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<STRONG>NAME</STRONG>
<STRONG>glClear</STRONG> - clear buffers to preset values
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glClear</STRONG>( GLbitfield <EM>mask</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>mask</EM> Bitwise OR of masks that indicate the buffers to be
cleared. The four masks are <STRONG>GL_COLOR_BUFFER_BIT</STRONG>,
<STRONG>GL_DEPTH_BUFFER_BIT</STRONG>, <STRONG>GL_ACCUM_BUFFER_BIT</STRONG>, and
<STRONG>GL_STENCIL_BUFFER_BIT</STRONG>.
<STRONG>DESCRIPTION</STRONG>
<STRONG>glClear</STRONG> sets the bitplane area of the window to values
previously selected by <STRONG>glClearColor</STRONG>, <STRONG>glClearIndex</STRONG>,
<STRONG>glClearDepth</STRONG>, <STRONG>glClearStencil</STRONG>, and <STRONG>glClearAccum</STRONG>. Multiple
color buffers can be cleared simultaneously by selecting
more than one buffer at a time using <STRONG>glDrawBuffer</STRONG>.
The pixel ownership test, the scissor test, dithering, and
the buffer writemasks affect the operation of <STRONG>glClear</STRONG>. The
scissor box bounds the cleared region. Alpha function,
blend function, logical operation, stenciling, texture
mapping, and depth-buffering are ignored by <STRONG>glClear</STRONG>.
<STRONG>glClear</STRONG> takes a single argument that is the bitwise OR of
several values indicating which buffer is to be cleared.
The values are as follows:
<STRONG>GL_COLOR_BUFFER_BIT</STRONG> Indicates the buffers currently
enabled for color writing.
<STRONG>GL_DEPTH_BUFFER_BIT</STRONG> Indicates the depth buffer.
<STRONG>GL_ACCUM_BUFFER_BIT</STRONG> Indicates the accumulation buffer.
<STRONG>GL_STENCIL_BUFFER_BIT</STRONG> Indicates the stencil buffer.
The value to which each buffer is cleared depends on the
setting of the clear value for that buffer.
<STRONG>NOTES</STRONG>
If a buffer is not present, then a <STRONG>glClear</STRONG> directed at that
buffer has no effect.
<STRONG>ERRORS</STRONG>
<STRONG>GL_INVALID_VALUE</STRONG> is generated if any bit other than the four
defined bits is set in <EM>mask</EM>.
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glClear</STRONG> is executed
between the execution of <STRONG>glBegin</STRONG> and the corresponding
execution of <STRONG>glEnd</STRONG>.
<STRONG>ASSOCIATED</STRONG> <STRONG>GETS</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_ACCUM_CLEAR_VALUE</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_DEPTH_CLEAR_VALUE</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_INDEX_CLEAR_VALUE</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_COLOR_CLEAR_VALUE</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_STENCIL_CLEAR_VALUE</STRONG>
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>glClearAccum</STRONG>, <STRONG>glClearColor</STRONG>, <STRONG>glClearDepth</STRONG>, <STRONG>glClearIndex</STRONG>,
<STRONG>glClearStencil</STRONG>, <STRONG>glDrawBuffer</STRONG>, <STRONG>glScissor</STRONG>
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