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1 /*
2  * Copyright 2014 Google Inc.
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 "SkDataTable.h"
10 #include "SkFixed.h"
11 #include "SkFontDescriptor.h"
12 #include "SkFontHost_FreeType_common.h"
13 #include "SkFontMgr.h"
14 #include "SkFontStyle.h"
15 #include "SkMakeUnique.h"
16 #include "SkMath.h"
17 #include "SkMutex.h"
18 #include "SkOSFile.h"
19 #include "SkRefCnt.h"
20 #include "SkStream.h"
21 #include "SkString.h"
22 #include "SkTDArray.h"
23 #include "SkTemplates.h"
24 #include "SkTypeface.h"
25 #include "SkTypefaceCache.h"
26 #include "SkTypes.h"
27 
28 #include <fontconfig/fontconfig.h>
29 #include <string.h>
30 
31 class SkData;
32 
33 // FC_POSTSCRIPT_NAME was added with b561ff20 which ended up in 2.10.92
34 // Ubuntu 12.04 is on 2.8.0, 13.10 is on 2.10.93
35 // Debian 7 is on 2.9.0, 8 is on 2.11
36 // OpenSUSE 12.2 is on 2.9.0, 12.3 is on 2.10.2, 13.1 2.11.0
37 // Fedora 19 is on 2.10.93
38 #ifndef FC_POSTSCRIPT_NAME
39 #    define FC_POSTSCRIPT_NAME  "postscriptname"
40 #endif
41 
42 #ifdef SK_DEBUG
43 #    include "SkTLS.h"
44 #endif
45 
46 /** Since FontConfig is poorly documented, this gives a high level overview:
47  *
48  *  FcConfig is a handle to a FontConfig configuration instance. Each 'configuration' is independent
49  *  from any others which may exist. There exists a default global configuration which is created
50  *  and destroyed by FcInit and FcFini, but this default should not normally be used.
51  *  Instead, one should use FcConfigCreate and FcInit* to have a named local state.
52  *
53  *  FcPatterns are {objectName -> [element]} (maps from object names to a list of elements).
54  *  Each element is some internal data plus an FcValue which is a variant (a union with a type tag).
55  *  Lists of elements are not typed, except by convention. Any collection of FcValues must be
56  *  assumed to be heterogeneous by the code, but the code need not do anything particularly
57  *  interesting if the values go against convention.
58  *
59  *  Somewhat like DirectWrite, FontConfig supports synthetics through FC_EMBOLDEN and FC_MATRIX.
60  *  Like all synthetic information, such information must be passed with the font data.
61  */
62 
63 namespace {
64 
65 // Fontconfig is not threadsafe before 2.10.91. Before that, we lock with a global mutex.
66 // See https://bug.skia.org/1497 for background.
67 SK_DECLARE_STATIC_MUTEX(gFCMutex);
68 
69 #ifdef SK_DEBUG
CreateThreadFcLocked()70 void* CreateThreadFcLocked() { return new bool(false); }
DeleteThreadFcLocked(void * v)71 void DeleteThreadFcLocked(void* v) { delete static_cast<bool*>(v); }
72 #   define THREAD_FC_LOCKED \
73         static_cast<bool*>(SkTLS::Get(CreateThreadFcLocked, DeleteThreadFcLocked))
74 #endif
75 
76 struct FCLocker {
77     // Assume FcGetVersion() has always been thread safe.
78 
FCLocker__anon8c71183d0111::FCLocker79     FCLocker() {
80         if (FcGetVersion() < 21091) {
81             gFCMutex.acquire();
82         } else {
83             SkDEBUGCODE(bool* threadLocked = THREAD_FC_LOCKED);
84             SkASSERT(false == *threadLocked);
85             SkDEBUGCODE(*threadLocked = true);
86         }
87     }
88 
~FCLocker__anon8c71183d0111::FCLocker89     ~FCLocker() {
90         AssertHeld();
91         if (FcGetVersion() < 21091) {
92             gFCMutex.release();
93         } else {
94             SkDEBUGCODE(*THREAD_FC_LOCKED = false);
95         }
96     }
97 
AssertHeld__anon8c71183d0111::FCLocker98     static void AssertHeld() { SkDEBUGCODE(
99         if (FcGetVersion() < 21091) {
100             gFCMutex.assertHeld();
101         } else {
102             SkASSERT(true == *THREAD_FC_LOCKED);
103         }
104     ) }
105 };
106 
107 } // namespace
108 
FcTDestroy(T * t)109 template<typename T, void (*D)(T*)> void FcTDestroy(T* t) {
110     FCLocker::AssertHeld();
111     D(t);
112 }
113 template <typename T, T* (*C)(), void (*D)(T*)> class SkAutoFc
114     : public SkAutoTCallVProc<T, FcTDestroy<T, D> > {
115 public:
SkAutoFc()116     SkAutoFc() : SkAutoTCallVProc<T, FcTDestroy<T, D> >(C()) {
117         T* obj = this->operator T*();
118         SkASSERT_RELEASE(nullptr != obj);
119     }
SkAutoFc(T * obj)120     explicit SkAutoFc(T* obj) : SkAutoTCallVProc<T, FcTDestroy<T, D> >(obj) {}
121 };
122 
123 typedef SkAutoFc<FcCharSet, FcCharSetCreate, FcCharSetDestroy> SkAutoFcCharSet;
124 typedef SkAutoFc<FcConfig, FcConfigCreate, FcConfigDestroy> SkAutoFcConfig;
125 typedef SkAutoFc<FcFontSet, FcFontSetCreate, FcFontSetDestroy> SkAutoFcFontSet;
126 typedef SkAutoFc<FcLangSet, FcLangSetCreate, FcLangSetDestroy> SkAutoFcLangSet;
127 typedef SkAutoFc<FcObjectSet, FcObjectSetCreate, FcObjectSetDestroy> SkAutoFcObjectSet;
128 typedef SkAutoFc<FcPattern, FcPatternCreate, FcPatternDestroy> SkAutoFcPattern;
129 
get_bool(FcPattern * pattern,const char object[],bool missing=false)130 static bool get_bool(FcPattern* pattern, const char object[], bool missing = false) {
131     FcBool value;
132     if (FcPatternGetBool(pattern, object, 0, &value) != FcResultMatch) {
133         return missing;
134     }
135     return value;
136 }
137 
get_int(FcPattern * pattern,const char object[],int missing)138 static int get_int(FcPattern* pattern, const char object[], int missing) {
139     int value;
140     if (FcPatternGetInteger(pattern, object, 0, &value) != FcResultMatch) {
141         return missing;
142     }
143     return value;
144 }
145 
get_string(FcPattern * pattern,const char object[],const char * missing="")146 static const char* get_string(FcPattern* pattern, const char object[], const char* missing = "") {
147     FcChar8* value;
148     if (FcPatternGetString(pattern, object, 0, &value) != FcResultMatch) {
149         return missing;
150     }
151     return (const char*)value;
152 }
153 
get_matrix(FcPattern * pattern,const char object[])154 static const FcMatrix* get_matrix(FcPattern* pattern, const char object[]) {
155     FcMatrix* matrix;
156     if (FcPatternGetMatrix(pattern, object, 0, &matrix) != FcResultMatch) {
157         return nullptr;
158     }
159     return matrix;
160 }
161 
162 enum SkWeakReturn {
163     kIsWeak_WeakReturn,
164     kIsStrong_WeakReturn,
165     kNoId_WeakReturn
166 };
167 /** Ideally there  would exist a call like
168  *  FcResult FcPatternIsWeak(pattern, object, id, FcBool* isWeak);
169  *
170  *  However, there is no such call and as of Fc 2.11.0 even FcPatternEquals ignores the weak bit.
171  *  Currently, the only reliable way of finding the weak bit is by its effect on matching.
172  *  The weak bit only affects the matching of FC_FAMILY and FC_POSTSCRIPT_NAME object values.
173  *  A element with the weak bit is scored after FC_LANG, without the weak bit is scored before.
174  *  Note that the weak bit is stored on the element, not on the value it holds.
175  */
is_weak(FcPattern * pattern,const char object[],int id)176 static SkWeakReturn is_weak(FcPattern* pattern, const char object[], int id) {
177     FCLocker::AssertHeld();
178 
179     FcResult result;
180 
181     // Create a copy of the pattern with only the value 'pattern'['object'['id']] in it.
182     // Internally, FontConfig pattern objects are linked lists, so faster to remove from head.
183     SkAutoFcObjectSet requestedObjectOnly(FcObjectSetBuild(object, nullptr));
184     SkAutoFcPattern minimal(FcPatternFilter(pattern, requestedObjectOnly));
185     FcBool hasId = true;
186     for (int i = 0; hasId && i < id; ++i) {
187         hasId = FcPatternRemove(minimal, object, 0);
188     }
189     if (!hasId) {
190         return kNoId_WeakReturn;
191     }
192     FcValue value;
193     result = FcPatternGet(minimal, object, 0, &value);
194     if (result != FcResultMatch) {
195         return kNoId_WeakReturn;
196     }
197     while (hasId) {
198         hasId = FcPatternRemove(minimal, object, 1);
199     }
200 
201     // Create a font set with two patterns.
202     // 1. the same 'object' as minimal and a lang object with only 'nomatchlang'.
203     // 2. a different 'object' from minimal and a lang object with only 'matchlang'.
204     SkAutoFcFontSet fontSet;
205 
206     SkAutoFcLangSet strongLangSet;
207     FcLangSetAdd(strongLangSet, (const FcChar8*)"nomatchlang");
208     SkAutoFcPattern strong(FcPatternDuplicate(minimal));
209     FcPatternAddLangSet(strong, FC_LANG, strongLangSet);
210 
211     SkAutoFcLangSet weakLangSet;
212     FcLangSetAdd(weakLangSet, (const FcChar8*)"matchlang");
213     SkAutoFcPattern weak;
214     FcPatternAddString(weak, object, (const FcChar8*)"nomatchstring");
215     FcPatternAddLangSet(weak, FC_LANG, weakLangSet);
216 
217     FcFontSetAdd(fontSet, strong.release());
218     FcFontSetAdd(fontSet, weak.release());
219 
220     // Add 'matchlang' to the copy of the pattern.
221     FcPatternAddLangSet(minimal, FC_LANG, weakLangSet);
222 
223     // Run a match against the copy of the pattern.
224     // If the 'id' was weak, then we should match the pattern with 'matchlang'.
225     // If the 'id' was strong, then we should match the pattern with 'nomatchlang'.
226 
227     // Note that this config is only used for FcFontRenderPrepare, which we don't even want.
228     // However, there appears to be no way to match/sort without it.
229     SkAutoFcConfig config;
230     FcFontSet* fontSets[1] = { fontSet };
231     SkAutoFcPattern match(FcFontSetMatch(config, fontSets, SK_ARRAY_COUNT(fontSets),
232                                          minimal, &result));
233 
234     FcLangSet* matchLangSet;
235     FcPatternGetLangSet(match, FC_LANG, 0, &matchLangSet);
236     return FcLangEqual == FcLangSetHasLang(matchLangSet, (const FcChar8*)"matchlang")
237                         ? kIsWeak_WeakReturn : kIsStrong_WeakReturn;
238 }
239 
240 /** Removes weak elements from either FC_FAMILY or FC_POSTSCRIPT_NAME objects in the property.
241  *  This can be quite expensive, and should not be used more than once per font lookup.
242  *  This removes all of the weak elements after the last strong element.
243  */
remove_weak(FcPattern * pattern,const char object[])244 static void remove_weak(FcPattern* pattern, const char object[]) {
245     FCLocker::AssertHeld();
246 
247     SkAutoFcObjectSet requestedObjectOnly(FcObjectSetBuild(object, nullptr));
248     SkAutoFcPattern minimal(FcPatternFilter(pattern, requestedObjectOnly));
249 
250     int lastStrongId = -1;
251     int numIds;
252     SkWeakReturn result;
253     for (int id = 0; ; ++id) {
254         result = is_weak(minimal, object, 0);
255         if (kNoId_WeakReturn == result) {
256             numIds = id;
257             break;
258         }
259         if (kIsStrong_WeakReturn == result) {
260             lastStrongId = id;
261         }
262         SkAssertResult(FcPatternRemove(minimal, object, 0));
263     }
264 
265     // If they were all weak, then leave the pattern alone.
266     if (lastStrongId < 0) {
267         return;
268     }
269 
270     // Remove everything after the last strong.
271     for (int id = lastStrongId + 1; id < numIds; ++id) {
272         SkAssertResult(FcPatternRemove(pattern, object, lastStrongId + 1));
273     }
274 }
275 
map_range(SkFixed value,SkFixed old_min,SkFixed old_max,SkFixed new_min,SkFixed new_max)276 static int map_range(SkFixed value,
277                      SkFixed old_min, SkFixed old_max,
278                      SkFixed new_min, SkFixed new_max)
279 {
280     SkASSERT(old_min < old_max);
281     SkASSERT(new_min <= new_max);
282     return new_min + SkMulDiv(value - old_min, new_max - new_min, old_max - old_min);
283 }
284 
285 struct MapRanges {
286     SkFixed old_val;
287     SkFixed new_val;
288 };
289 
map_ranges_fixed(SkFixed val,MapRanges const ranges[],int rangesCount)290 static SkFixed map_ranges_fixed(SkFixed val, MapRanges const ranges[], int rangesCount) {
291     // -Inf to [0]
292     if (val < ranges[0].old_val) {
293         return ranges[0].new_val;
294     }
295 
296     // Linear from [i] to [i+1]
297     for (int i = 0; i < rangesCount - 1; ++i) {
298         if (val < ranges[i+1].old_val) {
299             return map_range(val, ranges[i].old_val, ranges[i+1].old_val,
300                                   ranges[i].new_val, ranges[i+1].new_val);
301         }
302     }
303 
304     // From [n] to +Inf
305     // if (fcweight < Inf)
306     return ranges[rangesCount-1].new_val;
307 }
308 
map_ranges(int val,MapRanges const ranges[],int rangesCount)309 static int map_ranges(int val, MapRanges const ranges[], int rangesCount) {
310     return SkFixedRoundToInt(map_ranges_fixed(SkIntToFixed(val), ranges, rangesCount));
311 }
312 
313 template<int n> struct SkTFixed {
314     static_assert(-32768 <= n && n <= 32767, "SkTFixed_n_not_in_range");
315     static const SkFixed value = static_cast<SkFixed>(n << 16);
316 };
317 
skfontstyle_from_fcpattern(FcPattern * pattern)318 static SkFontStyle skfontstyle_from_fcpattern(FcPattern* pattern) {
319     typedef SkFontStyle SkFS;
320 
321     static const MapRanges weightRanges[] = {
322         { SkTFixed<FC_WEIGHT_THIN>::value,       SkTFixed<SkFS::kThin_Weight>::value },
323         { SkTFixed<FC_WEIGHT_EXTRALIGHT>::value, SkTFixed<SkFS::kExtraLight_Weight>::value },
324         { SkTFixed<FC_WEIGHT_LIGHT>::value,      SkTFixed<SkFS::kLight_Weight>::value },
325         { SkTFixed<FC_WEIGHT_REGULAR>::value,    SkTFixed<SkFS::kNormal_Weight>::value },
326         { SkTFixed<FC_WEIGHT_MEDIUM>::value,     SkTFixed<SkFS::kMedium_Weight>::value },
327         { SkTFixed<FC_WEIGHT_DEMIBOLD>::value,   SkTFixed<SkFS::kSemiBold_Weight>::value },
328         { SkTFixed<FC_WEIGHT_BOLD>::value,       SkTFixed<SkFS::kBold_Weight>::value },
329         { SkTFixed<FC_WEIGHT_EXTRABOLD>::value,  SkTFixed<SkFS::kExtraBold_Weight>::value },
330         { SkTFixed<FC_WEIGHT_BLACK>::value,      SkTFixed<SkFS::kBlack_Weight>::value },
331         { SkTFixed<FC_WEIGHT_EXTRABLACK>::value, SkTFixed<SkFS::kExtraBlack_Weight>::value },
332     };
333     int weight = map_ranges(get_int(pattern, FC_WEIGHT, FC_WEIGHT_REGULAR),
334                             weightRanges, SK_ARRAY_COUNT(weightRanges));
335 
336     static const MapRanges widthRanges[] = {
337         { SkTFixed<FC_WIDTH_ULTRACONDENSED>::value, SkTFixed<SkFS::kUltraCondensed_Width>::value },
338         { SkTFixed<FC_WIDTH_EXTRACONDENSED>::value, SkTFixed<SkFS::kExtraCondensed_Width>::value },
339         { SkTFixed<FC_WIDTH_CONDENSED>::value,      SkTFixed<SkFS::kCondensed_Width>::value },
340         { SkTFixed<FC_WIDTH_SEMICONDENSED>::value,  SkTFixed<SkFS::kSemiCondensed_Width>::value },
341         { SkTFixed<FC_WIDTH_NORMAL>::value,         SkTFixed<SkFS::kNormal_Width>::value },
342         { SkTFixed<FC_WIDTH_SEMIEXPANDED>::value,   SkTFixed<SkFS::kSemiExpanded_Width>::value },
343         { SkTFixed<FC_WIDTH_EXPANDED>::value,       SkTFixed<SkFS::kExpanded_Width>::value },
344         { SkTFixed<FC_WIDTH_EXTRAEXPANDED>::value,  SkTFixed<SkFS::kExtraExpanded_Width>::value },
345         { SkTFixed<FC_WIDTH_ULTRAEXPANDED>::value,  SkTFixed<SkFS::kUltraExpanded_Width>::value },
346     };
347     int width = map_ranges(get_int(pattern, FC_WIDTH, FC_WIDTH_NORMAL),
348                            widthRanges, SK_ARRAY_COUNT(widthRanges));
349 
350     SkFS::Slant slant = SkFS::kUpright_Slant;
351     switch (get_int(pattern, FC_SLANT, FC_SLANT_ROMAN)) {
352         case FC_SLANT_ROMAN:   slant = SkFS::kUpright_Slant; break;
353         case FC_SLANT_ITALIC : slant = SkFS::kItalic_Slant ; break;
354         case FC_SLANT_OBLIQUE: slant = SkFS::kOblique_Slant; break;
355         default: SkASSERT(false); break;
356     }
357 
358     return SkFontStyle(weight, width, slant);
359 }
360 
fcpattern_from_skfontstyle(SkFontStyle style,FcPattern * pattern)361 static void fcpattern_from_skfontstyle(SkFontStyle style, FcPattern* pattern) {
362     FCLocker::AssertHeld();
363 
364     typedef SkFontStyle SkFS;
365 
366     static const MapRanges weightRanges[] = {
367         { SkTFixed<SkFS::kThin_Weight>::value,       SkTFixed<FC_WEIGHT_THIN>::value },
368         { SkTFixed<SkFS::kExtraLight_Weight>::value, SkTFixed<FC_WEIGHT_EXTRALIGHT>::value },
369         { SkTFixed<SkFS::kLight_Weight>::value,      SkTFixed<FC_WEIGHT_LIGHT>::value },
370         { SkTFixed<SkFS::kNormal_Weight>::value,     SkTFixed<FC_WEIGHT_REGULAR>::value },
371         { SkTFixed<SkFS::kMedium_Weight>::value,     SkTFixed<FC_WEIGHT_MEDIUM>::value },
372         { SkTFixed<SkFS::kSemiBold_Weight>::value,   SkTFixed<FC_WEIGHT_DEMIBOLD>::value },
373         { SkTFixed<SkFS::kBold_Weight>::value,       SkTFixed<FC_WEIGHT_BOLD>::value },
374         { SkTFixed<SkFS::kExtraBold_Weight>::value,  SkTFixed<FC_WEIGHT_EXTRABOLD>::value },
375         { SkTFixed<SkFS::kBlack_Weight>::value,      SkTFixed<FC_WEIGHT_BLACK>::value },
376         { SkTFixed<SkFS::kExtraBlack_Weight>::value, SkTFixed<FC_WEIGHT_EXTRABLACK>::value },
377     };
378     int weight = map_ranges(style.weight(), weightRanges, SK_ARRAY_COUNT(weightRanges));
379 
380     static const MapRanges widthRanges[] = {
381         { SkTFixed<SkFS::kUltraCondensed_Width>::value, SkTFixed<FC_WIDTH_ULTRACONDENSED>::value },
382         { SkTFixed<SkFS::kExtraCondensed_Width>::value, SkTFixed<FC_WIDTH_EXTRACONDENSED>::value },
383         { SkTFixed<SkFS::kCondensed_Width>::value,      SkTFixed<FC_WIDTH_CONDENSED>::value },
384         { SkTFixed<SkFS::kSemiCondensed_Width>::value,  SkTFixed<FC_WIDTH_SEMICONDENSED>::value },
385         { SkTFixed<SkFS::kNormal_Width>::value,         SkTFixed<FC_WIDTH_NORMAL>::value },
386         { SkTFixed<SkFS::kSemiExpanded_Width>::value,   SkTFixed<FC_WIDTH_SEMIEXPANDED>::value },
387         { SkTFixed<SkFS::kExpanded_Width>::value,       SkTFixed<FC_WIDTH_EXPANDED>::value },
388         { SkTFixed<SkFS::kExtraExpanded_Width>::value,  SkTFixed<FC_WIDTH_EXTRAEXPANDED>::value },
389         { SkTFixed<SkFS::kUltraExpanded_Width>::value,  SkTFixed<FC_WIDTH_ULTRAEXPANDED>::value },
390     };
391     int width = map_ranges(style.width(), widthRanges, SK_ARRAY_COUNT(widthRanges));
392 
393     int slant = FC_SLANT_ROMAN;
394     switch (style.slant()) {
395         case SkFS::kUpright_Slant: slant = FC_SLANT_ROMAN  ; break;
396         case SkFS::kItalic_Slant : slant = FC_SLANT_ITALIC ; break;
397         case SkFS::kOblique_Slant: slant = FC_SLANT_OBLIQUE; break;
398         default: SkASSERT(false); break;
399     }
400 
401     FcPatternAddInteger(pattern, FC_WEIGHT, weight);
402     FcPatternAddInteger(pattern, FC_WIDTH , width);
403     FcPatternAddInteger(pattern, FC_SLANT , slant);
404 }
405 
406 class SkTypeface_stream : public SkTypeface_FreeType {
407 public:
408     /** @param data takes ownership of the font data.*/
SkTypeface_stream(std::unique_ptr<SkFontData> data,SkString familyName,const SkFontStyle & style,bool fixedWidth)409     SkTypeface_stream(std::unique_ptr<SkFontData> data,
410                       SkString familyName, const SkFontStyle& style, bool fixedWidth)
411         : INHERITED(style, fixedWidth)
412         , fFamilyName(std::move(familyName))
413         , fData(std::move(data))
414     { }
415 
onGetFamilyName(SkString * familyName) const416     void onGetFamilyName(SkString* familyName) const override {
417         *familyName = fFamilyName;
418     }
419 
onGetFontDescriptor(SkFontDescriptor * desc,bool * serialize) const420     void onGetFontDescriptor(SkFontDescriptor* desc, bool* serialize) const override {
421         *serialize = true;
422     }
423 
onOpenStream(int * ttcIndex) const424     SkStreamAsset* onOpenStream(int* ttcIndex) const override {
425         *ttcIndex = fData->getIndex();
426         return fData->getStream()->duplicate();
427     }
428 
onMakeFontData() const429     std::unique_ptr<SkFontData> onMakeFontData() const override {
430         return skstd::make_unique<SkFontData>(*fData);
431     }
432 
433 private:
434     SkString fFamilyName;
435     const std::unique_ptr<const SkFontData> fData;
436 
437     typedef SkTypeface_FreeType INHERITED;
438 };
439 
440 class SkTypeface_fontconfig : public SkTypeface_FreeType {
441 public:
442     /** @param pattern takes ownership of the reference. */
Create(FcPattern * pattern)443     static SkTypeface_fontconfig* Create(FcPattern* pattern) {
444         return new SkTypeface_fontconfig(pattern);
445     }
446     mutable SkAutoFcPattern fPattern;
447 
onGetFamilyName(SkString * familyName) const448     void onGetFamilyName(SkString* familyName) const override {
449         *familyName = get_string(fPattern, FC_FAMILY);
450     }
451 
onGetFontDescriptor(SkFontDescriptor * desc,bool * serialize) const452     void onGetFontDescriptor(SkFontDescriptor* desc, bool* serialize) const override {
453         FCLocker lock;
454         desc->setFamilyName(get_string(fPattern, FC_FAMILY));
455         desc->setFullName(get_string(fPattern, FC_FULLNAME));
456         desc->setPostscriptName(get_string(fPattern, FC_POSTSCRIPT_NAME));
457         desc->setStyle(this->fontStyle());
458         *serialize = false;
459     }
460 
onOpenStream(int * ttcIndex) const461     SkStreamAsset* onOpenStream(int* ttcIndex) const override {
462         FCLocker lock;
463         *ttcIndex = get_int(fPattern, FC_INDEX, 0);
464         return SkStream::MakeFromFile(get_string(fPattern, FC_FILE)).release();
465     }
466 
onFilterRec(SkScalerContextRec * rec) const467     void onFilterRec(SkScalerContextRec* rec) const override {
468         const FcMatrix* fcMatrix = get_matrix(fPattern, FC_MATRIX);
469         if (fcMatrix) {
470             // fPost2x2 is column-major, left handed (y down).
471             // FcMatrix is column-major, right handed (y up).
472             SkMatrix fm;
473             fm.setAll(fcMatrix->xx,-fcMatrix->xy, 0,
474                      -fcMatrix->yx, fcMatrix->yy, 0,
475                       0           , 0           , 1);
476 
477             SkMatrix sm;
478             rec->getMatrixFrom2x2(&sm);
479 
480             sm.preConcat(fm);
481             rec->fPost2x2[0][0] = sm.getScaleX();
482             rec->fPost2x2[0][1] = sm.getSkewX();
483             rec->fPost2x2[1][0] = sm.getSkewY();
484             rec->fPost2x2[1][1] = sm.getScaleY();
485         }
486         if (get_bool(fPattern, FC_EMBOLDEN)) {
487             rec->fFlags |= SkScalerContext::kEmbolden_Flag;
488         }
489         this->INHERITED::onFilterRec(rec);
490     }
491 
onGetAdvancedMetrics() const492     std::unique_ptr<SkAdvancedTypefaceMetrics> onGetAdvancedMetrics() const override {
493         std::unique_ptr<SkAdvancedTypefaceMetrics> info =
494             this->INHERITED::onGetAdvancedMetrics();
495 
496         // Simulated fonts shouldn't be considered to be of the type of their data.
497         if (get_matrix(fPattern, FC_MATRIX) || get_bool(fPattern, FC_EMBOLDEN)) {
498             info->fType = SkAdvancedTypefaceMetrics::kOther_Font;
499         }
500         return info;
501     }
502 
~SkTypeface_fontconfig()503     ~SkTypeface_fontconfig() override {
504         // Hold the lock while unrefing the pattern.
505         FCLocker lock;
506         fPattern.reset();
507     }
508 
509 private:
510     /** @param pattern takes ownership of the reference. */
SkTypeface_fontconfig(FcPattern * pattern)511     SkTypeface_fontconfig(FcPattern* pattern)
512         : INHERITED(skfontstyle_from_fcpattern(pattern),
513                     FC_PROPORTIONAL != get_int(pattern, FC_SPACING, FC_PROPORTIONAL))
514         , fPattern(pattern)
515     { }
516 
517     typedef SkTypeface_FreeType INHERITED;
518 };
519 
520 class SkFontMgr_fontconfig : public SkFontMgr {
521     mutable SkAutoFcConfig fFC;
522     sk_sp<SkDataTable> fFamilyNames;
523     SkTypeface_FreeType::Scanner fScanner;
524 
525     class StyleSet : public SkFontStyleSet {
526     public:
527         /** @param parent does not take ownership of the reference.
528          *  @param fontSet takes ownership of the reference.
529          */
StyleSet(const SkFontMgr_fontconfig * parent,FcFontSet * fontSet)530         StyleSet(const SkFontMgr_fontconfig* parent, FcFontSet* fontSet)
531             : fFontMgr(SkRef(parent)), fFontSet(fontSet)
532         { }
533 
~StyleSet()534         ~StyleSet() override {
535             // Hold the lock while unrefing the font set.
536             FCLocker lock;
537             fFontSet.reset();
538         }
539 
count()540         int count() override { return fFontSet->nfont; }
541 
getStyle(int index,SkFontStyle * style,SkString * styleName)542         void getStyle(int index, SkFontStyle* style, SkString* styleName) override {
543             if (index < 0 || fFontSet->nfont <= index) {
544                 return;
545             }
546 
547             FCLocker lock;
548             if (style) {
549                 *style = skfontstyle_from_fcpattern(fFontSet->fonts[index]);
550             }
551             if (styleName) {
552                 *styleName = get_string(fFontSet->fonts[index], FC_STYLE);
553             }
554         }
555 
createTypeface(int index)556         SkTypeface* createTypeface(int index) override {
557             FCLocker lock;
558 
559             FcPattern* match = fFontSet->fonts[index];
560             return fFontMgr->createTypefaceFromFcPattern(match);
561         }
562 
matchStyle(const SkFontStyle & style)563         SkTypeface* matchStyle(const SkFontStyle& style) override {
564             FCLocker lock;
565 
566             SkAutoFcPattern pattern;
567             fcpattern_from_skfontstyle(style, pattern);
568             FcConfigSubstitute(fFontMgr->fFC, pattern, FcMatchPattern);
569             FcDefaultSubstitute(pattern);
570 
571             FcResult result;
572             FcFontSet* fontSets[1] = { fFontSet };
573             SkAutoFcPattern match(FcFontSetMatch(fFontMgr->fFC,
574                                                  fontSets, SK_ARRAY_COUNT(fontSets),
575                                                  pattern, &result));
576             if (nullptr == match) {
577                 return nullptr;
578             }
579 
580             return fFontMgr->createTypefaceFromFcPattern(match);
581         }
582 
583     private:
584         sk_sp<const SkFontMgr_fontconfig> fFontMgr;
585         SkAutoFcFontSet fFontSet;
586     };
587 
FindName(const SkTDArray<const char * > & list,const char * str)588     static bool FindName(const SkTDArray<const char*>& list, const char* str) {
589         int count = list.count();
590         for (int i = 0; i < count; ++i) {
591             if (!strcmp(list[i], str)) {
592                 return true;
593             }
594         }
595         return false;
596     }
597 
GetFamilyNames(FcConfig * fcconfig)598     static sk_sp<SkDataTable> GetFamilyNames(FcConfig* fcconfig) {
599         FCLocker lock;
600 
601         SkTDArray<const char*> names;
602         SkTDArray<size_t> sizes;
603 
604         static const FcSetName fcNameSet[] = { FcSetSystem, FcSetApplication };
605         for (int setIndex = 0; setIndex < (int)SK_ARRAY_COUNT(fcNameSet); ++setIndex) {
606             // Return value of FcConfigGetFonts must not be destroyed.
607             FcFontSet* allFonts(FcConfigGetFonts(fcconfig, fcNameSet[setIndex]));
608             if (nullptr == allFonts) {
609                 continue;
610             }
611 
612             for (int fontIndex = 0; fontIndex < allFonts->nfont; ++fontIndex) {
613                 FcPattern* current = allFonts->fonts[fontIndex];
614                 for (int id = 0; ; ++id) {
615                     FcChar8* fcFamilyName;
616                     FcResult result = FcPatternGetString(current, FC_FAMILY, id, &fcFamilyName);
617                     if (FcResultNoId == result) {
618                         break;
619                     }
620                     if (FcResultMatch != result) {
621                         continue;
622                     }
623                     const char* familyName = reinterpret_cast<const char*>(fcFamilyName);
624                     if (familyName && !FindName(names, familyName)) {
625                         *names.append() = familyName;
626                         *sizes.append() = strlen(familyName) + 1;
627                     }
628                 }
629             }
630         }
631 
632         return SkDataTable::MakeCopyArrays((void const *const *)names.begin(),
633                                            sizes.begin(), names.count());
634     }
635 
FindByFcPattern(SkTypeface * cached,void * ctx)636     static bool FindByFcPattern(SkTypeface* cached, void* ctx) {
637         SkTypeface_fontconfig* cshFace = static_cast<SkTypeface_fontconfig*>(cached);
638         FcPattern* ctxPattern = static_cast<FcPattern*>(ctx);
639         return FcTrue == FcPatternEqual(cshFace->fPattern, ctxPattern);
640     }
641 
642     mutable SkMutex fTFCacheMutex;
643     mutable SkTypefaceCache fTFCache;
644     /** Creates a typeface using a typeface cache.
645      *  @param pattern a complete pattern from FcFontRenderPrepare.
646      */
createTypefaceFromFcPattern(FcPattern * pattern) const647     SkTypeface* createTypefaceFromFcPattern(FcPattern* pattern) const {
648         FCLocker::AssertHeld();
649         SkAutoMutexAcquire ama(fTFCacheMutex);
650         SkTypeface* face = fTFCache.findByProcAndRef(FindByFcPattern, pattern);
651         if (nullptr == face) {
652             FcPatternReference(pattern);
653             face = SkTypeface_fontconfig::Create(pattern);
654             if (face) {
655                 fTFCache.add(face);
656             }
657         }
658         return face;
659     }
660 
661 public:
662     /** Takes control of the reference to 'config'. */
SkFontMgr_fontconfig(FcConfig * config)663     explicit SkFontMgr_fontconfig(FcConfig* config)
664         : fFC(config ? config : FcInitLoadConfigAndFonts())
665         , fFamilyNames(GetFamilyNames(fFC)) { }
666 
~SkFontMgr_fontconfig()667     ~SkFontMgr_fontconfig() override {
668         // Hold the lock while unrefing the config.
669         FCLocker lock;
670         fFC.reset();
671     }
672 
673 protected:
onCountFamilies() const674     int onCountFamilies() const override {
675         return fFamilyNames->count();
676     }
677 
onGetFamilyName(int index,SkString * familyName) const678     void onGetFamilyName(int index, SkString* familyName) const override {
679         familyName->set(fFamilyNames->atStr(index));
680     }
681 
onCreateStyleSet(int index) const682     SkFontStyleSet* onCreateStyleSet(int index) const override {
683         return this->onMatchFamily(fFamilyNames->atStr(index));
684     }
685 
686     /** True if any string object value in the font is the same
687      *         as a string object value in the pattern.
688      */
AnyMatching(FcPattern * font,FcPattern * pattern,const char * object)689     static bool AnyMatching(FcPattern* font, FcPattern* pattern, const char* object) {
690         FcChar8* fontString;
691         FcChar8* patternString;
692         FcResult result;
693         // Set an arbitrary limit on the number of pattern object values to consider.
694         // TODO: re-write this to avoid N*M
695         static const int maxId = 16;
696         for (int patternId = 0; patternId < maxId; ++patternId) {
697             result = FcPatternGetString(pattern, object, patternId, &patternString);
698             if (FcResultNoId == result) {
699                 break;
700             }
701             if (FcResultMatch != result) {
702                 continue;
703             }
704             for (int fontId = 0; fontId < maxId; ++fontId) {
705                 result = FcPatternGetString(font, object, fontId, &fontString);
706                 if (FcResultNoId == result) {
707                     break;
708                 }
709                 if (FcResultMatch != result) {
710                     continue;
711                 }
712                 if (0 == FcStrCmpIgnoreCase(patternString, fontString)) {
713                     return true;
714                 }
715             }
716         }
717         return false;
718     }
719 
FontAccessible(FcPattern * font)720     static bool FontAccessible(FcPattern* font) {
721         // FontConfig can return fonts which are unreadable.
722         const char* filename = get_string(font, FC_FILE, nullptr);
723         if (nullptr == filename) {
724             return false;
725         }
726         return sk_exists(filename, kRead_SkFILE_Flag);
727     }
728 
FontFamilyNameMatches(FcPattern * font,FcPattern * pattern)729     static bool FontFamilyNameMatches(FcPattern* font, FcPattern* pattern) {
730         return AnyMatching(font, pattern, FC_FAMILY);
731     }
732 
FontContainsCharacter(FcPattern * font,uint32_t character)733     static bool FontContainsCharacter(FcPattern* font, uint32_t character) {
734         FcResult result;
735         FcCharSet* matchCharSet;
736         for (int charSetId = 0; ; ++charSetId) {
737             result = FcPatternGetCharSet(font, FC_CHARSET, charSetId, &matchCharSet);
738             if (FcResultNoId == result) {
739                 break;
740             }
741             if (FcResultMatch != result) {
742                 continue;
743             }
744             if (FcCharSetHasChar(matchCharSet, character)) {
745                 return true;
746             }
747         }
748         return false;
749     }
750 
onMatchFamily(const char familyName[]) const751     SkFontStyleSet* onMatchFamily(const char familyName[]) const override {
752         if (!familyName) {
753             return nullptr;
754         }
755         FCLocker lock;
756 
757         SkAutoFcPattern pattern;
758         FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
759         FcConfigSubstitute(fFC, pattern, FcMatchPattern);
760         FcDefaultSubstitute(pattern);
761 
762         FcPattern* matchPattern;
763         SkAutoFcPattern strongPattern(nullptr);
764         if (familyName) {
765             strongPattern.reset(FcPatternDuplicate(pattern));
766             remove_weak(strongPattern, FC_FAMILY);
767             matchPattern = strongPattern;
768         } else {
769             matchPattern = pattern;
770         }
771 
772         SkAutoFcFontSet matches;
773         // TODO: Some families have 'duplicates' due to symbolic links.
774         // The patterns are exactly the same except for the FC_FILE.
775         // It should be possible to collapse these patterns by normalizing.
776         static const FcSetName fcNameSet[] = { FcSetSystem, FcSetApplication };
777         for (int setIndex = 0; setIndex < (int)SK_ARRAY_COUNT(fcNameSet); ++setIndex) {
778             // Return value of FcConfigGetFonts must not be destroyed.
779             FcFontSet* allFonts(FcConfigGetFonts(fFC, fcNameSet[setIndex]));
780             if (nullptr == allFonts) {
781                 continue;
782             }
783 
784             for (int fontIndex = 0; fontIndex < allFonts->nfont; ++fontIndex) {
785                 FcPattern* font = allFonts->fonts[fontIndex];
786                 if (FontAccessible(font) && FontFamilyNameMatches(font, matchPattern)) {
787                     FcFontSetAdd(matches, FcFontRenderPrepare(fFC, pattern, font));
788                 }
789             }
790         }
791 
792         return new StyleSet(this, matches.release());
793     }
794 
onMatchFamilyStyle(const char familyName[],const SkFontStyle & style) const795     virtual SkTypeface* onMatchFamilyStyle(const char familyName[],
796                                            const SkFontStyle& style) const override
797     {
798         FCLocker lock;
799 
800         SkAutoFcPattern pattern;
801         FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
802         fcpattern_from_skfontstyle(style, pattern);
803         FcConfigSubstitute(fFC, pattern, FcMatchPattern);
804         FcDefaultSubstitute(pattern);
805 
806         // We really want to match strong (prefered) and same (acceptable) only here.
807         // If a family name was specified, assume that any weak matches after the last strong match
808         // are weak (default) and ignore them.
809         // The reason for is that after substitution the pattern for 'sans-serif' looks like
810         // "wwwwwwwwwwwwwwswww" where there are many weak but preferred names, followed by defaults.
811         // So it is possible to have weakly matching but preferred names.
812         // In aliases, bindings are weak by default, so this is easy and common.
813         // If no family name was specified, we'll probably only get weak matches, but that's ok.
814         FcPattern* matchPattern;
815         SkAutoFcPattern strongPattern(nullptr);
816         if (familyName) {
817             strongPattern.reset(FcPatternDuplicate(pattern));
818             remove_weak(strongPattern, FC_FAMILY);
819             matchPattern = strongPattern;
820         } else {
821             matchPattern = pattern;
822         }
823 
824         FcResult result;
825         SkAutoFcPattern font(FcFontMatch(fFC, pattern, &result));
826         if (nullptr == font || !FontAccessible(font) || !FontFamilyNameMatches(font, matchPattern)) {
827             return nullptr;
828         }
829 
830         return createTypefaceFromFcPattern(font);
831     }
832 
onMatchFamilyStyleCharacter(const char familyName[],const SkFontStyle & style,const char * bcp47[],int bcp47Count,SkUnichar character) const833     virtual SkTypeface* onMatchFamilyStyleCharacter(const char familyName[],
834                                                     const SkFontStyle& style,
835                                                     const char* bcp47[],
836                                                     int bcp47Count,
837                                                     SkUnichar character) const override
838     {
839         FCLocker lock;
840 
841         SkAutoFcPattern pattern;
842         if (familyName) {
843             FcValue familyNameValue;
844             familyNameValue.type = FcTypeString;
845             familyNameValue.u.s = reinterpret_cast<const FcChar8*>(familyName);
846             FcPatternAddWeak(pattern, FC_FAMILY, familyNameValue, FcFalse);
847         }
848         fcpattern_from_skfontstyle(style, pattern);
849 
850         SkAutoFcCharSet charSet;
851         FcCharSetAddChar(charSet, character);
852         FcPatternAddCharSet(pattern, FC_CHARSET, charSet);
853 
854         if (bcp47Count > 0) {
855             SkASSERT(bcp47);
856             SkAutoFcLangSet langSet;
857             for (int i = bcp47Count; i --> 0;) {
858                 FcLangSetAdd(langSet, (const FcChar8*)bcp47[i]);
859             }
860             FcPatternAddLangSet(pattern, FC_LANG, langSet);
861         }
862 
863         FcConfigSubstitute(fFC, pattern, FcMatchPattern);
864         FcDefaultSubstitute(pattern);
865 
866         FcResult result;
867         SkAutoFcPattern font(FcFontMatch(fFC, pattern, &result));
868         if (nullptr == font || !FontAccessible(font) || !FontContainsCharacter(font, character)) {
869             return nullptr;
870         }
871 
872         return createTypefaceFromFcPattern(font);
873     }
874 
onMatchFaceStyle(const SkTypeface * typeface,const SkFontStyle & style) const875     virtual SkTypeface* onMatchFaceStyle(const SkTypeface* typeface,
876                                          const SkFontStyle& style) const override
877     {
878         //TODO: should the SkTypeface_fontconfig know its family?
879         const SkTypeface_fontconfig* fcTypeface =
880                 static_cast<const SkTypeface_fontconfig*>(typeface);
881         return this->matchFamilyStyle(get_string(fcTypeface->fPattern, FC_FAMILY), style);
882     }
883 
onCreateFromStream(SkStreamAsset * bareStream,int ttcIndex) const884     SkTypeface* onCreateFromStream(SkStreamAsset* bareStream, int ttcIndex) const override {
885         std::unique_ptr<SkStreamAsset> stream(bareStream);
886         const size_t length = stream->getLength();
887         if (length <= 0 || (1u << 30) < length) {
888             return nullptr;
889         }
890 
891         SkString name;
892         SkFontStyle style;
893         bool isFixedWidth = false;
894         if (!fScanner.scanFont(stream.get(), ttcIndex, &name, &style, &isFixedWidth, nullptr)) {
895             return nullptr;
896         }
897 
898         auto data = skstd::make_unique<SkFontData>(std::move(stream), ttcIndex, nullptr, 0);
899         return new SkTypeface_stream(std::move(data), std::move(name), style, isFixedWidth);
900     }
901 
onCreateFromStream(SkStreamAsset * s,const SkFontArguments & args) const902     SkTypeface* onCreateFromStream(SkStreamAsset* s, const SkFontArguments& args) const override {
903         using Scanner = SkTypeface_FreeType::Scanner;
904         std::unique_ptr<SkStreamAsset> stream(s);
905         bool isFixedPitch;
906         SkFontStyle style;
907         SkString name;
908         Scanner::AxisDefinitions axisDefinitions;
909         if (!fScanner.scanFont(stream.get(), args.getCollectionIndex(),
910                                &name, &style, &isFixedPitch, &axisDefinitions))
911         {
912             return nullptr;
913         }
914 
915         SkAutoSTMalloc<4, SkFixed> axisValues(axisDefinitions.count());
916         Scanner::computeAxisValues(axisDefinitions, args.getVariationDesignPosition(),
917                                    axisValues, name);
918 
919         auto data = skstd::make_unique<SkFontData>(std::move(stream), args.getCollectionIndex(),
920                                                    axisValues.get(), axisDefinitions.count());
921         return new SkTypeface_stream(std::move(data), std::move(name), style, isFixedPitch);
922     }
923 
onCreateFromData(SkData * data,int ttcIndex) const924     SkTypeface* onCreateFromData(SkData* data, int ttcIndex) const override {
925         return this->createFromStream(new SkMemoryStream(sk_ref_sp(data)), ttcIndex);
926     }
927 
onCreateFromFile(const char path[],int ttcIndex) const928     SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
929         return this->createFromStream(SkStream::MakeFromFile(path).release(), ttcIndex);
930     }
931 
onCreateFromFontData(std::unique_ptr<SkFontData> fontData) const932     SkTypeface* onCreateFromFontData(std::unique_ptr<SkFontData> fontData) const override {
933         SkStreamAsset* stream(fontData->getStream());
934         const size_t length = stream->getLength();
935         if (length <= 0 || (1u << 30) < length) {
936             return nullptr;
937         }
938 
939         const int ttcIndex = fontData->getIndex();
940         SkString name;
941         SkFontStyle style;
942         bool isFixedWidth = false;
943         if (!fScanner.scanFont(stream, ttcIndex, &name, &style, &isFixedWidth, nullptr)) {
944             return nullptr;
945         }
946 
947         return new SkTypeface_stream(std::move(fontData), std::move(name), style, isFixedWidth);
948     }
949 
onLegacyCreateTypeface(const char familyName[],SkFontStyle style) const950     SkTypeface* onLegacyCreateTypeface(const char familyName[], SkFontStyle style) const override {
951         sk_sp<SkTypeface> typeface(this->matchFamilyStyle(familyName, style));
952         if (typeface.get()) {
953             return typeface.release();
954         }
955 
956         return this->matchFamilyStyle(nullptr, style);
957     }
958 };
959 
SkFontMgr_New_FontConfig(FcConfig * fc)960 SK_API sk_sp<SkFontMgr> SkFontMgr_New_FontConfig(FcConfig* fc) {
961     return sk_make_sp<SkFontMgr_fontconfig>(fc);
962 }
963