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_H
18#define MINIKIN_FONT_H
19
20#include <string>
21
22#include <minikin/MinikinRefCounted.h>
23#include <minikin/FontFamily.h>
24
25// An abstraction for platform fonts, allowing Minikin to be used with
26// multiple actual implementations of fonts.
27
28namespace android {
29
30// The hyphen edit represents an edit to the string when a word is
31// hyphenated. The most common hyphen edit is adding a "-" at the end
32// of a syllable, but nonstandard hyphenation allows for more choices.
33class HyphenEdit {
34public:
35    HyphenEdit() : hyphen(0) { }
36    HyphenEdit(uint32_t hyphenInt) : hyphen(hyphenInt) { }
37    bool hasHyphen() const { return hyphen != 0; }
38    bool operator==(const HyphenEdit &other) const { return hyphen == other.hyphen; }
39private:
40    uint32_t hyphen;
41};
42
43class MinikinFont;
44
45// Possibly move into own .h file?
46// Note: if you add a field here, either add it to LayoutCacheKey or to skipCache()
47struct MinikinPaint {
48    MinikinPaint() : font(0), size(0), scaleX(0), skewX(0), letterSpacing(0), paintFlags(0),
49            fakery(), fontFeatureSettings() { }
50
51    bool skipCache() const {
52        return !fontFeatureSettings.empty();
53    }
54
55    MinikinFont *font;
56    float size;
57    float scaleX;
58    float skewX;
59    float letterSpacing;
60    uint32_t paintFlags;
61    FontFakery fakery;
62    HyphenEdit hyphenEdit;
63    std::string fontFeatureSettings;
64};
65
66// Only a few flags affect layout, but those that do should have values
67// consistent with Android's paint flags.
68enum MinikinPaintFlags {
69    LinearTextFlag = 0x40,
70};
71
72struct MinikinRect {
73    float mLeft, mTop, mRight, mBottom;
74    bool isEmpty() const {
75        return mLeft == mRight || mTop == mBottom;
76    }
77    void set(const MinikinRect& r) {
78        mLeft = r.mLeft;
79        mTop = r.mTop;
80        mRight = r.mRight;
81        mBottom = r.mBottom;
82    }
83    void offset(float dx, float dy) {
84        mLeft += dx;
85        mTop += dy;
86        mRight += dx;
87        mBottom += dy;
88    }
89    void setEmpty() {
90        mLeft = mTop = mRight = mBottom = 0;
91    }
92    void join(const MinikinRect& r);
93};
94
95class MinikinFontFreeType;
96
97// Callback for freeing data
98typedef void (*MinikinDestroyFunc) (void* data);
99
100class MinikinFont : public MinikinRefCounted {
101public:
102    MinikinFont(int32_t uniqueId) : mUniqueId(uniqueId) {}
103
104    virtual ~MinikinFont();
105
106    virtual float GetHorizontalAdvance(uint32_t glyph_id,
107        const MinikinPaint &paint) const = 0;
108
109    virtual void GetBounds(MinikinRect* bounds, uint32_t glyph_id,
110        const MinikinPaint &paint) const = 0;
111
112    virtual const void* GetTable(uint32_t tag, size_t* size, MinikinDestroyFunc* destroy) = 0;
113
114    // Override if font can provide access to raw data
115    virtual const void* GetFontData() const {
116        return nullptr;
117    }
118
119    // Override if font can provide access to raw data
120    virtual size_t GetFontSize() const {
121        return 0;
122    }
123
124    // Override if font can provide access to raw data.
125    // Returns index within OpenType collection
126    virtual int GetFontIndex() const {
127        return 0;
128    }
129
130    static uint32_t MakeTag(char c1, char c2, char c3, char c4) {
131        return ((uint32_t)c1 << 24) | ((uint32_t)c2 << 16) |
132            ((uint32_t)c3 << 8) | (uint32_t)c4;
133    }
134
135    int32_t GetUniqueId() const { return mUniqueId; }
136private:
137    const int32_t mUniqueId;
138};
139
140}  // namespace android
141
142#endif  // MINIKIN_FONT_H
143