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