Sets the current cubic spline curve basis matrix.
FORTRAN (libfgl.a)
void curvebasis(Int32 basis_id)
SUBROUTINE CURVEB(basis_id) INTEGER*4 basis_id
The curvebasis subroutine sets a basis matrix as defined by the defbasis subroutine as the current basis matrix to draw curve segments. The basis matrix determines how the system uses the control points when drawing a curve.
Depending on the basis matrix, the system draws Bezier curves, Cardinal spline curves, B-spline curves, and others. The system does not restrict you to a limited set of basis matrices. You can define basis matrices to match whatever constraints you want to place on the curve.
| basis_id | Specifies the basis identifier of the basis matrix to use when drawing a curve. |
The example C language program curve1.c uses the curvebasis subroutine to select each of three previously defined basis matrices, then draws a curve using each basis matrix.
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.
Drawing a series of curve segments with the crvn 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.
AIX Graphics Library Overview, Drawing NURBS Curves and Surfaces, and Drawing Wire Frame Curves and Surface Patches.