82 lines
2.4 KiB
Plaintext
82 lines
2.4 KiB
Plaintext
'\" e
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'\"! eqn | mmdoc
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'\"macro stdmacro
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.ds Vn Version 1.2
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.ds Dt 24 September 1999
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.ds Re Release 1.2.1
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.ds Dp Jan 14 18:30
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.ds Dm 01 readbuffe
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.ds Xs 2004 4 readbuffer.gl
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.TH GLREADBUFFER 3G
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.SH NAME
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.B "glReadBuffer
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\- select a color buffer source for pixels
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.SH C SPECIFICATION
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void \f3glReadBuffer\fP(
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GLenum \fImode\fP )
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.nf
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.fi
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.SH PARAMETERS
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.TP \w'\f2mode\fP\ \ 'u
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\f2mode\fP
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Specifies a color buffer.
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Accepted values are
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\%\f3GL_FRONT_LEFT\fP,
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\%\f3GL_FRONT_RIGHT\fP,
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\%\f3GL_BACK_LEFT\fP,
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\%\f3GL_BACK_RIGHT\fP,
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\%\f3GL_FRONT\fP,
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\%\f3GL_BACK\fP,
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\%\f3GL_LEFT\fP,
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\%\f3GL_RIGHT\fP, and
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\%\f3GL_AUX\fP\f2i\fP,
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where \f2i\fP is between 0 and \%\f3GL_AUX_BUFFERS\fP \-1.
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.SH DESCRIPTION
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\%\f3glReadBuffer\fP specifies a color buffer as the source for subsequent
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\%\f3glReadPixels\fP, \%\f3glCopyTexImage1D\fP, \%\f3glCopyTexImage2D\fP,
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\%\f3glCopyTexSubImage1D\fP, \%\f3glCopyTexSubImage2D\fP,
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\%\f3glCopyTexSubImage3D\fP, and
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\%\f3glCopyPixels\fP commands.
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\f2mode\fP accepts one of twelve or more predefined values.
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(\%\f3GL_AUX0\fP through \%\f3GL_AUX3\fP are always defined.)
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In a fully configured system,
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\%\f3GL_FRONT\fP,
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\%\f3GL_LEFT\fP, and
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\%\f3GL_FRONT_LEFT\fP all name the front left buffer,
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\%\f3GL_FRONT_RIGHT\fP and
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\%\f3GL_RIGHT\fP name the front right buffer, and
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\%\f3GL_BACK_LEFT\fP and
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\%\f3GL_BACK\fP name the back left buffer.
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.P
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Nonstereo double-buffered configurations have only a front left and a
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back left buffer.
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Single-buffered configurations have a front left and a front right
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buffer if stereo, and only a front left buffer if nonstereo.
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It is an error to specify a nonexistent buffer to \%\f3glReadBuffer\fP.
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.P
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\f2mode\fP is initially \%\f3GL_FRONT\fP in single-buffered configurations,
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and \%\f3GL_BACK\fP in double-buffered configurations.
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.SH ERRORS
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\%\f3GL_INVALID_ENUM\fP is generated if \f2mode\fP is not one of the twelve
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(or more) accepted values.
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.P
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\%\f3GL_INVALID_OPERATION\fP is generated if \f2mode\fP specifies a buffer
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that does not exist.
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.P
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\%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glReadBuffer\fP
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is executed between the execution of \%\f3glBegin\fP
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and the corresponding execution of \%\f3glEnd\fP.
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.SH ASSOCIATED GETS
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\%\f3glGet\fP with argument \%\f3GL_READ_BUFFER\fP
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.SH SEE ALSO
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\%\f3glCopyPixels(3G)\fP,
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\%\f3glCopyTexImage1D(3G)\fP,
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\%\f3glCopyTexImage2D(3G)\fP,
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\%\f3glCopyTexSubImage1D(3G)\fP,
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\%\f3glCopyTexSubImage2D(3G)\fP,
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\%\f3glCopyTexSubImage3D(3G)\fP,
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\%\f3glDrawBuffer(3G)\fP,
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\%\f3glReadPixels(3G)\fP
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