C SPECIFICATION

       void GLAPIENTRY glDrawBuffer( GLenum mode )

PARAMETERS

       mode  Specifies  up  to  four color buffers to be drawn into.  Symbolic
             constants GL_NONE, GL_FRONT_LEFT,  GL_FRONT_RIGHT,  GL_BACK_LEFT,
             GL_BACK_RIGHT,     GL_FRONT,    GL_BACK,    GL_LEFT,    GL_RIGHT,
             GL_FRONT_AND_BACK, and GL_AUXi, where i is between 0 and
             ''GL_AUX_BUFFERS'' -1, are accepted (GL_AUX_BUFFERS  is  not  the
             upper  limit;  use  glGet  to  query  the number of available aux
             buffers.)  The initial value is GL_FRONT for single-buffered con-
             texts, and GL_BACK for double-buffered contexts.

DESCRIPTION

       When  colors are written to the frame buffer, they are written into the
       color buffers specified by glDrawBuffer.   The  specifications  are  as
       follows:

       GL_NONE                  No color buffers are written.

       GL_FRONT_LEFT            Only the front left color buffer is written.

       GL_FRONT_RIGHT           Only  the front right color buffer is written.

       GL_BACK_LEFT             Only the back left color buffer is written.

       GL_BACK_RIGHT            Only the back right color buffer is written.

       GL_FRONT                 Only the front  left  and  front  right  color
                                buffers  are  written.   If  there is no front
                                right color buffer, only the front left  color
                                buffer is written.

       GL_BACK                  Only  the  back  left  and  back  right  color
                                buffers are written.   If  there  is  no  back
                                right  color  buffer, only the back left color
                                buffer is written.

       GL_LEFT                  Only  the  front  left  and  back  left  color
                                buffers are written.  If there is no back left
                                color buffer, only the front left color buffer
                                is written.

       GL_RIGHT                 Only  the  front  right  and  back right color
                                buffers are written.   If  there  is  no  back
                                right color buffer, only the front right color
                                buffer is written.

       GL_FRONT_AND_BACK        All the front and back  color  buffers  (front
                                left,  front right, back left, back right) are

       Monoscopic contexts include only left buffers,  and  stereoscopic  con-
       texts  include  both left and right buffers.  Likewise, single-buffered
       contexts include  only  front  buffers,  and  double-buffered  contexts
       include  both  front  and  back buffers.  The context is selected at GL
       initialization.

NOTES

       It is always the case that GL_AUXi = GL_AUX0 + i.

ERRORS

       GL_INVALID_ENUM is generated if mode is not an accepted value.

       GL_INVALID_OPERATION is generated if none of the buffers  indicated  by
       mode exists.

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

ASSOCIATED GETS

       glGet with argument GL_DRAW_BUFFER
       glGet with argument GL_AUX_BUFFERS

SEE ALSO

       glBlendFunc, glColorMask, glIndexMask, glLogicOp, glReadBuffer



                                                              GLDRAWBUFFER(3G)