/**
* barsuift-simlife is a life simulator programm
*
* Copyright (C) 2010 Cyrille GACHOT
*
* This file is part of barsuift-simlife.
*
* barsuift-simlife 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 3 of the License, or (at your option) any later
* version.
*
* barsuift-simlife 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 barsuift-simlife. If not, see
* <http://www.gnu.org/licenses/>.
*/
package barsuift.simLife.j3d.universe.physic;
import javax.media.j3d.Alpha;
import javax.media.j3d.BoundingSphere;
import javax.media.j3d.BranchGroup;
import javax.media.j3d.Interpolator;
import javax.media.j3d.Node;
import javax.media.j3d.RotPosPathInterpolator;
import javax.media.j3d.Transform3D;
import javax.media.j3d.TransformGroup;
import javax.vecmath.Point3f;
import javax.vecmath.Quat4f;
import javax.vecmath.Vector3f;
import barsuift.simLife.j3d.universe.Universe3D;
import barsuift.simLife.j3d.util.ProjectionHelper;
public class BasicGravity implements Gravity {
private Universe3D universe3D;
public BasicGravity(Universe3D universe3D) {
this.universe3D = universe3D;
}
public void fall(BranchGroup groupToFall) {
TransformGroup tg = (TransformGroup) groupToFall.getChild(0);
Node node = tg.getChild(0);
// get the global transform before detaching to get all the transforms along the way
// the group will not be attached locally anymore, but at the root,
// so we need to get the global transform.
Transform3D transform3D = getGlobalTransform3D(node);
// we need to detach before changing the global transform, or it will move the group too far
groupToFall.detach();
tg.setTransform(transform3D);
Interpolator gravity = createGravityInterpolator(tg);
addToUniverse(groupToFall, gravity);
}
private void addToUniverse(BranchGroup groupToFall, Interpolator gravity) {
BranchGroup bg = new BranchGroup();
bg.addChild(groupToFall);
bg.addChild(gravity);
universe3D.addElement3D(bg);
}
/**
* Get the composite of all Transforms for the given Node in the scene graph as a new Transform3D object
*
* @param node the node to get transforms
* @return the global transform
*/
private Transform3D getGlobalTransform3D(Node node) {
Transform3D transform = new Transform3D();
node.getLocalToVworld(transform);
return transform;
}
private Interpolator createGravityInterpolator(TransformGroup newTransformGroup) {
Vector3f translationVector = new Vector3f();
Transform3D transform = new Transform3D();
newTransformGroup.getTransform(transform);
transform.get(translationVector);
Quat4f rotationQuat = new Quat4f();
transform.get(rotationQuat);
float[] knots = new float[] { 0, 1 };
Point3f position1 = new Point3f(translationVector.getX(), translationVector.getY(), translationVector.getZ());
Point3f position2 = ProjectionHelper.getProjectionPoint(position1);
Point3f[] positions = new Point3f[] { position1, position2 };
Quat4f[] rotations = new Quat4f[] { rotationQuat, rotationQuat };
Alpha alpha = new Alpha(1, (long) (translationVector.getY() * 1000));
alpha.setStartTime(System.currentTimeMillis());
RotPosPathInterpolator gravity = new RotPosPathInterpolator(alpha, newTransformGroup, new Transform3D(), knots,
rotations, positions);
gravity.setSchedulingBounds(new BoundingSphere());
return gravity;
}
@Override
public String toString() {
return "BasicGravity []";
}
@Override
public int hashCode() {
int result = 1;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
return true;
}
}