NAME
glReadBuffer
- select a color buffer source for pixels
C SPECIFICATION
void ggllRReeaaddBBuuffffeerr(
GLenum _m_o_d_e )
PARAMETERS
-
_m_o_d_e
-
Specifies a color buffer.
Accepted values are
GGLL__FFRROONNTT__LLEEFFTT,
GGLL__FFRROONNTT__RRIIGGHHTT,
GGLL__BBAACCKK__LLEEFFTT,
GGLL__BBAACCKK__RRIIGGHHTT,
GGLL__FFRROONNTT,
GGLL__BBAACCKK,
GGLL__LLEEFFTT,
GGLL__RRIIGGHHTT, and
GGLL__AAUUXX_i,
where _i is between 0 and GGLL__AAUUXX__BBUUFFFFEERRSS -1.
DESCRIPTION
ggllRReeaaddBBuuffffeerr specifies a color buffer as the source for subsequent
ggllRReeaaddPPiixxeellss, ggllCCooppyyTTeexxIImmaaggee11DD, ggllCCooppyyTTeexxIImmaaggee22DD,
ggllCCooppyyTTeexxSSuubbIImmaaggee11DD, ggllCCooppyyTTeexxSSuubbIImmaaggee22DD,
ggllCCooppyyTTeexxSSuubbIImmaaggee33DD, and
ggllCCooppyyPPiixxeellss commands.
_m_o_d_e accepts one of twelve or more predefined values.
(GGLL__AAUUXX00 through GGLL__AAUUXX33 are always defined.)
In a fully configured system,
GGLL__FFRROONNTT,
GGLL__LLEEFFTT, and
GGLL__FFRROONNTT__LLEEFFTT all name the front left buffer,
GGLL__FFRROONNTT__RRIIGGHHTT and
GGLL__RRIIGGHHTT name the front right buffer, and
GGLL__BBAACCKK__LLEEFFTT and
GGLL__BBAACCKK 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 ggllRReeaaddBBuuffffeerr.
_m_o_d_e is initially GGLL__FFRROONNTT in single-buffered configurations,
and GGLL__BBAACCKK in double-buffered configurations.
ERRORS
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _m_o_d_e is not one of the twelve
(or more) accepted values.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if _m_o_d_e specifies a buffer
that does not exist.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllRReeaaddBBuuffffeerr
is executed between the execution of ggllBBeeggiinn
and the corresponding execution of ggllEEnndd.
ASSOCIATED GETS
ggllGGeett with argument GGLL__RREEAADD__BBUUFFFFEERR
SEE ALSO
ggllCCooppyyPPiixxeellss((33GG)),
ggllCCooppyyTTeexxIImmaaggee11DD((33GG)),
ggllCCooppyyTTeexxIImmaaggee22DD((33GG)),
ggllCCooppyyTTeexxSSuubbIImmaaggee11DD((33GG)),
ggllCCooppyyTTeexxSSuubbIImmaaggee22DD((33GG)),
ggllCCooppyyTTeexxSSuubbIImmaaggee33DD((33GG)),
ggllDDrraawwBBuuffffeerr((33GG)),
ggllRReeaaddPPiixxeellss((33GG))