Flutter Engine
MinikinFont.h
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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 <memory>
21 #include <string>
22 
23 #include <minikin/FontFamily.h>
24 #include <minikin/Hyphenator.h>
25 
26 // An abstraction for platform fonts, allowing Minikin to be used with
27 // multiple actual implementations of fonts.
28 
29 namespace minikin {
30 
31 class MinikinFont;
32 
33 // Possibly move into own .h file?
34 // Note: if you add a field here, either add it to LayoutCacheKey or to
35 // skipCache()
36 struct MinikinPaint {
38  : font(nullptr),
39  size(0),
40  scaleX(0),
41  skewX(0),
42  letterSpacing(0),
43  wordSpacing(0),
44  paintFlags(0),
45  fakery(),
46  hyphenEdit(),
48 
49  bool skipCache() const { return !fontFeatureSettings.empty(); }
50 
52  float size;
53  float scaleX;
54  float skewX;
56  float wordSpacing;
57  uint32_t paintFlags;
60  std::string fontFeatureSettings;
61 };
62 
63 // Only a few flags affect layout, but those that do should have values
64 // consistent with Android's paint flags.
67 };
68 
69 struct MinikinRect {
70  float mLeft, mTop, mRight, mBottom;
71  bool isEmpty() const { return mLeft == mRight || mTop == mBottom; }
72  void set(const MinikinRect& r) {
73  mLeft = r.mLeft;
74  mTop = r.mTop;
75  mRight = r.mRight;
76  mBottom = r.mBottom;
77  }
78  void offset(float dx, float dy) {
79  mLeft += dx;
80  mTop += dy;
81  mRight += dx;
82  mBottom += dy;
83  }
84  void setEmpty() { mLeft = mTop = mRight = mBottom = 0; }
85  void join(const MinikinRect& r);
86 };
87 
88 // Callback for freeing data
89 typedef void (*MinikinDestroyFunc)(void* data);
90 
91 class MinikinFont {
92  public:
93  explicit MinikinFont(int32_t uniqueId) : mUniqueId(uniqueId) {}
94 
95  virtual ~MinikinFont();
96 
97  virtual float GetHorizontalAdvance(uint32_t glyph_id,
98  const MinikinPaint& paint) const = 0;
99 
100  virtual void GetBounds(MinikinRect* bounds,
101  uint32_t glyph_id,
102  const MinikinPaint& paint) const = 0;
103 
104  virtual hb_face_t* CreateHarfBuzzFace() const { return nullptr; }
105 
106  virtual const std::vector<minikin::FontVariation>& GetAxes() const = 0;
107 
108  virtual std::shared_ptr<MinikinFont> createFontWithVariation(
109  const std::vector<FontVariation>&) const {
110  return nullptr;
111  }
112 
113  static uint32_t MakeTag(char c1, char c2, char c3, char c4) {
114  return ((uint32_t)c1 << 24) | ((uint32_t)c2 << 16) | ((uint32_t)c3 << 8) |
115  (uint32_t)c4;
116  }
117 
118  int32_t GetUniqueId() const { return mUniqueId; }
119 
120  private:
121  const int32_t mUniqueId;
122 };
123 
124 } // namespace minikin
125 
126 #endif // MINIKIN_FONT_H
bool isEmpty() const
Definition: MinikinFont.h:71
bool skipCache() const
Definition: MinikinFont.h:49
MinikinPaintFlags
Definition: MinikinFont.h:65
std::string fontFeatureSettings
Definition: MinikinFont.h:60
void(* MinikinDestroyFunc)(void *data)
Definition: MinikinFont.h:89
HyphenEdit hyphenEdit
Definition: MinikinFont.h:59
void offset(float dx, float dy)
Definition: MinikinFont.h:78
MinikinFont(int32_t uniqueId)
Definition: MinikinFont.h:93
int32_t GetUniqueId() const
Definition: MinikinFont.h:118
static uint32_t MakeTag(char c1, char c2, char c3, char c4)
Definition: MinikinFont.h:113
virtual std::shared_ptr< MinikinFont > createFontWithVariation(const std::vector< FontVariation > &) const
Definition: MinikinFont.h:108
MinikinFont * font
Definition: MinikinFont.h:51
virtual hb_face_t * CreateHarfBuzzFace() const
Definition: MinikinFont.h:104