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41 
42 #ifndef QTEXTUREGLYPHCACHE_P_H
43 #define QTEXTUREGLYPHCACHE_P_H
44 
45 //
46 //  W A R N I N G
47 //  -------------
48 //
49 // This file is not part of the Qt API.  It exists for the convenience
50 // of other Qt classes.  This header file may change from version to
51 // version without notice, or even be removed.
52 //
53 // We mean it.
54 //
55 
56 #include <qhash.h>
57 #include <qimage.h>
58 #include <qobject.h>
59 #include <qtransform.h>
60 
61 #include <private/qfontengineglyphcache_p.h>
62 
63 #if defined(Q_OS_VXWORKS) && defined(m_type)
64 #  undef m_type
65 #endif
66 
67 #ifndef QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH
68 #define QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH 256
69 #endif
70 
71 struct glyph_metrics_t;
72 typedef unsigned int glyph_t;
73 
74 
75 QT_BEGIN_NAMESPACE
76 
77 class QTextItemInt;
78 
79 class Q_GUI_EXPORT QTextureGlyphCache : public QFontEngineGlyphCache
80 {
81 public:
QTextureGlyphCache(QFontEngineGlyphCache::Type type,const QTransform & matrix)82     QTextureGlyphCache(QFontEngineGlyphCache::Type type, const QTransform &matrix)
83         : QFontEngineGlyphCache(matrix, type), m_current_fontengine(0),
84                                                m_w(0), m_h(0), m_cx(0), m_cy(0), m_currentRowHeight(0), m_subPixelPositionCount(0)
85         { }
86 
~QTextureGlyphCache()87     virtual ~QTextureGlyphCache() { }
88 
89     struct GlyphAndSubPixelPosition
90     {
GlyphAndSubPixelPositionGlyphAndSubPixelPosition91         GlyphAndSubPixelPosition(glyph_t g, QFixed spp) : glyph(g), subPixelPosition(spp) {}
92 
93         bool operator==(const GlyphAndSubPixelPosition &other) const
94         {
95             return glyph == other.glyph && subPixelPosition == other.subPixelPosition;
96         }
97 
98         glyph_t glyph;
99         QFixed subPixelPosition;
100     };
101 
102     struct Coord {
103         int x;
104         int y;
105         int w;
106         int h;
107 
108         int baseLineX;
109         int baseLineY;
110 
isNullCoord111         bool isNull() const
112         {
113             return w == 0 || h == 0;
114         }
115     };
116 
117     bool populate(QFontEngine *fontEngine, int numGlyphs, const glyph_t *glyphs,
118                   const QFixedPoint *positions);
119     void fillInPendingGlyphs();
120 
121     virtual void createTextureData(int width, int height) = 0;
122     virtual void resizeTextureData(int width, int height) = 0;
glyphMargin()123     virtual int glyphMargin() const { return 0; }
glyphPadding()124     virtual int glyphPadding() const { return 0; }
125 
126     virtual void fillTexture(const Coord &coord, glyph_t glyph, QFixed subPixelPosition) = 0;
127 
createCache(int width,int height)128     inline void createCache(int width, int height) {
129         m_w = width;
130         m_h = height;
131         createTextureData(width, height);
132     }
133 
resizeCache(int width,int height)134     inline void resizeCache(int width, int height)
135     {
136         resizeTextureData(width, height);
137         m_w = width;
138         m_h = height;
139     }
140 
isNull()141     inline bool isNull() const { return m_h == 0; }
142 
143     QHash<GlyphAndSubPixelPosition, Coord> coords;
maxTextureWidth()144     virtual int maxTextureWidth() const { return QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH; }
maxTextureHeight()145     virtual int maxTextureHeight() const { return -1; }
146 
147     QImage textureMapForGlyph(glyph_t g, QFixed subPixelPosition) const;
148 
149     QFixed subPixelPositionForX(QFixed x) const;
150 
151 protected:
152     int calculateSubPixelPositionCount(glyph_t) const;
153 
154     QFontEngine *m_current_fontengine;
155     QHash<GlyphAndSubPixelPosition, Coord> m_pendingGlyphs;
156 
157     int m_w; // image width
158     int m_h; // image height
159     int m_cx; // current x
160     int m_cy; // current y
161     int m_currentRowHeight; // Height of last row
162     int m_subPixelPositionCount; // Number of positions within a single pixel for this cache
163 };
164 
qHash(const QTextureGlyphCache::GlyphAndSubPixelPosition & g)165 inline uint qHash(const QTextureGlyphCache::GlyphAndSubPixelPosition &g)
166 {
167     return (g.glyph << 8)  | (g.subPixelPosition * 10).round().toInt();
168 }
169 
170 
171 class Q_GUI_EXPORT QImageTextureGlyphCache : public QTextureGlyphCache
172 {
173 public:
QImageTextureGlyphCache(QFontEngineGlyphCache::Type type,const QTransform & matrix)174     QImageTextureGlyphCache(QFontEngineGlyphCache::Type type, const QTransform &matrix)
175         : QTextureGlyphCache(type, matrix) { }
176     virtual int glyphMargin() const;
177     virtual void createTextureData(int width, int height);
178     virtual void resizeTextureData(int width, int height);
179     virtual void fillTexture(const Coord &c, glyph_t glyph, QFixed subPixelPosition);
180 
image()181     inline const QImage &image() const { return m_image; }
182 
183 private:
184     QImage m_image;
185 };
186 
187 QT_END_NAMESPACE
188 
189 #endif
190