rcrvn Subroutine

Purpose

Draws a series of rational curve segments.

Libraries

Graphics Library

C (libgl.a)

FORTRAN (libfgl.a)

C Syntax

void rcrvn(Int32 n, Coord geom [ ][4]) 

FORTRAN Syntax

SUBROUTINE RCRVN(n, geom)
INTEGER*4 n
REAL geom(4,n)

Description

The rcrvn subroutine draws a series of rational cubic spline curve segments using the current basis and precision.

The control points specified in the geom parameter determine the shapes of the curve segments and are used four at a time. The n parameter specifies the number of control points to be used in drawing the curve. For example, if n is 6, three curve segments are drawn:

1. Using points 0,1,2,3 as control points.
2. Using points 1,2,3,4 as control points.
3. Using points 2,3,4,5 as control points.

If the current basis is a B-spline, Cardinal spline, or basis with similar properties, the curve segments are joined end to end and appear as a single curve.

Parameters

Implementation Specifics

This subroutine is part of GL in the AIXwindows Environment/6000 Version 1, Release 2 with AIXwindows/3D Feature.

Files

Related Information

Drawing a cubic spline curve with the crv subroutine.

Drawing a series of curve segments with the crvn 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.

AIX Graphics Library Overview, Drawing NURBS Curves and Surfaces, and Drawing Wire Frame Curves and Surface Patches.