/*
* jgeom: Geometry Library fo Java
*
* Copyright (C) 2005 Samuel Gerber
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package toxi.geom.nurbs;
import java.util.LinkedList;
import java.util.List;
import toxi.geom.Vec3D;
import toxi.geom.Vec4D;
/**
* Convenience class to create dynamically NurbsCurves.
*
* @author sg
* @version 1.0
*/
public class CurveCreator {
private List<Vec4D> cps = new LinkedList<Vec4D>();
private NurbsCurve curve = null;
private int degree;
private int incp = 0;
/**
* Create a new CurveCretor object which can create Curves from the given
* degree
*
* @param degree
* Degree the created NurbsCurve will have.
*/
public CurveCreator(int degree) {
this.degree = degree;
}
/**
* Add a normal Point as ControlPoint to the CurveCreator. The newly added
* Point has automatically the weight one.
*
* @param cp
* Controlpoint to add with weight one.
* @return the actual NurbsCurve if any exists, or null otherwise (to less
* control for the given degree).
*/
public NurbsCurve addControlPoint(Vec3D cp) {
return addControlPoint(new Vec4D(cp, 1));
}
/**
* Add a new Controlpoint to the current CurveCreator.
*
* @param cp
* ControlPoint to add.
* @return the actual NurbsCurve if any exists, or null otherwise (to less
* control for the given degree).
*/
public NurbsCurve addControlPoint(Vec4D cp) {
cps.add(cp);
int np = cps.size();
int tmp = degree;
if (np <= degree) {
if (incp == 0) {
incp++;
return null;
}
tmp = incp++;
}
float[] u = new float[np + tmp + 1];
for (int i = 0; i <= tmp; i++) {
u[u.length - 1 - i] = 1;
}
if (np > degree + 1) {
float val = 1.0f / (np - degree);
float step = val;
for (int i = degree + 1; i < u.length - 1 - degree; i++) {
u[i] = val;
val += step;
}
}
curve = new BasicNurbsCurve(cps.toArray(new Vec4D[cps.size()]), u, tmp);
return curve;
}
/**
* Get the curve NurbsCurve of the CurveCreator
*
* @return the actual NurbsCurve if any exists, or null otherwise (to less
* control for the given degree).
*/
public NurbsCurve getCurve() {
return curve;
}
}