AlgoOrthoLinePointConic.java example

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/* 
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.

 */

/*
 * AlgoOrthoLinePointLine.java
 *
 * line through P orthogonal to l
 *
 * Created on 30. August 2001, 21:37
 */

package org.geogebra.common.kernel.algos;

import org.geogebra.common.euclidian.EuclidianConstants;
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.GeoConic;
import org.geogebra.common.kernel.geos.GeoElement;
import org.geogebra.common.kernel.geos.GeoLine;
import org.geogebra.common.kernel.geos.GeoNumeric;
import org.geogebra.common.kernel.geos.GeoPoint;
import org.geogebra.common.kernel.geos.GeoVec3D;

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

	private GeoPoint P; // input
	private GeoConic l; // input
	private GeoLine[] g; // output

	private GeoNumeric[] n;
	private AlgoPointOnPath[] algoPoint;
	private AlgoClosestPoint closestPoint;

	/**
	 * Creates new AlgoOrthoLinePointLine
	 * 
	 * @param cons
	 * @param label
	 * @param P
	 * @param l
	 */
	public AlgoOrthoLinePointConic(Construction cons, String label, GeoPoint P,
			GeoConic l) {
		super(cons);
		this.P = P;
		this.l = l;
		g = new GeoLine[4];
		n = new GeoNumeric[4];
		algoPoint = new AlgoPointOnPath[4];
		closestPoint = new AlgoClosestPoint(cons, l, P);
		for (int i = 0; i < 4; i++) {
			g[i] = new GeoLine(cons);
			g[i].setStartPoint(P);
			n[i] = new GeoNumeric(cons);
			algoPoint[i] = new AlgoPointOnPath(cons, l, 0, 0, 0, n[i]);
			cons.removeFromConstructionList(algoPoint[i]);
			// algoPoint[i].remove();
		}
		setInputOutput(); // for AlgoElement

		// compute line
		compute();
		for (int i = 0; i < 4; i++) {
			g[0].setLabel(label);
		}

		addIncidence();
	}

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

	@Override
	public int getRelatedModeID() {
		return EuclidianConstants.MODE_ORTHOGONAL;
	}

	/**
	 * @author Tam
	 * 
	 *         for special cases of e.g. AlgoIntersectLineConic
	 */
	private void addIncidence() {
		// for (int i=0; i<4; i++)
		P.addIncidence(g[0], false);
	}

	// for AlgoElement
	@Override
	public void setInputOutput() {
		input = new GeoElement[2];
		input[0] = P;
		input[1] = l.toGeoElement();

		setOutputLength(4);
		for (int i = 0; i < 4; i++) {
			setOutput(i, g[i]);
		}

		setDependencies(); // done by AlgoElement
	}

	GeoConic getC() {
		return l;
	}

	GeoLine[] getLines() {
		return g;
	}

	GeoPoint getP() {
		return P;
	}

	/**
	 * calc the line g through P and normal to l
	 */
	@Override
	public final void compute() {
		/*
		 * if(l.getType()==GeoConic.CONIC_ELLIPSE){ double[] params =
		 * l.getPerpendicularParams(P.getCoords()); for(int i=0;i<4;i++){
		 * n[i].setValue
		 * (PathNormalizer.toNormalizedPathParameter(Math.asin(params
		 * [i]),l.getMinParameter(),l.getMaxParameter())); n[i].updateCascade();
		 * //algoPoint[i].update(); GeoVec3D.lineThroughPoints(P,
		 * algoPoint[i].getP(), g[i]); Application.debug(g[i]);
		 * g[i].setLabel("r_"+i); } } else{
		 */
		GeoVec3D.lineThroughPoints(P, (GeoPoint) closestPoint.getP(), g[0]);
		/* } */
	}

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

}