Java tutorial
/* * YoyoPointApp.java 1.0 98/11/23 * * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved. * * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use, * modify and redistribute this software in source and binary code form, * provided that i) this copyright notice and license appear on all copies of * the software; and ii) Licensee does not utilize the software in a manner * which is disparaging to Sun. * * This software is provided "AS IS," without a warranty of any kind. ALL * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY * OF SUCH DAMAGES. * * This software is not designed or intended for use in on-line control of * aircraft, air traffic, aircraft navigation or aircraft communications; or in * the design, construction, operation or maintenance of any nuclear facility. * Licensee represents and warrants that it will not use or redistribute the * Software for such purposes. */ /* * Getting Started with the Java 3D API written in Java 3D * * YoyoPointApp.java demonstrates using an Appearance to render only the points * from a more complex geometry. */ import java.applet.Applet; import java.awt.BorderLayout; import java.awt.Frame; import javax.media.j3d.Alpha; import javax.media.j3d.Appearance; import javax.media.j3d.BoundingSphere; import javax.media.j3d.BranchGroup; import javax.media.j3d.Canvas3D; import javax.media.j3d.Geometry; import javax.media.j3d.PolygonAttributes; import javax.media.j3d.RotationInterpolator; import javax.media.j3d.Shape3D; import javax.media.j3d.Transform3D; import javax.media.j3d.TransformGroup; import javax.media.j3d.TriangleFanArray; import javax.vecmath.Point3d; import javax.vecmath.Point3f; import com.sun.j3d.utils.applet.MainFrame; import com.sun.j3d.utils.universe.SimpleUniverse; public class YoyoPointApp extends Applet { ///////////////////////////////////////////////// // // create scene graph branch group // public class Yoyo extends Shape3D { //////////////////////////////////////////// // // create Shape3D with geometry and appearance // the geometry is created in method yoyoGeometry // the appearance is created in method yoyoAppearance // public Yoyo() { this.setGeometry(yoyoGeometry()); this.setAppearance(yoyoAppearance()); } // end of Yoyo constructor //////////////////////////////////////////// // // create yoyo geometry // four triangle fans represent the yoyo // strip indicies_______________ // 0 0N+0 to 1N+0 ( 0 to N ) // 1 1N+1 to 2N+1 // 2 2N+2 to 3N+2 // 3 3N+4 to 4N+3 // private Geometry yoyoGeometry() { TriangleFanArray tfa; int N = 17; int totalN = 4 * (N + 1); Point3f coords[] = new Point3f[totalN]; int stripCounts[] = { N + 1, N + 1, N + 1, N + 1 }; float r = 0.6f; float w = 0.4f; int n; double a; float x, y; // set the central points for four triangle fan strips coords[0 * (N + 1)] = new Point3f(0.0f, 0.0f, w); coords[1 * (N + 1)] = new Point3f(0.0f, 0.0f, 0.0f); coords[2 * (N + 1)] = new Point3f(0.0f, 0.0f, 0.0f); coords[3 * (N + 1)] = new Point3f(0.0f, 0.0f, -w); for (a = 0, n = 0; n < N; a = 2.0 * Math.PI / (N - 1) * ++n) { x = (float) (r * Math.cos(a)); y = (float) (r * Math.sin(a)); coords[0 * (N + 1) + n + 1] = new Point3f(x, y, w); coords[1 * (N + 1) + N - n] = new Point3f(x, y, w); coords[2 * (N + 1) + n + 1] = new Point3f(x, y, -w); coords[3 * (N + 1) + N - n] = new Point3f(x, y, -w); } tfa = new TriangleFanArray(totalN, TriangleFanArray.COORDINATES, stripCounts); tfa.setCoordinates(0, coords); return tfa; } // end of method yoyoGeometry in class Yoyo //////////////////////////////////////////// // // create yoyo geometry // private Appearance yoyoAppearance() { Appearance appearance = new Appearance(); PolygonAttributes polyAttrib = new PolygonAttributes(); polyAttrib.setPolygonMode(PolygonAttributes.POLYGON_POINT); appearance.setPolygonAttributes(polyAttrib); return appearance; } // end of method yoyoAppearance of class Yoyo } // end of class Yoyo ///////////////////////////////////////////////// // // create scene graph branch group // public BranchGroup createSceneGraph() { BranchGroup objRoot = new BranchGroup(); // Create the transform group node and initialize it to the // identity. Enable the TRANSFORM_WRITE capability so that // our behavior code can modify it at runtime. Add it to the // root of the subgraph. TransformGroup objSpin = new TransformGroup(); objSpin.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE); objRoot.addChild(objSpin); objSpin.addChild(new Yoyo()); // Create a new Behavior object that will perform the desired // operation on the specified transform object and add it into // the scene graph. Transform3D yAxis = new Transform3D(); Alpha rotationAlpha = new Alpha(-1, 4000); RotationInterpolator rotator = new RotationInterpolator(rotationAlpha, objSpin); BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0); rotator.setSchedulingBounds(bounds); objSpin.addChild(rotator); // Let Java 3D perform optimizations on this scene graph. objRoot.compile(); return objRoot; } // end of CreateSceneGraph method of YoyoPointApp // Create a simple scene and attach it to the virtual universe public YoyoPointApp() { setLayout(new BorderLayout()); Canvas3D canvas3D = new Canvas3D(null); add("Center", canvas3D); BranchGroup scene = createSceneGraph(); // SimpleUniverse is a Convenience Utility class SimpleUniverse simpleU = new SimpleUniverse(canvas3D); // This will move the ViewPlatform back a bit so the // objects in the scene can be viewed. simpleU.getViewingPlatform().setNominalViewingTransform(); simpleU.addBranchGraph(scene); } // end of YoyoPointApp constructor // The following allows this to be run as an application // as well as an applet public static void main(String[] args) { Frame frame = new MainFrame(new YoyoPointApp(), 256, 256); } // end of main method of YoyoPointApp } // end of class YoyoPointApp