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The QGLColormap class is used for installing custom colormaps into QGLWidgets. 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 PseudoColor or DirectColor visual class. If your X server currently only provides a GrayScale, TrueColor, StaticColor or StaticGray visual, you will not be able to allocate colorcells for writing. If this is the case, try setting your X server in 8 bit mode. It should then provide 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. Note that under Windows you are allowed to install colormaps into child widgets.
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 ); // A QGLWidget in color-index mode 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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Copyright © 2001 Trolltech | Trademarks | Qt version 3.0.0-beta1-beta1
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