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The QGLColormap class is used for installing custom colormaps into widgets. More...
#include <qglcolormap.h>
QGLColormap provides a platform independent way of specifying and installing indexed colormaps into QGLWidgets. QGLColormap is especially useful when using the OpenGL color-index mode.
Under X11 you will have to use an X server that supports either a GrayScale, PseudoColor or DirectColor visual class. If your X server currently only provides a TrueColor, StaticColor or StaticGray visual, you will not be able to allocate colorcells for writing. If your X server does not provide one of the needed visuals, try setting up your X server in 8 bit mode. It should then provide a you with at least a PseudoColor visual. Note that you may experience colormap flashing if your X server is running in 8 bit mode.
Under Windows the size of the colormap is always set to 256 colors.
This class uses explicit sharing (see Shared Classes).
Example of use:
#include <qapplication.h> #include <qglcolormap.h> int main() { QApplication a( argc, argv ); MySuperGLWidget widget( 0 ); QGLColormap colormap; // This will fill the colormap with colors ranging from // black to white. for ( int i = 0; i < colormap->size(); i++ ) colormap->setRgb( i, qRgb( i, i, i ) ); widget.setColormap( colormap ); widget.show(); return a.exec(); }
See also QGLWidget::setColormap() and QGLWidget::colormap().
The most common reason for a colormap to be invalid under X11, is that the X server does not support the visual class that is needed for a read/write colormap. An empty colormap (no color values set) is also considered to be invalid.
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