Java tutorial
/* * Copyright 1996-2008 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 java.util.Enumeration; import javax.vecmath.Color3f; /** * The Light leaf node is an abstract class that defines a set of * parameters common to all * types of light. These parameters include the light color, an enable * flag, and a region of influence in which this Light node is active. * A Light node also contains a list of Group nodes that specifies the * hierarchical scope of this Light. If the scope list is empty, * the Light node has universe scope: all nodes within the region of * influence are affected by this Light node. If the scope list is * non-empty, only those Leaf nodes under the Group nodes in the * scope list are affected by this Light node (subject to the * influencing bounds). * <p> * The light in a scene may come from several light sources that can * be individually defined. Some of the light in a scene may * come from a specific direction, known as a directional light, * from a specific position, known as a point light, or * from no particular direction or source as with ambient light. * <p> * Java 3D supports an arbitrary number of lights. However, the number * of lights that can be active within the region of influence is * implementation-dependent and cannot be defined here. * <p> * <b>Light Color</b> * <p> * The Java 3D lighting model approximates the way light works in * the real world. Light is defined in terms of the red, green, and * blue components that combine to create the light color. The * three color components represent the amount of light emitted * by the source. * <p> * Each of the three colors is represented by a * floating point value that ranges from 0.0 to 1.0. A combination * of the three colors such as (1.0, 1.0, 1.0), representing * the red, green, and blue color values respectively, creates a white * light with maximum brightness. A combination such as (0.0, 0.0, * 0.0) creates no light (black). Values between the minimum and * maximum values of the range produce corresponding brightness * and colors. For example, a combination of (0.5, 0.5, 0.5) * produces a 50% grey light. A combination of (1.0, 1.0, 0.0), * red and green but no blue, produces a yellow light. * <p> * If a scene has multiple lights and all lights illuminate an object, * the effect of the light on the object is the sum of the * lights. For example, in a scene with two lights, if the first * light emits (R<sub>1</sub>, G<sub>1</sub>, B<sub>1</sub>) and * the second light emits (R<sub>2</sub>, G<sub>2</sub>, * B<sub>2</sub>), the components are added together giving * (R<sub>1</sub>+R<sub>2</sub>, G<sub>1</sub>+G<sub>2</sub>, * B<sub>1</sub>+B<sub>2</sub>). * If the sums of any of the color values is greater than 1.0, * brighter than the maximum brightness permitted, the color value is * clamped to 1.0. * <p> * <b>Material Colors</b> * <p> * In the Java 3D lighting model, the light sources have an effect * on the scene only when there are object surfaces to absorb or * reflect the light. Java 3D approximates an object's color * by calculating the percentage of red, green, and blue light * the object reflects. An object with a surface color of pure green * absorbs all of the red and blue light that strikes it and * reflects all of the green light. Viewing the object in a * white light, the green color is reflected and you see a green * object. However, if the green object is viewed in a red light, * all of the red light is absorbed and the object appears black. * <p> * The surface of each object in the scene has * certain material properties that define how light affects its * appearance. The object might reflect light in various ways, * depending on the object's surface type. The object * might even emit its own light. The Java 3D lighting model specifies * these material properties as five independent components: emitted * color, ambient color, diffuse color, specular color, and shininess. * All of these properties are computed independently, then added * together to define how the surface of the object appears under * light (an exception is Ambient light, which does not contribute * to specular reflection). The material properties are defined * in the Material class. * <p> * <b>Influencing Bounds</b> * <p> * Since a scene may be quite large, as large as the universe for * example, it is often reasonable to limit the influence of lighting * to a region that is within viewing range. There is no reason * to waste all that computing power on illuminating objects that * are too far away to be viewed. In Java 3D, the influencing bounds * is defined by a Bounds object or a BoundingLeaf object. It should * be noted that a BoundingLeaf object overrides a Bounds object, * should both objects be set. * <p> * A Bounds object represents a convex, closed volume. Bounds * defines three different types of containing * volumes: an axis-aligned-box volume, a spherical volume, and a * bounding polytope. A BoundingLeaf object also specifies a region * of influence, but allows an application to specify a bounding * region in one coordinate system (the local coordinate system of * the BoundingLeaf node) other than the local coordinate * system of the node that references the bounds (the Light). * <p> * <b>Limiting the Scope</b> * <p> * In addition to limiting the lighting calculations to a given * region of a scene, lighting can also be limited to groups of * nodes, defined by a Group object. This is known as "scoping." * All nodes attached to a Group node define a <i>list of scopes</i>. * Methods in the Light class permit the setting, addition, insertion, * removal, and enumeration of nodes in the list of scopes. * <p> * <b>Two-sided Lighting of Polygons</b> * <p> * Java 3D performs lighting calculations for all polygons, whether * they are front-facing or back-facing. Since most polygon objects * are constructed with the front face in mind, the back-facing * portion may not be correctly illuminated. For example, a sphere * with part of the face cut away so you can see its inside. * You might want to have the inside surface lit as well as the * outside surface and you mught also want to define a different * Material description to reduce shininess, specular color, etc. * <p> * For more information, see the "Face culling" and "Back-facing * normal flip" descriptions in the PolygonAttributes class * description. * <p> * <b>Turning on the Lights</b> * <p> * Lighting needs to be explicitly enabled with the setEnable method * or with the lightOn parameter in the constructor * before any of the child light sources have any effect on illuminating * the scene. The child lights may also be enabled or disabled individually. * <p> * If lighting is not enabled, the current color of an * object in the scene is simply mapped onto the object, and none of * the lighting equations regarding Material properties, such as ambient * color, diffuse color, specular color, and shininess, are performed. * However, an object's emitted color, if specified and enabled, will * still affect that object's appearance. * <p> * To disable lighting, call setEnable with <code>false</code> as * the argument. * * @see Material * @see Bounds * @see BoundingLeaf * @see Group * @see PolygonAttributes */ public abstract class Light extends Leaf { /** * Specifies that this Light allows read access to its current state * information at runtime. */ public static final int ALLOW_STATE_READ = CapabilityBits.LIGHT_ALLOW_STATE_READ; /** * Specifies that this Light allows write access to its current state * information at runtime. */ public static final int ALLOW_STATE_WRITE = CapabilityBits.LIGHT_ALLOW_STATE_WRITE; /** * Specifies that this Light allows read access to its color * information at runtime. */ public static final int ALLOW_COLOR_READ = CapabilityBits.LIGHT_ALLOW_COLOR_READ; /** * Specifies that this Light allows write access to its color * information at runtime. */ public static final int ALLOW_COLOR_WRITE = CapabilityBits.LIGHT_ALLOW_COLOR_WRITE; /** * Specifies that this Light allows read access to its * influencing bounds and bounds leaf information. */ public static final int ALLOW_INFLUENCING_BOUNDS_READ = CapabilityBits.LIGHT_ALLOW_INFLUENCING_BOUNDS_READ; /** * Specifies that this Light allows write access to its * influencing bounds and bounds leaf information. */ public static final int ALLOW_INFLUENCING_BOUNDS_WRITE = CapabilityBits.LIGHT_ALLOW_INFLUENCING_BOUNDS_WRITE; /** * Specifies that this Light allows read access to its scope * information at runtime. */ public static final int ALLOW_SCOPE_READ = CapabilityBits.LIGHT_ALLOW_SCOPE_READ; /** * Specifies that this Light allows write access to its scope * information at runtime. */ public static final int ALLOW_SCOPE_WRITE = CapabilityBits.LIGHT_ALLOW_SCOPE_WRITE; // Array for setting default read capabilities private static final int[] readCapabilities = { ALLOW_STATE_READ, ALLOW_COLOR_READ, ALLOW_INFLUENCING_BOUNDS_READ, ALLOW_SCOPE_READ }; /** * Constructs a Light node with default parameters. The default * values are as follows: * <ul> * enable flag : true<br> * color : white (1,1,1)<br> * scope : empty (universe scope)<br> * influencing bounds : null<br> * influencing bounding leaf : null<br> * </ul> */ public Light() { // set default read capabilities setDefaultReadCapabilities(readCapabilities); } /** * Constructs and initializes a Light node using the specified color. * @param color the color of the light source */ public Light(Color3f color) { // set default read capabilities setDefaultReadCapabilities(readCapabilities); ((LightRetained) this.retained).initColor(color); } /** * Constructs and initializes a Light node using the specified enable * flag and color. * @param lightOn flag indicating whether this light is on or off * @param color the color of the light source */ public Light(boolean lightOn, Color3f color) { // set default read capabilities setDefaultReadCapabilities(readCapabilities); ((LightRetained) this.retained).initEnable(lightOn); ((LightRetained) this.retained).initColor(color); } /** * Turns the light on or off. * @param state true or false to set light on or off * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setEnable(boolean state) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_STATE_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light0")); if (isLive()) ((LightRetained) this.retained).setEnable(state); else ((LightRetained) this.retained).initEnable(state); } /** * Retrieves this Light's current state (on/off). * @return this node's current state (on/off) * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public boolean getEnable() { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_STATE_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light1")); return ((LightRetained) this.retained).getEnable(); } /** * Sets the Light's current color. * @param color the value of this node's new color * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setColor(Color3f color) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_COLOR_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light2")); if (isLive()) ((LightRetained) this.retained).setColor(color); else ((LightRetained) this.retained).initColor(color); } /** * Gets this Light's current color and places it in the parameter specified. * @param color the vector that will receive this node's color * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void getColor(Color3f color) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_COLOR_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light3")); ((LightRetained) this.retained).getColor(color); } /** * Replaces the node at the specified index in this Light node's * list of scopes with the specified Group node. * By default, Light nodes are scoped only by their influencing * bounds. This allows them to be further scoped by a list of * nodes in the hierarchy. * @param scope the Group node to be stored at the specified index. * @param index the index of the Group node to be replaced. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph * @exception RestrictedAccessException if the specified group node * is part of a compiled scene graph */ public void setScope(Group scope, int index) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light4")); if (isLive()) ((LightRetained) this.retained).setScope(scope, index); else ((LightRetained) this.retained).initScope(scope, index); } /** * Retrieves the Group node at the specified index from this Light node's * list of scopes. * @param index the index of the Group node to be returned. * @return the Group node at the specified index. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public Group getScope(int index) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light5")); return ((LightRetained) this.retained).getScope(index); } /** * Inserts the specified Group node into this Light node's * list of scopes at the specified index. * By default, Light nodes are scoped only by their influencing * bounds. This allows them to be further scoped by a list of * nodes in the hierarchy. * @param scope the Group node to be inserted at the specified index. * @param index the index at which the Group node is inserted. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph * @exception RestrictedAccessException if the specified group node * is part of a compiled scene graph */ public void insertScope(Group scope, int index) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light6")); if (isLive()) ((LightRetained) this.retained).insertScope(scope, index); else ((LightRetained) this.retained).initInsertScope(scope, index); } /** * Removes the node at the specified index from this Light node's * list of scopes. If this operation causes the list of scopes to * become empty, then this Light will have universe scope: all nodes * within the region of influence will be affected by this Light node. * @param index the index of the Group node to be removed. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph * @exception RestrictedAccessException if the group node at the * specified index is part of a compiled scene graph */ public void removeScope(int index) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light7")); if (isLive()) ((LightRetained) this.retained).removeScope(index); else ((LightRetained) this.retained).initRemoveScope(index); } /** * Returns an enumeration of this Light node's list of scopes. * @return an Enumeration object containing all nodes in this Light node's * list of scopes. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public Enumeration<Group> getAllScopes() { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light8")); return ((LightRetained) this.retained).getAllScopes(); } /** * Appends the specified Group node to this Light node's list of scopes. * By default, Light nodes are scoped only by their influencing * bounds. This allows them to be further scoped by a list of * nodes in the hierarchy. * @param scope the Group node to be appended. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph * @exception RestrictedAccessException if the specified group node * is part of a compiled scene graph */ public void addScope(Group scope) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light9")); if (isLive()) ((LightRetained) this.retained).addScope(scope); else ((LightRetained) this.retained).initAddScope(scope); } /** * Returns the number of nodes in this Light node's list of scopes. * If this number is 0, then the list of scopes is empty and this * Light node has universe scope: all nodes within the region of * influence are affected by this Light node. * @return the number of nodes in this Light node's list of scopes. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public int numScopes() { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light8")); return ((LightRetained) this.retained).numScopes(); } /** * Retrieves the index of the specified Group node in this * Light node's list of scopes. * * @param scope the Group node to be looked up. * @return the index of the specified Group node; * returns -1 if the object is not in the list. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph * * @since Java 3D 1.3 */ public int indexOfScope(Group scope) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light8")); return ((LightRetained) this.retained).indexOfScope(scope); } /** * Removes the specified Group node from this Light * node's list of scopes. If the specified object is not in the * list, the list is not modified. If this operation causes the * list of scopes to become empty, then this Light * will have universe scope: all nodes within the region of * influence will be affected by this Light node. * * @param scope the Group node to be removed. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph * @exception RestrictedAccessException if the specified group node * is part of a compiled scene graph * * @since Java 3D 1.3 */ public void removeScope(Group scope) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light7")); if (isLive()) ((LightRetained) this.retained).removeScope(scope); else ((LightRetained) this.retained).initRemoveScope(scope); } /** * Removes all Group nodes from this Light node's * list of scopes. The Light node will then have * universe scope: all nodes within the region of influence will * be affected by this Light node. * * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph * @exception RestrictedAccessException if any group node in this * node's list of scopes is part of a compiled scene graph * * @since Java 3D 1.3 */ public void removeAllScopes() { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_SCOPE_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light7")); if (isLive()) ((LightRetained) this.retained).removeAllScopes(); else ((LightRetained) this.retained).initRemoveAllScopes(); } /** * Sets the Light's influencing region to the specified bounds. * This is used when the influencing bounding leaf is set to null. * @param region the bounds that contains the Light's new influencing * region. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setInfluencingBounds(Bounds region) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_INFLUENCING_BOUNDS_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light11")); if (isLive()) ((LightRetained) this.retained).setInfluencingBounds(region); else ((LightRetained) this.retained).initInfluencingBounds(region); } /** * Retrieves the Light node's influencing bounds. * @return this Light's influencing bounds information * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public Bounds getInfluencingBounds() { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_INFLUENCING_BOUNDS_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light12")); return ((LightRetained) this.retained).getInfluencingBounds(); } /** * Sets the Light's influencing region to the specified bounding leaf. * When set to a value other than null, this overrides the influencing * bounds object. * @param region the bounding leaf node used to specify the Light * node's new influencing region. * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public void setInfluencingBoundingLeaf(BoundingLeaf region) { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_INFLUENCING_BOUNDS_WRITE)) throw new CapabilityNotSetException(J3dI18N.getString("Light11")); if (isLive()) ((LightRetained) this.retained).setInfluencingBoundingLeaf(region); else ((LightRetained) this.retained).initInfluencingBoundingLeaf(region); } /** * Retrieves the Light node's influencing bounding leaf. * @return this Light's influencing bounding leaf information * @exception CapabilityNotSetException if appropriate capability is * not set and this object is part of live or compiled scene graph */ public BoundingLeaf getInfluencingBoundingLeaf() { if (isLiveOrCompiled()) if (!this.getCapability(ALLOW_INFLUENCING_BOUNDS_READ)) throw new CapabilityNotSetException(J3dI18N.getString("Light12")); return ((LightRetained) this.retained).getInfluencingBoundingLeaf(); } /** * Copies all Light 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); LightRetained attr = (LightRetained) originalNode.retained; LightRetained rt = (LightRetained) retained; Color3f c = new Color3f(); attr.getColor(c); rt.initColor(c); rt.initInfluencingBounds(attr.getInfluencingBounds()); Enumeration<Group> elm = attr.getAllScopes(); while (elm.hasMoreElements()) { // this reference will set correctly in updateNodeReferences() callback rt.initAddScope(elm.nextElement()); } // this reference will set correctly in updateNodeReferences() callback rt.initInfluencingBoundingLeaf(attr.getInfluencingBoundingLeaf()); rt.initEnable(attr.getEnable()); } /** * Callback used to allow a node to check if any scene graph objects * referenced * by that node have been duplicated via a call to <code>cloneTree</code>. * This method is called by <code>cloneTree</code> after all nodes in * the sub-graph have been duplicated. The cloned Leaf node's method * will be called and the Leaf node can then look up any object references * by using the <code>getNewObjectReference</code> method found in the * <code>NodeReferenceTable</code> object. If a match is found, a * reference to the corresponding object in the newly cloned sub-graph * is returned. If no corresponding reference is found, either a * DanglingReferenceException is thrown or a reference to the original * object is returned depending on the value of the * <code>allowDanglingReferences</code> parameter passed in the * <code>cloneTree</code> call. * <p> * NOTE: Applications should <i>not</i> call this method directly. * It should only be called by the cloneTree method. * * @param referenceTable a NodeReferenceTableObject that contains the * <code>getNewObjectReference</code> method needed to search for * new object instances. * @see NodeReferenceTable * @see Node#cloneTree * @see DanglingReferenceException */ @Override public void updateNodeReferences(NodeReferenceTable referenceTable) { LightRetained rt = (LightRetained) retained; BoundingLeaf bl = rt.getInfluencingBoundingLeaf(); if (bl != null) { Object o = referenceTable.getNewObjectReference(bl); rt.initInfluencingBoundingLeaf((BoundingLeaf) o); } int num = rt.numScopes(); for (int i = 0; i < num; i++) { rt.initScope((Group) referenceTable.getNewObjectReference(rt.getScope(i)), i); } } }