/* * Copyright 2006 The Android Open Source Project * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "SkAdvancedTypefaceMetrics.h" #include "SkBitmap.h" #include "SkCanvas.h" #include "SkColorPriv.h" #include "SkDescriptor.h" #include "SkFDot6.h" #include "SkFontDescriptor.h" #include "SkFontHost_FreeType_common.h" #include "SkGlyph.h" #include "SkMask.h" #include "SkMaskGamma.h" #include "SkMatrix22.h" #include "SkMutex.h" #include "SkOTUtils.h" #include "SkPath.h" #include "SkScalerContext.h" #include "SkStream.h" #include "SkString.h" #include "SkTemplates.h" #include "SkTypes.h" #if defined(SK_CAN_USE_DLOPEN) #include #endif #include #include FT_ADVANCES_H #include FT_BITMAP_H #include FT_FREETYPE_H #include FT_LCD_FILTER_H #include FT_MODULE_H #include FT_MULTIPLE_MASTERS_H #include FT_OUTLINE_H #include FT_SIZES_H #include FT_SYSTEM_H #include FT_TRUETYPE_TABLES_H #include FT_TYPE1_TABLES_H #include FT_XFREE86_H // FT_LOAD_COLOR and the corresponding FT_Pixel_Mode::FT_PIXEL_MODE_BGRA // were introduced in FreeType 2.5.0. // The following may be removed once FreeType 2.5.0 is required to build. #ifndef FT_LOAD_COLOR # define FT_LOAD_COLOR ( 1L << 20 ) # define FT_PIXEL_MODE_BGRA 7 #endif //#define ENABLE_GLYPH_SPEW // for tracing calls //#define DUMP_STRIKE_CREATION //#define SK_FONTHOST_FREETYPE_USE_NORMAL_LCD_FILTER //#define SK_FONTHOST_FREETYPE_RUNTIME_VERSION //#define SK_GAMMA_APPLY_TO_A8 using namespace skia_advanced_typeface_metrics_utils; static bool isLCD(const SkScalerContext::Rec& rec) { return SkMask::kLCD16_Format == rec.fMaskFormat; } ////////////////////////////////////////////////////////////////////////// extern "C" { static void* sk_ft_alloc(FT_Memory, long size) { return sk_malloc_throw(size); } static void sk_ft_free(FT_Memory, void* block) { sk_free(block); } static void* sk_ft_realloc(FT_Memory, long cur_size, long new_size, void* block) { return sk_realloc_throw(block, new_size); } }; FT_MemoryRec_ gFTMemory = { nullptr, sk_ft_alloc, sk_ft_free, sk_ft_realloc }; class FreeTypeLibrary : SkNoncopyable { public: FreeTypeLibrary() : fLibrary(nullptr), fIsLCDSupported(false), fLCDExtra(0) { if (FT_New_Library(&gFTMemory, &fLibrary)) { return; } FT_Add_Default_Modules(fLibrary); // Setup LCD filtering. This reduces color fringes for LCD smoothed glyphs. // Default { 0x10, 0x40, 0x70, 0x40, 0x10 } adds up to 0x110, simulating ink spread. // SetLcdFilter must be called before SetLcdFilterWeights. if (FT_Library_SetLcdFilter(fLibrary, FT_LCD_FILTER_DEFAULT) == 0) { fIsLCDSupported = true; fLCDExtra = 2; //Using a filter adds one full pixel to each side. #ifdef SK_FONTHOST_FREETYPE_USE_NORMAL_LCD_FILTER // Adds to 0x110 simulating ink spread, but provides better results than default. static unsigned char gGaussianLikeHeavyWeights[] = { 0x1A, 0x43, 0x56, 0x43, 0x1A, }; # if SK_FONTHOST_FREETYPE_RUNTIME_VERSION > 0x020400 FT_Library_SetLcdFilterWeights(fLibrary, gGaussianLikeHeavyWeights); # elif SK_CAN_USE_DLOPEN == 1 //The FreeType library is already loaded, so symbols are available in process. void* self = dlopen(nullptr, RTLD_LAZY); if (self) { FT_Library_SetLcdFilterWeightsProc setLcdFilterWeights; //The following cast is non-standard, but safe for POSIX. *reinterpret_cast(&setLcdFilterWeights) = dlsym(self, "FT_Library_SetLcdFilterWeights"); dlclose(self); if (setLcdFilterWeights) { setLcdFilterWeights(fLibrary, gGaussianLikeHeavyWeights); } } # endif #endif } } ~FreeTypeLibrary() { if (fLibrary) { FT_Done_Library(fLibrary); } } FT_Library library() { return fLibrary; } bool isLCDSupported() { return fIsLCDSupported; } int lcdExtra() { return fLCDExtra; } private: FT_Library fLibrary; bool fIsLCDSupported; int fLCDExtra; // FT_Library_SetLcdFilterWeights was introduced in FreeType 2.4.0. // The following platforms provide FreeType of at least 2.4.0. // Ubuntu >= 11.04 (previous deprecated April 2013) // Debian >= 6.0 (good) // OpenSuse >= 11.4 (previous deprecated January 2012 / Nov 2013 for Evergreen 11.2) // Fedora >= 14 (good) // Android >= Gingerbread (good) typedef FT_Error (*FT_Library_SetLcdFilterWeightsProc)(FT_Library, unsigned char*); }; struct SkFaceRec; SK_DECLARE_STATIC_MUTEX(gFTMutex); static FreeTypeLibrary* gFTLibrary; static SkFaceRec* gFaceRecHead; // Private to RefFreeType and UnrefFreeType static int gFTCount; // Caller must lock gFTMutex before calling this function. static bool ref_ft_library() { gFTMutex.assertHeld(); SkASSERT(gFTCount >= 0); if (0 == gFTCount) { SkASSERT(nullptr == gFTLibrary); gFTLibrary = new FreeTypeLibrary; } ++gFTCount; return gFTLibrary->library(); } // Caller must lock gFTMutex before calling this function. static void unref_ft_library() { gFTMutex.assertHeld(); SkASSERT(gFTCount > 0); --gFTCount; if (0 == gFTCount) { SkASSERT(nullptr != gFTLibrary); delete gFTLibrary; SkDEBUGCODE(gFTLibrary = nullptr;) } } class SkScalerContext_FreeType : public SkScalerContext_FreeType_Base { public: SkScalerContext_FreeType(SkTypeface*, const SkDescriptor* desc); virtual ~SkScalerContext_FreeType(); bool success() const { return fFTSize != nullptr && fFace != nullptr; } protected: unsigned generateGlyphCount() override; uint16_t generateCharToGlyph(SkUnichar uni) override; void generateAdvance(SkGlyph* glyph) override; void generateMetrics(SkGlyph* glyph) override; void generateImage(const SkGlyph& glyph) override; void generatePath(const SkGlyph& glyph, SkPath* path) override; void generateFontMetrics(SkPaint::FontMetrics*) override; SkUnichar generateGlyphToChar(uint16_t glyph) override; private: FT_Face fFace; // reference to shared face in gFaceRecHead FT_Size fFTSize; // our own copy FT_Int fStrikeIndex; SkFixed fScaleX, fScaleY; FT_Matrix fMatrix22; uint32_t fLoadGlyphFlags; bool fDoLinearMetrics; bool fLCDIsVert; // Need scalar versions for generateFontMetrics SkVector fScale; SkMatrix fMatrix22Scalar; FT_Error setupSize(); void getBBoxForCurrentGlyph(SkGlyph* glyph, FT_BBox* bbox, bool snapToPixelBoundary = false); bool getCBoxForLetter(char letter, FT_BBox* bbox); // Caller must lock gFTMutex before calling this function. void updateGlyphIfLCD(SkGlyph* glyph); // Caller must lock gFTMutex before calling this function. // update FreeType2 glyph slot with glyph emboldened void emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph); }; /////////////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////// struct SkFaceRec { SkFaceRec* fNext; FT_Face fFace; FT_StreamRec fFTStream; SkAutoTDelete fSkStream; uint32_t fRefCnt; uint32_t fFontID; // assumes ownership of the stream, will delete when its done SkFaceRec(SkStreamAsset* strm, uint32_t fontID); }; extern "C" { static unsigned long sk_ft_stream_io(FT_Stream ftStream, unsigned long offset, unsigned char* buffer, unsigned long count) { SkStreamAsset* stream = static_cast(ftStream->descriptor.pointer); if (count) { if (!stream->seek(offset)) { return 0; } count = stream->read(buffer, count); } return count; } static void sk_ft_stream_close(FT_Stream) {} } SkFaceRec::SkFaceRec(SkStreamAsset* stream, uint32_t fontID) : fNext(nullptr), fSkStream(stream), fRefCnt(1), fFontID(fontID) { sk_bzero(&fFTStream, sizeof(fFTStream)); fFTStream.size = fSkStream->getLength(); fFTStream.descriptor.pointer = fSkStream; fFTStream.read = sk_ft_stream_io; fFTStream.close = sk_ft_stream_close; } static void ft_face_setup_axes(FT_Face face, const SkFontData& data) { if (!(face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS)) { return; } SkDEBUGCODE( FT_MM_Var* variations = nullptr; if (FT_Get_MM_Var(face, &variations)) { SkDEBUGF(("INFO: font %s claims variations, but none found.\n", face->family_name)); return; } SkAutoFree autoFreeVariations(variations); if (static_cast(data.getAxisCount()) != variations->num_axis) { SkDEBUGF(("INFO: font %s has %d variations, but %d were specified.\n", face->family_name, variations->num_axis, data.getAxisCount())); return; } ) SkAutoSTMalloc<4, FT_Fixed> coords(data.getAxisCount()); for (int i = 0; i < data.getAxisCount(); ++i) { coords[i] = data.getAxis()[i]; } if (FT_Set_Var_Design_Coordinates(face, data.getAxisCount(), coords.get())) { SkDEBUGF(("INFO: font %s has variations, but specified variations could not be set.\n", face->family_name)); return; } } // Will return 0 on failure // Caller must lock gFTMutex before calling this function. static FT_Face ref_ft_face(const SkTypeface* typeface) { gFTMutex.assertHeld(); const SkFontID fontID = typeface->uniqueID(); SkFaceRec* rec = gFaceRecHead; while (rec) { if (rec->fFontID == fontID) { SkASSERT(rec->fFace); rec->fRefCnt += 1; return rec->fFace; } rec = rec->fNext; } SkAutoTDelete data(typeface->createFontData()); if (nullptr == data || !data->hasStream()) { return nullptr; } // this passes ownership of stream to the rec rec = new SkFaceRec(data->detachStream(), fontID); FT_Open_Args args; memset(&args, 0, sizeof(args)); const void* memoryBase = rec->fSkStream->getMemoryBase(); if (memoryBase) { args.flags = FT_OPEN_MEMORY; args.memory_base = (const FT_Byte*)memoryBase; args.memory_size = rec->fSkStream->getLength(); } else { args.flags = FT_OPEN_STREAM; args.stream = &rec->fFTStream; } FT_Error err = FT_Open_Face(gFTLibrary->library(), &args, data->getIndex(), &rec->fFace); if (err) { SkDEBUGF(("ERROR: unable to open font '%x'\n", fontID)); delete rec; return nullptr; } SkASSERT(rec->fFace); ft_face_setup_axes(rec->fFace, *data); // FreeType will set the charmap to the "most unicode" cmap if it exists. // If there are no unicode cmaps, the charmap is set to nullptr. // However, "symbol" cmaps should also be considered "fallback unicode" cmaps // because they are effectively private use area only (even if they aren't). // This is the last on the fallback list at // https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6cmap.html if (!rec->fFace->charmap) { FT_Select_Charmap(rec->fFace, FT_ENCODING_MS_SYMBOL); } rec->fNext = gFaceRecHead; gFaceRecHead = rec; return rec->fFace; } // Caller must lock gFTMutex before calling this function. static void unref_ft_face(FT_Face face) { gFTMutex.assertHeld(); SkFaceRec* rec = gFaceRecHead; SkFaceRec* prev = nullptr; while (rec) { SkFaceRec* next = rec->fNext; if (rec->fFace == face) { if (--rec->fRefCnt == 0) { if (prev) { prev->fNext = next; } else { gFaceRecHead = next; } FT_Done_Face(face); delete rec; } return; } prev = rec; rec = next; } SkDEBUGFAIL("shouldn't get here, face not in list"); } class AutoFTAccess { public: AutoFTAccess(const SkTypeface* tf) : fFace(nullptr) { gFTMutex.acquire(); if (!ref_ft_library()) { sk_throw(); } fFace = ref_ft_face(tf); } ~AutoFTAccess() { if (fFace) { unref_ft_face(fFace); } unref_ft_library(); gFTMutex.release(); } FT_Face face() { return fFace; } private: FT_Face fFace; }; /////////////////////////////////////////////////////////////////////////// static bool canEmbed(FT_Face face) { FT_UShort fsType = FT_Get_FSType_Flags(face); return (fsType & (FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING | FT_FSTYPE_BITMAP_EMBEDDING_ONLY)) == 0; } static bool canSubset(FT_Face face) { FT_UShort fsType = FT_Get_FSType_Flags(face); return (fsType & FT_FSTYPE_NO_SUBSETTING) == 0; } static bool GetLetterCBox(FT_Face face, char letter, FT_BBox* bbox) { const FT_UInt glyph_id = FT_Get_Char_Index(face, letter); if (!glyph_id) return false; if (FT_Load_Glyph(face, glyph_id, FT_LOAD_NO_SCALE) != 0) return false; FT_Outline_Get_CBox(&face->glyph->outline, bbox); return true; } static bool getWidthAdvance(FT_Face face, int gId, int16_t* data) { FT_Fixed advance = 0; if (FT_Get_Advances(face, gId, 1, FT_LOAD_NO_SCALE, &advance)) { return false; } SkASSERT(data); *data = advance; return true; } static void populate_glyph_to_unicode(FT_Face& face, SkTDArray* glyphToUnicode) { glyphToUnicode->setCount(face->num_glyphs); sk_bzero(glyphToUnicode->begin(), sizeof((*glyphToUnicode)[0]) * face->num_glyphs); FT_UInt glyphIndex; SkUnichar charCode = FT_Get_First_Char(face, &glyphIndex); while (glyphIndex) { (*glyphToUnicode)[glyphIndex] = charCode; charCode = FT_Get_Next_Char(face, charCode, &glyphIndex); } } SkAdvancedTypefaceMetrics* SkTypeface_FreeType::onGetAdvancedTypefaceMetrics( PerGlyphInfo perGlyphInfo, const uint32_t* glyphIDs, uint32_t glyphIDsCount) const { #if defined(SK_BUILD_FOR_MAC) return nullptr; #else AutoFTAccess fta(this); FT_Face face = fta.face(); if (!face) { return nullptr; } SkAdvancedTypefaceMetrics* info = new SkAdvancedTypefaceMetrics; info->fFontName.set(FT_Get_Postscript_Name(face)); info->fFlags = SkAdvancedTypefaceMetrics::kEmpty_FontFlag; if (FT_HAS_MULTIPLE_MASTERS(face)) { info->fFlags = SkTBitOr( info->fFlags, SkAdvancedTypefaceMetrics::kMultiMaster_FontFlag); } if (!canEmbed(face)) { info->fFlags = SkTBitOr( info->fFlags, SkAdvancedTypefaceMetrics::kNotEmbeddable_FontFlag); } if (!canSubset(face)) { info->fFlags = SkTBitOr( info->fFlags, SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag); } info->fLastGlyphID = face->num_glyphs - 1; info->fEmSize = 1000; bool cid = false; const char* fontType = FT_Get_X11_Font_Format(face); if (strcmp(fontType, "Type 1") == 0) { info->fType = SkAdvancedTypefaceMetrics::kType1_Font; } else if (strcmp(fontType, "CID Type 1") == 0) { info->fType = SkAdvancedTypefaceMetrics::kType1CID_Font; cid = true; } else if (strcmp(fontType, "CFF") == 0) { info->fType = SkAdvancedTypefaceMetrics::kCFF_Font; } else if (strcmp(fontType, "TrueType") == 0) { info->fType = SkAdvancedTypefaceMetrics::kTrueType_Font; cid = true; TT_Header* ttHeader; if ((ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face, ft_sfnt_head)) != nullptr) { info->fEmSize = ttHeader->Units_Per_EM; } } else { info->fType = SkAdvancedTypefaceMetrics::kOther_Font; } info->fStyle = 0; if (FT_IS_FIXED_WIDTH(face)) info->fStyle |= SkAdvancedTypefaceMetrics::kFixedPitch_Style; if (face->style_flags & FT_STYLE_FLAG_ITALIC) info->fStyle |= SkAdvancedTypefaceMetrics::kItalic_Style; PS_FontInfoRec ps_info; TT_Postscript* tt_info; if (FT_Get_PS_Font_Info(face, &ps_info) == 0) { info->fItalicAngle = ps_info.italic_angle; } else if ((tt_info = (TT_Postscript*)FT_Get_Sfnt_Table(face, ft_sfnt_post)) != nullptr) { info->fItalicAngle = SkFixedToScalar(tt_info->italicAngle); } else { info->fItalicAngle = 0; } info->fAscent = face->ascender; info->fDescent = face->descender; // Figure out a good guess for StemV - Min width of i, I, !, 1. // This probably isn't very good with an italic font. int16_t min_width = SHRT_MAX; info->fStemV = 0; char stem_chars[] = {'i', 'I', '!', '1'}; for (size_t i = 0; i < SK_ARRAY_COUNT(stem_chars); i++) { FT_BBox bbox; if (GetLetterCBox(face, stem_chars[i], &bbox)) { int16_t width = bbox.xMax - bbox.xMin; if (width > 0 && width < min_width) { min_width = width; info->fStemV = min_width; } } } TT_PCLT* pclt_info; TT_OS2* os2_table; if ((pclt_info = (TT_PCLT*)FT_Get_Sfnt_Table(face, ft_sfnt_pclt)) != nullptr) { info->fCapHeight = pclt_info->CapHeight; uint8_t serif_style = pclt_info->SerifStyle & 0x3F; if (serif_style >= 2 && serif_style <= 6) info->fStyle |= SkAdvancedTypefaceMetrics::kSerif_Style; else if (serif_style >= 9 && serif_style <= 12) info->fStyle |= SkAdvancedTypefaceMetrics::kScript_Style; } else if (((os2_table = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != nullptr) && // sCapHeight is available only when version 2 or later. os2_table->version != 0xFFFF && os2_table->version >= 2) { info->fCapHeight = os2_table->sCapHeight; } else { // Figure out a good guess for CapHeight: average the height of M and X. FT_BBox m_bbox, x_bbox; bool got_m, got_x; got_m = GetLetterCBox(face, 'M', &m_bbox); got_x = GetLetterCBox(face, 'X', &x_bbox); if (got_m && got_x) { info->fCapHeight = (m_bbox.yMax - m_bbox.yMin + x_bbox.yMax - x_bbox.yMin) / 2; } else if (got_m && !got_x) { info->fCapHeight = m_bbox.yMax - m_bbox.yMin; } else if (!got_m && got_x) { info->fCapHeight = x_bbox.yMax - x_bbox.yMin; } else { // Last resort, use the ascent. info->fCapHeight = info->fAscent; } } info->fBBox = SkIRect::MakeLTRB(face->bbox.xMin, face->bbox.yMax, face->bbox.xMax, face->bbox.yMin); if (!FT_IS_SCALABLE(face)) { perGlyphInfo = kNo_PerGlyphInfo; } if (perGlyphInfo & kHAdvance_PerGlyphInfo) { if (FT_IS_FIXED_WIDTH(face)) { appendRange(&info->fGlyphWidths, 0); int16_t advance = face->max_advance_width; info->fGlyphWidths->fAdvance.append(1, &advance); finishRange(info->fGlyphWidths.get(), 0, SkAdvancedTypefaceMetrics::WidthRange::kDefault); } else if (!cid) { appendRange(&info->fGlyphWidths, 0); // So as to not blow out the stack, get advances in batches. for (int gID = 0; gID < face->num_glyphs; gID += 128) { FT_Fixed advances[128]; int advanceCount = 128; if (gID + advanceCount > face->num_glyphs) { advanceCount = face->num_glyphs - gID; } FT_Get_Advances(face, gID, advanceCount, FT_LOAD_NO_SCALE, advances); for (int i = 0; i < advanceCount; i++) { int16_t advance = advances[i]; info->fGlyphWidths->fAdvance.append(1, &advance); } } finishRange(info->fGlyphWidths.get(), face->num_glyphs - 1, SkAdvancedTypefaceMetrics::WidthRange::kRange); } else { info->fGlyphWidths.reset( getAdvanceData(face, face->num_glyphs, glyphIDs, glyphIDsCount, &getWidthAdvance)); } } if (perGlyphInfo & kVAdvance_PerGlyphInfo && FT_HAS_VERTICAL(face)) { SkASSERT(false); // Not implemented yet. } if (perGlyphInfo & kGlyphNames_PerGlyphInfo && info->fType == SkAdvancedTypefaceMetrics::kType1_Font) { // Postscript fonts may contain more than 255 glyphs, so we end up // using multiple font descriptions with a glyph ordering. Record // the name of each glyph. info->fGlyphNames.reset( new SkAutoTArray(face->num_glyphs)); for (int gID = 0; gID < face->num_glyphs; gID++) { char glyphName[128]; // PS limit for names is 127 bytes. FT_Get_Glyph_Name(face, gID, glyphName, 128); info->fGlyphNames->get()[gID].set(glyphName); } } if (perGlyphInfo & kToUnicode_PerGlyphInfo && info->fType != SkAdvancedTypefaceMetrics::kType1_Font && face->num_charmaps) { populate_glyph_to_unicode(face, &(info->fGlyphToUnicode)); } return info; #endif } /////////////////////////////////////////////////////////////////////////// static bool bothZero(SkScalar a, SkScalar b) { return 0 == a && 0 == b; } // returns false if there is any non-90-rotation or skew static bool isAxisAligned(const SkScalerContext::Rec& rec) { return 0 == rec.fPreSkewX && (bothZero(rec.fPost2x2[0][1], rec.fPost2x2[1][0]) || bothZero(rec.fPost2x2[0][0], rec.fPost2x2[1][1])); } SkScalerContext* SkTypeface_FreeType::onCreateScalerContext( const SkDescriptor* desc) const { SkScalerContext_FreeType* c = new SkScalerContext_FreeType(const_cast(this), desc); if (!c->success()) { delete c; c = nullptr; } return c; } void SkTypeface_FreeType::onFilterRec(SkScalerContextRec* rec) const { //BOGUS: http://code.google.com/p/chromium/issues/detail?id=121119 //Cap the requested size as larger sizes give bogus values. //Remove when http://code.google.com/p/skia/issues/detail?id=554 is fixed. if (rec->fTextSize > SkIntToScalar(1 << 14)) { rec->fTextSize = SkIntToScalar(1 << 14); } if (isLCD(*rec)) { // TODO: re-work so that FreeType is set-up and selected by the SkFontMgr. SkAutoMutexAcquire ama(gFTMutex); ref_ft_library(); if (!gFTLibrary->isLCDSupported()) { // If the runtime Freetype library doesn't support LCD, disable it here. rec->fMaskFormat = SkMask::kA8_Format; } unref_ft_library(); } SkPaint::Hinting h = rec->getHinting(); if (SkPaint::kFull_Hinting == h && !isLCD(*rec)) { // collapse full->normal hinting if we're not doing LCD h = SkPaint::kNormal_Hinting; } if ((rec->fFlags & SkScalerContext::kSubpixelPositioning_Flag)) { if (SkPaint::kNo_Hinting != h) { h = SkPaint::kSlight_Hinting; } } // rotated text looks bad with hinting, so we disable it as needed if (!isAxisAligned(*rec)) { h = SkPaint::kNo_Hinting; } rec->setHinting(h); #ifndef SK_GAMMA_APPLY_TO_A8 if (!isLCD(*rec)) { rec->ignorePreBlend(); } #endif } int SkTypeface_FreeType::onGetUPEM() const { AutoFTAccess fta(this); FT_Face face = fta.face(); return face ? face->units_per_EM : 0; } bool SkTypeface_FreeType::onGetKerningPairAdjustments(const uint16_t glyphs[], int count, int32_t adjustments[]) const { AutoFTAccess fta(this); FT_Face face = fta.face(); if (!face || !FT_HAS_KERNING(face)) { return false; } for (int i = 0; i < count - 1; ++i) { FT_Vector delta; FT_Error err = FT_Get_Kerning(face, glyphs[i], glyphs[i+1], FT_KERNING_UNSCALED, &delta); if (err) { return false; } adjustments[i] = delta.x; } return true; } static FT_Int chooseBitmapStrike(FT_Face face, SkFixed scaleY) { // early out if face is bad if (face == nullptr) { SkDEBUGF(("chooseBitmapStrike aborted due to nullptr face\n")); return -1; } // determine target ppem FT_Pos targetPPEM = SkFixedToFDot6(scaleY); // find a bitmap strike equal to or just larger than the requested size FT_Int chosenStrikeIndex = -1; FT_Pos chosenPPEM = 0; for (FT_Int strikeIndex = 0; strikeIndex < face->num_fixed_sizes; ++strikeIndex) { FT_Pos thisPPEM = face->available_sizes[strikeIndex].y_ppem; if (thisPPEM == targetPPEM) { // exact match - our search stops here chosenPPEM = thisPPEM; chosenStrikeIndex = strikeIndex; break; } else if (chosenPPEM < targetPPEM) { // attempt to increase chosenPPEM if (thisPPEM > chosenPPEM) { chosenPPEM = thisPPEM; chosenStrikeIndex = strikeIndex; } } else { // attempt to decrease chosenPPEM, but not below targetPPEM if (thisPPEM < chosenPPEM && thisPPEM > targetPPEM) { chosenPPEM = thisPPEM; chosenStrikeIndex = strikeIndex; } } } if (chosenStrikeIndex != -1) { // use the chosen strike FT_Error err = FT_Select_Size(face, chosenStrikeIndex); if (err != 0) { SkDEBUGF(("FT_Select_Size(%s, %d) returned 0x%x\n", face->family_name, chosenStrikeIndex, err)); chosenStrikeIndex = -1; } } return chosenStrikeIndex; } SkScalerContext_FreeType::SkScalerContext_FreeType(SkTypeface* typeface, const SkDescriptor* desc) : SkScalerContext_FreeType_Base(typeface, desc) { SkAutoMutexAcquire ac(gFTMutex); if (!ref_ft_library()) { sk_throw(); } // load the font file fStrikeIndex = -1; fFTSize = nullptr; fFace = ref_ft_face(typeface); if (nullptr == fFace) { return; } fRec.computeMatrices(SkScalerContextRec::kFull_PreMatrixScale, &fScale, &fMatrix22Scalar); fMatrix22Scalar.setSkewX(-fMatrix22Scalar.getSkewX()); fMatrix22Scalar.setSkewY(-fMatrix22Scalar.getSkewY()); fScaleX = SkScalarToFixed(fScale.fX); fScaleY = SkScalarToFixed(fScale.fY); fMatrix22.xx = SkScalarToFixed(fMatrix22Scalar.getScaleX()); fMatrix22.xy = SkScalarToFixed(fMatrix22Scalar.getSkewX()); fMatrix22.yx = SkScalarToFixed(fMatrix22Scalar.getSkewY()); fMatrix22.yy = SkScalarToFixed(fMatrix22Scalar.getScaleY()); fLCDIsVert = SkToBool(fRec.fFlags & SkScalerContext::kLCD_Vertical_Flag); // compute the flags we send to Load_Glyph bool linearMetrics = SkToBool(fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag); { FT_Int32 loadFlags = FT_LOAD_DEFAULT; if (SkMask::kBW_Format == fRec.fMaskFormat) { // See http://code.google.com/p/chromium/issues/detail?id=43252#c24 loadFlags = FT_LOAD_TARGET_MONO; if (fRec.getHinting() == SkPaint::kNo_Hinting) { loadFlags = FT_LOAD_NO_HINTING; linearMetrics = true; } } else { switch (fRec.getHinting()) { case SkPaint::kNo_Hinting: loadFlags = FT_LOAD_NO_HINTING; linearMetrics = true; break; case SkPaint::kSlight_Hinting: loadFlags = FT_LOAD_TARGET_LIGHT; // This implies FORCE_AUTOHINT break; case SkPaint::kNormal_Hinting: if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) { loadFlags = FT_LOAD_FORCE_AUTOHINT; #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK } else { loadFlags = FT_LOAD_NO_AUTOHINT; #endif } break; case SkPaint::kFull_Hinting: if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) { loadFlags = FT_LOAD_FORCE_AUTOHINT; break; } loadFlags = FT_LOAD_TARGET_NORMAL; if (isLCD(fRec)) { if (fLCDIsVert) { loadFlags = FT_LOAD_TARGET_LCD_V; } else { loadFlags = FT_LOAD_TARGET_LCD; } } break; default: SkDebugf("---------- UNKNOWN hinting %d\n", fRec.getHinting()); break; } } if ((fRec.fFlags & SkScalerContext::kEmbeddedBitmapText_Flag) == 0) { loadFlags |= FT_LOAD_NO_BITMAP; } // Always using FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH to get correct // advances, as fontconfig and cairo do. // See http://code.google.com/p/skia/issues/detail?id=222. loadFlags |= FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH; // Use vertical layout if requested. if (fRec.fFlags & SkScalerContext::kVertical_Flag) { loadFlags |= FT_LOAD_VERTICAL_LAYOUT; } loadFlags |= FT_LOAD_COLOR; fLoadGlyphFlags = loadFlags; } FT_Error err = FT_New_Size(fFace, &fFTSize); if (err != 0) { SkDEBUGF(("FT_New_Size returned %x for face %s\n", err, fFace->family_name)); fFace = nullptr; return; } err = FT_Activate_Size(fFTSize); if (err != 0) { SkDEBUGF(("FT_Activate_Size(%08x, 0x%x, 0x%x) returned 0x%x\n", fFace, fScaleX, fScaleY, err)); fFTSize = nullptr; return; } if (FT_IS_SCALABLE(fFace)) { err = FT_Set_Char_Size(fFace, SkFixedToFDot6(fScaleX), SkFixedToFDot6(fScaleY), 72, 72); if (err != 0) { SkDEBUGF(("FT_Set_CharSize(%08x, 0x%x, 0x%x) returned 0x%x\n", fFace, fScaleX, fScaleY, err)); fFace = nullptr; return; } FT_Set_Transform(fFace, &fMatrix22, nullptr); } else if (FT_HAS_FIXED_SIZES(fFace)) { fStrikeIndex = chooseBitmapStrike(fFace, fScaleY); if (fStrikeIndex == -1) { SkDEBUGF(("no glyphs for font \"%s\" size %f?\n", fFace->family_name, SkFixedToScalar(fScaleY))); } else { // FreeType does no provide linear metrics for bitmap fonts. linearMetrics = false; // FreeType documentation says: // FT_LOAD_NO_BITMAP -- Ignore bitmap strikes when loading. // Bitmap-only fonts ignore this flag. // // However, in FreeType 2.5.1 color bitmap only fonts do not ignore this flag. // Force this flag off for bitmap only fonts. fLoadGlyphFlags &= ~FT_LOAD_NO_BITMAP; } } else { SkDEBUGF(("unknown kind of font \"%s\" size %f?\n", fFace->family_name, SkFixedToScalar(fScaleY))); } fDoLinearMetrics = linearMetrics; } SkScalerContext_FreeType::~SkScalerContext_FreeType() { SkAutoMutexAcquire ac(gFTMutex); if (fFTSize != nullptr) { FT_Done_Size(fFTSize); } if (fFace != nullptr) { unref_ft_face(fFace); } unref_ft_library(); } /* We call this before each use of the fFace, since we may be sharing this face with other context (at different sizes). */ FT_Error SkScalerContext_FreeType::setupSize() { gFTMutex.assertHeld(); FT_Error err = FT_Activate_Size(fFTSize); if (err != 0) { SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%s %s, 0x%x, 0x%x) returned 0x%x\n", fFace->family_name, fFace->style_name, fScaleX, fScaleY, err)); fFTSize = nullptr; return err; } // seems we need to reset this every time (not sure why, but without it // I get random italics from some other fFTSize) FT_Set_Transform(fFace, &fMatrix22, nullptr); return 0; } unsigned SkScalerContext_FreeType::generateGlyphCount() { return fFace->num_glyphs; } uint16_t SkScalerContext_FreeType::generateCharToGlyph(SkUnichar uni) { SkAutoMutexAcquire ac(gFTMutex); return SkToU16(FT_Get_Char_Index( fFace, uni )); } SkUnichar SkScalerContext_FreeType::generateGlyphToChar(uint16_t glyph) { SkAutoMutexAcquire ac(gFTMutex); // iterate through each cmap entry, looking for matching glyph indices FT_UInt glyphIndex; SkUnichar charCode = FT_Get_First_Char( fFace, &glyphIndex ); while (glyphIndex != 0) { if (glyphIndex == glyph) { return charCode; } charCode = FT_Get_Next_Char( fFace, charCode, &glyphIndex ); } return 0; } void SkScalerContext_FreeType::generateAdvance(SkGlyph* glyph) { /* unhinted and light hinted text have linearly scaled advances * which are very cheap to compute with some font formats... */ if (fDoLinearMetrics) { SkAutoMutexAcquire ac(gFTMutex); if (this->setupSize()) { glyph->zeroMetrics(); return; } FT_Error error; FT_Fixed advance; error = FT_Get_Advance( fFace, glyph->getGlyphID(), fLoadGlyphFlags | FT_ADVANCE_FLAG_FAST_ONLY, &advance ); if (0 == error) { glyph->fRsbDelta = 0; glyph->fLsbDelta = 0; glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, advance); glyph->fAdvanceY = - SkFixedMul(fMatrix22.yx, advance); return; } } /* otherwise, we need to load/hint the glyph, which is slower */ this->generateMetrics(glyph); return; } void SkScalerContext_FreeType::getBBoxForCurrentGlyph(SkGlyph* glyph, FT_BBox* bbox, bool snapToPixelBoundary) { FT_Outline_Get_CBox(&fFace->glyph->outline, bbox); if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) { int dx = SkFixedToFDot6(glyph->getSubXFixed()); int dy = SkFixedToFDot6(glyph->getSubYFixed()); // negate dy since freetype-y-goes-up and skia-y-goes-down bbox->xMin += dx; bbox->yMin -= dy; bbox->xMax += dx; bbox->yMax -= dy; } // outset the box to integral boundaries if (snapToPixelBoundary) { bbox->xMin &= ~63; bbox->yMin &= ~63; bbox->xMax = (bbox->xMax + 63) & ~63; bbox->yMax = (bbox->yMax + 63) & ~63; } // Must come after snapToPixelBoundary so that the width and height are // consistent. Otherwise asserts will fire later on when generating the // glyph image. if (fRec.fFlags & SkScalerContext::kVertical_Flag) { FT_Vector vector; vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX; vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY; FT_Vector_Transform(&vector, &fMatrix22); bbox->xMin += vector.x; bbox->xMax += vector.x; bbox->yMin += vector.y; bbox->yMax += vector.y; } } bool SkScalerContext_FreeType::getCBoxForLetter(char letter, FT_BBox* bbox) { const FT_UInt glyph_id = FT_Get_Char_Index(fFace, letter); if (!glyph_id) { return false; } if (FT_Load_Glyph(fFace, glyph_id, fLoadGlyphFlags) != 0) { return false; } emboldenIfNeeded(fFace, fFace->glyph); FT_Outline_Get_CBox(&fFace->glyph->outline, bbox); return true; } void SkScalerContext_FreeType::updateGlyphIfLCD(SkGlyph* glyph) { if (isLCD(fRec)) { if (fLCDIsVert) { glyph->fHeight += gFTLibrary->lcdExtra(); glyph->fTop -= gFTLibrary->lcdExtra() >> 1; } else { glyph->fWidth += gFTLibrary->lcdExtra(); glyph->fLeft -= gFTLibrary->lcdExtra() >> 1; } } } inline void scaleGlyphMetrics(SkGlyph& glyph, SkScalar scale) { glyph.fWidth *= scale; glyph.fHeight *= scale; glyph.fTop *= scale; glyph.fLeft *= scale; SkFixed fixedScale = SkScalarToFixed(scale); glyph.fAdvanceX = SkFixedMul(glyph.fAdvanceX, fixedScale); glyph.fAdvanceY = SkFixedMul(glyph.fAdvanceY, fixedScale); } void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) { SkAutoMutexAcquire ac(gFTMutex); glyph->fRsbDelta = 0; glyph->fLsbDelta = 0; FT_Error err; if (this->setupSize()) { glyph->zeroMetrics(); return; } err = FT_Load_Glyph( fFace, glyph->getGlyphID(), fLoadGlyphFlags ); if (err != 0) { glyph->zeroMetrics(); return; } emboldenIfNeeded(fFace, fFace->glyph); switch ( fFace->glyph->format ) { case FT_GLYPH_FORMAT_OUTLINE: if (0 == fFace->glyph->outline.n_contours) { glyph->fWidth = 0; glyph->fHeight = 0; glyph->fTop = 0; glyph->fLeft = 0; } else { FT_BBox bbox; getBBoxForCurrentGlyph(glyph, &bbox, true); glyph->fWidth = SkToU16(SkFDot6Floor(bbox.xMax - bbox.xMin)); glyph->fHeight = SkToU16(SkFDot6Floor(bbox.yMax - bbox.yMin)); glyph->fTop = -SkToS16(SkFDot6Floor(bbox.yMax)); glyph->fLeft = SkToS16(SkFDot6Floor(bbox.xMin)); updateGlyphIfLCD(glyph); } break; case FT_GLYPH_FORMAT_BITMAP: if (fRec.fFlags & SkScalerContext::kVertical_Flag) { FT_Vector vector; vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX; vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY; FT_Vector_Transform(&vector, &fMatrix22); fFace->glyph->bitmap_left += SkFDot6Floor(vector.x); fFace->glyph->bitmap_top += SkFDot6Floor(vector.y); } if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_BGRA) { glyph->fMaskFormat = SkMask::kARGB32_Format; } glyph->fWidth = SkToU16(fFace->glyph->bitmap.width); glyph->fHeight = SkToU16(fFace->glyph->bitmap.rows); glyph->fTop = -SkToS16(fFace->glyph->bitmap_top); glyph->fLeft = SkToS16(fFace->glyph->bitmap_left); break; default: SkDEBUGFAIL("unknown glyph format"); glyph->zeroMetrics(); return; } if (fRec.fFlags & SkScalerContext::kVertical_Flag) { if (fDoLinearMetrics) { glyph->fAdvanceX = -SkFixedMul(fMatrix22.xy, fFace->glyph->linearVertAdvance); glyph->fAdvanceY = SkFixedMul(fMatrix22.yy, fFace->glyph->linearVertAdvance); } else { glyph->fAdvanceX = -SkFDot6ToFixed(fFace->glyph->advance.x); glyph->fAdvanceY = SkFDot6ToFixed(fFace->glyph->advance.y); } } else { if (fDoLinearMetrics) { glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance); glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance); } else { glyph->fAdvanceX = SkFDot6ToFixed(fFace->glyph->advance.x); glyph->fAdvanceY = -SkFDot6ToFixed(fFace->glyph->advance.y); if (fRec.fFlags & kDevKernText_Flag) { glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta); glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta); } } } // If the font isn't scalable, scale the metrics from the non-scalable strike. // This means do not try to scale embedded bitmaps; only scale bitmaps in bitmap only fonts. if (!FT_IS_SCALABLE(fFace) && fScaleY && fFace->size->metrics.y_ppem) { // NOTE: both dimensions are scaled by y_ppem. this is WAI. scaleGlyphMetrics(*glyph, SkFixedToScalar(fScaleY) / fFace->size->metrics.y_ppem); } #ifdef ENABLE_GLYPH_SPEW SkDEBUGF(("FT_Set_Char_Size(this:%p sx:%x sy:%x ", this, fScaleX, fScaleY)); SkDEBUGF(("Metrics(glyph:%d flags:0x%x) w:%d\n", glyph->getGlyphID(), fLoadGlyphFlags, glyph->fWidth)); #endif } static void clear_glyph_image(const SkGlyph& glyph) { sk_bzero(glyph.fImage, glyph.rowBytes() * glyph.fHeight); } void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) { SkAutoMutexAcquire ac(gFTMutex); if (this->setupSize()) { clear_glyph_image(glyph); return; } FT_Error err = FT_Load_Glyph(fFace, glyph.getGlyphID(), fLoadGlyphFlags); if (err != 0) { SkDEBUGF(("SkScalerContext_FreeType::generateImage: FT_Load_Glyph(glyph:%d width:%d height:%d rb:%d flags:%d) returned 0x%x\n", glyph.getGlyphID(), glyph.fWidth, glyph.fHeight, glyph.rowBytes(), fLoadGlyphFlags, err)); clear_glyph_image(glyph); return; } emboldenIfNeeded(fFace, fFace->glyph); generateGlyphImage(fFace, glyph); } void SkScalerContext_FreeType::generatePath(const SkGlyph& glyph, SkPath* path) { SkAutoMutexAcquire ac(gFTMutex); SkASSERT(path); if (this->setupSize()) { path->reset(); return; } uint32_t flags = fLoadGlyphFlags; flags |= FT_LOAD_NO_BITMAP; // ignore embedded bitmaps so we're sure to get the outline flags &= ~FT_LOAD_RENDER; // don't scan convert (we just want the outline) FT_Error err = FT_Load_Glyph( fFace, glyph.getGlyphID(), flags); if (err != 0) { SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n", glyph.getGlyphID(), flags, err)); path->reset(); return; } emboldenIfNeeded(fFace, fFace->glyph); generateGlyphPath(fFace, path); // The path's origin from FreeType is always the horizontal layout origin. // Offset the path so that it is relative to the vertical origin if needed. if (fRec.fFlags & SkScalerContext::kVertical_Flag) { FT_Vector vector; vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX; vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY; FT_Vector_Transform(&vector, &fMatrix22); path->offset(SkFDot6ToScalar(vector.x), -SkFDot6ToScalar(vector.y)); } } void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* metrics) { if (nullptr == metrics) { return; } SkAutoMutexAcquire ac(gFTMutex); if (this->setupSize()) { ERROR: sk_bzero(metrics, sizeof(*metrics)); return; } FT_Face face = fFace; SkScalar scaleX = fScale.x(); SkScalar scaleY = fScale.y(); SkScalar mxy = fMatrix22Scalar.getSkewX() * scaleY; SkScalar myy = fMatrix22Scalar.getScaleY() * scaleY; // fetch units/EM from "head" table if needed (ie for bitmap fonts) SkScalar upem = SkIntToScalar(face->units_per_EM); if (!upem) { TT_Header* ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face, ft_sfnt_head); if (ttHeader) { upem = SkIntToScalar(ttHeader->Units_Per_EM); } } // use the os/2 table as a source of reasonable defaults. SkScalar x_height = 0.0f; SkScalar avgCharWidth = 0.0f; SkScalar cap_height = 0.0f; TT_OS2* os2 = (TT_OS2*) FT_Get_Sfnt_Table(face, ft_sfnt_os2); if (os2) { x_height = scaleX * SkIntToScalar(os2->sxHeight) / upem; avgCharWidth = SkIntToScalar(os2->xAvgCharWidth) / upem; if (os2->version != 0xFFFF && os2->version >= 2) { cap_height = scaleX * SkIntToScalar(os2->sCapHeight) / upem; } } // pull from format-specific metrics as needed SkScalar ascent, descent, leading, xmin, xmax, ymin, ymax; SkScalar underlineThickness, underlinePosition; if (face->face_flags & FT_FACE_FLAG_SCALABLE) { // scalable outline font // FreeType will always use HHEA metrics if they're not zero. // It completely ignores the OS/2 fsSelection::UseTypoMetrics bit. // It also ignores the VDMX tables, which are also of interest here // (and override everything else when they apply). static const int kUseTypoMetricsMask = (1 << 7); if (os2 && os2->version != 0xFFFF && (os2->fsSelection & kUseTypoMetricsMask)) { ascent = -SkIntToScalar(os2->sTypoAscender) / upem; descent = -SkIntToScalar(os2->sTypoDescender) / upem; leading = SkIntToScalar(os2->sTypoLineGap) / upem; } else { ascent = -SkIntToScalar(face->ascender) / upem; descent = -SkIntToScalar(face->descender) / upem; leading = SkIntToScalar(face->height + (face->descender - face->ascender)) / upem; } xmin = SkIntToScalar(face->bbox.xMin) / upem; xmax = SkIntToScalar(face->bbox.xMax) / upem; ymin = -SkIntToScalar(face->bbox.yMin) / upem; ymax = -SkIntToScalar(face->bbox.yMax) / upem; underlineThickness = SkIntToScalar(face->underline_thickness) / upem; underlinePosition = -SkIntToScalar(face->underline_position + face->underline_thickness / 2) / upem; metrics->fFlags |= SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag; metrics->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag; // we may be able to synthesize x_height and cap_height from outline if (!x_height) { FT_BBox bbox; if (getCBoxForLetter('x', &bbox)) { x_height = SkIntToScalar(bbox.yMax) / 64.0f; } } if (!cap_height) { FT_BBox bbox; if (getCBoxForLetter('H', &bbox)) { cap_height = SkIntToScalar(bbox.yMax) / 64.0f; } } } else if (fStrikeIndex != -1) { // bitmap strike metrics SkScalar xppem = SkIntToScalar(face->size->metrics.x_ppem); SkScalar yppem = SkIntToScalar(face->size->metrics.y_ppem); ascent = -SkIntToScalar(face->size->metrics.ascender) / (yppem * 64.0f); descent = -SkIntToScalar(face->size->metrics.descender) / (yppem * 64.0f); leading = (SkIntToScalar(face->size->metrics.height) / (yppem * 64.0f)) + ascent - descent; xmin = 0.0f; xmax = SkIntToScalar(face->available_sizes[fStrikeIndex].width) / xppem; ymin = descent + leading; ymax = ascent - descent; underlineThickness = 0; underlinePosition = 0; metrics->fFlags &= ~SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag; metrics->fFlags &= ~SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag; } else { goto ERROR; } // synthesize elements that were not provided by the os/2 table or format-specific metrics if (!x_height) { x_height = -ascent; } if (!avgCharWidth) { avgCharWidth = xmax - xmin; } if (!cap_height) { cap_height = -ascent; } // disallow negative linespacing if (leading < 0.0f) { leading = 0.0f; } SkScalar scale = myy; if (this->isVertical()) { scale = mxy; } metrics->fTop = ymax * scale; metrics->fAscent = ascent * scale; metrics->fDescent = descent * scale; metrics->fBottom = ymin * scale; metrics->fLeading = leading * scale; metrics->fAvgCharWidth = avgCharWidth * scale; metrics->fXMin = xmin * scale; metrics->fXMax = xmax * scale; metrics->fXHeight = x_height; metrics->fCapHeight = cap_height; metrics->fUnderlineThickness = underlineThickness * scale; metrics->fUnderlinePosition = underlinePosition * scale; } /////////////////////////////////////////////////////////////////////////////// // hand-tuned value to reduce outline embolden strength #ifndef SK_OUTLINE_EMBOLDEN_DIVISOR #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK #define SK_OUTLINE_EMBOLDEN_DIVISOR 34 #else #define SK_OUTLINE_EMBOLDEN_DIVISOR 24 #endif #endif /////////////////////////////////////////////////////////////////////////////// void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph) { // check to see if the embolden bit is set if (0 == (fRec.fFlags & SkScalerContext::kEmbolden_Flag)) { return; } switch (glyph->format) { case FT_GLYPH_FORMAT_OUTLINE: FT_Pos strength; strength = FT_MulFix(face->units_per_EM, face->size->metrics.y_scale) / SK_OUTLINE_EMBOLDEN_DIVISOR; FT_Outline_Embolden(&glyph->outline, strength); break; case FT_GLYPH_FORMAT_BITMAP: FT_GlyphSlot_Own_Bitmap(glyph); FT_Bitmap_Embolden(glyph->library, &glyph->bitmap, kBitmapEmboldenStrength, 0); break; default: SkDEBUGFAIL("unknown glyph format"); } } /////////////////////////////////////////////////////////////////////////////// #include "SkUtils.h" static SkUnichar next_utf8(const void** chars) { return SkUTF8_NextUnichar((const char**)chars); } static SkUnichar next_utf16(const void** chars) { return SkUTF16_NextUnichar((const uint16_t**)chars); } static SkUnichar next_utf32(const void** chars) { const SkUnichar** uniChars = (const SkUnichar**)chars; SkUnichar uni = **uniChars; *uniChars += 1; return uni; } typedef SkUnichar (*EncodingProc)(const void**); static EncodingProc find_encoding_proc(SkTypeface::Encoding enc) { static const EncodingProc gProcs[] = { next_utf8, next_utf16, next_utf32 }; SkASSERT((size_t)enc < SK_ARRAY_COUNT(gProcs)); return gProcs[enc]; } int SkTypeface_FreeType::onCharsToGlyphs(const void* chars, Encoding encoding, uint16_t glyphs[], int glyphCount) const { AutoFTAccess fta(this); FT_Face face = fta.face(); if (!face) { if (glyphs) { sk_bzero(glyphs, glyphCount * sizeof(glyphs[0])); } return 0; } EncodingProc next_uni_proc = find_encoding_proc(encoding); if (nullptr == glyphs) { for (int i = 0; i < glyphCount; ++i) { if (0 == FT_Get_Char_Index(face, next_uni_proc(&chars))) { return i; } } return glyphCount; } else { int first = glyphCount; for (int i = 0; i < glyphCount; ++i) { unsigned id = FT_Get_Char_Index(face, next_uni_proc(&chars)); glyphs[i] = SkToU16(id); if (0 == id && i < first) { first = i; } } return first; } } int SkTypeface_FreeType::onCountGlyphs() const { // we cache this value, using -1 as a sentinel for "not computed" if (fGlyphCount < 0) { AutoFTAccess fta(this); FT_Face face = fta.face(); // if the face failed, we still assign a non-negative value fGlyphCount = face ? face->num_glyphs : 0; } return fGlyphCount; } SkTypeface::LocalizedStrings* SkTypeface_FreeType::onCreateFamilyNameIterator() const { SkTypeface::LocalizedStrings* nameIter = SkOTUtils::LocalizedStrings_NameTable::CreateForFamilyNames(*this); if (nullptr == nameIter) { SkString familyName; this->getFamilyName(&familyName); SkString language("und"); //undetermined nameIter = new SkOTUtils::LocalizedStrings_SingleName(familyName, language); } return nameIter; } int SkTypeface_FreeType::onGetTableTags(SkFontTableTag tags[]) const { AutoFTAccess fta(this); FT_Face face = fta.face(); FT_ULong tableCount = 0; FT_Error error; // When 'tag' is nullptr, returns number of tables in 'length'. error = FT_Sfnt_Table_Info(face, 0, nullptr, &tableCount); if (error) { return 0; } if (tags) { for (FT_ULong tableIndex = 0; tableIndex < tableCount; ++tableIndex) { FT_ULong tableTag; FT_ULong tablelength; error = FT_Sfnt_Table_Info(face, tableIndex, &tableTag, &tablelength); if (error) { return 0; } tags[tableIndex] = static_cast(tableTag); } } return tableCount; } size_t SkTypeface_FreeType::onGetTableData(SkFontTableTag tag, size_t offset, size_t length, void* data) const { AutoFTAccess fta(this); FT_Face face = fta.face(); FT_ULong tableLength = 0; FT_Error error; // When 'length' is 0 it is overwritten with the full table length; 'offset' is ignored. error = FT_Load_Sfnt_Table(face, tag, 0, nullptr, &tableLength); if (error) { return 0; } if (offset > tableLength) { return 0; } FT_ULong size = SkTMin((FT_ULong)length, tableLength - (FT_ULong)offset); if (data) { error = FT_Load_Sfnt_Table(face, tag, offset, reinterpret_cast(data), &size); if (error) { return 0; } } return size; } /////////////////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////// SkTypeface_FreeType::Scanner::Scanner() : fLibrary(nullptr) { if (FT_New_Library(&gFTMemory, &fLibrary)) { return; } FT_Add_Default_Modules(fLibrary); } SkTypeface_FreeType::Scanner::~Scanner() { if (fLibrary) { FT_Done_Library(fLibrary); } } FT_Face SkTypeface_FreeType::Scanner::openFace(SkStream* stream, int ttcIndex, FT_Stream ftStream) const { if (fLibrary == nullptr) { return nullptr; } FT_Open_Args args; memset(&args, 0, sizeof(args)); const void* memoryBase = stream->getMemoryBase(); if (memoryBase) { args.flags = FT_OPEN_MEMORY; args.memory_base = (const FT_Byte*)memoryBase; args.memory_size = stream->getLength(); } else { memset(ftStream, 0, sizeof(*ftStream)); ftStream->size = stream->getLength(); ftStream->descriptor.pointer = stream; ftStream->read = sk_ft_stream_io; ftStream->close = sk_ft_stream_close; args.flags = FT_OPEN_STREAM; args.stream = ftStream; } FT_Face face; if (FT_Open_Face(fLibrary, &args, ttcIndex, &face)) { return nullptr; } return face; } bool SkTypeface_FreeType::Scanner::recognizedFont(SkStream* stream, int* numFaces) const { SkAutoMutexAcquire libraryLock(fLibraryMutex); FT_StreamRec streamRec; FT_Face face = this->openFace(stream, -1, &streamRec); if (nullptr == face) { return false; } *numFaces = face->num_faces; FT_Done_Face(face); return true; } #include "SkTSearch.h" bool SkTypeface_FreeType::Scanner::scanFont( SkStream* stream, int ttcIndex, SkString* name, SkFontStyle* style, bool* isFixedPitch, AxisDefinitions* axes) const { SkAutoMutexAcquire libraryLock(fLibraryMutex); FT_StreamRec streamRec; FT_Face face = this->openFace(stream, ttcIndex, &streamRec); if (nullptr == face) { return false; } int weight = SkFontStyle::kNormal_Weight; int width = SkFontStyle::kNormal_Width; SkFontStyle::Slant slant = SkFontStyle::kUpright_Slant; if (face->style_flags & FT_STYLE_FLAG_BOLD) { weight = SkFontStyle::kBold_Weight; } if (face->style_flags & FT_STYLE_FLAG_ITALIC) { slant = SkFontStyle::kItalic_Slant; } PS_FontInfoRec psFontInfo; TT_OS2* os2 = static_cast(FT_Get_Sfnt_Table(face, ft_sfnt_os2)); if (os2 && os2->version != 0xffff) { weight = os2->usWeightClass; width = os2->usWidthClass; } else if (0 == FT_Get_PS_Font_Info(face, &psFontInfo) && psFontInfo.weight) { static const struct { char const * const name; int const weight; } commonWeights [] = { // There are probably more common names, but these are known to exist. { "all", SkFontStyle::kNormal_Weight }, // Multiple Masters usually default to normal. { "black", SkFontStyle::kBlack_Weight }, { "bold", SkFontStyle::kBold_Weight }, { "book", (SkFontStyle::kNormal_Weight + SkFontStyle::kLight_Weight)/2 }, { "demi", SkFontStyle::kSemiBold_Weight }, { "demibold", SkFontStyle::kSemiBold_Weight }, { "extra", SkFontStyle::kExtraBold_Weight }, { "extrabold", SkFontStyle::kExtraBold_Weight }, { "extralight", SkFontStyle::kExtraLight_Weight }, { "hairline", SkFontStyle::kThin_Weight }, { "heavy", SkFontStyle::kBlack_Weight }, { "light", SkFontStyle::kLight_Weight }, { "medium", SkFontStyle::kMedium_Weight }, { "normal", SkFontStyle::kNormal_Weight }, { "plain", SkFontStyle::kNormal_Weight }, { "regular", SkFontStyle::kNormal_Weight }, { "roman", SkFontStyle::kNormal_Weight }, { "semibold", SkFontStyle::kSemiBold_Weight }, { "standard", SkFontStyle::kNormal_Weight }, { "thin", SkFontStyle::kThin_Weight }, { "ultra", SkFontStyle::kExtraBold_Weight }, { "ultrablack", 1000 }, { "ultrabold", SkFontStyle::kExtraBold_Weight }, { "ultraheavy", 1000 }, { "ultralight", SkFontStyle::kExtraLight_Weight }, }; int const index = SkStrLCSearch(&commonWeights[0].name, SK_ARRAY_COUNT(commonWeights), psFontInfo.weight, sizeof(commonWeights[0])); if (index >= 0) { weight = commonWeights[index].weight; } else { SkDEBUGF(("Do not know weight for: %s (%s) \n", face->family_name, psFontInfo.weight)); } } if (name) { name->set(face->family_name); } if (style) { *style = SkFontStyle(weight, width, slant); } if (isFixedPitch) { *isFixedPitch = FT_IS_FIXED_WIDTH(face); } if (axes && face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS) { FT_MM_Var* variations = nullptr; FT_Error err = FT_Get_MM_Var(face, &variations); if (err) { SkDEBUGF(("INFO: font %s claims to have variations, but none found.\n", face->family_name)); return false; } SkAutoFree autoFreeVariations(variations); axes->reset(variations->num_axis); for (FT_UInt i = 0; i < variations->num_axis; ++i) { const FT_Var_Axis& ftAxis = variations->axis[i]; (*axes)[i].fTag = ftAxis.tag; (*axes)[i].fMinimum = ftAxis.minimum; (*axes)[i].fDefault = ftAxis.def; (*axes)[i].fMaximum = ftAxis.maximum; } } FT_Done_Face(face); return true; } /*static*/ void SkTypeface_FreeType::Scanner::computeAxisValues( AxisDefinitions axisDefinitions, const SkFontMgr::FontParameters::Axis* requestedAxes, int requestedAxisCount, SkFixed* axisValues, const SkString& name) { for (int i = 0; i < axisDefinitions.count(); ++i) { const Scanner::AxisDefinition& axisDefinition = axisDefinitions[i]; axisValues[i] = axisDefinition.fDefault; for (int j = 0; j < requestedAxisCount; ++j) { const SkFontMgr::FontParameters::Axis& axisSpecified = requestedAxes[j]; if (axisDefinition.fTag == axisSpecified.fTag) { SkFixed axisValue = SkScalarToFixed(axisSpecified.fStyleValue); axisValues[i] = SkTPin(axisValue, axisDefinition.fMinimum, axisDefinition.fMaximum); if (axisValues[i] != axisValue) { SkDEBUGF(("Requested font axis value out of range: " "%s '%c%c%c%c' %f; pinned to %f.\n", name.c_str(), (axisDefinition.fTag >> 24) & 0xFF, (axisDefinition.fTag >> 16) & 0xFF, (axisDefinition.fTag >> 8) & 0xFF, (axisDefinition.fTag ) & 0xFF, SkScalarToDouble(axisSpecified.fStyleValue), SkFixedToDouble(axisValues[i]))); } break; } } // TODO: warn on defaulted axis? } SkDEBUGCODE( // Check for axis specified, but not matched in font. for (int i = 0; i < requestedAxisCount; ++i) { SkFourByteTag skTag = requestedAxes[i].fTag; bool found = false; for (int j = 0; j < axisDefinitions.count(); ++j) { if (skTag == axisDefinitions[j].fTag) { found = true; break; } } if (!found) { SkDEBUGF(("Requested font axis not found: %s '%c%c%c%c'\n", name.c_str(), (skTag >> 24) & 0xFF, (skTag >> 16) & 0xFF, (skTag >> 8) & 0xFF, (skTag) & 0xFF)); } } ) }