glPolygonStipple(3) glPolygonStipple(3)
NAME
glPolygonStipple - set the polygon stippling pattern
C SPECIFICATION
void glPolygonStipple( const GLubyte *mask )
PARAMETERS
mask Specifies a pointer to a 32x32 stipple pattern that will be
unpacked from memory in the same way that glDrawPixels unpacks
pixels.
DESCRIPTION
Polygon stippling, like line stippling (see glLineStipple), masks out
certain fragments produced by rasterization, creating a pattern. Stip-
pling is independent of polygon antialiasing.
mask is a pointer to a 32x32 stipple pattern that is stored in memory
just like the pixel data supplied to a glDrawPixels call with height
and width both equal to 32, a pixel of GL_COLOR_INDEX, and data type of
GL_BITMAP. That is, the stipple pattern is represented as a 32x32
array of 1-bit color indices packed in unsigned bytes. glPixelStore
parameters like GL_UNPACK_SWAP_BYTES and GL_UNPACK_LSB_FIRST affect the
assembling of the bits into a stipple pattern. Pixel transfer opera-
tions (shift, offset, pixel map) are not applied to the stipple image,
however.
To enable and disable polygon stippling, call glEnable and glDisable
with argument GL_POLYGON_STIPPLE. Polygon stippling is initially dis-
abled. If it's enabled, a rasterized polygon fragment with window coor-
dinates 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 stip-
ple pattern consists of all 1's.
ERRORS
GL_INVALID_OPERATION is generated if glPolygonStipple is executed
between the execution of glBegin and the corresponding execution of
glEnd.
ASSOCIATED GETS
glGetPolygonStipple
glIsEnabled with argument GL_POLYGON_STIPPLE
SEE ALSO
glDrawPixels(3), glLineStipple(3), glPixelStore(3), glPixelTransfer(3)
glPolygonStipple(3)
Mac OS X 10.6 - Generated Thu Sep 17 20:20:27 CDT 2009