Specify whether red, green, blue, and alpha can or cannot be written
into the frame buffer.
The initial values are all GL_TRUE,
indicating that the color components can be written.
DESCRIPTION
glColorMask specifies whether the individual color components in the frame buffer
can or cannot be written.
If red is GL_FALSE,
for example,
no change is made to the red component of any pixel in any of the
color buffers,
regardless of the drawing operation attempted.
Changes to individual bits of components cannot be controlled.
Rather,
changes are either enabled or disabled for entire color components.
ERRORS
GL_INVALID_OPERATION is generated if glColorMask
is executed between the execution of glBegin
and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_COLOR_WRITEMASK glGet with argument GL_RGBA_MODE
