GLPOLYGONSTIPPLE()GLPOLYGONSTIPPLE()NAMEglPolygonStipple - set the polygon stippling pattern
C SPECIFICATION
void glPolygonStipple( const GLubyte *mask )
delim $$
PARAMETERS
mask Specifies a pointer to a $32 times 32$ 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 $32 times 32$ 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 format of GL_COLOR_INDEX,
and data type of GL_BITMAP. That is, the stipple pattern is repre‐
sented as a $32 times 32$ 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 operations (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 $x sub w$ and $y sub w$ is sent to the next stage of the GL if
and only if the ($x sub w~roman mod~32$)th bit in the ($y sub w~roman
mod~32$)th row of the stipple pattern is 1 (one). When polygon stip‐
pling is disabled, it is as if the stipple 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, glLineStipple, glPixelStore, glPixelTransfer
GLPOLYGONSTIPPLE()
