QGLColormap¶
The
QGLColormap
class is used for installing custom colormaps into aQGLWidget
. More…

Synopsis¶
Detailed Description¶
QGLColormap
provides a platform independent way of specifying and installing indexed colormaps for aQGLWidget
.QGLColormap
is especially useful when using the OpenGL color-index mode.Under X11 you must use an X server that supports either a
PseudoColor
orDirectColor
visual class. If your X server currently only provides aGrayScale
,TrueColor
,StaticColor
orStaticGray
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 aPseudoColor
visual. Note that you may experience colormap flashing if your X server is running in 8 bit mode.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 implicit sharing as a memory and speed optimization.
Example of use:
import sys from PySide2.QtGui import QApplication, qRgb from PySide2.QtOpenGL import QGLColormap def main(argv): app = QApplication(argv) widget = MySuperGLWidget() # a QGLWidget in color-index mode colormap = QGLColormap() # This will fill the colormap with colors ranging from # black to white. for i in range(0, colormap.size()): colormap.setEntry(i, qRgb(i, i, i)) widget.setColormap(colormap) widget.show() return app.exec_() if __name__ == "__main__": main(sys.argv)See also
-
class
QGLColormap
¶ QGLColormap(arg__1)
- param arg__1
Construct a
QGLColormap
.Construct a shallow copy of
map
.
-
PySide2.QtOpenGL.QGLColormap.
entryColor
(idx)¶ - Parameters
idx –
int
- Return type
QColor
Returns the
QRgb
value in the colorcell with indexidx
.
-
PySide2.QtOpenGL.QGLColormap.
entryRgb
(idx)¶ - Parameters
idx –
int
- Return type
long
Returns the
QRgb
value in the colorcell with indexidx
.
-
PySide2.QtOpenGL.QGLColormap.
find
(color)¶ - Parameters
color – long
- Return type
int
Returns the index of the color
color
. Ifcolor
is not in the map, -1 is returned.
-
PySide2.QtOpenGL.QGLColormap.
findNearest
(color)¶ - Parameters
color – long
- Return type
int
Returns the index of the color that is the closest match to color
color
.
-
PySide2.QtOpenGL.QGLColormap.
handle
()¶ - Return type
HANDLE
Returns the handle for this color map.
-
PySide2.QtOpenGL.QGLColormap.
isEmpty
()¶ - Return type
bool
Returns
true
if the colormap is empty or it is not in use by aQGLWidget
; otherwise returnsfalse
.A colormap with no color values set is considered to be empty. For historical reasons, a colormap that has color values set but which is not in use by a
QGLWidget
is also considered empty.Compare
size()
with zero to determine if the colormap is empty regardless of whether it is in use by aQGLWidget
or not.See also
-
PySide2.QtOpenGL.QGLColormap.
setEntry
(idx, color)¶ - Parameters
idx –
int
color –
QColor
This is an overloaded function.
Set the cell with index
idx
in the colormap to colorcolor
.
-
PySide2.QtOpenGL.QGLColormap.
setEntry
(idx, color) - Parameters
idx –
int
color – long
-
PySide2.QtOpenGL.QGLColormap.
setHandle
(ahandle)¶ - Parameters
ahandle –
HANDLE
Sets the handle for this color map to
handle
.
-
PySide2.QtOpenGL.QGLColormap.
size
()¶ - Return type
int
Returns the number of colorcells in the colormap.