crvn(3G) crvn(3G)
NAME
crvn - draws a series of curve segments
C SPECIFICATION
void crvn(n, geom)
long n;
Coord geom[][3];
PARAMETERS
geom expects a matrix of 3-D points.
n expects the number of points in the matrix referenced by geom.
DESCRIPTION
crvn draws a series of cubic spline segments using the current basis and
precision. The control points determine the shapes of the curve segments
and are used sequentially four at a time.
For example, if there are six control points, there are three possible
sequential selections of four control points. Thus, crvn draws three
curve segments: the first using control points 0,1,2,3; the second using
control points 1,2,3,4; and the third using control points 2,3,4,5.
If the current basis is a B-spline, a Cardinal spline, or a basis with
similar properties, the curve segments are joined end to end and appear
as a single curve.
Each curve segment is approximated by a sequence of straight lines. All
lines use the current linestyle, which is reset prior to the first line
and continues through subsequent lines. Other line modes, including
depthcueing, line width, and line antialiasing, also apply to the lines
generated by crvn.
After crvn executes, the graphics position is undefined.
SEE ALSO
crv, curvebasis, curveprecision, defbasis, depthcue, linesmooth,
linewidth, rcrv, rcrvn, setlinestyle
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