedStrings* SkTypeface_FreeType::onCreateFamilyNameIterator() const {
1527 SkTypeface::LocalizedStrings* nameIter =
1528 SkOTUtils::LocalizedStrings_NameTable::CreateForFamilyNames(*this);
1529 if (nullptr == nameIter) {
1530 SkString familyName;
1531 this->getFamilyName(&familyName);
1532 SkString language("und"); //undetermined
1533 nameIter = new SkOTUtils::LocalizedStrings_SingleName(familyName, language);
1534 }
1535 return nameIter;
1536 }
1537
onGetTableTags(SkFontTableTag tags[]) const1538 int SkTypeface_FreeType::onGetTableTags(SkFontTableTag tags[]) const {
1539 AutoFTAccess fta(this);
1540 FT_Face face = fta.face();
1541
1542 FT_ULong tableCount = 0;
1543 FT_Error error;
1544
1545 // When 'tag' is nullptr, returns number of tables in 'length'.
1546 error = FT_Sfnt_Table_Info(face, 0, nullptr, &tableCount);
1547 if (error) {
1548 return 0;
1549 }
1550
1551 if (tags) {
1552 for (FT_ULong tableIndex = 0; tableIndex < tableCount; ++tableIndex) {
1553 FT_ULong tableTag;
1554 FT_ULong tablelength;
1555 error = FT_Sfnt_Table_Info(face, tableIndex, &tableTag, &tablelength);
1556 if (error) {
1557 return 0;
1558 }
1559 tags[tableIndex] = static_cast<SkFontTableTag>(tableTag);
1560 }
1561 }
1562 return tableCount;
1563 }
1564
onGetTableData(SkFontTableTag tag,size_t offset,size_t length,void * data) const1565 size_t SkTypeface_FreeType::onGetTableData(SkFontTableTag tag, size_t offset,
1566 size_t length, void* data) const
1567 {
1568 AutoFTAccess fta(this);
1569 FT_Face face = fta.face();
1570
1571 FT_ULong tableLength = 0;
1572 FT_Error error;
1573
1574 // When 'length' is 0 it is overwritten with the full table length; 'offset' is ignored.
1575 error = FT_Load_Sfnt_Table(face, tag, 0, nullptr, &tableLength);
1576 if (error) {
1577 return 0;
1578 }
1579
1580 if (offset > tableLength) {
1581 return 0;
1582 }
1583 FT_ULong size = SkTMin((FT_ULong)length, tableLength - (FT_ULong)offset);
1584 if (data) {
1585 error = FT_Load_Sfnt_Table(face, tag, offset, reinterpret_cast<FT_Byte*>(data), &size);
1586 if (error) {
1587 return 0;
1588 }
1589 }
1590
1591 return size;
1592 }
1593
1594 ///////////////////////////////////////////////////////////////////////////////
1595 ///////////////////////////////////////////////////////////////////////////////
1596
Scanner()1597 SkTypeface_FreeType::Scanner::Scanner() : fLibrary(nullptr) {
1598 if (FT_New_Library(&gFTMemory, &fLibrary)) {
1599 return;
1600 }
1601 FT_Add_Default_Modules(fLibrary);
1602 }
~Scanner()1603 SkTypeface_FreeType::Scanner::~Scanner() {
1604 if (fLibrary) {
1605 FT_Done_Library(fLibrary);
1606 }
1607 }
1608
openFace(SkStream * stream,int ttcIndex,FT_Stream ftStream) const1609 FT_Face SkTypeface_FreeType::Scanner::openFace(SkStream* stream, int ttcIndex,
1610 FT_Stream ftStream) const
1611 {
1612 if (fLibrary == nullptr) {
1613 return nullptr;
1614 }
1615
1616 FT_Open_Args args;
1617 memset(&args, 0, sizeof(args));
1618
1619 const void* memoryBase = stream->getMemoryBase();
1620
1621 if (memoryBase) {
1622 args.flags = FT_OPEN_MEMORY;
1623 args.memory_base = (const FT_Byte*)memoryBase;
1624 args.memory_size = stream->getLength();
1625 } else {
1626 memset(ftStream, 0, sizeof(*ftStream));
1627 ftStream->size = stream->getLength();
1628 ftStream->descriptor.pointer = stream;
1629 ftStream->read = sk_ft_stream_io;
1630 ftStream->close = sk_ft_stream_close;
1631
1632 args.flags = FT_OPEN_STREAM;
1633 args.stream = ftStream;
1634 }
1635
1636 FT_Face face;
1637 if (FT_Open_Face(fLibrary, &args, ttcIndex, &face)) {
1638 return nullptr;
1639 }
1640 return face;
1641 }
1642
recognizedFont(SkStream * stream,int * numFaces) const1643 bool SkTypeface_FreeType::Scanner::recognizedFont(SkStream* stream, int* numFaces) const {
1644 SkAutoMutexAcquire libraryLock(fLibraryMutex);
1645
1646 FT_StreamRec streamRec;
1647 FT_Face face = this->openFace(stream, -1, &streamRec);
1648 if (nullptr == face) {
1649 return false;
1650 }
1651
1652 *numFaces = face->num_faces;
1653
1654 FT_Done_Face(face);
1655 return true;
1656 }
1657
1658 #include "SkTSearch.h"
scanFont(SkStream * stream,int ttcIndex,SkString * name,SkFontStyle * style,bool * isFixedPitch,AxisDefinitions * axes) const1659 bool SkTypeface_FreeType::Scanner::scanFont(
1660 SkStream* stream, int ttcIndex,
1661 SkString* name, SkFontStyle* style, bool* isFixedPitch, AxisDefinitions* axes) const
1662 {
1663 SkAutoMutexAcquire libraryLock(fLibraryMutex);
1664
1665 FT_StreamRec streamRec;
1666 FT_Face face = this->openFace(stream, ttcIndex, &streamRec);
1667 if (nullptr == face) {
1668 return false;
1669 }
1670
1671 int weight = SkFontStyle::kNormal_Weight;
1672 int width = SkFontStyle::kNormal_Width;
1673 SkFontStyle::Slant slant = SkFontStyle::kUpright_Slant;
1674 if (face->style_flags & FT_STYLE_FLAG_BOLD) {
1675 weight = SkFontStyle::kBold_Weight;
1676 }
1677 if (face->style_flags & FT_STYLE_FLAG_ITALIC) {
1678 slant = SkFontStyle::kItalic_Slant;
1679 }
1680
1681 PS_FontInfoRec psFontInfo;
1682 TT_OS2* os2 = static_cast<TT_OS2*>(FT_Get_Sfnt_Table(face, ft_sfnt_os2));
1683 if (os2 && os2->version != 0xffff) {
1684 weight = os2->usWeightClass;
1685 width = os2->usWidthClass;
1686 } else if (0 == FT_Get_PS_Font_Info(face, &psFontInfo) && psFontInfo.weight) {
1687 static const struct {
1688 char const * const name;
1689 int const weight;
1690 } commonWeights [] = {
1691 // There are probably more common names, but these are known to exist.
1692 { "all", SkFontStyle::kNormal_Weight }, // Multiple Masters usually default to normal.
1693 { "black", SkFontStyle::kBlack_Weight },
1694 { "bold", SkFontStyle::kBold_Weight },
1695 { "book", (SkFontStyle::kNormal_Weight + SkFontStyle::kLight_Weight)/2 },
1696 { "demi", SkFontStyle::kSemiBold_Weight },
1697 { "demibold", SkFontStyle::kSemiBold_Weight },
1698 { "extra", SkFontStyle::kExtraBold_Weight },
1699 { "extrabold", SkFontStyle::kExtraBold_Weight },
1700 { "extralight", SkFontStyle::kExtraLight_Weight },
1701 { "hairline", SkFontStyle::kThin_Weight },
1702 { "heavy", SkFontStyle::kBlack_Weight },
1703 { "light", SkFontStyle::kLight_Weight },
1704 { "medium", SkFontStyle::kMedium_Weight },
1705 { "normal", SkFontStyle::kNormal_Weight },
1706 { "plain", SkFontStyle::kNormal_Weight },
1707 { "regular", SkFontStyle::kNormal_Weight },
1708 { "roman", SkFontStyle::kNormal_Weight },
1709 { "semibold", SkFontStyle::kSemiBold_Weight },
1710 { "standard", SkFontStyle::kNormal_Weight },
1711 { "thin", SkFontStyle::kThin_Weight },
1712 { "ultra", SkFontStyle::kExtraBold_Weight },
1713 { "ultrablack", 1000 },
1714 { "ultrabold", SkFontStyle::kExtraBold_Weight },
1715 { "ultraheavy", 1000 },
1716 { "ultralight", SkFontStyle::kExtraLight_Weight },
1717 };
1718 int const index = SkStrLCSearch(&commonWeights[0].name, SK_ARRAY_COUNT(commonWeights),
1719 psFontInfo.weight, sizeof(commonWeights[0]));
1720 if (index >= 0) {
1721 weight = commonWeights[index].weight;
1722 } else {
1723 SkDEBUGF(("Do not know weight for: %s (%s) \n", face->family_name, psFontInfo.weight));
1724 }
1725 }
1726
1727 if (name) {
1728 name->set(face->family_name);
1729 }
1730 if (style) {
1731 *style = SkFontStyle(weight, width, slant);
1732 }
1733 if (isFixedPitch) {
1734 *isFixedPitch = FT_IS_FIXED_WIDTH(face);
1735 }
1736
1737 if (axes && face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS) {
1738 FT_MM_Var* variations = nullptr;
1739 FT_Error err = FT_Get_MM_Var(face, &variations);
1740 if (err) {
1741 SkDEBUGF(("INFO: font %s claims to have variations, but none found.\n",
1742 face->family_name));
1743 return false;
1744 }
1745 SkAutoFree autoFreeVariations(variations);
1746
1747 axes->reset(variations->num_axis);
1748 for (FT_UInt i = 0; i < variations->num_axis; ++i) {
1749 const FT_Var_Axis& ftAxis = variations->axis[i];
1750 (*axes)[i].fTag = ftAxis.tag;
1751 (*axes)[i].fMinimum = ftAxis.minimum;
1752 (*axes)[i].fDefault = ftAxis.def;
1753 (*axes)[i].fMaximum = ftAxis.maximum;
1754 }
1755 }
1756
1757 FT_Done_Face(face);
1758 return true;
1759 }
1760
computeAxisValues(AxisDefinitions axisDefinitions,const SkFontMgr::FontParameters::Axis * requestedAxes,int requestedAxisCount,SkFixed * axisValues,const SkString & name)1761 /*static*/ void SkTypeface_FreeType::Scanner::computeAxisValues(
1762 AxisDefinitions axisDefinitions,
1763 const SkFontMgr::FontParameters::Axis* requestedAxes, int requestedAxisCount,
1764 SkFixed* axisValues,
1765 const SkString& name)
1766 {
1767 for (int i = 0; i < axisDefinitions.count(); ++i) {
1768 const Scanner::AxisDefinition& axisDefinition = axisDefinitions[i];
1769 const SkScalar axisMin = SkFixedToScalar(axisDefinition.fMinimum);
1770 const SkScalar axisMax = SkFixedToScalar(axisDefinition.fMaximum);
1771 axisValues[i] = axisDefinition.fDefault;
1772 for (int j = 0; j < requestedAxisCount; ++j) {
1773 const SkFontMgr::FontParameters::Axis& axisSpecified = requestedAxes[j];
1774 if (axisDefinition.fTag == axisSpecified.fTag) {
1775 const SkScalar axisValue = SkTPin(axisSpecified.fStyleValue, axisMin, axisMax);
1776 if (axisSpecified.fStyleValue != axisValue) {
1777 SkDEBUGF(("Requested font axis value out of range: "
1778 "%s '%c%c%c%c' %f; pinned to %f.\n",
1779 name.c_str(),
1780 (axisDefinition.fTag >> 24) & 0xFF,
1781 (axisDefinition.fTag >> 16) & 0xFF,
1782 (axisDefinition.fTag >> 8) & 0xFF,
1783 (axisDefinition.fTag ) & 0xFF,
1784 SkScalarToDouble(axisSpecified.fStyleValue),
1785 SkScalarToDouble(axisValue)));
1786 }
1787 axisValues[i] = SkScalarToFixed(axisValue);
1788 break;
1789 }
1790 }
1791 // TODO: warn on defaulted axis?
1792 }
1793
1794 SkDEBUGCODE(
1795 // Check for axis specified, but not matched in font.
1796 for (int i = 0; i < requestedAxisCount; ++i) {
1797 SkFourByteTag skTag = requestedAxes[i].fTag;
1798 bool found = false;
1799 for (int j = 0; j < axisDefinitions.count(); ++j) {
1800 if (skTag == axisDefinitions[j].fTag) {
1801 found = true;
1802 break;
1803 }
1804 }
1805 if (!found) {
1806 SkDEBUGF(("Requested font axis not found: %s '%c%c%c%c'\n",
1807 name.c_str(),
1808 (skTag >> 24) & 0xFF,
1809 (skTag >> 16) & 0xFF,
1810 (skTag >> 8) & 0xFF,
1811 (skTag) & 0xFF));
1812 }
1813 }
1814 )
1815 }
1816