msalpha(3G) — IRIX 6.5.3f



msalpha(3G)                                                        msalpha(3G)



NAME
     msalpha - specifies treatment of alpha values during multisample
     rendering

C SPECIFICATION
     void msalpha(long mode)

PARAMETERS
     mode   is a symbolic constant.  MSA_MASK and MSA_MASK_ONE indicates that
            alpha values are to be converted to multisample mask values just
            prior to the alpha test.  MSA_ALPHA indicates that no such
            conversion is to be done.  The default is MSA_ALPHA.

DESCRIPTION
     When msalpha is set to MSA_MASK or MSA_MASK_ONE, while multisampling is
     enabled, source alpha values generated by rasterization are converted to
     multisample masks immediately prior to the per-pixel alpha tests.  At
     each pixel the resulting multisample mask is logically ANDed with the
     mask specified by msmask.  Only multisample locations enabled by the
     resulting mask are considered for modification.

     When msalpha is set to MSA_MASK_ONE, the source alpha becomes 1.0 after
     the mask has been generated.

     When msalpha is set to MSA_ALPHA, no change is made to the alpha values
     generated by rasterization or to the mask specified by msmask.

     msalpha has no effect when multisample is not enabled.

SEE ALSO
     msmask, mspattern, mssize, multisample

NOTE
     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
     msalpha.



















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