msalpha(3G)msalpha(3G)NAMEmsalpha - 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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