clear(3G) clear(3G)
NAME
clear - clears the viewport
C SPECIFICATION
void clear()
PARAMETERS
none
DESCRIPTION
clear sets the bitplane area of the viewport to the current color.
Multiple bitplane buffers can be cleared simultaneously using the
backbuffer, frontbuffer, and zdraw commands. Current polygon fill
pattern and writemask affect the operation of clear. The screen mask,
when it is set to a subregion of the viewport, bounds the cleared region.
Alpha function, blend function, logical operation, stenciling, texture
mapping, and z buffering, however, are ignored by clear. Stencil and z
buffer contents are not affected by clear (except in the special case of
zdraw).
Like other drawing commands, clear operates on the currently active
framebuffer, one of normal, popup, overlay, or underlay, based on the
current draw mode (see drawmode).
After clear executes, the graphics position is undefined.
SEE ALSO
afunction, backbuffer, blendfunction, czclear, defpattern, drawmode,
frontbuffer, logicop, scrmask, setpattern, stencil, texbind, zbuffer,
zdraw
NOTE
On the IRIS-4D B, G, GT, GTX, and VGX models, clear runs faster when the
window is completely unobscured.
On the Personal Iris, XS, XS24, XZ, Elan and Extreme systems, clear runs
faster when the visible window area consists of four or fewer rectangular
regions.
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