AlgoAngleLines3D.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.

 */

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

package org.geogebra.common.geogebra3D.kernel3D.algos;

import org.geogebra.common.euclidian.draw.DrawAngle;
import org.geogebra.common.geogebra3D.kernel3D.geos.GeoAngle3D;
import org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.Kernel;
import org.geogebra.common.kernel.Matrix.CoordMatrixUtil;
import org.geogebra.common.kernel.Matrix.Coords;
import org.geogebra.common.kernel.algos.AlgoAngleLinesND;
import org.geogebra.common.kernel.geos.GeoAngle;
import org.geogebra.common.kernel.geos.GeoElement;
import org.geogebra.common.kernel.kernelND.GeoDirectionND;
import org.geogebra.common.kernel.kernelND.GeoLineND;

/**
 *
 * @author mathieu
 */
public class AlgoAngleLines3D extends AlgoAngleLinesND {

	protected Coords vn;
	private Coords o;
	private Coords v1;
	private Coords v2;

	AlgoAngleLines3D(Construction cons, String label, GeoLineND g, GeoLineND h,
			GeoDirectionND orientation) {
		super(cons, label, g, h, orientation);
	}

	AlgoAngleLines3D(Construction cons, String label, GeoLineND g,
			GeoLineND h) {
		this(cons, label, g, h, null);
	}

	@Override
	protected GeoAngle newGeoAngle(Construction cons1) {
		GeoAngle ret = new GeoAngle3D(cons1);
		ret.setDrawable(true);
		return ret;
	}

	@Override
	public void compute() {

		if (!getg().isDefined() || !geth().isDefined()) {
			getAngle().setUndefined();
			return;
		}

		// lines origins and directions
		Coords o1 = getg().getStartInhomCoords();
		v1 = getg().getDirectionInD3();
		Coords o2 = geth().getStartInhomCoords();
		v2 = geth().getDirectionInD3();

		// normal vector
		vn = v1.crossProduct4(v2);

		if (!vn.isDefined() || vn.isZero()) { // parallel lines
			// check if lines are opposite rays
			if (!((GeoElement) getg()).isGeoRay()
					|| !((GeoElement) geth()).isGeoRay()
					|| Kernel.isGreaterEqual(v1.dotproduct(v2), 0)) {
				getAngle().setValue(0);
				o = Coords.UNDEFINED; // for drawing
				return;
			}

			getAngle().setValue(Math.PI);
			if (o1.equalsForKernel(o2)) { // opposite rays
				o = o1.copyVector();
				v1.completeOrthonormal(vn);
			} else {
				o = Coords.UNDEFINED; // for drawing
				return;
			}
		} else { // non parallel lines
					// nearest points
			Coords[] points = CoordMatrixUtil.nearestPointsFromTwoLines(o1, v1,
					o2, v2);

			if (!points[0].equalsForKernel(points[1])) { // lines are not
															// coplanar
				getAngle().setUndefined();
				return;
			}

			o = points[0];
			vn.normalize();
		}

		v1.calcNorm();
		double l1 = v1.getNorm();
		v2.calcNorm();
		double l2 = v2.getNorm();

		double c = v1.dotproduct(v2) / (l1 * l2); // cosinus of the angle

		getAngle().setValue(AlgoAnglePoints3D.acos(c));

	}

	@Override
	public boolean updateDrawInfo(double[] m, double[] firstVec,
			DrawAngle drawable) {

		if (drawable == null) { // TODO : this is a pgf / asymptote / pstricks
								// call
			return false;
		}

		if (!o.isDefined()) {
			return false;
		}

		Coords ov = drawable.getCoordsInView(o);
		if (!drawable.inView(ov)) {
			return false;
		}

		m[0] = ov.get()[0];
		m[1] = ov.get()[1];

		Coords v1v = drawable.getCoordsInView(v1);
		if (!drawable.inView(v1v)) {
			return false;
		}

		Coords v2v = drawable.getCoordsInView(v2);
		if (!drawable.inView(v2v)) {
			return false;
		}

		firstVec[0] = v1v.get()[0];
		firstVec[1] = v1v.get()[1];

		return true;
	}

	@Override
	public Coords getVn() {
		return vn;
	}

	@Override
	public boolean getCoordsInD3(Coords[] drawCoords) {

		if (!o.isDefined()) {
			return false;
		}

		drawCoords[0] = o;
		drawCoords[1] = v1;
		drawCoords[2] = v2;

		return true;
	}

	private AlgoAngleLines3D(GeoLineND g, GeoLineND h) {
		super(g, h);
	}

	@Override
	public AlgoAngleLines3D copy() {
		return new AlgoAngleLines3D(g.copy(), h.copy());
	}

}