glClear

GLCLEAR(3G)							  GLCLEAR(3G)



NAME
       glClear - clear buffers to preset values


C SPECIFICATION
       void glClear( GLbitfield mask )


PARAMETERS
       mask  Bitwise  OR  of  masks  that indicate the buffers to be cleared.
	     The four  masks  are  GL_COLOR_BUFFER_BIT,	 GL_DEPTH_BUFFER_BIT,
	     GL_ACCUM_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.

DESCRIPTION
       glClear	sets  the  bitplane  area  of the window to values previously
       selected by glClearColor, glClearIndex, glClearDepth,  glClearStencil,
       and  glClearAccum.   Multiple  color buffers can be cleared simultane-
       ously by selecting more than one buffer at a time using	glDrawBuffer.

       The  pixel ownership test, the scissor test, dithering, and the buffer
       writemasks affect the operation of glClear.  The	 scissor  box  bounds
       the  cleared  region.   Alpha function, blend function, logical opera-
       tion, stenciling, texture mapping, and depth-buffering are ignored  by
       glClear.

       glClear takes a single argument that is the bitwise OR of several val-
       ues indicating which buffer is to be cleared.

       The values are as follows:

       GL_COLOR_BUFFER_BIT	   Indicates the  buffers  currently  enabled
				   for color writing.

       GL_DEPTH_BUFFER_BIT	   Indicates the depth buffer.

       GL_ACCUM_BUFFER_BIT	   Indicates the accumulation buffer.

       GL_STENCIL_BUFFER_BIT	   Indicates the stencil buffer.

       The  value  to  which each buffer is cleared depends on the setting of
       the clear value for that buffer.

NOTES
       If a buffer is not present, then a glClear directed at that buffer has
       no effect.

ERRORS
       GL_INVALID_VALUE	 is  generated if any bit other than the four defined
       bits is set in mask.

       GL_INVALID_OPERATION is generated if glClear is executed	 between  the
       execution of glBegin and the corresponding execution of glEnd.

ASSOCIATED GETS
       glGet with argument GL_ACCUM_CLEAR_VALUE
       glGet with argument GL_DEPTH_CLEAR_VALUE
       glGet with argument GL_INDEX_CLEAR_VALUE
       glGet with argument GL_COLOR_CLEAR_VALUE
       glGet with argument GL_STENCIL_CLEAR_VALUE

SEE ALSO
       glClearAccum(3G),	  glClearColor(3G),	    glClearDepth(3G),
       glClearIndex(3G),	 glClearStencil(3G),	     glColorMask(3G),
       glDepthMask(3G), glDrawBuffer(3G), glScissor(3G), glStencilMask(3G)



								  GLCLEAR(3G)