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.