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      1 
      2 /*
      3  * Copyright 2006 The Android Open Source Project
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 #include "SkAdvancedTypefaceMetrics.h"
     10 #include "SkBitmap.h"
     11 #include "SkCanvas.h"
     12 #include "SkColorPriv.h"
     13 #include "SkDescriptor.h"
     14 #include "SkFDot6.h"
     15 #include "SkFloatingPoint.h"
     16 #include "SkFontHost.h"
     17 #include "SkFontHost_FreeType_common.h"
     18 #include "SkGlyph.h"
     19 #include "SkMask.h"
     20 #include "SkMaskGamma.h"
     21 #include "SkMatrix22.h"
     22 #include "SkOTUtils.h"
     23 #include "SkOnce.h"
     24 #include "SkScalerContext.h"
     25 #include "SkStream.h"
     26 #include "SkString.h"
     27 #include "SkTemplates.h"
     28 #include "SkThread.h"
     29 
     30 #if defined(SK_CAN_USE_DLOPEN)
     31 #include <dlfcn.h>
     32 #endif
     33 #include <ft2build.h>
     34 #include FT_FREETYPE_H
     35 #include FT_OUTLINE_H
     36 #include FT_SIZES_H
     37 #include FT_TRUETYPE_TABLES_H
     38 #include FT_TYPE1_TABLES_H
     39 #include FT_BITMAP_H
     40 // In the past, FT_GlyphSlot_Own_Bitmap was defined in this header file.
     41 #include FT_SYNTHESIS_H
     42 #include FT_XFREE86_H
     43 #ifdef FT_LCD_FILTER_H
     44 #include FT_LCD_FILTER_H
     45 #endif
     46 
     47 // Defined in FreeType 2.3.8 and later.
     48 // This is a silly build time check, we would need a runtime check if we really cared.
     49 #ifdef   FT_ADVANCES_H
     50 #include FT_ADVANCES_H
     51 #endif
     52 
     53 #if 0
     54 // Also include the files by name for build tools which require this.
     55 #include <freetype/freetype.h>
     56 #include <freetype/ftoutln.h>
     57 #include <freetype/ftsizes.h>
     58 #include <freetype/tttables.h>
     59 #include <freetype/ftadvanc.h>
     60 #include <freetype/ftlcdfil.h>
     61 #include <freetype/ftbitmap.h>
     62 #include <freetype/ftsynth.h>
     63 #endif
     64 
     65 // FT_LOAD_COLOR and the corresponding FT_Pixel_Mode::FT_PIXEL_MODE_BGRA
     66 // were introduced in FreeType 2.5.0.
     67 // The following may be removed once FreeType 2.5.0 is required to build.
     68 #ifndef FT_LOAD_COLOR
     69 #    define FT_LOAD_COLOR ( 1L << 20 )
     70 #    define FT_PIXEL_MODE_BGRA 7
     71 #endif
     72 
     73 // FT_HAS_COLOR and the corresponding FT_FACE_FLAG_COLOR
     74 // were introduced in FreeType 2.5.1
     75 // The following may be removed once FreeType 2.5.1 is required to build.
     76 #ifndef FT_HAS_COLOR
     77 #    define FT_HAS_COLOR(face) false
     78 #endif
     79 
     80 //#define ENABLE_GLYPH_SPEW     // for tracing calls
     81 //#define DUMP_STRIKE_CREATION
     82 
     83 //#define SK_GAMMA_APPLY_TO_A8
     84 
     85 using namespace skia_advanced_typeface_metrics_utils;
     86 
     87 static bool isLCD(const SkScalerContext::Rec& rec) {
     88     switch (rec.fMaskFormat) {
     89         case SkMask::kLCD16_Format:
     90         case SkMask::kLCD32_Format:
     91             return true;
     92         default:
     93             return false;
     94     }
     95 }
     96 
     97 //////////////////////////////////////////////////////////////////////////
     98 
     99 struct SkFaceRec;
    100 
    101 SK_DECLARE_STATIC_MUTEX(gFTMutex);
    102 static int          gFTCount;
    103 static FT_Library   gFTLibrary;
    104 static SkFaceRec*   gFaceRecHead;
    105 static bool         gLCDSupportValid;  // true iff |gLCDSupport| has been set.
    106 static bool         gLCDSupport;  // true iff LCD is supported by the runtime.
    107 static int          gLCDExtra;  // number of extra pixels for filtering.
    108 
    109 /////////////////////////////////////////////////////////////////////////
    110 
    111 // FT_Library_SetLcdFilterWeights was introduced in FreeType 2.4.0.
    112 // The following platforms provide FreeType of at least 2.4.0.
    113 // Ubuntu >= 11.04 (previous deprecated April 2013)
    114 // Debian >= 6.0 (good)
    115 // OpenSuse >= 11.4 (previous deprecated January 2012 / Nov 2013 for Evergreen 11.2)
    116 // Fedora >= 14 (good)
    117 // Android >= Gingerbread (good)
    118 typedef FT_Error (*FT_Library_SetLcdFilterWeightsProc)(FT_Library, unsigned char*);
    119 
    120 // Caller must lock gFTMutex before calling this function.
    121 static bool InitFreetype() {
    122     FT_Error err = FT_Init_FreeType(&gFTLibrary);
    123     if (err) {
    124         return false;
    125     }
    126 
    127     // Setup LCD filtering. This reduces color fringes for LCD smoothed glyphs.
    128 #ifdef FT_LCD_FILTER_H
    129     // Use default { 0x10, 0x40, 0x70, 0x40, 0x10 }, as it adds up to 0x110, simulating ink spread.
    130     // SetLcdFilter must be called before SetLcdFilterWeights.
    131     err = FT_Library_SetLcdFilter(gFTLibrary, FT_LCD_FILTER_DEFAULT);
    132     if (0 == err) {
    133         gLCDSupport = true;
    134         gLCDExtra = 2; //Using a filter adds one full pixel to each side.
    135 
    136 #ifdef SK_FONTHOST_FREETYPE_USE_NORMAL_LCD_FILTER
    137         // This also adds to 0x110 simulating ink spread, but provides better results than default.
    138         static unsigned char gGaussianLikeHeavyWeights[] = { 0x1A, 0x43, 0x56, 0x43, 0x1A, };
    139 
    140 #if defined(SK_FONTHOST_FREETYPE_RUNTIME_VERSION) && \
    141             SK_FONTHOST_FREETYPE_RUNTIME_VERSION > 0x020400
    142         err = FT_Library_SetLcdFilterWeights(gFTLibrary, gGaussianLikeHeavyWeights);
    143 #elif defined(SK_CAN_USE_DLOPEN) && SK_CAN_USE_DLOPEN == 1
    144         //The FreeType library is already loaded, so symbols are available in process.
    145         void* self = dlopen(NULL, RTLD_LAZY);
    146         if (NULL != self) {
    147             FT_Library_SetLcdFilterWeightsProc setLcdFilterWeights;
    148             //The following cast is non-standard, but safe for POSIX.
    149             *reinterpret_cast<void**>(&setLcdFilterWeights) = dlsym(self, "FT_Library_SetLcdFilterWeights");
    150             dlclose(self);
    151 
    152             if (NULL != setLcdFilterWeights) {
    153                 err = setLcdFilterWeights(gFTLibrary, gGaussianLikeHeavyWeights);
    154             }
    155         }
    156 #endif
    157 #endif
    158     }
    159 #else
    160     gLCDSupport = false;
    161 #endif
    162     gLCDSupportValid = true;
    163 
    164     return true;
    165 }
    166 
    167 // Called while holding gFTMutex.
    168 static void determine_lcd_support(bool* lcdSupported) {
    169     if (!gLCDSupportValid) {
    170         // This will determine LCD support as a side effect.
    171         InitFreetype();
    172         FT_Done_FreeType(gFTLibrary);
    173     }
    174     SkASSERT(gLCDSupportValid);
    175     *lcdSupported = gLCDSupport;
    176 }
    177 
    178 // Lazy, once, wrapper to ask the FreeType Library if it can support LCD text
    179 static bool is_lcd_supported() {
    180     static bool lcdSupported = false;
    181     SkOnce(&gLCDSupportValid, &gFTMutex, determine_lcd_support, &lcdSupported);
    182     return lcdSupported;
    183 }
    184 
    185 class SkScalerContext_FreeType : public SkScalerContext_FreeType_Base {
    186 public:
    187     SkScalerContext_FreeType(SkTypeface*, const SkDescriptor* desc);
    188     virtual ~SkScalerContext_FreeType();
    189 
    190     bool success() const {
    191         return fFaceRec != NULL &&
    192                fFTSize != NULL &&
    193                fFace != NULL;
    194     }
    195 
    196 protected:
    197     virtual unsigned generateGlyphCount() SK_OVERRIDE;
    198     virtual uint16_t generateCharToGlyph(SkUnichar uni) SK_OVERRIDE;
    199     virtual void generateAdvance(SkGlyph* glyph) SK_OVERRIDE;
    200     virtual void generateMetrics(SkGlyph* glyph) SK_OVERRIDE;
    201     virtual void generateImage(const SkGlyph& glyph) SK_OVERRIDE;
    202     virtual void generatePath(const SkGlyph& glyph, SkPath* path) SK_OVERRIDE;
    203     virtual void generateFontMetrics(SkPaint::FontMetrics* mx,
    204                                      SkPaint::FontMetrics* my) SK_OVERRIDE;
    205     virtual SkUnichar generateGlyphToChar(uint16_t glyph) SK_OVERRIDE;
    206 
    207 private:
    208     SkFaceRec*  fFaceRec;
    209     FT_Face     fFace;              // reference to shared face in gFaceRecHead
    210     FT_Size     fFTSize;            // our own copy
    211     FT_Int      fStrikeIndex;
    212     SkFixed     fScaleX, fScaleY;
    213     FT_Matrix   fMatrix22;
    214     uint32_t    fLoadGlyphFlags;
    215     bool        fDoLinearMetrics;
    216     bool        fLCDIsVert;
    217 
    218     // Need scalar versions for generateFontMetrics
    219     SkVector    fScale;
    220     SkMatrix    fMatrix22Scalar;
    221 
    222     FT_Error setupSize();
    223     void getBBoxForCurrentGlyph(SkGlyph* glyph, FT_BBox* bbox,
    224                                 bool snapToPixelBoundary = false);
    225     bool getCBoxForLetter(char letter, FT_BBox* bbox);
    226     // Caller must lock gFTMutex before calling this function.
    227     void updateGlyphIfLCD(SkGlyph* glyph);
    228     // Caller must lock gFTMutex before calling this function.
    229     // update FreeType2 glyph slot with glyph emboldened
    230     void emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph);
    231 };
    232 
    233 ///////////////////////////////////////////////////////////////////////////
    234 ///////////////////////////////////////////////////////////////////////////
    235 
    236 struct SkFaceRec {
    237     SkFaceRec*      fNext;
    238     FT_Face         fFace;
    239     FT_StreamRec    fFTStream;
    240     SkStream*       fSkStream;
    241     uint32_t        fRefCnt;
    242     uint32_t        fFontID;
    243 
    244     // assumes ownership of the stream, will call unref() when its done
    245     SkFaceRec(SkStream* strm, uint32_t fontID);
    246     ~SkFaceRec() {
    247         fSkStream->unref();
    248     }
    249 };
    250 
    251 extern "C" {
    252     static unsigned long sk_stream_read(FT_Stream       stream,
    253                                         unsigned long   offset,
    254                                         unsigned char*  buffer,
    255                                         unsigned long   count ) {
    256         SkStream* str = (SkStream*)stream->descriptor.pointer;
    257 
    258         if (count) {
    259             if (!str->rewind()) {
    260                 return 0;
    261             } else {
    262                 unsigned long ret;
    263                 if (offset) {
    264                     ret = str->read(NULL, offset);
    265                     if (ret != offset) {
    266                         return 0;
    267                     }
    268                 }
    269                 ret = str->read(buffer, count);
    270                 if (ret != count) {
    271                     return 0;
    272                 }
    273                 count = ret;
    274             }
    275         }
    276         return count;
    277     }
    278 
    279     static void sk_stream_close(FT_Stream) {}
    280 }
    281 
    282 SkFaceRec::SkFaceRec(SkStream* strm, uint32_t fontID)
    283         : fNext(NULL), fSkStream(strm), fRefCnt(1), fFontID(fontID) {
    284 //    SkDEBUGF(("SkFaceRec: opening %s (%p)\n", key.c_str(), strm));
    285 
    286     sk_bzero(&fFTStream, sizeof(fFTStream));
    287     fFTStream.size = fSkStream->getLength();
    288     fFTStream.descriptor.pointer = fSkStream;
    289     fFTStream.read  = sk_stream_read;
    290     fFTStream.close = sk_stream_close;
    291 }
    292 
    293 // Will return 0 on failure
    294 // Caller must lock gFTMutex before calling this function.
    295 static SkFaceRec* ref_ft_face(const SkTypeface* typeface) {
    296     const SkFontID fontID = typeface->uniqueID();
    297     SkFaceRec* rec = gFaceRecHead;
    298     while (rec) {
    299         if (rec->fFontID == fontID) {
    300             SkASSERT(rec->fFace);
    301             rec->fRefCnt += 1;
    302             return rec;
    303         }
    304         rec = rec->fNext;
    305     }
    306 
    307     int face_index;
    308     SkStream* strm = typeface->openStream(&face_index);
    309     if (NULL == strm) {
    310         return NULL;
    311     }
    312 
    313     // this passes ownership of strm to the rec
    314     rec = SkNEW_ARGS(SkFaceRec, (strm, fontID));
    315 
    316     FT_Open_Args    args;
    317     memset(&args, 0, sizeof(args));
    318     const void* memoryBase = strm->getMemoryBase();
    319 
    320     if (NULL != memoryBase) {
    321 //printf("mmap(%s)\n", keyString.c_str());
    322         args.flags = FT_OPEN_MEMORY;
    323         args.memory_base = (const FT_Byte*)memoryBase;
    324         args.memory_size = strm->getLength();
    325     } else {
    326 //printf("fopen(%s)\n", keyString.c_str());
    327         args.flags = FT_OPEN_STREAM;
    328         args.stream = &rec->fFTStream;
    329     }
    330 
    331     FT_Error err = FT_Open_Face(gFTLibrary, &args, face_index, &rec->fFace);
    332     if (err) {    // bad filename, try the default font
    333         fprintf(stderr, "ERROR: unable to open font '%x'\n", fontID);
    334         SkDELETE(rec);
    335         return NULL;
    336     } else {
    337         SkASSERT(rec->fFace);
    338         //fprintf(stderr, "Opened font '%s'\n", filename.c_str());
    339         rec->fNext = gFaceRecHead;
    340         gFaceRecHead = rec;
    341         return rec;
    342     }
    343 }
    344 
    345 // Caller must lock gFTMutex before calling this function.
    346 static void unref_ft_face(FT_Face face) {
    347     SkFaceRec*  rec = gFaceRecHead;
    348     SkFaceRec*  prev = NULL;
    349     while (rec) {
    350         SkFaceRec* next = rec->fNext;
    351         if (rec->fFace == face) {
    352             if (--rec->fRefCnt == 0) {
    353                 if (prev) {
    354                     prev->fNext = next;
    355                 } else {
    356                     gFaceRecHead = next;
    357                 }
    358                 FT_Done_Face(face);
    359                 SkDELETE(rec);
    360             }
    361             return;
    362         }
    363         prev = rec;
    364         rec = next;
    365     }
    366     SkDEBUGFAIL("shouldn't get here, face not in list");
    367 }
    368 
    369 class AutoFTAccess {
    370 public:
    371     AutoFTAccess(const SkTypeface* tf) : fRec(NULL), fFace(NULL) {
    372         gFTMutex.acquire();
    373         if (1 == ++gFTCount) {
    374             if (!InitFreetype()) {
    375                 sk_throw();
    376             }
    377         }
    378         fRec = ref_ft_face(tf);
    379         if (fRec) {
    380             fFace = fRec->fFace;
    381         }
    382     }
    383 
    384     ~AutoFTAccess() {
    385         if (fFace) {
    386             unref_ft_face(fFace);
    387         }
    388         if (0 == --gFTCount) {
    389             FT_Done_FreeType(gFTLibrary);
    390         }
    391         gFTMutex.release();
    392     }
    393 
    394     SkFaceRec* rec() { return fRec; }
    395     FT_Face face() { return fFace; }
    396 
    397 private:
    398     SkFaceRec*  fRec;
    399     FT_Face     fFace;
    400 };
    401 
    402 ///////////////////////////////////////////////////////////////////////////
    403 
    404 // Work around for old versions of freetype.
    405 static FT_Error getAdvances(FT_Face face, FT_UInt start, FT_UInt count,
    406                            FT_Int32 loadFlags, FT_Fixed* advances) {
    407 #ifdef FT_ADVANCES_H
    408     return FT_Get_Advances(face, start, count, loadFlags, advances);
    409 #else
    410     if (!face || start >= face->num_glyphs ||
    411             start + count > face->num_glyphs || loadFlags != FT_LOAD_NO_SCALE) {
    412         return 6;  // "Invalid argument."
    413     }
    414     if (count == 0)
    415         return 0;
    416 
    417     for (int i = 0; i < count; i++) {
    418         FT_Error err = FT_Load_Glyph(face, start + i, FT_LOAD_NO_SCALE);
    419         if (err)
    420             return err;
    421         advances[i] = face->glyph->advance.x;
    422     }
    423 
    424     return 0;
    425 #endif
    426 }
    427 
    428 static bool canEmbed(FT_Face face) {
    429 #ifdef FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING
    430     FT_UShort fsType = FT_Get_FSType_Flags(face);
    431     return (fsType & (FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING |
    432                       FT_FSTYPE_BITMAP_EMBEDDING_ONLY)) == 0;
    433 #else
    434     // No embedding is 0x2 and bitmap embedding only is 0x200.
    435     TT_OS2* os2_table;
    436     if ((os2_table = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != NULL) {
    437         return (os2_table->fsType & 0x202) == 0;
    438     }
    439     return false;  // We tried, fail safe.
    440 #endif
    441 }
    442 
    443 static bool canSubset(FT_Face face) {
    444 #ifdef FT_FSTYPE_NO_SUBSETTING
    445     FT_UShort fsType = FT_Get_FSType_Flags(face);
    446     return (fsType & FT_FSTYPE_NO_SUBSETTING) == 0;
    447 #else
    448     // No subset is 0x100.
    449     TT_OS2* os2_table;
    450     if ((os2_table = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != NULL) {
    451         return (os2_table->fsType & 0x100) == 0;
    452     }
    453     return false;  // We tried, fail safe.
    454 #endif
    455 }
    456 
    457 static bool GetLetterCBox(FT_Face face, char letter, FT_BBox* bbox) {
    458     const FT_UInt glyph_id = FT_Get_Char_Index(face, letter);
    459     if (!glyph_id)
    460         return false;
    461     if (FT_Load_Glyph(face, glyph_id, FT_LOAD_NO_SCALE) != 0)
    462         return false;
    463     FT_Outline_Get_CBox(&face->glyph->outline, bbox);
    464     return true;
    465 }
    466 
    467 static bool getWidthAdvance(FT_Face face, int gId, int16_t* data) {
    468     FT_Fixed advance = 0;
    469     if (getAdvances(face, gId, 1, FT_LOAD_NO_SCALE, &advance)) {
    470         return false;
    471     }
    472     SkASSERT(data);
    473     *data = advance;
    474     return true;
    475 }
    476 
    477 static void populate_glyph_to_unicode(FT_Face& face,
    478                                       SkTDArray<SkUnichar>* glyphToUnicode) {
    479     // Check and see if we have Unicode cmaps.
    480     for (int i = 0; i < face->num_charmaps; ++i) {
    481         // CMaps known to support Unicode:
    482         // Platform ID   Encoding ID   Name
    483         // -----------   -----------   -----------------------------------
    484         // 0             0,1           Apple Unicode
    485         // 0             3             Apple Unicode 2.0 (preferred)
    486         // 3             1             Microsoft Unicode UCS-2
    487         // 3             10            Microsoft Unicode UCS-4 (preferred)
    488         //
    489         // See Apple TrueType Reference Manual
    490         // http://developer.apple.com/fonts/TTRefMan/RM06/Chap6cmap.html
    491         // http://developer.apple.com/fonts/TTRefMan/RM06/Chap6name.html#ID
    492         // Microsoft OpenType Specification
    493         // http://www.microsoft.com/typography/otspec/cmap.htm
    494 
    495         FT_UShort platformId = face->charmaps[i]->platform_id;
    496         FT_UShort encodingId = face->charmaps[i]->encoding_id;
    497 
    498         if (platformId != 0 && platformId != 3) {
    499             continue;
    500         }
    501         if (platformId == 3 && encodingId != 1 && encodingId != 10) {
    502             continue;
    503         }
    504         bool preferredMap = ((platformId == 3 && encodingId == 10) ||
    505                              (platformId == 0 && encodingId == 3));
    506 
    507         FT_Set_Charmap(face, face->charmaps[i]);
    508         if (glyphToUnicode->isEmpty()) {
    509             glyphToUnicode->setCount(face->num_glyphs);
    510             memset(glyphToUnicode->begin(), 0,
    511                    sizeof(SkUnichar) * face->num_glyphs);
    512         }
    513 
    514         // Iterate through each cmap entry.
    515         FT_UInt glyphIndex;
    516         for (SkUnichar charCode = FT_Get_First_Char(face, &glyphIndex);
    517              glyphIndex != 0;
    518              charCode = FT_Get_Next_Char(face, charCode, &glyphIndex)) {
    519             if (charCode &&
    520                     ((*glyphToUnicode)[glyphIndex] == 0 || preferredMap)) {
    521                 (*glyphToUnicode)[glyphIndex] = charCode;
    522             }
    523         }
    524     }
    525 }
    526 
    527 SkAdvancedTypefaceMetrics* SkTypeface_FreeType::onGetAdvancedTypefaceMetrics(
    528         SkAdvancedTypefaceMetrics::PerGlyphInfo perGlyphInfo,
    529         const uint32_t* glyphIDs,
    530         uint32_t glyphIDsCount) const {
    531 #if defined(SK_BUILD_FOR_MAC)
    532     return NULL;
    533 #else
    534     AutoFTAccess fta(this);
    535     FT_Face face = fta.face();
    536     if (!face) {
    537         return NULL;
    538     }
    539 
    540     SkAdvancedTypefaceMetrics* info = new SkAdvancedTypefaceMetrics;
    541     info->fFontName.set(FT_Get_Postscript_Name(face));
    542     info->fFlags = SkAdvancedTypefaceMetrics::kEmpty_FontFlag;
    543     if (FT_HAS_MULTIPLE_MASTERS(face)) {
    544         info->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
    545                 info->fFlags, SkAdvancedTypefaceMetrics::kMultiMaster_FontFlag);
    546     }
    547     if (!canEmbed(face)) {
    548         info->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
    549                 info->fFlags,
    550                 SkAdvancedTypefaceMetrics::kNotEmbeddable_FontFlag);
    551     }
    552     if (!canSubset(face)) {
    553         info->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
    554                 info->fFlags,
    555                 SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag);
    556     }
    557     info->fLastGlyphID = face->num_glyphs - 1;
    558     info->fEmSize = 1000;
    559 
    560     bool cid = false;
    561     const char* fontType = FT_Get_X11_Font_Format(face);
    562     if (strcmp(fontType, "Type 1") == 0) {
    563         info->fType = SkAdvancedTypefaceMetrics::kType1_Font;
    564     } else if (strcmp(fontType, "CID Type 1") == 0) {
    565         info->fType = SkAdvancedTypefaceMetrics::kType1CID_Font;
    566         cid = true;
    567     } else if (strcmp(fontType, "CFF") == 0) {
    568         info->fType = SkAdvancedTypefaceMetrics::kCFF_Font;
    569     } else if (strcmp(fontType, "TrueType") == 0) {
    570         info->fType = SkAdvancedTypefaceMetrics::kTrueType_Font;
    571         cid = true;
    572         TT_Header* ttHeader;
    573         if ((ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face,
    574                                                       ft_sfnt_head)) != NULL) {
    575             info->fEmSize = ttHeader->Units_Per_EM;
    576         }
    577     } else {
    578         info->fType = SkAdvancedTypefaceMetrics::kOther_Font;
    579     }
    580 
    581     info->fStyle = 0;
    582     if (FT_IS_FIXED_WIDTH(face))
    583         info->fStyle |= SkAdvancedTypefaceMetrics::kFixedPitch_Style;
    584     if (face->style_flags & FT_STYLE_FLAG_ITALIC)
    585         info->fStyle |= SkAdvancedTypefaceMetrics::kItalic_Style;
    586 
    587     PS_FontInfoRec ps_info;
    588     TT_Postscript* tt_info;
    589     if (FT_Get_PS_Font_Info(face, &ps_info) == 0) {
    590         info->fItalicAngle = ps_info.italic_angle;
    591     } else if ((tt_info =
    592                 (TT_Postscript*)FT_Get_Sfnt_Table(face,
    593                                                   ft_sfnt_post)) != NULL) {
    594         info->fItalicAngle = SkFixedToScalar(tt_info->italicAngle);
    595     } else {
    596         info->fItalicAngle = 0;
    597     }
    598 
    599     info->fAscent = face->ascender;
    600     info->fDescent = face->descender;
    601 
    602     // Figure out a good guess for StemV - Min width of i, I, !, 1.
    603     // This probably isn't very good with an italic font.
    604     int16_t min_width = SHRT_MAX;
    605     info->fStemV = 0;
    606     char stem_chars[] = {'i', 'I', '!', '1'};
    607     for (size_t i = 0; i < SK_ARRAY_COUNT(stem_chars); i++) {
    608         FT_BBox bbox;
    609         if (GetLetterCBox(face, stem_chars[i], &bbox)) {
    610             int16_t width = bbox.xMax - bbox.xMin;
    611             if (width > 0 && width < min_width) {
    612                 min_width = width;
    613                 info->fStemV = min_width;
    614             }
    615         }
    616     }
    617 
    618     TT_PCLT* pclt_info;
    619     TT_OS2* os2_table;
    620     if ((pclt_info = (TT_PCLT*)FT_Get_Sfnt_Table(face, ft_sfnt_pclt)) != NULL) {
    621         info->fCapHeight = pclt_info->CapHeight;
    622         uint8_t serif_style = pclt_info->SerifStyle & 0x3F;
    623         if (serif_style >= 2 && serif_style <= 6)
    624             info->fStyle |= SkAdvancedTypefaceMetrics::kSerif_Style;
    625         else if (serif_style >= 9 && serif_style <= 12)
    626             info->fStyle |= SkAdvancedTypefaceMetrics::kScript_Style;
    627     } else if (((os2_table = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != NULL) &&
    628                // sCapHeight is available only when version 2 or later.
    629                os2_table->version != 0xFFFF &&
    630                os2_table->version >= 2) {
    631         info->fCapHeight = os2_table->sCapHeight;
    632     } else {
    633         // Figure out a good guess for CapHeight: average the height of M and X.
    634         FT_BBox m_bbox, x_bbox;
    635         bool got_m, got_x;
    636         got_m = GetLetterCBox(face, 'M', &m_bbox);
    637         got_x = GetLetterCBox(face, 'X', &x_bbox);
    638         if (got_m && got_x) {
    639             info->fCapHeight = (m_bbox.yMax - m_bbox.yMin + x_bbox.yMax -
    640                     x_bbox.yMin) / 2;
    641         } else if (got_m && !got_x) {
    642             info->fCapHeight = m_bbox.yMax - m_bbox.yMin;
    643         } else if (!got_m && got_x) {
    644             info->fCapHeight = x_bbox.yMax - x_bbox.yMin;
    645         } else {
    646             // Last resort, use the ascent.
    647             info->fCapHeight = info->fAscent;
    648         }
    649     }
    650 
    651     info->fBBox = SkIRect::MakeLTRB(face->bbox.xMin, face->bbox.yMax,
    652                                     face->bbox.xMax, face->bbox.yMin);
    653 
    654     if (!FT_IS_SCALABLE(face)) {
    655         perGlyphInfo = SkAdvancedTypefaceMetrics::kNo_PerGlyphInfo;
    656     }
    657 
    658     if (perGlyphInfo & SkAdvancedTypefaceMetrics::kHAdvance_PerGlyphInfo) {
    659         if (FT_IS_FIXED_WIDTH(face)) {
    660             appendRange(&info->fGlyphWidths, 0);
    661             int16_t advance = face->max_advance_width;
    662             info->fGlyphWidths->fAdvance.append(1, &advance);
    663             finishRange(info->fGlyphWidths.get(), 0,
    664                         SkAdvancedTypefaceMetrics::WidthRange::kDefault);
    665         } else if (!cid) {
    666             appendRange(&info->fGlyphWidths, 0);
    667             // So as to not blow out the stack, get advances in batches.
    668             for (int gID = 0; gID < face->num_glyphs; gID += 128) {
    669                 FT_Fixed advances[128];
    670                 int advanceCount = 128;
    671                 if (gID + advanceCount > face->num_glyphs)
    672                     advanceCount = face->num_glyphs - gID;
    673                 getAdvances(face, gID, advanceCount, FT_LOAD_NO_SCALE,
    674                             advances);
    675                 for (int i = 0; i < advanceCount; i++) {
    676                     int16_t advance = advances[i];
    677                     info->fGlyphWidths->fAdvance.append(1, &advance);
    678                 }
    679             }
    680             finishRange(info->fGlyphWidths.get(), face->num_glyphs - 1,
    681                         SkAdvancedTypefaceMetrics::WidthRange::kRange);
    682         } else {
    683             info->fGlyphWidths.reset(
    684                 getAdvanceData(face,
    685                                face->num_glyphs,
    686                                glyphIDs,
    687                                glyphIDsCount,
    688                                &getWidthAdvance));
    689         }
    690     }
    691 
    692     if (perGlyphInfo & SkAdvancedTypefaceMetrics::kVAdvance_PerGlyphInfo &&
    693             FT_HAS_VERTICAL(face)) {
    694         SkASSERT(false);  // Not implemented yet.
    695     }
    696 
    697     if (perGlyphInfo & SkAdvancedTypefaceMetrics::kGlyphNames_PerGlyphInfo &&
    698             info->fType == SkAdvancedTypefaceMetrics::kType1_Font) {
    699         // Postscript fonts may contain more than 255 glyphs, so we end up
    700         // using multiple font descriptions with a glyph ordering.  Record
    701         // the name of each glyph.
    702         info->fGlyphNames.reset(
    703                 new SkAutoTArray<SkString>(face->num_glyphs));
    704         for (int gID = 0; gID < face->num_glyphs; gID++) {
    705             char glyphName[128];  // PS limit for names is 127 bytes.
    706             FT_Get_Glyph_Name(face, gID, glyphName, 128);
    707             info->fGlyphNames->get()[gID].set(glyphName);
    708         }
    709     }
    710 
    711     if (perGlyphInfo & SkAdvancedTypefaceMetrics::kToUnicode_PerGlyphInfo &&
    712            info->fType != SkAdvancedTypefaceMetrics::kType1_Font &&
    713            face->num_charmaps) {
    714         populate_glyph_to_unicode(face, &(info->fGlyphToUnicode));
    715     }
    716 
    717     return info;
    718 #endif
    719 }
    720 
    721 ///////////////////////////////////////////////////////////////////////////
    722 
    723 static bool bothZero(SkScalar a, SkScalar b) {
    724     return 0 == a && 0 == b;
    725 }
    726 
    727 // returns false if there is any non-90-rotation or skew
    728 static bool isAxisAligned(const SkScalerContext::Rec& rec) {
    729     return 0 == rec.fPreSkewX &&
    730            (bothZero(rec.fPost2x2[0][1], rec.fPost2x2[1][0]) ||
    731             bothZero(rec.fPost2x2[0][0], rec.fPost2x2[1][1]));
    732 }
    733 
    734 SkScalerContext* SkTypeface_FreeType::onCreateScalerContext(
    735                                                const SkDescriptor* desc) const {
    736     SkScalerContext_FreeType* c = SkNEW_ARGS(SkScalerContext_FreeType,
    737                                         (const_cast<SkTypeface_FreeType*>(this),
    738                                          desc));
    739     if (!c->success()) {
    740         SkDELETE(c);
    741         c = NULL;
    742     }
    743     return c;
    744 }
    745 
    746 void SkTypeface_FreeType::onFilterRec(SkScalerContextRec* rec) const {
    747     //BOGUS: http://code.google.com/p/chromium/issues/detail?id=121119
    748     //Cap the requested size as larger sizes give bogus values.
    749     //Remove when http://code.google.com/p/skia/issues/detail?id=554 is fixed.
    750     if (rec->fTextSize > SkIntToScalar(1 << 14)) {
    751         rec->fTextSize = SkIntToScalar(1 << 14);
    752     }
    753 
    754     if (!is_lcd_supported() && isLCD(*rec)) {
    755         // If the runtime Freetype library doesn't support LCD mode, we disable
    756         // it here.
    757         rec->fMaskFormat = SkMask::kA8_Format;
    758     }
    759 
    760     SkPaint::Hinting h = rec->getHinting();
    761     if (SkPaint::kFull_Hinting == h && !isLCD(*rec)) {
    762         // collapse full->normal hinting if we're not doing LCD
    763         h = SkPaint::kNormal_Hinting;
    764     }
    765     if ((rec->fFlags & SkScalerContext::kSubpixelPositioning_Flag)) {
    766         if (SkPaint::kNo_Hinting != h) {
    767             h = SkPaint::kSlight_Hinting;
    768         }
    769     }
    770 
    771     // rotated text looks bad with hinting, so we disable it as needed
    772     if (!isAxisAligned(*rec)) {
    773         h = SkPaint::kNo_Hinting;
    774     }
    775     rec->setHinting(h);
    776 
    777 #ifndef SK_GAMMA_APPLY_TO_A8
    778     if (!isLCD(*rec)) {
    779       rec->ignorePreBlend();
    780     }
    781 #endif
    782 }
    783 
    784 int SkTypeface_FreeType::onGetUPEM() const {
    785     AutoFTAccess fta(this);
    786     FT_Face face = fta.face();
    787     return face ? face->units_per_EM : 0;
    788 }
    789 
    790 bool SkTypeface_FreeType::onGetKerningPairAdjustments(const uint16_t glyphs[],
    791                                       int count, int32_t adjustments[]) const {
    792     AutoFTAccess fta(this);
    793     FT_Face face = fta.face();
    794     if (!face || !FT_HAS_KERNING(face)) {
    795         return false;
    796     }
    797 
    798     for (int i = 0; i < count - 1; ++i) {
    799         FT_Vector delta;
    800         FT_Error err = FT_Get_Kerning(face, glyphs[i], glyphs[i+1],
    801                                       FT_KERNING_UNSCALED, &delta);
    802         if (err) {
    803             return false;
    804         }
    805         adjustments[i] = delta.x;
    806     }
    807     return true;
    808 }
    809 
    810 static FT_Int chooseBitmapStrike(FT_Face face, SkFixed scaleY) {
    811     // early out if face is bad
    812     if (face == NULL) {
    813         SkDEBUGF(("chooseBitmapStrike aborted due to NULL face\n"));
    814         return -1;
    815     }
    816     // determine target ppem
    817     FT_Pos targetPPEM = SkFixedToFDot6(scaleY);
    818     // find a bitmap strike equal to or just larger than the requested size
    819     FT_Int chosenStrikeIndex = -1;
    820     FT_Pos chosenPPEM = 0;
    821     for (FT_Int strikeIndex = 0; strikeIndex < face->num_fixed_sizes; ++strikeIndex) {
    822         FT_Pos thisPPEM = face->available_sizes[strikeIndex].y_ppem;
    823         if (thisPPEM == targetPPEM) {
    824             // exact match - our search stops here
    825             chosenPPEM = thisPPEM;
    826             chosenStrikeIndex = strikeIndex;
    827             break;
    828         } else if (chosenPPEM < targetPPEM) {
    829             // attempt to increase chosenPPEM
    830             if (thisPPEM > chosenPPEM) {
    831                 chosenPPEM = thisPPEM;
    832                 chosenStrikeIndex = strikeIndex;
    833             }
    834         } else {
    835             // attempt to decrease chosenPPEM, but not below targetPPEM
    836             if (thisPPEM < chosenPPEM && thisPPEM > targetPPEM) {
    837                 chosenPPEM = thisPPEM;
    838                 chosenStrikeIndex = strikeIndex;
    839             }
    840         }
    841     }
    842     if (chosenStrikeIndex != -1) {
    843         // use the chosen strike
    844         FT_Error err = FT_Select_Size(face, chosenStrikeIndex);
    845         if (err != 0) {
    846             SkDEBUGF(("FT_Select_Size(%s, %d) returned 0x%x\n", face->family_name,
    847                       chosenStrikeIndex, err));
    848             chosenStrikeIndex = -1;
    849         }
    850     }
    851     return chosenStrikeIndex;
    852 }
    853 
    854 SkScalerContext_FreeType::SkScalerContext_FreeType(SkTypeface* typeface,
    855                                                    const SkDescriptor* desc)
    856         : SkScalerContext_FreeType_Base(typeface, desc) {
    857     SkAutoMutexAcquire  ac(gFTMutex);
    858 
    859     if (gFTCount == 0) {
    860         if (!InitFreetype()) {
    861             sk_throw();
    862         }
    863     }
    864     ++gFTCount;
    865 
    866     // load the font file
    867     fStrikeIndex = -1;
    868     fFTSize = NULL;
    869     fFace = NULL;
    870     fFaceRec = ref_ft_face(typeface);
    871     if (NULL == fFaceRec) {
    872         return;
    873     }
    874     fFace = fFaceRec->fFace;
    875 
    876     // A is the total matrix.
    877     SkMatrix A;
    878     fRec.getSingleMatrix(&A);
    879 
    880     SkScalar sx = A.getScaleX();
    881     SkScalar sy = A.getScaleY();
    882     fMatrix22Scalar.reset();
    883 
    884     // In GDI, the hinter is aware of the current transformation
    885     // (the transform is in some sense applied before/with the hinting).
    886     // The bytecode can then test if it is rotated or stretched and decide
    887     // to apply instructions or not.
    888     //
    889     // FreeType, however, always does the transformation strictly after hinting.
    890     // It just sets 'rotated' and 'stretched' to false and only applies the
    891     // size before hinting.
    892     //
    893     // Also, FreeType respects the head::flags::IntegerScaling flag,
    894     // (although this is patched out on most major distros)
    895     // so it is critical to get the size correct on the request.
    896     //
    897     // This also gets us the actual closest size on bitmap fonts as well.
    898     if (A.getSkewX() || A.getSkewY() || sx < 0 || sy < 0) {
    899         // h is where A maps the horizontal baseline.
    900         SkPoint h = SkPoint::Make(SK_Scalar1, 0);
    901         A.mapPoints(&h, 1);
    902 
    903         // G is the Givens Matrix for A (rotational matrix where GA[0][1] == 0).
    904         SkMatrix G;
    905         SkComputeGivensRotation(h, &G);
    906 
    907         // GA is the matrix A with rotation removed.
    908         SkMatrix GA(G);
    909         GA.preConcat(A);
    910 
    911         sx = SkScalarAbs(GA.get(SkMatrix::kMScaleX));
    912         sy = SkScalarAbs(GA.get(SkMatrix::kMScaleY));
    913 
    914         // sA is the total matrix A without the text scale.
    915         SkMatrix sA(A);
    916         sA.preScale(SkScalarInvert(sx), SkScalarInvert(sy)); //remove text size
    917 
    918         fMatrix22Scalar.setScaleX(sA.getScaleX());
    919         fMatrix22Scalar.setSkewX(-sA.getSkewX());
    920         fMatrix22Scalar.setSkewY(-sA.getSkewY());
    921         fMatrix22Scalar.setScaleY(sA.getScaleY());
    922     }
    923     fScale.set(sx, sy);
    924     fScaleX = SkScalarToFixed(sx);
    925     fScaleY = SkScalarToFixed(sy);
    926     fMatrix22.xx = SkScalarToFixed(fMatrix22Scalar.getScaleX());
    927     fMatrix22.xy = SkScalarToFixed(fMatrix22Scalar.getSkewX());
    928     fMatrix22.yx = SkScalarToFixed(fMatrix22Scalar.getSkewY());
    929     fMatrix22.yy = SkScalarToFixed(fMatrix22Scalar.getScaleY());
    930 
    931     fLCDIsVert = SkToBool(fRec.fFlags & SkScalerContext::kLCD_Vertical_Flag);
    932 
    933     // compute the flags we send to Load_Glyph
    934     bool linearMetrics = SkToBool(fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag);
    935     {
    936         FT_Int32 loadFlags = FT_LOAD_DEFAULT;
    937 
    938         if (SkMask::kBW_Format == fRec.fMaskFormat) {
    939             // See http://code.google.com/p/chromium/issues/detail?id=43252#c24
    940             loadFlags = FT_LOAD_TARGET_MONO;
    941             if (fRec.getHinting() == SkPaint::kNo_Hinting) {
    942                 loadFlags = FT_LOAD_NO_HINTING;
    943                 linearMetrics = true;
    944             }
    945         } else {
    946             switch (fRec.getHinting()) {
    947             case SkPaint::kNo_Hinting:
    948                 loadFlags = FT_LOAD_NO_HINTING;
    949                 linearMetrics = true;
    950                 break;
    951             case SkPaint::kSlight_Hinting:
    952                 loadFlags = FT_LOAD_TARGET_LIGHT;  // This implies FORCE_AUTOHINT
    953                 break;
    954             case SkPaint::kNormal_Hinting:
    955                 if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) {
    956                     loadFlags = FT_LOAD_FORCE_AUTOHINT;
    957 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
    958                 } else {
    959                     loadFlags = FT_LOAD_NO_AUTOHINT;
    960 #endif
    961                 }
    962                 break;
    963             case SkPaint::kFull_Hinting:
    964                 if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) {
    965                     loadFlags = FT_LOAD_FORCE_AUTOHINT;
    966                     break;
    967                 }
    968                 loadFlags = FT_LOAD_TARGET_NORMAL;
    969                 if (isLCD(fRec)) {
    970                     if (fLCDIsVert) {
    971                         loadFlags = FT_LOAD_TARGET_LCD_V;
    972                     } else {
    973                         loadFlags = FT_LOAD_TARGET_LCD;
    974                     }
    975                 }
    976                 break;
    977             default:
    978                 SkDebugf("---------- UNKNOWN hinting %d\n", fRec.getHinting());
    979                 break;
    980             }
    981         }
    982 
    983         if ((fRec.fFlags & SkScalerContext::kEmbeddedBitmapText_Flag) == 0) {
    984             loadFlags |= FT_LOAD_NO_BITMAP;
    985         }
    986 
    987         // Always using FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH to get correct
    988         // advances, as fontconfig and cairo do.
    989         // See http://code.google.com/p/skia/issues/detail?id=222.
    990         loadFlags |= FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH;
    991 
    992         // Use vertical layout if requested.
    993         if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
    994             loadFlags |= FT_LOAD_VERTICAL_LAYOUT;
    995         }
    996 
    997         loadFlags |= FT_LOAD_COLOR;
    998 
    999         fLoadGlyphFlags = loadFlags;
   1000     }
   1001 
   1002     FT_Error err = FT_New_Size(fFace, &fFTSize);
   1003     if (err != 0) {
   1004         SkDEBUGF(("FT_New_Size returned %x for face %s\n", err, fFace->family_name));
   1005         fFace = NULL;
   1006         return;
   1007     }
   1008     err = FT_Activate_Size(fFTSize);
   1009     if (err != 0) {
   1010         SkDEBUGF(("FT_Activate_Size(%08x, 0x%x, 0x%x) returned 0x%x\n", fFace, fScaleX, fScaleY,
   1011                   err));
   1012         fFTSize = NULL;
   1013         return;
   1014     }
   1015 
   1016     if (FT_IS_SCALABLE(fFace)) {
   1017         err = FT_Set_Char_Size(fFace, SkFixedToFDot6(fScaleX), SkFixedToFDot6(fScaleY), 72, 72);
   1018         if (err != 0) {
   1019             SkDEBUGF(("FT_Set_CharSize(%08x, 0x%x, 0x%x) returned 0x%x\n",
   1020                                     fFace, fScaleX, fScaleY,      err));
   1021             fFace = NULL;
   1022             return;
   1023         }
   1024         FT_Set_Transform(fFace, &fMatrix22, NULL);
   1025     } else if (FT_HAS_FIXED_SIZES(fFace)) {
   1026         fStrikeIndex = chooseBitmapStrike(fFace, fScaleY);
   1027         if (fStrikeIndex == -1) {
   1028             SkDEBUGF(("no glyphs for font \"%s\" size %f?\n",
   1029                             fFace->family_name,       SkFixedToScalar(fScaleY)));
   1030         } else {
   1031             // FreeType does no provide linear metrics for bitmap fonts.
   1032             linearMetrics = false;
   1033 
   1034             // FreeType documentation says:
   1035             // FT_LOAD_NO_BITMAP -- Ignore bitmap strikes when loading.
   1036             // Bitmap-only fonts ignore this flag.
   1037             //
   1038             // However, in FreeType 2.5.1 color bitmap only fonts do not ignore this flag.
   1039             // Force this flag off for bitmap only fonts.
   1040             fLoadGlyphFlags &= ~FT_LOAD_NO_BITMAP;
   1041         }
   1042     } else {
   1043         SkDEBUGF(("unknown kind of font \"%s\" size %f?\n",
   1044                             fFace->family_name,       SkFixedToScalar(fScaleY)));
   1045     }
   1046 
   1047     fDoLinearMetrics = linearMetrics;
   1048 }
   1049 
   1050 SkScalerContext_FreeType::~SkScalerContext_FreeType() {
   1051     SkAutoMutexAcquire  ac(gFTMutex);
   1052 
   1053     if (fFTSize != NULL) {
   1054         FT_Done_Size(fFTSize);
   1055     }
   1056 
   1057     if (fFace != NULL) {
   1058         unref_ft_face(fFace);
   1059     }
   1060     if (--gFTCount == 0) {
   1061         FT_Done_FreeType(gFTLibrary);
   1062         SkDEBUGCODE(gFTLibrary = NULL;)
   1063     }
   1064 }
   1065 
   1066 /*  We call this before each use of the fFace, since we may be sharing
   1067     this face with other context (at different sizes).
   1068 */
   1069 FT_Error SkScalerContext_FreeType::setupSize() {
   1070     FT_Error err = FT_Activate_Size(fFTSize);
   1071     if (err != 0) {
   1072         SkDEBUGF(("SkScalerContext_FreeType::FT_Activate_Size(%x, 0x%x, 0x%x) returned 0x%x\n",
   1073                   fFaceRec->fFontID, fScaleX, fScaleY, err));
   1074         fFTSize = NULL;
   1075         return err;
   1076     }
   1077 
   1078     // seems we need to reset this every time (not sure why, but without it
   1079     // I get random italics from some other fFTSize)
   1080     FT_Set_Transform(fFace, &fMatrix22, NULL);
   1081     return 0;
   1082 }
   1083 
   1084 unsigned SkScalerContext_FreeType::generateGlyphCount() {
   1085     return fFace->num_glyphs;
   1086 }
   1087 
   1088 uint16_t SkScalerContext_FreeType::generateCharToGlyph(SkUnichar uni) {
   1089     return SkToU16(FT_Get_Char_Index( fFace, uni ));
   1090 }
   1091 
   1092 SkUnichar SkScalerContext_FreeType::generateGlyphToChar(uint16_t glyph) {
   1093     // iterate through each cmap entry, looking for matching glyph indices
   1094     FT_UInt glyphIndex;
   1095     SkUnichar charCode = FT_Get_First_Char( fFace, &glyphIndex );
   1096 
   1097     while (glyphIndex != 0) {
   1098         if (glyphIndex == glyph) {
   1099             return charCode;
   1100         }
   1101         charCode = FT_Get_Next_Char( fFace, charCode, &glyphIndex );
   1102     }
   1103 
   1104     return 0;
   1105 }
   1106 
   1107 void SkScalerContext_FreeType::generateAdvance(SkGlyph* glyph) {
   1108 #ifdef FT_ADVANCES_H
   1109    /* unhinted and light hinted text have linearly scaled advances
   1110     * which are very cheap to compute with some font formats...
   1111     */
   1112     if (fDoLinearMetrics) {
   1113         SkAutoMutexAcquire  ac(gFTMutex);
   1114 
   1115         if (this->setupSize()) {
   1116             glyph->zeroMetrics();
   1117             return;
   1118         }
   1119 
   1120         FT_Error    error;
   1121         FT_Fixed    advance;
   1122 
   1123         error = FT_Get_Advance( fFace, glyph->getGlyphID(fBaseGlyphCount),
   1124                                 fLoadGlyphFlags | FT_ADVANCE_FLAG_FAST_ONLY,
   1125                                 &advance );
   1126         if (0 == error) {
   1127             glyph->fRsbDelta = 0;
   1128             glyph->fLsbDelta = 0;
   1129             glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, advance);
   1130             glyph->fAdvanceY = - SkFixedMul(fMatrix22.yx, advance);
   1131             return;
   1132         }
   1133     }
   1134 #endif /* FT_ADVANCES_H */
   1135     /* otherwise, we need to load/hint the glyph, which is slower */
   1136     this->generateMetrics(glyph);
   1137     return;
   1138 }
   1139 
   1140 void SkScalerContext_FreeType::getBBoxForCurrentGlyph(SkGlyph* glyph,
   1141                                                       FT_BBox* bbox,
   1142                                                       bool snapToPixelBoundary) {
   1143 
   1144     FT_Outline_Get_CBox(&fFace->glyph->outline, bbox);
   1145 
   1146     if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) {
   1147         int dx = SkFixedToFDot6(glyph->getSubXFixed());
   1148         int dy = SkFixedToFDot6(glyph->getSubYFixed());
   1149         // negate dy since freetype-y-goes-up and skia-y-goes-down
   1150         bbox->xMin += dx;
   1151         bbox->yMin -= dy;
   1152         bbox->xMax += dx;
   1153         bbox->yMax -= dy;
   1154     }
   1155 
   1156     // outset the box to integral boundaries
   1157     if (snapToPixelBoundary) {
   1158         bbox->xMin &= ~63;
   1159         bbox->yMin &= ~63;
   1160         bbox->xMax  = (bbox->xMax + 63) & ~63;
   1161         bbox->yMax  = (bbox->yMax + 63) & ~63;
   1162     }
   1163 
   1164     // Must come after snapToPixelBoundary so that the width and height are
   1165     // consistent. Otherwise asserts will fire later on when generating the
   1166     // glyph image.
   1167     if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
   1168         FT_Vector vector;
   1169         vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
   1170         vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
   1171         FT_Vector_Transform(&vector, &fMatrix22);
   1172         bbox->xMin += vector.x;
   1173         bbox->xMax += vector.x;
   1174         bbox->yMin += vector.y;
   1175         bbox->yMax += vector.y;
   1176     }
   1177 }
   1178 
   1179 bool SkScalerContext_FreeType::getCBoxForLetter(char letter, FT_BBox* bbox) {
   1180     const FT_UInt glyph_id = FT_Get_Char_Index(fFace, letter);
   1181     if (!glyph_id)
   1182         return false;
   1183     if (FT_Load_Glyph(fFace, glyph_id, fLoadGlyphFlags) != 0)
   1184         return false;
   1185     emboldenIfNeeded(fFace, fFace->glyph);
   1186     FT_Outline_Get_CBox(&fFace->glyph->outline, bbox);
   1187     return true;
   1188 }
   1189 
   1190 void SkScalerContext_FreeType::updateGlyphIfLCD(SkGlyph* glyph) {
   1191     if (isLCD(fRec)) {
   1192         if (fLCDIsVert) {
   1193             glyph->fHeight += gLCDExtra;
   1194             glyph->fTop -= gLCDExtra >> 1;
   1195         } else {
   1196             glyph->fWidth += gLCDExtra;
   1197             glyph->fLeft -= gLCDExtra >> 1;
   1198         }
   1199     }
   1200 }
   1201 
   1202 inline void scaleGlyphMetrics(SkGlyph& glyph, SkScalar scale) {
   1203     glyph.fWidth *= scale;
   1204     glyph.fHeight *= scale;
   1205     glyph.fTop *= scale;
   1206     glyph.fLeft *= scale;
   1207 
   1208     SkFixed fixedScale = SkScalarToFixed(scale);
   1209     glyph.fAdvanceX = SkFixedMul(glyph.fAdvanceX, fixedScale);
   1210     glyph.fAdvanceY = SkFixedMul(glyph.fAdvanceY, fixedScale);
   1211 }
   1212 
   1213 void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) {
   1214     SkAutoMutexAcquire  ac(gFTMutex);
   1215 
   1216     glyph->fRsbDelta = 0;
   1217     glyph->fLsbDelta = 0;
   1218 
   1219     FT_Error    err;
   1220 
   1221     if (this->setupSize()) {
   1222         goto ERROR;
   1223     }
   1224 
   1225     err = FT_Load_Glyph( fFace, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags );
   1226     if (err != 0) {
   1227 #if 0
   1228         SkDEBUGF(("SkScalerContext_FreeType::generateMetrics(%x): FT_Load_Glyph(glyph:%d flags:%x) returned 0x%x\n",
   1229                     fFaceRec->fFontID, glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, err));
   1230 #endif
   1231     ERROR:
   1232         glyph->zeroMetrics();
   1233         return;
   1234     }
   1235     emboldenIfNeeded(fFace, fFace->glyph);
   1236 
   1237     switch ( fFace->glyph->format ) {
   1238       case FT_GLYPH_FORMAT_OUTLINE:
   1239         if (0 == fFace->glyph->outline.n_contours) {
   1240             glyph->fWidth = 0;
   1241             glyph->fHeight = 0;
   1242             glyph->fTop = 0;
   1243             glyph->fLeft = 0;
   1244         } else {
   1245             FT_BBox bbox;
   1246             getBBoxForCurrentGlyph(glyph, &bbox, true);
   1247 
   1248             glyph->fWidth   = SkToU16(SkFDot6Floor(bbox.xMax - bbox.xMin));
   1249             glyph->fHeight  = SkToU16(SkFDot6Floor(bbox.yMax - bbox.yMin));
   1250             glyph->fTop     = -SkToS16(SkFDot6Floor(bbox.yMax));
   1251             glyph->fLeft    = SkToS16(SkFDot6Floor(bbox.xMin));
   1252 
   1253             updateGlyphIfLCD(glyph);
   1254         }
   1255         break;
   1256 
   1257       case FT_GLYPH_FORMAT_BITMAP:
   1258         if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
   1259             FT_Vector vector;
   1260             vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
   1261             vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
   1262             FT_Vector_Transform(&vector, &fMatrix22);
   1263             fFace->glyph->bitmap_left += SkFDot6Floor(vector.x);
   1264             fFace->glyph->bitmap_top  += SkFDot6Floor(vector.y);
   1265         }
   1266 
   1267         if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_BGRA) {
   1268             glyph->fMaskFormat = SkMask::kARGB32_Format;
   1269         }
   1270 
   1271         glyph->fWidth   = SkToU16(fFace->glyph->bitmap.width);
   1272         glyph->fHeight  = SkToU16(fFace->glyph->bitmap.rows);
   1273         glyph->fTop     = -SkToS16(fFace->glyph->bitmap_top);
   1274         glyph->fLeft    = SkToS16(fFace->glyph->bitmap_left);
   1275         break;
   1276 
   1277       default:
   1278         SkDEBUGFAIL("unknown glyph format");
   1279         goto ERROR;
   1280     }
   1281 
   1282     if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
   1283         if (fDoLinearMetrics) {
   1284             glyph->fAdvanceX = -SkFixedMul(fMatrix22.xy, fFace->glyph->linearVertAdvance);
   1285             glyph->fAdvanceY = SkFixedMul(fMatrix22.yy, fFace->glyph->linearVertAdvance);
   1286         } else {
   1287             glyph->fAdvanceX = -SkFDot6ToFixed(fFace->glyph->advance.x);
   1288             glyph->fAdvanceY = SkFDot6ToFixed(fFace->glyph->advance.y);
   1289         }
   1290     } else {
   1291         if (fDoLinearMetrics) {
   1292             glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance);
   1293             glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance);
   1294         } else {
   1295             glyph->fAdvanceX = SkFDot6ToFixed(fFace->glyph->advance.x);
   1296             glyph->fAdvanceY = -SkFDot6ToFixed(fFace->glyph->advance.y);
   1297 
   1298             if (fRec.fFlags & kDevKernText_Flag) {
   1299                 glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta);
   1300                 glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta);
   1301             }
   1302         }
   1303     }
   1304 
   1305     if (fFace->glyph->format == FT_GLYPH_FORMAT_BITMAP && fScaleY && fFace->size->metrics.y_ppem) {
   1306         // NOTE: both dimensions are scaled by y_ppem. this is WAI.
   1307         scaleGlyphMetrics(*glyph, SkScalarDiv(SkFixedToScalar(fScaleY),
   1308                                               SkIntToScalar(fFace->size->metrics.y_ppem)));
   1309     }
   1310 
   1311 #ifdef ENABLE_GLYPH_SPEW
   1312     SkDEBUGF(("FT_Set_Char_Size(this:%p sx:%x sy:%x ", this, fScaleX, fScaleY));
   1313     SkDEBUGF(("Metrics(glyph:%d flags:0x%x) w:%d\n", glyph->getGlyphID(fBaseGlyphCount), fLoadGlyphFlags, glyph->fWidth));
   1314 #endif
   1315 }
   1316 
   1317 
   1318 void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) {
   1319     SkAutoMutexAcquire  ac(gFTMutex);
   1320 
   1321     FT_Error    err;
   1322 
   1323     if (this->setupSize()) {
   1324         goto ERROR;
   1325     }
   1326 
   1327     err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), fLoadGlyphFlags);
   1328     if (err != 0) {
   1329         SkDEBUGF(("SkScalerContext_FreeType::generateImage: FT_Load_Glyph(glyph:%d width:%d height:%d rb:%d flags:%d) returned 0x%x\n",
   1330                     glyph.getGlyphID(fBaseGlyphCount), glyph.fWidth, glyph.fHeight, glyph.rowBytes(), fLoadGlyphFlags, err));
   1331     ERROR:
   1332         memset(glyph.fImage, 0, glyph.rowBytes() * glyph.fHeight);
   1333         return;
   1334     }
   1335 
   1336     emboldenIfNeeded(fFace, fFace->glyph);
   1337     generateGlyphImage(fFace, glyph);
   1338 }
   1339 
   1340 
   1341 void SkScalerContext_FreeType::generatePath(const SkGlyph& glyph,
   1342                                             SkPath* path) {
   1343     SkAutoMutexAcquire  ac(gFTMutex);
   1344 
   1345     SkASSERT(&glyph && path);
   1346 
   1347     if (this->setupSize()) {
   1348         path->reset();
   1349         return;
   1350     }
   1351 
   1352     uint32_t flags = fLoadGlyphFlags;
   1353     flags |= FT_LOAD_NO_BITMAP; // ignore embedded bitmaps so we're sure to get the outline
   1354     flags &= ~FT_LOAD_RENDER;   // don't scan convert (we just want the outline)
   1355 
   1356     FT_Error err = FT_Load_Glyph( fFace, glyph.getGlyphID(fBaseGlyphCount), flags);
   1357 
   1358     if (err != 0) {
   1359         SkDEBUGF(("SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d flags:%d) returned 0x%x\n",
   1360                     glyph.getGlyphID(fBaseGlyphCount), flags, err));
   1361         path->reset();
   1362         return;
   1363     }
   1364     emboldenIfNeeded(fFace, fFace->glyph);
   1365 
   1366     generateGlyphPath(fFace, path);
   1367 
   1368     // The path's origin from FreeType is always the horizontal layout origin.
   1369     // Offset the path so that it is relative to the vertical origin if needed.
   1370     if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
   1371         FT_Vector vector;
   1372         vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
   1373         vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
   1374         FT_Vector_Transform(&vector, &fMatrix22);
   1375         path->offset(SkFDot6ToScalar(vector.x), -SkFDot6ToScalar(vector.y));
   1376     }
   1377 }
   1378 
   1379 void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* mx,
   1380                                                    SkPaint::FontMetrics* my) {
   1381     if (NULL == mx && NULL == my) {
   1382         return;
   1383     }
   1384 
   1385     SkAutoMutexAcquire  ac(gFTMutex);
   1386 
   1387     if (this->setupSize()) {
   1388         ERROR:
   1389         if (mx) {
   1390             sk_bzero(mx, sizeof(SkPaint::FontMetrics));
   1391         }
   1392         if (my) {
   1393             sk_bzero(my, sizeof(SkPaint::FontMetrics));
   1394         }
   1395         return;
   1396     }
   1397 
   1398     FT_Face face = fFace;
   1399     SkScalar scaleX = fScale.x();
   1400     SkScalar scaleY = fScale.y();
   1401     SkScalar mxy = fMatrix22Scalar.getSkewX() * scaleY;
   1402     SkScalar myy = fMatrix22Scalar.getScaleY() * scaleY;
   1403 
   1404     // fetch units/EM from "head" table if needed (ie for bitmap fonts)
   1405     SkScalar upem = SkIntToScalar(face->units_per_EM);
   1406     if (!upem) {
   1407         TT_Header* ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face, ft_sfnt_head);
   1408         if (ttHeader) {
   1409             upem = SkIntToScalar(ttHeader->Units_Per_EM);
   1410         }
   1411     }
   1412 
   1413     // use the os/2 table as a source of reasonable defaults.
   1414     SkScalar x_height = 0.0f;
   1415     SkScalar avgCharWidth = 0.0f;
   1416     SkScalar cap_height = 0.0f;
   1417     TT_OS2* os2 = (TT_OS2*) FT_Get_Sfnt_Table(face, ft_sfnt_os2);
   1418     if (os2) {
   1419         x_height = scaleX * SkIntToScalar(os2->sxHeight) / upem;
   1420         avgCharWidth = SkIntToScalar(os2->xAvgCharWidth) / upem;
   1421         if (os2->version != 0xFFFF && os2->version >= 2) {
   1422             cap_height = scaleX * SkIntToScalar(os2->sCapHeight) / upem;
   1423         }
   1424     }
   1425 
   1426     // pull from format-specific metrics as needed
   1427     SkScalar ascent, descent, leading, xmin, xmax, ymin, ymax;
   1428     SkScalar underlineThickness, underlinePosition;
   1429     if (face->face_flags & FT_FACE_FLAG_SCALABLE) { // scalable outline font
   1430         ascent = -SkIntToScalar(face->ascender) / upem;
   1431         descent = -SkIntToScalar(face->descender) / upem;
   1432         leading = SkIntToScalar(face->height + (face->descender - face->ascender)) / upem;
   1433         xmin = SkIntToScalar(face->bbox.xMin) / upem;
   1434         xmax = SkIntToScalar(face->bbox.xMax) / upem;
   1435         ymin = -SkIntToScalar(face->bbox.yMin) / upem;
   1436         ymax = -SkIntToScalar(face->bbox.yMax) / upem;
   1437         underlineThickness = SkIntToScalar(face->underline_thickness) / upem;
   1438         underlinePosition = -SkIntToScalar(face->underline_position +
   1439                                            face->underline_thickness / 2) / upem;
   1440 
   1441         if(mx) {
   1442             mx->fFlags |= SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag;
   1443             mx->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
   1444         }
   1445         if(my){
   1446             my->fFlags |= SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag;
   1447             my->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
   1448         }
   1449         // we may be able to synthesize x_height and cap_height from outline
   1450         if (!x_height) {
   1451             FT_BBox bbox;
   1452             if (getCBoxForLetter('x', &bbox)) {
   1453                 x_height = SkIntToScalar(bbox.yMax) / 64.0f;
   1454             }
   1455         }
   1456         if (!cap_height) {
   1457             FT_BBox bbox;
   1458             if (getCBoxForLetter('H', &bbox)) {
   1459                 cap_height = SkIntToScalar(bbox.yMax) / 64.0f;
   1460             }
   1461         }
   1462     } else if (fStrikeIndex != -1) { // bitmap strike metrics
   1463         SkScalar xppem = SkIntToScalar(face->size->metrics.x_ppem);
   1464         SkScalar yppem = SkIntToScalar(face->size->metrics.y_ppem);
   1465         ascent = -SkIntToScalar(face->size->metrics.ascender) / (yppem * 64.0f);
   1466         descent = -SkIntToScalar(face->size->metrics.descender) / (yppem * 64.0f);
   1467         leading = (SkIntToScalar(face->size->metrics.height) / (yppem * 64.0f))
   1468                 + ascent - descent;
   1469         xmin = 0.0f;
   1470         xmax = SkIntToScalar(face->available_sizes[fStrikeIndex].width) / xppem;
   1471         ymin = descent + leading;
   1472         ymax = ascent - descent;
   1473         underlineThickness = 0;
   1474         underlinePosition = 0;
   1475 
   1476         if(mx) {
   1477             mx->fFlags &= ~SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag;
   1478             mx->fFlags &= ~SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
   1479         }
   1480         if(my){
   1481             my->fFlags &= ~SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag;
   1482             my->fFlags &= ~SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
   1483         }
   1484     } else {
   1485         goto ERROR;
   1486     }
   1487 
   1488     // synthesize elements that were not provided by the os/2 table or format-specific metrics
   1489     if (!x_height) {
   1490         x_height = -ascent;
   1491     }
   1492     if (!avgCharWidth) {
   1493         avgCharWidth = xmax - xmin;
   1494     }
   1495     if (!cap_height) {
   1496       cap_height = -ascent;
   1497     }
   1498 
   1499     // disallow negative linespacing
   1500     if (leading < 0.0f) {
   1501         leading = 0.0f;
   1502     }
   1503 
   1504     if (mx) {
   1505         mx->fTop = ymax * mxy;
   1506         mx->fAscent = ascent * mxy;
   1507         mx->fDescent = descent * mxy;
   1508         mx->fBottom = ymin * mxy;
   1509         mx->fLeading = leading * mxy;
   1510         mx->fAvgCharWidth = avgCharWidth * mxy;
   1511         mx->fXMin = xmin;
   1512         mx->fXMax = xmax;
   1513         mx->fXHeight = x_height;
   1514         mx->fCapHeight = cap_height;
   1515         mx->fUnderlineThickness = underlineThickness * mxy;
   1516         mx->fUnderlinePosition = underlinePosition * mxy;
   1517     }
   1518     if (my) {
   1519         my->fTop = ymax * myy;
   1520         my->fAscent = ascent * myy;
   1521         my->fDescent = descent * myy;
   1522         my->fBottom = ymin * myy;
   1523         my->fLeading = leading * myy;
   1524         my->fAvgCharWidth = avgCharWidth * myy;
   1525         my->fXMin = xmin;
   1526         my->fXMax = xmax;
   1527         my->fXHeight = x_height;
   1528         my->fCapHeight = cap_height;
   1529         my->fUnderlineThickness = underlineThickness * myy;
   1530         my->fUnderlinePosition = underlinePosition * myy;
   1531     }
   1532 }
   1533 
   1534 ///////////////////////////////////////////////////////////////////////////////
   1535 
   1536 // hand-tuned value to reduce outline embolden strength
   1537 #ifndef SK_OUTLINE_EMBOLDEN_DIVISOR
   1538     #ifdef SK_BUILD_FOR_ANDROID
   1539         #define SK_OUTLINE_EMBOLDEN_DIVISOR   34
   1540     #else
   1541         #define SK_OUTLINE_EMBOLDEN_DIVISOR   24
   1542     #endif
   1543 #endif
   1544 
   1545 ///////////////////////////////////////////////////////////////////////////////
   1546 
   1547 void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph)
   1548 {
   1549     // check to see if the embolden bit is set
   1550     if (0 == (fRec.fFlags & SkScalerContext::kEmbolden_Flag)) {
   1551         return;
   1552     }
   1553 
   1554 #if defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
   1555     // Android doesn't want to embolden a font that is already bold.
   1556     if ((fFace->style_flags & FT_STYLE_FLAG_BOLD)) {
   1557         return;
   1558     }
   1559 #endif
   1560 
   1561     switch (glyph->format) {
   1562         case FT_GLYPH_FORMAT_OUTLINE:
   1563             FT_Pos strength;
   1564             strength = FT_MulFix(face->units_per_EM, face->size->metrics.y_scale)
   1565                        / SK_OUTLINE_EMBOLDEN_DIVISOR;
   1566             FT_Outline_Embolden(&glyph->outline, strength);
   1567             break;
   1568         case FT_GLYPH_FORMAT_BITMAP:
   1569             FT_GlyphSlot_Own_Bitmap(glyph);
   1570             FT_Bitmap_Embolden(glyph->library, &glyph->bitmap, kBitmapEmboldenStrength, 0);
   1571             break;
   1572         default:
   1573             SkDEBUGFAIL("unknown glyph format");
   1574     }
   1575 }
   1576 
   1577 ///////////////////////////////////////////////////////////////////////////////
   1578 
   1579 #include "SkUtils.h"
   1580 
   1581 static SkUnichar next_utf8(const void** chars) {
   1582     return SkUTF8_NextUnichar((const char**)chars);
   1583 }
   1584 
   1585 static SkUnichar next_utf16(const void** chars) {
   1586     return SkUTF16_NextUnichar((const uint16_t**)chars);
   1587 }
   1588 
   1589 static SkUnichar next_utf32(const void** chars) {
   1590     const SkUnichar** uniChars = (const SkUnichar**)chars;
   1591     SkUnichar uni = **uniChars;
   1592     *uniChars += 1;
   1593     return uni;
   1594 }
   1595 
   1596 typedef SkUnichar (*EncodingProc)(const void**);
   1597 
   1598 static EncodingProc find_encoding_proc(SkTypeface::Encoding enc) {
   1599     static const EncodingProc gProcs[] = {
   1600         next_utf8, next_utf16, next_utf32
   1601     };
   1602     SkASSERT((size_t)enc < SK_ARRAY_COUNT(gProcs));
   1603     return gProcs[enc];
   1604 }
   1605 
   1606 int SkTypeface_FreeType::onCharsToGlyphs(const void* chars, Encoding encoding,
   1607                                       uint16_t glyphs[], int glyphCount) const {
   1608     AutoFTAccess fta(this);
   1609     FT_Face face = fta.face();
   1610     if (!face) {
   1611         if (glyphs) {
   1612             sk_bzero(glyphs, glyphCount * sizeof(glyphs[0]));
   1613         }
   1614         return 0;
   1615     }
   1616 
   1617     EncodingProc next_uni_proc = find_encoding_proc(encoding);
   1618 
   1619     if (NULL == glyphs) {
   1620         for (int i = 0; i < glyphCount; ++i) {
   1621             if (0 == FT_Get_Char_Index(face, next_uni_proc(&chars))) {
   1622                 return i;
   1623             }
   1624         }
   1625         return glyphCount;
   1626     } else {
   1627         int first = glyphCount;
   1628         for (int i = 0; i < glyphCount; ++i) {
   1629             unsigned id = FT_Get_Char_Index(face, next_uni_proc(&chars));
   1630             glyphs[i] = SkToU16(id);
   1631             if (0 == id && i < first) {
   1632                 first = i;
   1633             }
   1634         }
   1635         return first;
   1636     }
   1637 }
   1638 
   1639 int SkTypeface_FreeType::onCountGlyphs() const {
   1640     // we cache this value, using -1 as a sentinel for "not computed"
   1641     if (fGlyphCount < 0) {
   1642         AutoFTAccess fta(this);
   1643         FT_Face face = fta.face();
   1644         // if the face failed, we still assign a non-negative value
   1645         fGlyphCount = face ? face->num_glyphs : 0;
   1646     }
   1647     return fGlyphCount;
   1648 }
   1649 
   1650 SkTypeface::LocalizedStrings* SkTypeface_FreeType::onCreateFamilyNameIterator() const {
   1651     SkTypeface::LocalizedStrings* nameIter =
   1652         SkOTUtils::LocalizedStrings_NameTable::CreateForFamilyNames(*this);
   1653     if (NULL == nameIter) {
   1654         SkString familyName;
   1655         this->getFamilyName(&familyName);
   1656         SkString language("und"); //undetermined
   1657         nameIter = new SkOTUtils::LocalizedStrings_SingleName(familyName, language);
   1658     }
   1659     return nameIter;
   1660 }
   1661 
   1662 int SkTypeface_FreeType::onGetTableTags(SkFontTableTag tags[]) const {
   1663     AutoFTAccess fta(this);
   1664     FT_Face face = fta.face();
   1665 
   1666     FT_ULong tableCount = 0;
   1667     FT_Error error;
   1668 
   1669     // When 'tag' is NULL, returns number of tables in 'length'.
   1670     error = FT_Sfnt_Table_Info(face, 0, NULL, &tableCount);
   1671     if (error) {
   1672         return 0;
   1673     }
   1674 
   1675     if (tags) {
   1676         for (FT_ULong tableIndex = 0; tableIndex < tableCount; ++tableIndex) {
   1677             FT_ULong tableTag;
   1678             FT_ULong tablelength;
   1679             error = FT_Sfnt_Table_Info(face, tableIndex, &tableTag, &tablelength);
   1680             if (error) {
   1681                 return 0;
   1682             }
   1683             tags[tableIndex] = static_cast<SkFontTableTag>(tableTag);
   1684         }
   1685     }
   1686     return tableCount;
   1687 }
   1688 
   1689 size_t SkTypeface_FreeType::onGetTableData(SkFontTableTag tag, size_t offset,
   1690                                            size_t length, void* data) const
   1691 {
   1692     AutoFTAccess fta(this);
   1693     FT_Face face = fta.face();
   1694 
   1695     FT_ULong tableLength = 0;
   1696     FT_Error error;
   1697 
   1698     // When 'length' is 0 it is overwritten with the full table length; 'offset' is ignored.
   1699     error = FT_Load_Sfnt_Table(face, tag, 0, NULL, &tableLength);
   1700     if (error) {
   1701         return 0;
   1702     }
   1703 
   1704     if (offset > tableLength) {
   1705         return 0;
   1706     }
   1707     FT_ULong size = SkTMin((FT_ULong)length, tableLength - (FT_ULong)offset);
   1708     if (NULL != data) {
   1709         error = FT_Load_Sfnt_Table(face, tag, offset, reinterpret_cast<FT_Byte*>(data), &size);
   1710         if (error) {
   1711             return 0;
   1712         }
   1713     }
   1714 
   1715     return size;
   1716 }
   1717 
   1718 ///////////////////////////////////////////////////////////////////////////////
   1719 ///////////////////////////////////////////////////////////////////////////////
   1720 
   1721 /*  Export this so that other parts of our FonttHost port can make use of our
   1722     ability to extract the name+style from a stream, using FreeType's api.
   1723 */
   1724 bool find_name_and_attributes(SkStream* stream, SkString* name,
   1725                               SkTypeface::Style* style, bool* isFixedPitch) {
   1726     FT_Library  library;
   1727     if (FT_Init_FreeType(&library)) {
   1728         return false;
   1729     }
   1730 
   1731     FT_Open_Args    args;
   1732     memset(&args, 0, sizeof(args));
   1733 
   1734     const void* memoryBase = stream->getMemoryBase();
   1735     FT_StreamRec    streamRec;
   1736 
   1737     if (NULL != memoryBase) {
   1738         args.flags = FT_OPEN_MEMORY;
   1739         args.memory_base = (const FT_Byte*)memoryBase;
   1740         args.memory_size = stream->getLength();
   1741     } else {
   1742         memset(&streamRec, 0, sizeof(streamRec));
   1743         streamRec.size = stream->getLength();
   1744         streamRec.descriptor.pointer = stream;
   1745         streamRec.read  = sk_stream_read;
   1746         streamRec.close = sk_stream_close;
   1747 
   1748         args.flags = FT_OPEN_STREAM;
   1749         args.stream = &streamRec;
   1750     }
   1751 
   1752     FT_Face face;
   1753     if (FT_Open_Face(library, &args, 0, &face)) {
   1754         FT_Done_FreeType(library);
   1755         return false;
   1756     }
   1757 
   1758     int tempStyle = SkTypeface::kNormal;
   1759     if (face->style_flags & FT_STYLE_FLAG_BOLD) {
   1760         tempStyle |= SkTypeface::kBold;
   1761     }
   1762     if (face->style_flags & FT_STYLE_FLAG_ITALIC) {
   1763         tempStyle |= SkTypeface::kItalic;
   1764     }
   1765 
   1766     if (name) {
   1767         name->set(face->family_name);
   1768     }
   1769     if (style) {
   1770         *style = (SkTypeface::Style) tempStyle;
   1771     }
   1772     if (isFixedPitch) {
   1773         *isFixedPitch = FT_IS_FIXED_WIDTH(face);
   1774     }
   1775 
   1776     FT_Done_Face(face);
   1777     FT_Done_FreeType(library);
   1778     return true;
   1779 }
   1780