fglColorMask(3G)

NAME
     fglColorMask - enable and disable writing of frame buffer color
     components


FORTRAN SPECIFICATION
     SUBROUTINE fglColorMask( LOGICAL*1 red,
                              LOGICAL*1 green,
                              LOGICAL*1 blue,
                              LOGICAL*1 alpha )


PARAMETERS
     red, green, blue, alpha
                           Specify whether red, green, blue, and alpha can or
                           cannot be written into the frame buffer.  The
                           default values are all GL_TRUE, indicating that the
                           color components can be written.

DESCRIPTION
     fglColorMask 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 fglColorMask is executed between the
     execution of fglBegin and the corresponding execution of fglEnd.

ASSOCIATED GETS
     fglGet with argument GL_COLOR_WRITEMASK
     fglGet with argument GL_RGBA_MODE


SEE ALSO
     fglColor, fglIndex, fglIndexMask, fglDepthMask, fglStencilMask