Java tutorial
/* * Copyright (C) 2012 Tim Vaughan <tgvaughan@gmail.com> * * 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 3 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, see <http://www.gnu.org/licenses/>. */ package jtrace.texture; import java.util.List; import jtrace.Colour; import jtrace.LightSource; import jtrace.Ray; import jtrace.Scene; import jtrace.object.SceneObject; import org.apache.commons.math3.geometry.euclidean.threed.Vector3D; /** * Finish for adding specular highlights to a texture. * * @author Tim Vaughan <tgvaughan@gmail.com> */ public class SpecularFinish extends Finish { double specular; double tightness; /** * Create specular finish. * * @param specularStrength Intensity of highlights * @param specularTightness Tightness of highlights */ public SpecularFinish(double specularStrength, double specularTightness) { this.specular = specularStrength; this.tightness = specularTightness; } @Override public Colour layerFinish(SceneObject object, Colour pigmentColour, Colour colour) { Colour specularColour = new Colour(0, 0, 0); Ray incidentRay = object.getIncidentRay(); Ray normalRay = object.getNormalRay(); Ray reflectedRay = object.getReflectedRay(); for (LightSource light : object.getVisibleLights()) { // Determine distance and direction to light: Vector3D lightDir = light.getLocation().subtract(normalRay.origin); double lightDistanceSq = lightDir.getNormSq(); lightDir = lightDir.normalize(); // Projection of light direction onto reflected ray: double projection = lightDir.dotProduct(reflectedRay.direction); if (projection > 0) { // Digree of illumination: double illum = Math.pow(projection, tightness) * light.getIntensity(lightDistanceSq); // Scale light colour by intensity and add to specular colour: specularColour = specularColour.add(light.getColour().scale(illum)); } } return colour.add(specularColour); } }