package lecture10;


import com.jme3.app.SimpleApplication;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.FastMath;
import com.jme3.math.Quaternion;
import com.jme3.math.Vector3f;
import com.jme3.scene.shape.Box;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import com.jme3.scene.Spatial;
import com.jme3.scene.debug.Arrow;
import com.jme3.system.Timer;


public class cross_product extends SimpleApplication {
    
    public static void main(String[] args) {
	cross_product app = new cross_product();
        // app.setConfigShowMode(ConfigShowMode.AlwaysShow);
	app.start();
    }
    @Override
    public void simpleInitApp() {
        Material mat = new Material(assetManager, 
                "Common/MatDefs/Misc/Unshaded.j3md"); // create a simple material
        mat.setColor("Color", ColorRGBA.Blue);  
        Material mat1 = new Material(assetManager, 
                "Common/MatDefs/Misc/Unshaded.j3md"); // create a simple material
        mat1.setColor("Color", ColorRGBA.White); 
        
        // from v rotate to u
        
        Vector3f u = new Vector3f(1, 0, 0).normalize();
        Vector3f v = new Vector3f(0, 1, 0).normalize();        
        
        // draw a v as the starting vector
        // but with a different color to differentiate with later vector
        Arrow orig_Arrow = new Arrow(v);
        Spatial gOrigArrow = new Geometry("X",orig_Arrow);
        gOrigArrow.setMaterial(mat1);
        rootNode.attachChild(gOrigArrow);
        
        // initialise another v
        // for rotation
        Arrow yArrow = new Arrow(v);
        Spatial gyArrow = new Geometry("Y", yArrow);
        gyArrow.setMaterial(mat);
        rootNode.attachChild(gyArrow);

        // compute axis and angle by 
        // cross and dot product, respectively
        Vector3f axis = v.cross(u);
        float angle = FastMath.acos(v.dot(u));
	
        // do rotation
        Quaternion q = new Quaternion();
        q.fromAngleAxis(angle, axis);
        gyArrow.setLocalRotation(q);

    }
    @Override
    public void simpleUpdate(float tpf) {
        //
    }
}