'\"! tbl|eqn | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 6 March 1997
.ds Re Release 1.1.0
.ds Dp Mar 17 18:05
.ds Dm  Mar  6 20:0
.ds Xs 6675 7 getmap.gl
.TH GLGETMAP
.SH NAME
.B "glGetMapdv, glGetMapfv, glGetMapiv
\- return evaluator parameters

.SH C SPECIFICATION
void \f3glGetMapdv\fP(
GLenum \fItarget\fP,
.nf
.ta \w'\f3void \fPglGetMapdv( 'u
	GLenum \fIquery\fP,
	GLdouble \fI*v\fP )
.fi
void \f3glGetMapfv\fP(
GLenum \fItarget\fP,
.nf
.ta \w'\f3void \fPglGetMapfv( 'u
	GLenum \fIquery\fP,
	GLfloat \fI*v\fP )
.fi
void \f3glGetMapiv\fP(
GLenum \fItarget\fP,
.nf
.ta \w'\f3void \fPglGetMapiv( 'u
	GLenum \fIquery\fP,
	GLint \fI*v\fP )
.fi

.EQ
delim $$
.EN
.SH PARAMETERS
.TP \w'\f2target\fP\ \ 'u 
\f2target\fP
Specifies the symbolic name of a map.
Accepted values are
\f3GL_MAP1_COLOR_4\fP,
\f3GL_MAP1_INDEX\fP,
\f3GL_MAP1_NORMAL\fP,
\f3GL_MAP1_TEXTURE_COORD_1\fP,
\f3GL_MAP1_TEXTURE_COORD_2\fP,
\f3GL_MAP1_TEXTURE_COORD_3\fP,
\f3GL_MAP1_TEXTURE_COORD_4\fP,
\f3GL_MAP1_VERTEX_3\fP,
\f3GL_MAP1_VERTEX_4\fP,
\f3GL_MAP2_COLOR_4\fP,
\f3GL_MAP2_INDEX\fP,
\f3GL_MAP2_NORMAL\fP,
\f3GL_MAP2_TEXTURE_COORD_1\fP,
\f3GL_MAP2_TEXTURE_COORD_2\fP,
\f3GL_MAP2_TEXTURE_COORD_3\fP,
\f3GL_MAP2_TEXTURE_COORD_4\fP,
\f3GL_MAP2_VERTEX_3\fP, and
\f3GL_MAP2_VERTEX_4\fP.
.TP
\f2query\fP
Specifies which parameter to return.
Symbolic names
\f3GL_COEFF\fP,
\f3GL_ORDER\fP, and
\f3GL_DOMAIN\fP are accepted.
.TP
\f2v\fP
Returns the requested data.
.SH DESCRIPTION
\f3glMap1\fP and \f3glMap2\fP define evaluators.
\f3glGetMap\fP returns evaluator parameters.
\f2target\fP chooses a map,
\f2query\fP selects a specific parameter,
and \f2v\fP points to storage where the values will be returned.
.P
The acceptable values for the \f2target\fP parameter are described
in the \f3glMap1\fP and \f3glMap2\fP reference pages.
.P
\f2query\fP can assume the following values:
.TP 15
\f3GL_COEFF\fP
\f2v\fP returns the control points for the evaluator function.
One-dimensional evaluators return $order$ control points,
and two-dimensional evaluators return $uorder times vorder$ control points.
Each control point consists of one, two, three, or four integer,
single-precision floating-point,
or double-precision floating-point values,
depending on the type of the evaluator.
The GL returns two-dimensional control points in row-major order,
incrementing the $uorder$ index quickly
and the $vorder$ index after each row.
Integer values,
when requested,
are computed by rounding the internal floating-point values to the
nearest integer values. 
.TP
\f3GL_ORDER\fP
\f2v\fP returns the order of the evaluator function.
One-dimensional evaluators return a single value,
$order$. The initial value is 1.
Two-dimensional evaluators return two values,
$uorder$ and $vorder$. The initial value is 1,1. 
.TP
\f3GL_DOMAIN\fP
\f2v\fP returns the linear $u$ and $v$ mapping parameters.
One-dimensional evaluators return two values,
$u1$ and $u2$,
as specified by \f3glMap1\fP.
Two-dimensional evaluators return four values
($u1$, $u2$, $v1$, and $v2$)
as specified by \f3glMap2\fP.
Integer values,
when requested,
are computed by rounding the internal floating-point values to the
nearest integer values.
.SH NOTES
If an error is generated,
no change is made to the contents of \f2v\fP.
.SH ERRORS
\f3GL_INVALID_ENUM\fP is generated if either \f2target\fP or \f2query\fP is not
an accepted value.
.P
\f3GL_INVALID_OPERATION\fP is generated if \f3glGetMap\fP
is executed between the execution of \f3glBegin\fP
and the corresponding execution of \f3glEnd\fP.
.SH SEE ALSO
\f3glEvalCoord\fP,
\f3glMap1\fP,
\f3glMap2\fP