mssize(3G)

NAME
     mssize - specifies multisample buffer configuration

C SPECIFICATION
     void mssize(long samples, long zsize, long ssize)

PARAMETERS
     samples   is the number of samples to be stored at each framebuffer pixel
               location. The default is zero.

     zsize     is the number of bits per depth component desired in the
               multisample buffer.

     ssize     is the number of bits per stencil field desired in the
               multisample buffer.

DESCRIPTION
     By default the normal framebuffer is configured to store one sample at
     each pixel location.  This sample can include one, two, or four color
     buffers, a single depth value, and a stencil value.  mssize allows
     configuration of the normal framebuffer to store many samples at each
     pixel location.  Because the samples specified by mssize are distinct
     from the single sample that is normally stored, the default mssize of
     zero corresponds to the default single-sample configuration.

     mssize takes effect when gconfig is called.  The requested sample count
     and multisample buffer sizes are considered along with the other gconfig
     requests, such as double buffering and RGB mode.  Multisample red, green,
     blue, and alpha component sizes are made identical to those in the normal
     framebuffer.

     For example, consider the following request:

          RGBmode();
          doublebuffer();
          mssize(4,32,1);
          zbsize(0);
          stensize(0);
          gconfig();


     If this request is honored, the framebuffer will be configured with 2 RGB
     color buffers (front and back) and 4 separate samples each consisting of
     a single RGB color, a 32-bit depth value, and a 1-bit stencil value.
     Note that no depth or stencil bits are directly associated with the front
     and back color buffers, because none were requested.

     Likewise, the request:
          RGBmode();
          doublebuffer();
          mssize(4,32,1);
          zbsize(32);
          stensize(1);
          gconfig();


     if granted, results in the same multisample configuration, but includes a
     regular zbuffer and a stencil buffer.

     The samples, zsize and ssize granted may not be exactly what was
     requested.  After a call to mssize and gconfig call getgconfig to
     determine how the framebuffer was actually configured.

     Just as the default single sample at each framebuffer pixel is considered
     to be located at the center of that pixel, the samples multisamples each
     have a fixed location near the corresponding pixel center.  These
     locations are chosen by the GL to provide good area sampling.

SEE ALSO
     gconfig, getgconfig, msalpha, msmask, mspattern, mssize, multisample,
     RGBsize, stensize, zbsize

NOTES
     This routine is available only in immediate mode.

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

     Although separate specifications are allowed for normal and multisample
     z-buffer sizes, and for normal and multisample stencil buffer sizes,
     implementations need not support differing non-zero buffer sizes.

     The IRIS-4D RealityEngine models support at least the following values
     for samples:  0, 4, 8, 16 with a zsize of 0, 24 or 32 and with an ssize
     of 0 through 8.

BUGS
     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 the IRIS-4D RealityEngine models the framebuffer cannot be configured
     to consist of more than 1 stencil plane in the multisample buffer, and 8
     color planes for each of the RGB color buffers simultaneously.