QGLColormap Class Reference

Detailed Description

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 must 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 to 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 can also install colormaps in 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.setEntry( i, qRgb( i, i, i ) );

        widget.setColormap( colormap );
        widget.show();
        return a.exec();
    }
    

See also QGLWidget::setColormap(), QGLWidget::colormap(), Graphics Classes and Image Processing Classes.

Member Function Documentation

QGLColormap::QGLColormap ()

QGLColormap::QGLColormap ( const QGLColormap & map )

QGLColormap::~QGLColormap ()

void QGLColormap::detach ()

QColor QGLColormap::entryColor ( int idx ) const

QRgb QGLColormap::entryRgb ( int idx ) const

int QGLColormap::find ( QRgb color ) const

int QGLColormap::findNearest ( QRgb color ) const

bool QGLColormap::isEmpty () const

QGLColormap & QGLColormap::operator= ( const QGLColormap & map )

void QGLColormap::setEntries ( int count, const QRgb * colors, int base = 0 )

void QGLColormap::setEntry ( int idx, QRgb color )

void QGLColormap::setEntry ( int idx, const QColor & color )

Set the cell with index idx in the colormap to color color.

int QGLColormap::size () const

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