void GLAPIENTRY glColorMask( GLboolean red,
                                    GLboolean green,
                                    GLboolean blue,
                                    GLboolean alpha )

PARAMETERS
       red, green, blue, alpha
                             Specify whether red, green, blue, and alpha can or
                             cannot be written into the frame buffer.  The ini‐
                             tial 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

SEE ALSO
       glClear, glColor, glColorPointer, glDepthMask, glIndex,  glIndexPointer,
       glIndexMask, glStencilMask

                                                                GLCOLORMASK(3G)