NAME

glDrawBuffer - specify which color buffers are to be drawn into

C SPECIFICATION

void ggllDDrraawwBBuuffffeerr( GLenum _m_o_d_e )

        

delim $$

PARAMETERS

_m_o_d_e
Specifies up to four color buffers to be drawn into. Symbolic constants GGLL__NNOONNEE, GGLL__FFRROONNTT__LLEEFFTT, GGLL__FFRROONNTT__RRIIGGHHTT, GGLL__BBAACCKK__LLEEFFTT, GGLL__BBAACCKK__RRIIGGHHTT, GGLL__FFRROONNTT, GGLL__BBAACCKK, GGLL__LLEEFFTT, GGLL__RRIIGGHHTT, GGLL__FFRROONNTT__AANNDD__BBAACCKK, and GGLL__AAUUXX_i, where _i is between 0 and
``GGLL__AAUUXX__BBUUFFFFEERRSS'' -1, are accepted (GGLL__AAUUXX__BBUUFFFFEERRSS is not the upper limit; use ggllGGeett to query the number of available aux buffers.) The initial value is GGLL__FFRROONNTT for single-buffered contexts, and GGLL__BBAACCKK for double-buffered contexts.

DESCRIPTION

When colors are written to the frame buffer, they are written into the color buffers specified by ggllDDrraawwBBuuffffeerr. The specifications are as follows:
GGLL__NNOONNEE
No color buffers are written.
GGLL__FFRROONNTT__LLEEFFTT
Only the front left color buffer is written.
GGLL__FFRROONNTT__RRIIGGHHTT
Only the front right color buffer is written.
GGLL__BBAACCKK__LLEEFFTT
Only the back left color buffer is written.
GGLL__BBAACCKK__RRIIGGHHTT
Only the back right color buffer is written.
GGLL__FFRROONNTT
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.
GGLL__BBAACCKK
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.
GGLL__LLEEFFTT
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.
GGLL__RRIIGGHHTT
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.
GGLL__FFRROONNTT__AANNDD__BBAACCKK
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.
GGLL__AAUUXX_i
Only auxiliary color buffer _i is written.

If more than one color buffer is selected for drawing, then blending or logical operations are computed 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 GGLL__AAUUXX$i$ = GGLL__AAUUXX00 + $i$.

ERRORS

GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _m_o_d_e is not an accepted value.

GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if none of the buffers indicated by _m_o_d_e exists.

GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllDDrraawwBBuuffffeerr is executed between the execution of ggllBBeeggiinn and the corresponding execution of ggllEEnndd.

ASSOCIATED GETS

ggllGGeett with argument GGLL__DDRRAAWW__BBUUFFFFEERR
ggllGGeett with argument GGLL__AAUUXX__BBUUFFFFEERRSS

SEE ALSO

ggllBBlleennddFFuunncc((33GG)), ggllCCoolloorrMMaasskk((33GG)), ggllIInnddeexxMMaasskk((33GG)), ggllLLooggiiccOOpp((33GG)), ggllRReeaaddBBuuffffeerr((33GG))