1 // Copyright 2018 Google LLC.
2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3
4 #include "src/pdf/SkPDFSubsetFont.h"
5
6 #if defined(SK_USING_THIRD_PARTY_ICU)
7 #include "SkLoadICU.h"
8 #endif
9
10 #if defined(SK_PDF_USE_HARFBUZZ_SUBSET)
11
12 #include "include/private/SkTemplates.h"
13 #include "include/private/SkTo.h"
14 #include "src/utils/SkCallableTraits.h"
15
16 #include "hb.h"
17 #include "hb-subset.h"
18
19 template <class T, void(*P)(T*)> using resource = std::unique_ptr<T, SkFunctionWrapper<void, T, P>>;
20 using HBBlob = resource<hb_blob_t, hb_blob_destroy>;
21 using HBFace = resource<hb_face_t, hb_face_destroy>;
22 using HBSubsetInput = resource<hb_subset_input_t, hb_subset_input_destroy>;
23 using HBSet = resource<hb_set_t, hb_set_destroy>;
24
to_blob(sk_sp<SkData> data)25 static HBBlob to_blob(sk_sp<SkData> data) {
26 using blob_size_t = SkCallableTraits<decltype(hb_blob_create)>::argument<1>::type;
27 if (!SkTFitsIn<blob_size_t>(data->size())) {
28 return nullptr;
29 }
30 const char* blobData = static_cast<const char*>(data->data());
31 blob_size_t blobSize = SkTo<blob_size_t>(data->size());
32 return HBBlob(hb_blob_create(blobData, blobSize,
33 HB_MEMORY_MODE_READONLY,
34 data.release(), [](void* p){ ((SkData*)p)->unref(); }));
35 }
36
to_data(HBBlob blob)37 static sk_sp<SkData> to_data(HBBlob blob) {
38 if (!blob) {
39 return nullptr;
40 }
41 unsigned int length;
42 const char* data = hb_blob_get_data(blob.get(), &length);
43 if (!data || !length) {
44 return nullptr;
45 }
46 return SkData::MakeWithProc(data, SkToSizeT(length),
47 [](const void*, void* ctx) { hb_blob_destroy((hb_blob_t*)ctx); },
48 blob.release());
49 }
50
subset_harfbuzz(sk_sp<SkData> fontData,const SkPDFGlyphUse & glyphUsage,int ttcIndex)51 static sk_sp<SkData> subset_harfbuzz(sk_sp<SkData> fontData,
52 const SkPDFGlyphUse& glyphUsage,
53 int ttcIndex) {
54 #if defined(SK_USING_THIRD_PARTY_ICU)
55 if (!SkLoadICU()) {
56 return nullptr;
57 }
58 #endif
59 if (!fontData) {
60 return nullptr;
61 }
62 HBFace face(hb_face_create(to_blob(std::move(fontData)).get(), ttcIndex));
63 SkASSERT(face);
64
65 HBSubsetInput input(hb_subset_input_create_or_fail());
66 SkASSERT(input);
67 if (!face || !input) {
68 return nullptr;
69 }
70 hb_set_t* glyphs = hb_subset_input_glyph_set(input.get());
71 hb_set_add(glyphs, 0);
72 glyphUsage.getSetValues([&glyphs](unsigned gid) { hb_set_add(glyphs, gid);});
73
74 hb_subset_input_set_retain_gids(input.get(), true);
75 hb_subset_input_set_drop_hints(input.get(), true);
76 HBFace subset(hb_subset(face.get(), input.get()));
77 HBBlob result(hb_face_reference_blob(subset.get()));
78 return to_data(std::move(result));
79 }
80
81 #endif // defined(SK_PDF_USE_HARFBUZZ_SUBSET)
82
83 ////////////////////////////////////////////////////////////////////////////////
84
85 #if defined(SK_PDF_USE_SFNTLY)
86
87 #include "sample/chromium/font_subsetter.h"
88 #include <vector>
89
subset_sfntly(sk_sp<SkData> fontData,const SkPDFGlyphUse & glyphUsage,const char * fontName,int ttcIndex)90 static sk_sp<SkData> subset_sfntly(sk_sp<SkData> fontData,
91 const SkPDFGlyphUse& glyphUsage,
92 const char* fontName,
93 int ttcIndex) {
94 #if defined(SK_USING_THIRD_PARTY_ICU)
95 if (!SkLoadICU()) {
96 return nullptr;
97 }
98 #endif
99 // Generate glyph id array in format needed by sfntly.
100 // TODO(halcanary): sfntly should take a more compact format.
101 std::vector<unsigned> subset;
102 if (!glyphUsage.has(0)) {
103 subset.push_back(0); // Always include glyph 0.
104 }
105 glyphUsage.getSetValues([&subset](unsigned v) { subset.push_back(v); });
106
107 unsigned char* subsetFont{nullptr};
108 #if defined(SK_BUILD_FOR_GOOGLE3)
109 // TODO(halcanary): update SK_BUILD_FOR_GOOGLE3 to newest version of Sfntly.
110 (void)ttcIndex;
111 int subsetFontSize = SfntlyWrapper::SubsetFont(fontName,
112 fontData->bytes(),
113 fontData->size(),
114 subset.data(),
115 subset.size(),
116 &subsetFont);
117 #else // defined(SK_BUILD_FOR_GOOGLE3)
118 (void)fontName;
119 int subsetFontSize = SfntlyWrapper::SubsetFont(ttcIndex,
120 fontData->bytes(),
121 fontData->size(),
122 subset.data(),
123 subset.size(),
124 &subsetFont);
125 #endif // defined(SK_BUILD_FOR_GOOGLE3)
126 SkASSERT(subsetFontSize > 0 || subsetFont == nullptr);
127 if (subsetFontSize < 1 || subsetFont == nullptr) {
128 return nullptr;
129 }
130 return SkData::MakeWithProc(subsetFont, subsetFontSize,
131 [](const void* p, void*) { delete[] (unsigned char*)p; },
132 nullptr);
133 }
134
135 #endif // defined(SK_PDF_USE_SFNTLY)
136
137 ////////////////////////////////////////////////////////////////////////////////
138
139 #if defined(SK_PDF_USE_SFNTLY) && defined(SK_PDF_USE_HARFBUZZ_SUBSET)
140
SkPDFSubsetFont(sk_sp<SkData> fontData,const SkPDFGlyphUse & glyphUsage,SkPDF::Metadata::Subsetter subsetter,const char * fontName,int ttcIndex)141 sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData> fontData,
142 const SkPDFGlyphUse& glyphUsage,
143 SkPDF::Metadata::Subsetter subsetter,
144 const char* fontName,
145 int ttcIndex) {
146 switch (subsetter) {
147 case SkPDF::Metadata::kHarfbuzz_Subsetter:
148 return subset_harfbuzz(std::move(fontData), glyphUsage, ttcIndex);
149 case SkPDF::Metadata::kSfntly_Subsetter:
150 return subset_sfntly(std::move(fontData), glyphUsage, fontName, ttcIndex);
151 }
152 return nullptr;
153 }
154
155 #elif defined(SK_PDF_USE_SFNTLY)
156
SkPDFSubsetFont(sk_sp<SkData> fontData,const SkPDFGlyphUse & glyphUsage,SkPDF::Metadata::Subsetter,const char * fontName,int ttcIndex)157 sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData> fontData,
158 const SkPDFGlyphUse& glyphUsage,
159 SkPDF::Metadata::Subsetter,
160 const char* fontName,
161 int ttcIndex) {
162 return subset_sfntly(std::move(fontData), glyphUsage, fontName, ttcIndex);
163 }
164
165 #elif defined(SK_PDF_USE_HARFBUZZ_SUBSET)
166
SkPDFSubsetFont(sk_sp<SkData> fontData,const SkPDFGlyphUse & glyphUsage,SkPDF::Metadata::Subsetter,const char *,int ttcIndex)167 sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData> fontData,
168 const SkPDFGlyphUse& glyphUsage,
169 SkPDF::Metadata::Subsetter,
170 const char*,
171 int ttcIndex) {
172 return subset_harfbuzz(std::move(fontData), glyphUsage, ttcIndex);
173 }
174
175 #else
176
SkPDFSubsetFont(sk_sp<SkData>,const SkPDFGlyphUse &,SkPDF::Metadata::Subsetter,const char *,int)177 sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData>, const SkPDFGlyphUse&, SkPDF::Metadata::Subsetter,
178 const char*, int) {
179 return nullptr;
180 }
181 #endif // defined(SK_PDF_USE_SFNTLY)
182
183