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39 
40 #ifndef QTEXTUREGLYPHCACHE_P_H
41 #define QTEXTUREGLYPHCACHE_P_H
42 
43 //
44 //  W A R N I N G
45 //  -------------
46 //
47 // This file is not part of the Qt API.  It exists for the convenience
48 // of other Qt classes.  This header file may change from version to
49 // version without notice, or even be removed.
50 //
51 // We mean it.
52 //
53 
54 #include <QtGui/private/qtguiglobal_p.h>
55 #include <qhash.h>
56 #include <qimage.h>
57 #include <qobject.h>
58 #include <qtransform.h>
59 
60 #include <private/qfontengineglyphcache_p.h>
61 
62 #ifndef QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH
63 #define QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH 256
64 #endif
65 
66 struct glyph_metrics_t;
67 typedef unsigned int glyph_t;
68 
69 
70 QT_BEGIN_NAMESPACE
71 
72 class QTextItemInt;
73 
74 class Q_GUI_EXPORT QTextureGlyphCache : public QFontEngineGlyphCache
75 {
76 public:
77     QTextureGlyphCache(QFontEngine::GlyphFormat format, const QTransform &matrix, const QColor &color = QColor())
QFontEngineGlyphCache(format,matrix,color)78         : QFontEngineGlyphCache(format, matrix, color), m_current_fontengine(nullptr),
79                                                m_w(0), m_h(0), m_cx(0), m_cy(0), m_currentRowHeight(0)
80         { }
81 
82     ~QTextureGlyphCache();
83 
84     struct GlyphAndSubPixelPosition
85     {
GlyphAndSubPixelPositionGlyphAndSubPixelPosition86         GlyphAndSubPixelPosition(glyph_t g, QFixed spp) : glyph(g), subPixelPosition(spp) {}
87 
88         bool operator==(const GlyphAndSubPixelPosition &other) const
89         {
90             return glyph == other.glyph && subPixelPosition == other.subPixelPosition;
91         }
92 
93         glyph_t glyph;
94         QFixed subPixelPosition;
95     };
96 
97     struct Coord {
98         int x;
99         int y;
100         int w;
101         int h;
102 
103         int baseLineX;
104         int baseLineY;
105 
isNullCoord106         bool isNull() const
107         {
108             return w == 0 || h == 0;
109         }
110     };
111 
112     bool populate(QFontEngine *fontEngine, int numGlyphs, const glyph_t *glyphs,
113                   const QFixedPoint *positions);
hasPendingGlyphs()114     bool hasPendingGlyphs() const { return !m_pendingGlyphs.isEmpty(); };
115     void fillInPendingGlyphs();
116 
117     virtual void createTextureData(int width, int height) = 0;
118     virtual void resizeTextureData(int width, int height) = 0;
glyphPadding()119     virtual int glyphPadding() const { return 0; }
120 
beginFillTexture()121     virtual void beginFillTexture() { }
122     virtual void fillTexture(const Coord &coord, glyph_t glyph, QFixed subPixelPosition) = 0;
endFillTexture()123     virtual void endFillTexture() { }
124 
createCache(int width,int height)125     inline void createCache(int width, int height) {
126         m_w = width;
127         m_h = height;
128         createTextureData(width, height);
129     }
130 
resizeCache(int width,int height)131     inline void resizeCache(int width, int height)
132     {
133         resizeTextureData(width, height);
134         m_w = width;
135         m_h = height;
136     }
137 
isNull()138     inline bool isNull() const { return m_h == 0; }
139 
140     QHash<GlyphAndSubPixelPosition, Coord> coords;
maxTextureWidth()141     virtual int maxTextureWidth() const { return QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH; }
maxTextureHeight()142     virtual int maxTextureHeight() const { return -1; }
143 
144     QImage textureMapForGlyph(glyph_t g, QFixed subPixelPosition) const;
145 
146 protected:
147     int calculateSubPixelPositionCount(glyph_t) const;
148 
149     QFontEngine *m_current_fontengine;
150     QHash<GlyphAndSubPixelPosition, Coord> m_pendingGlyphs;
151 
152     int m_w; // image width
153     int m_h; // image height
154     int m_cx; // current x
155     int m_cy; // current y
156     int m_currentRowHeight; // Height of last row
157 };
158 
qHash(const QTextureGlyphCache::GlyphAndSubPixelPosition & g)159 inline uint qHash(const QTextureGlyphCache::GlyphAndSubPixelPosition &g)
160 {
161     return (g.glyph << 8)  | (g.subPixelPosition * 10).round().toInt();
162 }
163 
164 
165 class Q_GUI_EXPORT QImageTextureGlyphCache : public QTextureGlyphCache
166 {
167 public:
168     QImageTextureGlyphCache(QFontEngine::GlyphFormat format, const QTransform &matrix, const QColor &color = QColor())
QTextureGlyphCache(format,matrix,color)169         : QTextureGlyphCache(format, matrix, color) { }
170     ~QImageTextureGlyphCache();
171 
172     virtual void createTextureData(int width, int height) override;
173     virtual void resizeTextureData(int width, int height) override;
174     virtual void fillTexture(const Coord &c, glyph_t glyph, QFixed subPixelPosition) override;
175 
image()176     inline const QImage &image() const { return m_image; }
177 
178 private:
179     QImage m_image;
180 };
181 
182 QT_END_NAMESPACE
183 
184 #endif
185