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_LAYOUT_H 18 #define MINIKIN_LAYOUT_H 19 20 #include <hb.h> 21 22 #include <vector> 23 24 #include <minikin/FontCollection.h> 25 #include <minikin/MinikinFontFreeType.h> 26 27 namespace android { 28 29 // The Bitmap class is for debugging. We'll probably move it out 30 // of here into a separate lightweight software rendering module 31 // (optional, as we'd hope most clients would do their own) 32 class Bitmap { 33 public: 34 Bitmap(int width, int height); 35 ~Bitmap(); 36 void writePnm(std::ofstream& o) const; 37 void drawGlyph(const GlyphBitmap& bitmap, int x, int y); 38 private: 39 int width; 40 int height; 41 uint8_t* buf; 42 }; 43 44 struct LayoutGlyph { 45 // index into mFaces and mHbFonts vectors. We could imagine 46 // moving this into a run length representation, because it's 47 // more efficient for long strings, and we'll probably need 48 // something like that for paint attributes (color, underline, 49 // fake b/i, etc), as having those per-glyph is bloated. 50 int font_ix; 51 52 unsigned int glyph_id; 53 float x; 54 float y; 55 }; 56 57 // Internal state used during layout operation 58 class LayoutContext; 59 60 // Lifecycle and threading assumptions for Layout: 61 // The object is assumed to be owned by a single thread; multiple threads 62 // may not mutate it at the same time. 63 // The lifetime of the FontCollection set through setFontCollection must 64 // extend through the lifetime of the Layout object. 65 class Layout { 66 public: 67 68 Layout() : mGlyphs(), mAdvances(), mCollection(0), mFaces(), mAdvance(0), mBounds() { 69 mBounds.setEmpty(); 70 } 71 72 // Clears layout, ready to be used again 73 void reset(); 74 75 void dump() const; 76 void setFontCollection(const FontCollection* collection); 77 78 void doLayout(const uint16_t* buf, size_t start, size_t count, size_t bufSize, 79 int bidiFlags, const FontStyle &style, const MinikinPaint &paint); 80 81 void draw(Bitmap*, int x0, int y0, float size) const; 82 83 // Deprecated. Nont needed. Remove when callers are removed. 84 static void init(); 85 86 // public accessors 87 size_t nGlyphs() const; 88 // Does not bump reference; ownership is still layout 89 MinikinFont *getFont(int i) const; 90 FontFakery getFakery(int i) const; 91 unsigned int getGlyphId(int i) const; 92 float getX(int i) const; 93 float getY(int i) const; 94 95 float getAdvance() const; 96 97 // Get advances, copying into caller-provided buffer. The size of this 98 // buffer must match the length of the string (nchars arg to doLayout). 99 void getAdvances(float* advances); 100 101 void getBounds(MinikinRect* rect); 102 103 // Purge all caches, useful in low memory conditions 104 static void purgeCaches(); 105 106 private: 107 friend class LayoutCacheKey; 108 109 // Find a face in the mFaces vector, or create a new entry 110 int findFace(FakedFont face, LayoutContext* ctx); 111 112 // Lay out a single bidi run 113 void doLayoutRunCached(const uint16_t* buf, size_t start, size_t count, size_t bufSize, 114 bool isRtl, LayoutContext* ctx, size_t dstStart); 115 116 // Lay out a single word 117 void doLayoutWord(const uint16_t* buf, size_t start, size_t count, size_t bufSize, 118 bool isRtl, LayoutContext* ctx, size_t bufStart); 119 120 // Lay out a single bidi run 121 void doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t bufSize, 122 bool isRtl, LayoutContext* ctx); 123 124 // Append another layout (for example, cached value) into this one 125 void appendLayout(Layout* src, size_t start); 126 127 std::vector<LayoutGlyph> mGlyphs; 128 std::vector<float> mAdvances; 129 130 const FontCollection* mCollection; 131 std::vector<FakedFont> mFaces; 132 float mAdvance; 133 MinikinRect mBounds; 134 }; 135 136 } // namespace android 137 138 #endif // MINIKIN_LAYOUT_H 139
