xenocara/doc/gl-docs/GLU/pwlcurve.3gl
2006-11-29 17:01:51 +00:00

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'\" e
'\"! eqn | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 6 March 1997
.ds Re Release 1.2.0
.ds Dp May 02 11:53
.ds Dm 37 pwlcurve.
.ds Xs 35475 4 pwlcurve.gl
.TH GLUPWLCURVE 3G
.SH NAME
.B "gluPwlCurve
\- describe a piecewise linear NURBS trimming curve
.SH C SPECIFICATION
void \f3gluPwlCurve\fP(
GLUnurbs* \fInurb\fP,
.nf
.ta \w'\f3void \fPgluPwlCurve( 'u
GLint \fIcount\fP,
GLfloat* \fIdata\fP,
GLint \fIstride\fP,
GLenum \fItype\fP )
.fi
.EQ
delim $$
.EN
.SH PARAMETERS
.TP \w'\fIstride\fP\ \ 'u
\f2nurb\fP
Specifies the NURBS object (created with \%\f3gluNewNurbsRenderer\fP).
.TP
\f2count\fP
Specifies the number of points on the curve.
.TP
\f2data\fP
Specifies an array containing the curve points.
.TP
\f2stride\fP
Specifies the offset (a number of single-precision floating-point values)
between points on the curve.
.TP
\f2type\fP
Specifies the type of curve.
Must be either \%\f3GLU_MAP1_TRIM_2\fP or \%\f3GLU_MAP1_TRIM_3\fP.
.SH DESCRIPTION
\%\f3gluPwlCurve\fP describes a piecewise linear trimming curve for a NURBS surface.
A piecewise linear curve consists of a list of
coordinates of points in the parameter space for the
NURBS surface to be trimmed. These points are connected
with line segments to form a curve. If the curve is
an approximation to a curve that is not piecewise linear,
the points should be close enough in parameter space that the
resulting path appears curved at the resolution used in the application.
.P
If \f2type\fP is
\%\f3GLU_MAP1_TRIM_2\fP, then it describes a curve in two-dimensional (\f2u\fP
and \f2v\fP) parameter space. If it is \%\f3GLU_MAP1_TRIM_3\fP, then it
describes a curve in two-dimensional homogeneous (\f2u\fP, \f2v\fP,
and \f2w\fP) parameter space.
See the \%\f3gluBeginTrim\fP reference page for more information
about trimming curves.
.SH NOTES
To describe a trim curve that closely follows the contours of a NURBS
surface, call \%\f3gluNurbsCurve\fP.
.SH SEE ALSO
\%\f3gluBeginCurve(3G)\fP, \%\f3gluBeginTrim(3G)\fP, \%\f3gluNewNurbsRenderer(3G)\fP, \%\f3gluNurbsCurve(3G)\fP