sync code with last improvements from OpenBSD

doc/gl-docs/GL/gl/getmap.3gl

@@ -0,0 +1,134 @@
+'\" te
+'\"! tbl|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 getmap.gl
+.ds Xs 19970 5 getmap.gl
+.TH GLGETMAP 3G
+.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(3G)\fP,
+\%\f3glMap1(3G)\fP,
+\%\f3glMap2(3G)\fP