writemask(3G) writemask(3G)
NAME
writemask - grants write permission to bitplanes
C SPECIFICATION
void writemask(wtm)
Colorindex wtm;
PARAMETERS
wtm expects a mask whose bits control which bitplanes are available for
drawing and which are read only.
The mask contains one bit per available bitplane. If a bit is set
in the writemask, the system writes the current color index into
the corresponding bitplane. If a bit is set to zero in the
writemask, the corresponding bitplane is read-only.
DESCRIPTION
Use writemask to reserve bitplanes for special purposes. When the
writemask marks a bitplane as read-only, that bitplane is write protected
from ordinary drawing routines.
Use RGBwritemask in RGB mode.
SEE ALSO
color, drawmode, RGBwritemask
BUGS
writemask does not work properly on the IRIS-4D VGX, VGXT and SKYWRITER
models when the current drawmode is not NORMALDRAW.
Page 1