1 /*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "Minikin"
18
19 #include "minikin/FontFamily.h"
20
21 #include <cstdint>
22 #include <vector>
23
24 #include <hb-ot.h>
25 #include <hb.h>
26 #include <log/log.h>
27
28 #include "minikin/CmapCoverage.h"
29 #include "minikin/FamilyVariant.h"
30 #include "minikin/HbUtils.h"
31 #include "minikin/MinikinFont.h"
32
33 #include "FontUtils.h"
34 #include "Locale.h"
35 #include "LocaleListCache.h"
36 #include "MinikinInternal.h"
37
38 namespace minikin {
39
build()40 Font Font::Builder::build() {
41 if (mIsWeightSet && mIsSlantSet) {
42 // No need to read OS/2 header of the font file.
43 return Font(std::move(mTypeface), FontStyle(mWeight, mSlant), prepareFont(mTypeface));
44 }
45
46 HbFontUniquePtr font = prepareFont(mTypeface);
47 FontStyle styleFromFont = analyzeStyle(font);
48 if (!mIsWeightSet) {
49 mWeight = styleFromFont.weight();
50 }
51 if (!mIsSlantSet) {
52 mSlant = styleFromFont.slant();
53 }
54 return Font(std::move(mTypeface), FontStyle(mWeight, mSlant), std::move(font));
55 }
56
57 // static
prepareFont(const std::shared_ptr<MinikinFont> & typeface)58 HbFontUniquePtr Font::prepareFont(const std::shared_ptr<MinikinFont>& typeface) {
59 const char* buf = reinterpret_cast<const char*>(typeface->GetFontData());
60 size_t size = typeface->GetFontSize();
61 uint32_t ttcIndex = typeface->GetFontIndex();
62
63 HbBlobUniquePtr blob(hb_blob_create(buf, size, HB_MEMORY_MODE_READONLY, nullptr, nullptr));
64 HbFaceUniquePtr face(hb_face_create(blob.get(), ttcIndex));
65 HbFontUniquePtr parent(hb_font_create(face.get()));
66 hb_ot_font_set_funcs(parent.get());
67
68 uint32_t upem = hb_face_get_upem(face.get());
69 hb_font_set_scale(parent.get(), upem, upem);
70
71 HbFontUniquePtr font(hb_font_create_sub_font(parent.get()));
72 std::vector<hb_variation_t> variations;
73 variations.reserve(typeface->GetAxes().size());
74 for (const FontVariation& variation : typeface->GetAxes()) {
75 variations.push_back({variation.axisTag, variation.value});
76 }
77 hb_font_set_variations(font.get(), variations.data(), variations.size());
78 return font;
79 }
80
81 // static
analyzeStyle(const HbFontUniquePtr & font)82 FontStyle Font::analyzeStyle(const HbFontUniquePtr& font) {
83 HbBlob os2Table(font, MinikinFont::MakeTag('O', 'S', '/', '2'));
84 if (!os2Table) {
85 return FontStyle();
86 }
87
88 int weight;
89 bool italic;
90 if (!::minikin::analyzeStyle(os2Table.get(), os2Table.size(), &weight, &italic)) {
91 return FontStyle();
92 }
93 // TODO: Update weight/italic based on fvar value.
94 return FontStyle(static_cast<uint16_t>(weight), static_cast<FontStyle::Slant>(italic));
95 }
96
getSupportedAxes() const97 std::unordered_set<AxisTag> Font::getSupportedAxes() const {
98 HbBlob fvarTable(mBaseFont, MinikinFont::MakeTag('f', 'v', 'a', 'r'));
99 if (!fvarTable) {
100 return std::unordered_set<AxisTag>();
101 }
102 std::unordered_set<AxisTag> supportedAxes;
103 analyzeAxes(fvarTable.get(), fvarTable.size(), &supportedAxes);
104 return supportedAxes;
105 }
106
FontFamily(std::vector<Font> && fonts)107 FontFamily::FontFamily(std::vector<Font>&& fonts)
108 : FontFamily(FamilyVariant::DEFAULT, std::move(fonts)) {}
109
FontFamily(FamilyVariant variant,std::vector<Font> && fonts)110 FontFamily::FontFamily(FamilyVariant variant, std::vector<Font>&& fonts)
111 : FontFamily(LocaleListCache::kEmptyListId, variant, std::move(fonts),
112 false /* isCustomFallback */) {}
113
FontFamily(uint32_t localeListId,FamilyVariant variant,std::vector<Font> && fonts,bool isCustomFallback)114 FontFamily::FontFamily(uint32_t localeListId, FamilyVariant variant, std::vector<Font>&& fonts,
115 bool isCustomFallback)
116 : mLocaleListId(localeListId),
117 mVariant(variant),
118 mFonts(std::move(fonts)),
119 mIsColorEmoji(LocaleListCache::getById(localeListId).getEmojiStyle() ==
120 EmojiStyle::EMOJI),
121 mIsCustomFallback(isCustomFallback) {
122 MINIKIN_ASSERT(!mFonts.empty(), "FontFamily must contain at least one font.");
123 computeCoverage();
124 }
125
126 // Compute a matching metric between two styles - 0 is an exact match
computeMatch(FontStyle style1,FontStyle style2)127 static int computeMatch(FontStyle style1, FontStyle style2) {
128 if (style1 == style2) return 0;
129 int score = abs(style1.weight() / 100 - style2.weight() / 100);
130 if (style1.slant() != style2.slant()) {
131 score += 2;
132 }
133 return score;
134 }
135
computeFakery(FontStyle wanted,FontStyle actual)136 static FontFakery computeFakery(FontStyle wanted, FontStyle actual) {
137 // If desired weight is semibold or darker, and 2 or more grades
138 // higher than actual (for example, medium 500 -> bold 700), then
139 // select fake bold.
140 bool isFakeBold = wanted.weight() >= 600 && (wanted.weight() - actual.weight()) >= 200;
141 bool isFakeItalic = wanted.slant() == FontStyle::Slant::ITALIC &&
142 actual.slant() == FontStyle::Slant::UPRIGHT;
143 return FontFakery(isFakeBold, isFakeItalic);
144 }
145
getClosestMatch(FontStyle style) const146 FakedFont FontFamily::getClosestMatch(FontStyle style) const {
147 const Font* bestFont = &mFonts[0];
148 int bestMatch = computeMatch(bestFont->style(), style);
149 for (size_t i = 1; i < mFonts.size(); i++) {
150 const Font& font = mFonts[i];
151 int match = computeMatch(font.style(), style);
152 if (i == 0 || match < bestMatch) {
153 bestFont = &font;
154 bestMatch = match;
155 }
156 }
157 return FakedFont{bestFont, computeFakery(style, bestFont->style())};
158 }
159
computeCoverage()160 void FontFamily::computeCoverage() {
161 const Font* font = getClosestMatch(FontStyle()).font;
162 HbBlob cmapTable(font->baseFont(), MinikinFont::MakeTag('c', 'm', 'a', 'p'));
163 if (cmapTable.get() == nullptr) {
164 ALOGE("Could not get cmap table size!\n");
165 return;
166 }
167
168 mCoverage = CmapCoverage::getCoverage(cmapTable.get(), cmapTable.size(), &mCmapFmt14Coverage);
169
170 for (size_t i = 0; i < mFonts.size(); ++i) {
171 std::unordered_set<AxisTag> supportedAxes = mFonts[i].getSupportedAxes();
172 mSupportedAxes.insert(supportedAxes.begin(), supportedAxes.end());
173 }
174 }
175
hasGlyph(uint32_t codepoint,uint32_t variationSelector) const176 bool FontFamily::hasGlyph(uint32_t codepoint, uint32_t variationSelector) const {
177 if (variationSelector == 0) {
178 return mCoverage.get(codepoint);
179 }
180
181 if (mCmapFmt14Coverage.empty()) {
182 return false;
183 }
184
185 const uint16_t vsIndex = getVsIndex(variationSelector);
186
187 if (vsIndex >= mCmapFmt14Coverage.size()) {
188 // Even if vsIndex is INVALID_VS_INDEX, we reach here since INVALID_VS_INDEX is defined to
189 // be at the maximum end of the range.
190 return false;
191 }
192
193 const std::unique_ptr<SparseBitSet>& bitset = mCmapFmt14Coverage[vsIndex];
194 if (bitset.get() == nullptr) {
195 return false;
196 }
197
198 return bitset->get(codepoint);
199 }
200
createFamilyWithVariation(const std::vector<FontVariation> & variations) const201 std::shared_ptr<FontFamily> FontFamily::createFamilyWithVariation(
202 const std::vector<FontVariation>& variations) const {
203 if (variations.empty() || mSupportedAxes.empty()) {
204 return nullptr;
205 }
206
207 bool hasSupportedAxis = false;
208 for (const FontVariation& variation : variations) {
209 if (mSupportedAxes.find(variation.axisTag) != mSupportedAxes.end()) {
210 hasSupportedAxis = true;
211 break;
212 }
213 }
214 if (!hasSupportedAxis) {
215 // None of variation axes are suppored by this family.
216 return nullptr;
217 }
218
219 std::vector<Font> fonts;
220 for (const Font& font : mFonts) {
221 bool supportedVariations = false;
222 std::unordered_set<AxisTag> supportedAxes = font.getSupportedAxes();
223 if (!supportedAxes.empty()) {
224 for (const FontVariation& variation : variations) {
225 if (supportedAxes.find(variation.axisTag) != supportedAxes.end()) {
226 supportedVariations = true;
227 break;
228 }
229 }
230 }
231 std::shared_ptr<MinikinFont> minikinFont;
232 if (supportedVariations) {
233 minikinFont = font.typeface()->createFontWithVariation(variations);
234 }
235 if (minikinFont == nullptr) {
236 minikinFont = font.typeface();
237 }
238 fonts.push_back(Font::Builder(minikinFont).setStyle(font.style()).build());
239 }
240
241 return std::shared_ptr<FontFamily>(
242 new FontFamily(mLocaleListId, mVariant, std::move(fonts), mIsCustomFallback));
243 }
244
245 } // namespace minikin
246