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. Stippling 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 format 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 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 disabled. If it's enabled, a
rasterized polygon fragment with window coordinates x and
y is sent to the next stage of the GL if and only ifwthe
(x mod 32)th bit in the (y 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, glLineStipple, glPixelStore, glPixelTransfer