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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
       simultaneously 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
       operation, stenciling, texture mapping, and depth-buffering are ignored by glClear.

       glClear takes a single argument that is the bitwise OR of several values 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)