Java tutorial
/* * Java Terrain and Stellar System Ports * * Copyright (C) 2006 Martin H. Smith based on work by original * authors. * * Released under the terms of the GNU General Public License * * 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; either version 2 * of the License, or (at your option) any later version. * * This program 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 this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301, USA. * * Linking TerraJ statically or dynamically with other modules is making a * combined work based on TerraJ. Thus, the terms and conditions of the * GNU General Public License cover the whole combination. * * In addition, as a special exception, the copyright holders of TerraJ * give you permission to combine this program with free software programs * or libraries that are released under the GNU LGPL and with code included * in the standard release of JOGL, Java Getopt and FreeMarker under the BSD * license (or modified versions of such code, with unchanged license) and with * Apache Commons and Log4J libraries under the Apache license (or modified versions * of such code. You may copy and distribute such a system following the terms * of the GNU GPL for TerraJ and the licenses of the other code concerned, * provided that you include the source code of that other code when and as the * GNU GPL requires distribution of source code. * * Note that people who make modified versions of TerraJ are not obligated to grant * this special exception for their modified versions; it is their choice whether * to do so. The GNU General Public License gives permission to release a modified * version without this exception; this exception also makes it possible to release * a modified version which carries forward this exception. */ /* * TriangleMeshCloud.java * * Created on 18 April 2006, 15:28 */ package com.alvermont.terraj.fracplanet.geom; import com.alvermont.terraj.fracplanet.CloudParameters; import com.alvermont.terraj.fracplanet.colour.ByteRGBA; import com.alvermont.terraj.fracplanet.noise.MultiscaleNoise; import com.alvermont.terraj.fracplanet.util.Progress; import com.alvermont.terraj.stargen.util.MathUtils; import java.util.Random; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * A mesh used to represent a cloud layer * * @author martin * @version $Id: TriangleMeshCloud.java,v 1.6 2006/07/06 06:58:35 martin Exp $ */ public abstract class TriangleMeshCloud extends AbstractTriangleMesh { /** Our logger object */ private static Log log = LogFactory.getLog(TriangleMeshCloud.class); /** * Creates a new instance of TriangleMeshCloud * * @param progress The object to use for reporting progress * @param geometry The geometry object to be used */ public TriangleMeshCloud(Progress progress, Geometry geometry) { super(progress, geometry); } /** * Do the cloud alpha colouring based on a noise function * * @param parameters The cloud parameters */ protected void doCloud(final CloudParameters parameters) { computeVertexNormals(); getProgress().progressStart(100, "Cloud colouring"); final ByteRGBA c = new ByteRGBA(parameters.getColour()); //! \todo Wire up terms, decay and base fequency and thresholds MultiscaleNoise noise = new MultiscaleNoise(new MathUtils(new Random(parameters.getSeed())), 6, 0.5f); for (int i = 0; i < getVertexCount(); ++i) { getProgress().progressStep((100 * i) / getVertexCount()); final float v = 0.5f + 0.5f * noise.getNoise(XYZMath.opMultiply(4.0f, getVertices().get(i).getPosition())); final float v_min = 0.5f; final float v_max = 0.6f; final float v_k = 1.0f / (v_max - v_min); final float vs = Math.min(1.0f, Math.max(0.0f, (v - v_min) * v_k)); ByteRGBA col = new ByteRGBA(c.getR(), c.getG(), c.getB(), (byte) (Byte.MAX_VALUE * vs)); getVertices().get(i).setColour(0, col); // Set other colour (unused) to red for debug getVertices().get(i).setColour(1, new ByteRGBA(255, 0, 0, 255)); } getProgress().progressComplete("Cloud colouring completed"); // TODO: Eliminate all-transparent triangles & unused vertices. // Leave if nothing left // TODO: Bias weather into temperate bands (maybe not) getProgress().progressStart(100, "Weather systems"); MathUtils utils = new MathUtils(new Random(parameters.getSeed())); final int steps = 100 * getVertexCount(); int step = 0; // note following block was commented out in C++ and hasn't been // translated to Java yet. // if (false) //for (uint i=0;i<0;i++) // Number of twisters parameter // { // final uint random_vertex=static_cast<uint>(r01()*vertices()); // final XYZ position(vertex(random_vertex).position()); // final XYZ axis(geometry().up(position)); // // // Rotate opposite direction in other hemisphere // final float strength=r01()*(position.z<0.0 ? -M_PI : M_PI); // // for (uint j=0;j<vertices();j++) // { // progress_step((100*step)/steps); // step++; // // final XYZ p(vertex(j).position()); // final XYZ pn=geometry().up(p); // final float pna=pn%axis; // // if (pna>0.0f) // Don't create same feature on other side of planet (actually the distance would be big so could drop this) // { // final float distance=(p-position).magnitude(); // final float rotation_angle=strength*exp(-10.0*distance); // // // Now rotate p about axis through position by the rotation angle // // TODO: Optimise. axis and position is the same for all points; we're constantly recomputing the basis change matrices. // // Create a stateful version of Matrix34RotateAboutAxisThrough. // vertex(j).position // ( // Matrix34RotateAboutAxisThrough(axis,rotation_angle,position)*p // ); // } // } // } getProgress().progressComplete("Weather systems completed"); setSwitchColour(getTriangleCount()); } }