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GLCLEAR(3G)                                      OpenGL 3.3                                      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 three masks are
           GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.

DESCRIPTION
       glClear sets the bitplane area of the window to values previously selected by glClearColor,
       glClearDepth, and glClearStencil. 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_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 three defined bits is set in mask.

ASSOCIATED GETS
       glGet() with argument GL_DEPTH_CLEAR_VALUE


       glGet() with argument GL_COLOR_CLEAR_VALUE


       glGet() with argument GL_STENCIL_CLEAR_VALUE

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


COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software
       B License. For details, see http://oss.sgi.com/projects/FreeB/.



OpenGL 3.3                                       03/08/2011                                      GLCLEAR(3G)