NAME

RGBwritemask − grants write access to a subset of the available bitplanes

SPECIFICATION

C
RGBwritemask(red, green, blue)
short red, green, blue;

FORTRAN
subroutine RGBwri(red, green, blue)
integer*4 red, green, blue

Pascal
procedure RGBwritemask(red, green, blue: longint);

DESCRIPTION

RGBwritemask shields bitplanes that have special uses from ordinary drawing routines in RGB mode.  red, green, and blue are masks for each of the three sets of eight bitplanes.  Wherever the digit 1 is in the writemask, the system writes the corresponding bits in the RGB color into the bitplanes.  Zeros (0s) in the writemask mark bitplanes as read-only.  These bitplanes are not changed, regardless of the bits in the RGB color. 

SEE ALSO

gRGBmask, RGBcolor, writemask IRIS Graphics Programming, Section 6.3, Colors and Writemasks

Version 2.5  —  April 22, 1987