PEConstraints.mesa
Copyright (C) 1984 by Xerox Corporation. All rights reserved.
Written by Darlene Plebon on August 22, 1983 10:36 am
Last editted by Pauline Ts'o on May 31, 1984 12:59:13 pm PDT
Routines for imposing continuity constaints on the bezier spline segments. First order continuity is achieved by imposing colinearity on the tangent vectors at the junction of the two bezier spline segments.
DIRECTORY
PETypes,
ViewerClasses USING [Viewer];
PEConstraints: CEDAR DEFINITIONS =
BEGIN OPEN PETypes;
Constrain:
PROCEDURE [pathViewer: ViewerClasses.Viewer, vertex: VertexNode, segment: SegmentNode, newPosition: Point];
This updates the position of the specified vertex in the specified segment according to the continuity constraints specified for it with respect to adjacent vertices. The application of the constraints may result in other vertices being moved too. This routine also updates the display accordingly.