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GLDRAWBUFFER(3G)                                                                            GLDRAWBUFFER(3G)



NAME
       glDrawBuffer - specify which color buffers are to be drawn into


C SPECIFICATION
       void 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, contexts,
             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 written.  If there are no back color buffers, only the front
                                left and front right color buffers are written.  If there are no right color
                                buffers,  only  the  front left and back left color buffers are written.  If
                                there are no right or back color buffers, only the front left  color  buffer
                                is written.

       GL_AUXi                  Only auxiliary color buffer i is written.

       If  more  than one color buffer is selected for drawing, then blending or logical operations are com-puted computed
       puted and applied independently for each color buffer and  can  produce  different  results  in  each
       buffer.

       Monoscopic  contexts include only left buffers, and stereoscopic contexts 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(3G), glColorMask(3G), glIndexMask(3G), glLogicOp(3G), glReadBuffer(3G)




                                                                                            GLDRAWBUFFER(3G)