Next: Colour Database
Previous: Displaying Colour
X allows the setting of colour in a variety of ways.
Recall: Xlib performs all colour operation in X.
At the heart of all colour operations is the XColor structure, which uses
3 basic elements:
- - the colour index to the colourmap. It is an unsigned
long data type.
- red, green, blue
- - Direct coding of RGB values. The values of
theses can range from 0 (off) - 65535 (full) as they are defined as unsigned shorts.
- - allow specification of which RGB values are used. Or together DoRed, DoGreen, DoBlue as required.
There are 2 basic methods that can be used to allocate colour in X.