NAME    [Toc]    [Back]

       glReadBuffer - select a color buffer source for pixels

SYNOPSIS    [Toc]    [Back]

       void glReadBuffer(
               GLenum mode );

PARAMETERS    [Toc]    [Back]

       Specifies    a   color   buffer.   Accepted   values   are
       GL_FRONT_LEFT,        GL_FRONT_RIGHT,        GL_BACK_LEFT,
       GL_BACK_RIGHT,  GL_FRONT,  GL_BACK, GL_LEFT, GL_RIGHT, and
       GL_AUXi, where i is between 0 and GL_AUX_BUFFERS -1.

DESCRIPTION    [Toc]    [Back]

       glReadBuffer() specifies a color buffer as the source  for
       subsequent  glReadPixels(), glCopyTexImage1D(), glCopyTexImage2D(),
  glCopyTexSubImage1D(),  glCopyTexSubImage2D(),
       glCopyTexSubImage3D(),  and glCopyPixels() commands.  mode
       accepts one of twelve or more predefined values.  (GL_AUX0
       through  GL_AUX3  are always defined.)  In a fully configured
 system, GL_FRONT, GL_LEFT, and GL_FRONT_LEFT all name
       the  front  left  buffer, GL_FRONT_RIGHT and GL_RIGHT name
       the front right buffer, and GL_BACK_LEFT and GL_BACK  name
       the back left buffer.

       Nonstereo double-buffered configurations have only a front
       left and a back left  buffer.  Single-buffered  configurations
  have  a  front  left  and  a  front right buffer if
       stereo, and only a front left buffer if nonstereo.  It  is
       an  error  to  specify  a  nonexistent  buffer  to glReadBuffer().


       mode is initially GL_FRONT in  single-buffered  configurations,
 and GL_BACK in double-buffered configurations.

ERRORS    [Toc]    [Back]

       GL_INVALID_ENUM  is  generated  if  mode is not one of the
       twelve (or more) accepted values.

       GL_INVALID_OPERATION is  generated  if  mode  specifies  a
       buffer that does not exist.

       GL_INVALID_OPERATION  is  generated  if  glReadBuffer() is
       executed between the execution of glBegin() and the corresponding
 execution of glEnd().

ASSOCIATED GETS    [Toc]    [Back]

       glGet() with argument GL_READ_BUFFER

SEE ALSO    [Toc]    [Back]

       glCopyPixels(3), glCopyTexImage1D(3), glCopyTexImage2D(3),
       glCopyTexSubImage1D(3), glCopyTexSubImage2D(3), glCopyTexSubImage3D(3), glDrawBuffer(3), glReadPixels(3)



                                                 glReadBuffer(3G)