NAME

writemask − grants write permission to available bitplanes

SPECIFICATION

C
writemask(wtm)
Colorindex wtm;

FORTRAN
subroutine writem(wtm)
integer*4 wtm

Pascal
procedure writemask(wtm: longint);

DESCRIPTION

writemask protects bitplanes which are reserved for special uses from ordinary drawing routines.  wtm is a mask with 1 bit per available bitplane.  Wherever there are ones (1s) in the writemask, the corresponding bits in the color index are written into the bitplanes.  Zeros (0s) in the writemask mark bitplanes as read-only.  These bitplanes will not be changed, regardless of the bits in the color. 

Use RGBwritemask in RGB mode. 

SEE ALSO

RGBwritemask, color IRIS Graphics Programming, Section 6.3, Colors and Writemasks

Version 2.5r1  —  October 29, 1986