Java tutorial
/* * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Sun designates this * particular file as subject to the "Classpath" exception as provided * by Sun in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ package javax.media.j3d; import javax.vecmath.Color3f; import javax.vecmath.Point3f; /** * The PointLight object specifies an attenuated light source at a * fixed point in space that radiates light equally in all directions * away from the light source. PointLight has the same attributes as * a Light node, with the addition of location and attenuation * parameters. * <p> * A point light contributes to diffuse and specular reflections, * which in turn depend on the orientation and position of a * surface. A point light does not contribute to ambient reflections. * <p> * A PointLight is attenuated by multiplying the contribution of the * light by an attenuation factor. The attenuation factor causes the * the PointLight's brightness to decrease as distance from the light * source increases. * A PointLight's attenuation factor contains three values: * <P><UL> * <LI>Constant attenuation</LI> * <LI>Linear attenuation</LI> * <LI>Quadratic attenuation</LI></UL> * <p> * A PointLight is attenuated by the reciprocal of the sum of: * <p> * <ul> * The constant attenuation factor<br> * The Linear attenuation factor times the distance between the light * and the vertex being illuminated<br> * The quadratic attenuation factor times the square of the distance * between the light and the vertex * </ul> * <p> * By default, the constant attenuation value is 1 and the other * two values are 0, resulting in no attenuation. */ public class PointLight extends Light { /** * Specifies that this PointLight node allows reading its position * information. */ public static final int ALLOW_POSITION_READ = CapabilityBits.POINT_LIGHT_ALLOW_POSITION_READ; /** * Specifies that this PointLight node allows writing its position * information. */ public static final int ALLOW_POSITION_WRITE = CapabilityBits.POINT_LIGHT_ALLOW_POSITION_WRITE; /** * Specifies that this PointLight node allows reading its attenuation * information. */ public static final int ALLOW_ATTENUATION_READ = CapabilityBits.POINT_LIGHT_ALLOW_ATTENUATION_READ; /** * Specifies that this PointLight node allows writing its attenuation * information. */ public static final int ALLOW_ATTENUATION_WRITE = CapabilityBits.POINT_LIGHT_ALLOW_ATTENUATION_WRITE; // Array for setting default read capabilities private static final int[] readCapabilities = { ALLOW_POSITION_READ, ALLOW_ATTENUATION_READ }; /** * Constructs a PointLight node with default parameters. * The default values are as follows: * <ul> * position : (0,0,0)<br> * attenuation : (1,0,0)<br> * </ul> */ public PointLight() { // set default read capabilities setDefaultReadCapabilities(readCapabilities); } /** * Constructs and initializes a point light. * @param color the color of the light source * @param position the position of the light in three-space * @param attenuation the attenutation (constant, linear, quadratic) of the light */ public PointLight(Color3f color, Point3f position, Point3f attenuation) { super(color); // set default read capabilities setDefaultReadCapabilities(readCapabilities); ((PointLightRetained) this.retained).initPosition(position); ((PointLightRetained) this.retained).initAttenuation(attenuation); } /** * Constructs and initializes a point light. * @param lightOn flag indicating whether this light is on or off * @param color the color of the light source * @param position the position of the light in three-space * @param attenuation the attenuation (constant, linear, quadratic) of the light */ public PointLight(boolean lightOn, Color3f color, Point3f position, Point3f attenuation) { super(lightOn, color); // set default read capabilities setDefaultReadCapabilities(readCapabilities); ((PointLightRetained) this.retained).initPosition(position); ((PointLightRetained) this.retained).initAttenuation(attenuation); } /** * Creates the retained mode PointLightRetained object that this * PointLight component object will point to. */ @Override void createRetained() { this.retained = new PointLightRetained(); this.retained.setSource(this); } /** * Set light position. * @param position the new position * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setPosition(Point3f position) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_POSITION_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("PointLight0")); if (isLive()) ((PointLightRetained) this.retained).setPosition(position); else ((PointLightRetained) this.retained).initPosition(position); } /** * Set light position. * @param x the new X position * @param y the new Y position * @param z the new Z position * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setPosition(float x, float y, float z) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_POSITION_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("PointLight1")); if (isLive()) ((PointLightRetained) this.retained).setPosition(x, y, z); else ((PointLightRetained) this.retained).initPosition(x, y, z); } /** * Gets this Light's current position and places it in the parameter specified. * @param position the vector that will receive this node's position * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void getPosition(Point3f position) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_POSITION_READ)) throw new CapabilityNotSetException(J3dI18N.getString("PointLight2")); ((PointLightRetained) this.retained).getPosition(position); } /** * Sets this Light's current attenuation values and places it in the parameter specified. * @param attenuation the vector that will receive the attenuation values * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setAttenuation(Point3f attenuation) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_ATTENUATION_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("PointLight3")); if (isLive()) ((PointLightRetained) this.retained).setAttenuation(attenuation); else ((PointLightRetained) this.retained).initAttenuation(attenuation); } /** * Sets this Light's current attenuation values and places it in the parameter specified. * @param constant the light's constant attenuation * @param linear the light's linear attenuation * @param quadratic the light's quadratic attenuation * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setAttenuation(float constant, float linear, float quadratic) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_ATTENUATION_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("PointLight3")); if (isLive()) ((PointLightRetained) this.retained).setAttenuation(constant, linear, quadratic); else ((PointLightRetained) this.retained).initAttenuation(constant, linear, quadratic); } /** * Gets this Light's current attenuation values and places it in the parameter specified. * @param attenuation the vector that will receive the attenuation values * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void getAttenuation(Point3f attenuation) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_ATTENUATION_READ)) throw new CapabilityNotSetException(J3dI18N.getString("PointLight5")); ((PointLightRetained) this.retained).getAttenuation(attenuation); } /** * Used to create a new instance of the node. This routine is called * by <code>cloneTree</code> to duplicate the current node. * @param forceDuplicate when set to <code>true</code>, causes the * <code>duplicateOnCloneTree</code> flag to be ignored. When * <code>false</code>, the value of each node's * <code>duplicateOnCloneTree</code> variable determines whether * NodeComponent data is duplicated or copied. * * @see Node#cloneTree * @see Node#cloneNode * @see Node#duplicateNode * @see NodeComponent#setDuplicateOnCloneTree */ @Override public Node cloneNode(boolean forceDuplicate) { PointLight p = new PointLight(); p.duplicateNode(this, forceDuplicate); return p; } /** * Copies all PointLight information from * <code>originalNode</code> into * the current node. This method is called from the * <code>cloneNode</code> method which is, in turn, called by the * <code>cloneTree</code> method.<P> * * @param originalNode the original node to duplicate. * @param forceDuplicate when set to <code>true</code>, causes the * <code>duplicateOnCloneTree</code> flag to be ignored. When * <code>false</code>, the value of each node's * <code>duplicateOnCloneTree</code> variable determines whether * NodeComponent data is duplicated or copied. * * @exception RestrictedAccessException if this object is part of a live * or compiled scenegraph. * * @see Node#duplicateNode * @see Node#cloneTree * @see NodeComponent#setDuplicateOnCloneTree */ @Override void duplicateAttributes(Node originalNode, boolean forceDuplicate) { super.duplicateAttributes(originalNode, forceDuplicate); PointLightRetained attr = (PointLightRetained) originalNode.retained; PointLightRetained rt = (PointLightRetained) retained; Point3f p = new Point3f(); attr.getPosition(p); rt.initPosition(p); attr.getAttenuation(p); rt.initAttenuation(p); } }