Layout.h revision 9cc9bbe1461f359f0b27c5e7645c17dda001ab1d 
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 <ft2build.h>
21#include FT_FREETYPE_H
22
23#include <hb.h>
24
25#include <vector>
26
27#include <minikin/CssParse.h>
28#include <minikin/FontCollection.h>
29
30namespace android {
31
32// The Bitmap class is for debugging. We'll probably move it out
33// of here into a separate lightweight software rendering module
34// (optional, as we'd hope most clients would do their own)
35class Bitmap {
36public:
37    Bitmap(int width, int height);
38    ~Bitmap();
39    void writePnm(std::ofstream& o) const;
40    void drawGlyph(const FT_Bitmap& bitmap, int x, int y);
41private:
42    int width;
43    int height;
44    uint8_t* buf;
45};
46
47struct LayoutGlyph {
48    // index into mFaces and mHbFonts vectors. We could imagine
49    // moving this into a run length representation, because it's
50    // more efficient for long strings, and we'll probably need
51    // something like that for paint attributes (color, underline,
52    // fake b/i, etc), as having those per-glyph is bloated.
53    int font_ix;
54
55    unsigned int glyph_id;
56    float x;
57    float y;
58};
59
60class Layout {
61public:
62    void dump() const;
63    void setFontCollection(const FontCollection *collection);
64    void doLayout(const uint16_t* buf, size_t nchars);
65    void draw(Bitmap*, int x0, int y0) const;
66    void setProperties(const std::string css);
67
68    // This must be called before any invocations.
69	// TODO: probably have a factory instead
70    static void init();
71private:
72    // Find a face in the mFaces vector, or create a new entry
73    int findFace(FT_Face face);
74
75    CssProperties mProps;  // TODO: want spans
76    std::vector<LayoutGlyph> mGlyphs;
77
78    // In future, this will be some kind of mapping from the
79    // identifier used to represent font-family to a font collection.
80    // But for the time being, it should be ok to have just one
81    // per layout.
82    const FontCollection *mCollection;
83    std::vector<FT_Face> mFaces;
84    std::vector<hb_font_t *> mHbFonts;
85};
86
87}  // namespace android
88
89#endif  // MINIKIN_LAYOUT_H
90