QGLColormap(3qt)

1QGLColormap(3qt)                                              QGLColormap(3qt)
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NAME

6       QGLColormap - Used for installing custom colormaps into QGLWidgets
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SYNOPSIS

9       #include <qglcolormap.h>
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11   Public Members
12       QGLColormap ()
13       QGLColormap ( const QGLColormap & map )
14       ~QGLColormap ()
15       QGLColormap & operator= ( const QGLColormap & map )
16       bool isEmpty () const
17       int size () const
18       void detach ()
19       void setEntries ( int count, const QRgb * colors, int base = 0 )
20       void setEntry ( int idx, QRgb color )
21       void setEntry ( int idx, const QColor & color )
22       QRgb entryRgb ( int idx ) const
23       QColor entryColor ( int idx ) const
24       int find ( QRgb color ) const
25       int findNearest ( QRgb color ) const
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DESCRIPTION

28       The QGLColormap class is used for installing custom colormaps into
29       QGLWidgets.
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31       QGLColormap provides a platform independent way of specifying and
32       installing indexed colormaps into QGLWidgets. QGLColormap is especially
33       useful when using the OpenGL color-index mode.
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35       Under X11 you must use an X server that supports either a PseudoColor
36       or DirectColor visual class. If your X server currently only provides a
37       GrayScale, TrueColor, StaticColor or StaticGray visual, you will not be
38       able to allocate colorcells for writing. If this is the case, try
39       setting your X server to 8 bit mode. It should then provide you with at
40       least a PseudoColor visual. Note that you may experience colormap
41       flashing if your X server is running in 8 bit mode.
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43       Under Windows the size of the colormap is always set to 256 colors.
44       Note that under Windows you can also install colormaps in child
45       widgets.
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47       This class uses explicit sharing (see Shared Classes).
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49       Example of use:
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51           #include <qapplication.h>
52           #include <qglcolormap.h>
53           int main()
54           {
55               QApplication a( argc, argv );
56               MySuperGLWidget widget( 0 ); // A QGLWidget in color-index mode
57               QGLColormap colormap;
58               // This will fill the colormap with colors ranging from
59               // black to white.
60               for ( int i = 0; i < colormap.size(); i++ )
61                   colormap.setEntry( i, qRgb( i, i, i ) );
62               widget.setColormap( colormap );
63               widget.show();
64               return a.exec();
65           }
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67       See also QGLWidget::setColormap(), QGLWidget::colormap(), Graphics
68       Classes, and Image Processing Classes.
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MEMBER FUNCTION DOCUMENTATION

QGLColormap::QGLColormap ()

72       Construct a QGLColormap.
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QGLColormap::QGLColormap ( const QGLColormap & map )

75       Construct a shallow copy of map.
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QGLColormap::~QGLColormap ()

78       Dereferences the QGLColormap and deletes it if this was the last
79       reference to it.
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void QGLColormap::detach ()

82       Detaches this QGLColormap from the shared block.
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QColor QGLColormap::entryColor ( int idx ) const

85       Returns the QRgb value in the colorcell with index idx.
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QRgb QGLColormap::entryRgb ( int idx ) const

88       Returns the QRgb value in the colorcell with index idx.
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