'\" e '\"! eqn | mmdoc '\"macro stdmacro .ds Vn Version 1.2 .ds Dt 24 September 1999 .ds Re Release 1.2.1 .ds Dp Jan 14 18:30 .ds Dm 01 indexmask .ds Xs 54319 4 indexmask.gl .TH GLINDEXMASK 3G .SH NAME .B "glIndexMask \- control the writing of individual bits in the color index buffers .SH C SPECIFICATION void \f3glIndexMask\fP( GLuint \fImask\fP ) .nf .fi .EQ delim $$ .EN .SH PARAMETERS .TP \w'\f2mask\fP\ \ 'u \f2mask\fP Specifies a bit mask to enable and disable the writing of individual bits in the color index buffers. Initially, the mask is all 1's. .SH DESCRIPTION \%\f3glIndexMask\fP controls the writing of individual bits in the color index buffers. The least significant $n$ bits of \f2mask\fP, where $n$ is the number of bits in a color index buffer, specify a mask. Where a 1 (one) appears in the mask, it's possible to write to the corresponding bit in the color index buffer (or buffers). Where a 0 (zero) appears, the corresponding bit is write-protected. .P This mask is used only in color index mode, and it affects only the buffers currently selected for writing (see \%\f3glDrawBuffer\fP). Initially, all bits are enabled for writing. .SH ERRORS \%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glIndexMask\fP is executed between the execution of \%\f3glBegin\fP and the corresponding execution of \%\f3glEnd\fP. .SH ASSOCIATED GETS \%\f3glGet\fP with argument \%\f3GL_INDEX_WRITEMASK\fP .SH SEE ALSO \%\f3glColorMask(3G)\fP, \%\f3glDepthMask(3G)\fP, \%\f3glDrawBuffer(3G)\fP, \%\f3glIndex(3G)\fP, \%\f3glIndexPointer(3G)\fP, \%\f3glStencilMask(3G)\fP