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 #ifndef MINIKIN_FONT_FAMILY_H
18 #define MINIKIN_FONT_FAMILY_H
19
20 #include <memory>
21 #include <string>
22 #include <unordered_set>
23 #include <vector>
24
25 #include <hb.h>
26
27 #include <utils/TypeHelpers.h>
28
29 #include <minikin/SparseBitSet.h>
30
31 namespace minikin {
32
33 class MinikinFont;
34
35 // FontStyle represents all style information needed to select an actual font
36 // from a collection. The implementation is packed into two 32-bit words
37 // so it can be efficiently copied, embedded in other objects, etc.
38 class FontStyle {
39 public:
FontStyle()40 FontStyle() : FontStyle(0 /* variant */, 4 /* weight */, false /* italic */) {}
FontStyle(int weight,bool italic)41 FontStyle(int weight, bool italic) : FontStyle(0 /* variant */, weight, italic) {}
FontStyle(uint32_t langListId)42 FontStyle(uint32_t langListId) // NOLINT(implicit)
43 : FontStyle(langListId, 0 /* variant */, 4 /* weight */, false /* italic */) {}
44
45 FontStyle(int variant, int weight, bool italic);
46 FontStyle(uint32_t langListId, int variant, int weight, bool italic);
47
getWeight()48 int getWeight() const { return bits & kWeightMask; }
getItalic()49 bool getItalic() const { return (bits & kItalicMask) != 0; }
getVariant()50 int getVariant() const { return (bits >> kVariantShift) & kVariantMask; }
getLanguageListId()51 uint32_t getLanguageListId() const { return mLanguageListId; }
52
53 bool operator==(const FontStyle other) const {
54 return bits == other.bits && mLanguageListId == other.mLanguageListId;
55 }
56
57 android::hash_t hash() const;
58
59 // Looks up a language list from an internal cache and returns its ID.
60 // If the passed language list is not in the cache, registers it and returns newly assigned ID.
61 static uint32_t registerLanguageList(const std::string& languages);
62 private:
63 static const uint32_t kWeightMask = (1 << 4) - 1;
64 static const uint32_t kItalicMask = 1 << 4;
65 static const int kVariantShift = 5;
66 static const uint32_t kVariantMask = (1 << 2) - 1;
67
68 static uint32_t pack(int variant, int weight, bool italic);
69
70 uint32_t bits;
71 uint32_t mLanguageListId;
72 };
73
74 enum FontVariant {
75 VARIANT_DEFAULT = 0,
76 VARIANT_COMPACT = 1,
77 VARIANT_ELEGANT = 2,
78 };
79
hash_type(const FontStyle & style)80 inline android::hash_t hash_type(const FontStyle &style) {
81 return style.hash();
82 }
83
84 // attributes representing transforms (fake bold, fake italic) to match styles
85 class FontFakery {
86 public:
FontFakery()87 FontFakery() : mFakeBold(false), mFakeItalic(false) { }
FontFakery(bool fakeBold,bool fakeItalic)88 FontFakery(bool fakeBold, bool fakeItalic) : mFakeBold(fakeBold), mFakeItalic(fakeItalic) { }
89 // TODO: want to support graded fake bolding
isFakeBold()90 bool isFakeBold() { return mFakeBold; }
isFakeItalic()91 bool isFakeItalic() { return mFakeItalic; }
92 private:
93 bool mFakeBold;
94 bool mFakeItalic;
95 };
96
97 struct FakedFont {
98 // ownership is the enclosing FontCollection
99 MinikinFont* font;
100 FontFakery fakery;
101 };
102
103 typedef uint32_t AxisTag;
104
105 struct Font {
106 Font(const std::shared_ptr<MinikinFont>& typeface, FontStyle style);
107 Font(std::shared_ptr<MinikinFont>&& typeface, FontStyle style);
108 Font(Font&& o);
109 Font(const Font& o);
110
111 std::shared_ptr<MinikinFont> typeface;
112 FontStyle style;
113
114 std::unordered_set<AxisTag> getSupportedAxesLocked() const;
115 };
116
117 struct FontVariation {
FontVariationFontVariation118 FontVariation(AxisTag axisTag, float value) : axisTag(axisTag), value(value) {}
119 AxisTag axisTag;
120 float value;
121 };
122
123 class FontFamily {
124 public:
125 explicit FontFamily(std::vector<Font>&& fonts);
126 FontFamily(int variant, std::vector<Font>&& fonts);
127 FontFamily(uint32_t langId, int variant, std::vector<Font>&& fonts);
128
129 // TODO: Good to expose FontUtil.h.
130 static bool analyzeStyle(const std::shared_ptr<MinikinFont>& typeface, int* weight,
131 bool* italic);
132 FakedFont getClosestMatch(FontStyle style) const;
133
langId()134 uint32_t langId() const { return mLangId; }
variant()135 int variant() const { return mVariant; }
136
137 // API's for enumerating the fonts in a family. These don't guarantee any particular order
getNumFonts()138 size_t getNumFonts() const { return mFonts.size(); }
getFont(size_t index)139 const std::shared_ptr<MinikinFont>& getFont(size_t index) const {
140 return mFonts[index].typeface;
141 }
getStyle(size_t index)142 FontStyle getStyle(size_t index) const { return mFonts[index].style; }
143 bool isColorEmojiFamily() const;
supportedAxes()144 const std::unordered_set<AxisTag>& supportedAxes() const { return mSupportedAxes; }
145
146 // Get Unicode coverage.
getCoverage()147 const SparseBitSet& getCoverage() const { return mCoverage; }
148
149 // Returns true if the font has a glyph for the code point and variation selector pair.
150 // Caller should acquire a lock before calling the method.
151 bool hasGlyph(uint32_t codepoint, uint32_t variationSelector) const;
152
153 // Returns true if this font family has a variaion sequence table (cmap format 14 subtable).
hasVSTable()154 bool hasVSTable() const { return !mCmapFmt14Coverage.empty(); }
155
156 // Creates new FontFamily based on this family while applying font variations. Returns nullptr
157 // if none of variations apply to this family.
158 std::shared_ptr<FontFamily> createFamilyWithVariation(
159 const std::vector<FontVariation>& variations) const;
160
161 private:
162 void computeCoverage();
163
164 uint32_t mLangId;
165 int mVariant;
166 std::vector<Font> mFonts;
167 std::unordered_set<AxisTag> mSupportedAxes;
168
169 SparseBitSet mCoverage;
170 std::vector<std::unique_ptr<SparseBitSet>> mCmapFmt14Coverage;
171
172 // Forbid copying and assignment.
173 FontFamily(const FontFamily&) = delete;
174 void operator=(const FontFamily&) = delete;
175 };
176
177 } // namespace minikin
178
179 #endif // MINIKIN_FONT_FAMILY_H
180