wmpack(3G)

NAME
     wmpack - specifies RGBA writemask with a single packed integer

C SPECIFICATION
     void wmpack(pack)
     unsigned long pack;

PARAMETERS
     pack   expects a packed integer containing the RGBA (red, green, blue,
            alpha) values you want to assign as the current write mask.
            Expressed in hexadecimal, the format of the packed integer is
            0xaabbggrr, where:

               aa   is the alpha value,
               bb   is the blue value,
               gg   is the green value, and
               rr   is the red value.

            RGBA component values range from 0 to 0xFF (255).

DESCRIPTION
     wmpack sets the red, green, blue, and alpha write mask components of the
     currently active GL framebuffer, one of normal, popup, overlay, or
     underlay as specified by drawmode.  The current framebuffer must be in
     RGB mode for the wmpack command to be applicable.  All drawing into the
     color bitplanes of the current framebuffer is masked by the current write
     mask.  Write mask components are retained in each draw mode, so when a
     draw mode is re-entered, the red, green, blue, and alpha masks are reset
     to the last values specified in that draw mode.

     Each write mask component is an 8-bit mask, which allows changes only to
     bitplanes corresponding to ones in the mask.  For example,
     wmpack(0xFF0000F0) allows changes only to the 4 most significant bits of
     red, and to all the bits of alpha.

     It is an error to call wmpack while the current framebuffer is in color
     map mode.

     The write mask components of all framebuffers in RGB mode are set to 0xFF
     when gconfig is called.

SEE ALSO
     cpack, drawmode, gRGBmask, RGBmode

NOTE
     Because only the normal framebuffer currently supports RGB mode, wmpack
     should be called only while draw mode is NORMALDRAW.  Use getgdesc to
     determine whether RGB mode is available in draw mode NORMALDRAW.

     On Impact and Infinite Reality only whole components can be masked.  RGB
     and A can be completely masked or not masked at all.