Draws a series of curve segments.
FORTRAN (libfgl.a)
void crvn(Int32 n, Coord geom [ ][3])
SUBROUTINE CRVN(n, geom) INTEGER*4 n REAL geom(3, n)
The crvn subroutine 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.
| geom | Specifies a matrix of 3-D points. |
| n | Number of points in the matrix referenced by geom. |
The example C language program curve2.c uses the crvn subroutine to draw a curve with six control points.
This subroutine is part of GL in the AIXwindows Environment/6000 Version 1, Release 2 with AIXwindows/3D Feature.
| /usr/include/gl/gl.h | Contains C language constant and variable type definitions for GL. |
| /usr/include/gl/fgl.h | Contains FORTRAN constant and variable type definitions for GL. |
Drawing a cubic spline curve with the crv subroutine.
Setting the current cubic spline curve basis matrix with the curvebasis subroutine.
Setting the number of line segments that compose a cubic spline curve with the curveprecision subroutine.
Defining a cubic spline basis matrix with the defbasis subroutine.
Drawing a rational curve with the rcrv subroutine.
Drawing a series of rational curve segments with the rcrvn subroutine.
AIX Graphics Library Overview, Drawing NURBS Curves and Surfaces, and Drawing Wire Frame Curves and Surface Patches.