GLPOLYGONSTIPPLE(3G)UNIX Programmer's Manual GLPOLYGONSTIPPLE(3G)
NAME
glPolygonStipple - set the polygon stippling pattern
C SPECIFICATION
void glPolygonStipple( const GLubyte *mask )
PARAMETERS
mask Specifies a pointer to a 32 x 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. Stippling is independent of polygon
antialiasing.
mask is a pointer to a 32 x 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 of GL_COLOR_INDEX, and data type of GL_BITMAP. That
is, the stipple pattern is represented as a 32 x 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 stip-
pling 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.
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(3G), glLineStipple(3G), glPixelStore(3G),
glPixelTransfer(3G)
MirBSD #10-current Printed 2021-12-07 1