'\" e  
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 24 September 1999
.ds Re Release 1.2.1
.ds Dp May 22 14:46
.ds Dm 8 May 22 14:
.ds Xs 22714     4
.TH GLPOLYGONSTIPPLE 3G
.SH NAME
.B "glPolygonStipple
\- set the polygon stippling pattern

.SH C SPECIFICATION
void \f3glPolygonStipple\fP(
const GLubyte \fI*mask\fP )
.nf
.fi

.SH PARAMETERS
.TP \w'\f2mask\fP\ \ 'u 
\f2mask\fP
Specifies a pointer to a 32x32 stipple pattern that will be unpacked
from memory in the same way that \%\f3glDrawPixels\fP unpacks pixels.
.SH DESCRIPTION
Polygon stippling,
like line stippling
(see \%\f3glLineStipple\fP),
masks out certain fragments produced by rasterization,
creating a pattern.
Stippling is independent of polygon antialiasing.
.P
\f2mask\fP is a pointer to a 32x32 stipple pattern that is stored
in memory just like the pixel data supplied to a \%\f3glDrawPixels\fP
call with 
.I
height
and
.I width
both equal to 32, a pixel 
of \%\f3GL_COLOR_INDEX\fP, and data type 
of \%\f3GL_BITMAP\fP.
That is,
the stipple pattern is represented as a 32x32 array
of 1-bit color indices packed in unsigned bytes.
\%\f3glPixelStore\fP parameters like \%\f3GL_UNPACK_SWAP_BYTES\fP
and \%\f3GL_UNPACK_LSB_FIRST\fP affect the assembling of the bits into a
stipple pattern.
Pixel transfer operations
(shift, offset, pixel map)
are not applied to the stipple image,
however.
.P
To enable and disable polygon stippling, call
\%\f3glEnable\fP and \%\f3glDisable\fP
with argument \%\f3GL_POLYGON_STIPPLE\fP. Polygon stippling is initially
disabled. If it's enabled,
a rasterized polygon fragment with window coordinates xw and yw
is sent to the next stage of the GL if and only if the
(xw mod 32)th bit in the (yw mod 32)th row
of the stipple pattern is 1 (one).
When polygon stippling is disabled, it is as if the stipple pattern
consists of all 1's.
.SH ERRORS
\%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glPolygonStipple\fP
is executed between the execution of \%\f3glBegin\fP
and the corresponding execution of \%\f3glEnd\fP.
.SH ASSOCIATED GETS
\%\f3glGetPolygonStipple\fP
.br
\%\f3glIsEnabled\fP with argument \%\f3GL_POLYGON_STIPPLE\fP
.SH SEE ALSO
\%\f3glDrawPixels\fP,
\%\f3glLineStipple\fP,
\%\f3glPixelStore\fP,
\%\f3glPixelTransfer\fP