/* jCAE stand for Java Computer Aided Engineering. Features are : Small CAD
modeler, Finite element mesher, Plugin architecture.
Copyright (C) 2008, by EADS France
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
package org.jcae.mesh.amibe.projection;
import org.jcae.mesh.amibe.ds.Vertex;
import org.jcae.mesh.amibe.metrics.Location;
public class TangentPlaneProjection implements LocalSurfaceProjection
{
private final Location origin = new Location();
private final double[] normal;
public TangentPlaneProjection(Vertex o)
{
if (!o.isManifold() || o.getRef() > 0)
{
normal = null;
return;
}
double [] avgNormal = new double[3];
if (!o.discreteAverageNormal(avgNormal))
{
normal = null;
return;
}
normal = avgNormal;
origin.moveTo(o);
}
/**
* Project a point on this average plane.
*
* @param pt point to project on the approximated surface.
* @return <code>true</code> if projection has been performed
* successfully, <code>false</code> otherwise.
*/
public boolean project(Location pt)
{
double [] loc = new double[3];
pt.sub(origin, loc);
double dist = loc[0] * normal[0] + loc[1] * normal[1] + loc[2] * normal[2];
for (int i = 0; i < 3; i++)
loc[i] -= dist * normal[i];
pt.moveTo(origin.getX() + loc[0], origin.getY() + loc[1], origin.getZ() + loc[2]);
return true;
}
public boolean canProject()
{
return normal != null;
}
}