RGBsiz(3G)

NAME
     RGBsiz - specifies the number of bit planes desired to comprise each
     single-color component buffer.

FORTRAN 77 SPECIFICATION
     subroutine RGBsiz(planes)
     integer*4 planes

PARAMETERS
     planes   is the number of bit planes requested to be configured as color
              planes for each single-color component.  Only positive values
              are accepted.  The default is machine dependent, usually 8 or
              12.

DESCRIPTION
     RGBsiz specifies how may bit planes are requested to be configured as
     planes for each one of the red, green, blue, and alpha color component.
     The constraints on planes are machine dependent.  Call getgde() with the
     appropriate parameter to determine the maximum number of bit planes
     available for color buffers operation.

     RGBsiz takes effect only after gconfi has been called.  The number of bit
     planes granted for the color buffers may not be exactly what was
     requested.  Call getgco with the appropriate parameter to determine how
     many bit planes were configured as color planes.

     Since RGBA color bit planes are available only in the normal framebuffer,
     RGBsiz should be called only while draw mode is NORMAL.

SEE ALSO
     gconfi, getgco, getgde

NOTES
     This routine is available only in immediate mode.

     Since most machines support only a finite set of RGBA color buffer sizes,
     planes is rounded to the nearest supported size.

     IRIS-4D G, GT, GTX, VGX, and VGXT models, the Personal Iris, Indy, Indigo
     Entry, XL, XS, XS24, XZ, Elan and Extreme systems do not support RGBsize.

     The IRIS-4D RealityEngine models support only values of 8 or 12 planes.

BUGS
     On the IRIS-4D RealityEngine models when the number of planes configured
     for each single-color component is 8, the framebuffer consist of no alpha
     bit planes.

     On the IRIS-4D RealityEngine models the framebuffer cannot be configured
     to consist of 32 Z buffer planes (or 32 depth planes in the multisample
     buffer) and 8 color planes for each of the RGB color buffers
     simultaneously.
     On Impact and Infinite reality RGBsiz chooses the deepest visual whose
     alpha depth is as deep as Red, Green, and Blue.  In order to get more
     depth of RGB, while possibly sacrificing Alpha depth set glcomp GLCNOD to
     TRUE.