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
31namespace minikin {
32
33class 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.
38class FontStyle {
39public:
40    FontStyle() : FontStyle(0 /* variant */, 4 /* weight */, false /* italic */) {}
41    FontStyle(int weight, bool italic) : FontStyle(0 /* variant */, weight, italic) {}
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
48    int getWeight() const { return bits & kWeightMask; }
49    bool getItalic() const { return (bits & kItalicMask) != 0; }
50    int getVariant() const { return (bits >> kVariantShift) & kVariantMask; }
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);
62private:
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
74enum FontVariant {
75    VARIANT_DEFAULT = 0,
76    VARIANT_COMPACT = 1,
77    VARIANT_ELEGANT = 2,
78};
79
80inline 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
85class FontFakery {
86public:
87    FontFakery() : mFakeBold(false), mFakeItalic(false) { }
88    FontFakery(bool fakeBold, bool fakeItalic) : mFakeBold(fakeBold), mFakeItalic(fakeItalic) { }
89    // TODO: want to support graded fake bolding
90    bool isFakeBold() { return mFakeBold; }
91    bool isFakeItalic() { return mFakeItalic; }
92private:
93    bool mFakeBold;
94    bool mFakeItalic;
95};
96
97struct FakedFont {
98    // ownership is the enclosing FontCollection
99    MinikinFont* font;
100    FontFakery fakery;
101};
102
103typedef uint32_t AxisTag;
104
105struct 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
117struct FontVariation {
118    FontVariation(AxisTag axisTag, float value) : axisTag(axisTag), value(value) {}
119    AxisTag axisTag;
120    float value;
121};
122
123class FontFamily {
124public:
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
134    uint32_t langId() const { return mLangId; }
135    int variant() const { return mVariant; }
136
137    // API's for enumerating the fonts in a family. These don't guarantee any particular order
138    size_t getNumFonts() const { return mFonts.size(); }
139    const std::shared_ptr<MinikinFont>& getFont(size_t index) const {
140        return mFonts[index].typeface;
141    }
142    FontStyle getStyle(size_t index) const { return mFonts[index].style; }
143    bool isColorEmojiFamily() const;
144    const std::unordered_set<AxisTag>& supportedAxes() const { return mSupportedAxes; }
145
146    // Get Unicode coverage.
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).
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
161private:
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