/* 
GeoGebra - Dynamic Mathematics for Everyone
http://www.geogebra.org

This file is part of GeoGebra.

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.

 */

/*
 * AlgoOrthoVectorVector.java
 *
 * Created on 30. August 2001, 21:37
 */

package org.geogebra.common.kernel.algos;

import org.geogebra.common.kernel.CircularDefinitionException;
import org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.StringTemplate;
import org.geogebra.common.kernel.commands.Commands;
import org.geogebra.common.kernel.geos.GeoElement;
import org.geogebra.common.kernel.geos.GeoVector;
import org.geogebra.common.kernel.kernelND.GeoPointND;
import org.geogebra.common.util.MyMath;

/**
 *
 * @author Markus
 */
public class AlgoUnitOrthoVectorVector extends AlgoElement {

	private GeoVector v; // input
	private GeoVector n; // output

	private double length;

	/** Creates new AlgoUnitOrthoVectorVector */
	public AlgoUnitOrthoVectorVector(Construction cons, String label,
			GeoVector v) {
		super(cons);
		this.v = v;
		n = new GeoVector(cons);

		GeoPointND possStartPoint = v.getStartPoint();
		if (possStartPoint != null && possStartPoint.isLabelSet()) {
			try {
				n.setStartPoint(possStartPoint);
			} catch (CircularDefinitionException e) {
			}
		}

		setInputOutput(); // for AlgoElement

		// compute line through P, Q
		n.z = 0.0d;
		compute();
		n.setLabel(label);
	}

	@Override
	public Commands getClassName() {
		return Commands.UnitOrthogonalVector;
	}

	// for AlgoElement
	@Override
	protected void setInputOutput() {
		input = new GeoElement[1];
		input[0] = v;

		super.setOutputLength(1);
		super.setOutput(0, n);
		setDependencies(); // done by AlgoElement
	}

	public GeoVector getVector() {
		return n;
	}

	GeoVector getv() {
		return v;
	}

	// line through P normal to v
	@Override
	public final void compute() {
		length = MyMath.length(v.x, v.y);
		n.x = -v.y / length;
		n.y = v.x / length;
	}

	@Override
	final public String toString(StringTemplate tpl) {
		// Michael Borcherds 2008-03-30
		// simplified to allow better Chinese translation
		return getLoc().getPlain("UnitVectorPerpendicularToA", v.getLabel(tpl));

	}

}