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'\" e
'\"! eqn | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 24 September 1999
.ds Re Release 1.2.1
.ds Dp Jan 14 18:30
.ds Dm 01 gettexgen
.ds Xs 2655 5 gettexgen.gl
.TH GLGETTEXGEN 3G
.SH NAME
.B "glGetTexGendv, glGetTexGenfv, glGetTexGeniv
\- return texture coordinate generation parameters
.SH C SPECIFICATION
void \f3glGetTexGendv\fP(
GLenum \fIcoord\fP,
.nf
.ta \w'\f3void \fPglGetTexGendv( 'u
GLenum \fIpname\fP,
GLdouble \fI*params\fP )
.fi
void \f3glGetTexGenfv\fP(
GLenum \fIcoord\fP,
.nf
.ta \w'\f3void \fPglGetTexGenfv( 'u
GLenum \fIpname\fP,
GLfloat \fI*params\fP )
.fi
void \f3glGetTexGeniv\fP(
GLenum \fIcoord\fP,
.nf
.ta \w'\f3void \fPglGetTexGeniv( 'u
GLenum \fIpname\fP,
GLint \fI*params\fP )
.fi
.EQ
delim $$
.EN
.SH PARAMETERS
.TP \w'\fIparams\fP\ \ 'u
\f2coord\fP
Specifies a texture coordinate.
Must be
\%\f3GL_S\fP,
\%\f3GL_T\fP,
\%\f3GL_R\fP, or
\%\f3GL_Q\fP.
.TP
\f2pname\fP
Specifies the symbolic name of the value(s) to be returned.
Must be either \%\f3GL_TEXTURE_GEN_MODE\fP
or the name of one of the texture generation plane equations:
\%\f3GL_OBJECT_PLANE\fP or \%\f3GL_EYE_PLANE\fP.
.TP
\f2params\fP
Returns the requested data.
.SH DESCRIPTION
\%\f3glGetTexGen\fP returns in \f2params\fP selected parameters of a texture coordinate
generation function that was specified using \%\f3glTexGen\fP.
\f2coord\fP names one of the (\f2s\fP, \f2t\fP, \f2r\fP, \f2q\fP)
texture coordinates,
using the symbolic constant
\%\f3GL_S\fP,
\%\f3GL_T\fP,
\%\f3GL_R\fP, or
\%\f3GL_Q\fP.
.P
\f2pname\fP specifies one of three symbolic names:
.TP 28
\%\f3GL_TEXTURE_GEN_MODE\fP
\f2params\fP returns the single-valued texture generation function,
a symbolic constant. The initial value is \%\f3GL_EYE_LINEAR\fP.
.TP
\%\f3GL_OBJECT_PLANE\fP
\f2params\fP returns the four plane equation coefficients that specify
object linear-coordinate generation.
Integer values, when requested,
are mapped directly from the internal floating-point representation.
.BP
.TP
\%\f3GL_EYE_PLANE\fP
\f2params\fP returns the four plane equation coefficients that specify
eye linear-coordinate generation.
Integer values,
when requested,
are mapped directly from the internal floating-point representation.
The returned values are those maintained in eye coordinates.
They are not equal to the values specified using \%\f3glTexGen\fP,
unless the modelview matrix was identity when \%\f3glTexGen\fP was called.
.SH NOTES
If an error is generated,
no change is made to the contents of \f2params\fP.
.P
When the \%\f3GL_ARB_multitexture\fP extension is supported, \%\f3glGetTexGen\fP returns
the texture coordinate generation parameters for the active texture unit.
.SH ERRORS
\%\f3GL_INVALID_ENUM\fP is generated if \f2coord\fP or \f2pname\fP is not an
accepted value.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glGetTexGen\fP
is executed between the execution of \%\f3glBegin\fP
and the corresponding execution of \%\f3glEnd\fP.
.SH SEE ALSO
\%\f3glActiveTextureARB(3G)\fP,
\%\f3glTexGen(3G)\fP
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