Late Night VRML 2.0 with Java CD-ROM/code.zip/Ch15/NurbsSurface.java

Java Source | 1997-02-02 | 5.6 KB | 162 lines

/*
 * Copyright (c) 1997 ORC Incorporated.  All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please contact <[e-mail]> for
 * further information regarding copyright and licensing.
 * This code is provided without warranty, either expressed or implied.
 */
/*
 * Portions of this code appear in the book
 * "Late Night VRML 2.0 with Java", Ziff-Davis Press, 1997
 *
 * NurbsSurface.java
 *
 * author   Timothy F. Rohaly
 * version  1.0, 01/15/97
 */

import vrml.*;
import vrml.field.*;
import vrml.node.*;

import nurbs.*;


/**
 * VRML 2.0 Script node implementing the NurbsSurface prototype.
 * @author   Timothy F. Rohaly
 * @version  1.0, 1/15/97
 */
public class NurbsSurface extends Script {

    private SFBool   debug;
    private SFInt32  uSegments;
    private SFInt32  vSegments;
    private MFFloat  uKnotSequence;
    private MFFloat  vKnotSequence;
    private SFInt32  numUControlPoints;
    private SFInt32  numVControlPoints;
    private MFFloat  controlPoints;

    private MFInt32  coordIndex_changed;
    private SFNode   coord_changed;

    public void initialize() {
        debug              = (SFBool)  getField("debug");
        uSegments          = (SFInt32) getField("uSegments");
        vSegments          = (SFInt32) getField("vSegments");
        uKnotSequence      = (MFFloat) getField("uKnotSequence");
        vKnotSequence      = (MFFloat) getField("vKnotSequence");
        numUControlPoints  = (SFInt32) getField("numUControlPoints");
        numVControlPoints  = (SFInt32) getField("numVControlPoints");
        controlPoints      = (MFFloat) getField("controlPoints");

        coordIndex_changed = (MFInt32) getEventOut("coordIndex_changed");
        coord_changed      = (SFNode)  getEventOut("coord_changed");

        //
        // First create the Knots
        //
        int numControlPoints = numUControlPoints.getValue();
        int numKnots         = uKnotSequence.getSize();
        int order            = numKnots - numControlPoints;

        float[] knot = new float[numKnots];
        for (int i=0; i<numKnots; i++) {
            knot[i] = uKnotSequence.get1Value(i);
        }
        if (debug.getValue()) {
            System.err.print("U Knot Sequence = [ ");
            for (int i=0; i<numKnots; i++) {
                System.err.print(uKnotSequence.get1Value(i) + ", ");
            }
            System.err.println("]");
        }

        Knot u = new Knot(order, numControlPoints);
        u.setKnots(knot);

        numControlPoints = numVControlPoints.getValue();
        numKnots         = vKnotSequence.getSize();
        order            = numKnots - numControlPoints;

        knot = new float[numKnots];
        for (int i=0; i<numKnots; i++) {
            knot[i] = vKnotSequence.get1Value(i);
        }
        if (debug.getValue()) {
            System.err.print("V Knot Sequence = [ ");
            for (int i=0; i<numKnots; i++) {
                System.err.print(vKnotSequence.get1Value(i) + ", ");
            }
            System.err.println("]");
        }

        Knot v = new Knot(order, numControlPoints);
        v.setKnots(knot);


        //
        // Second create the ControlNet
        //
        Point4[][] points = new Point4[u.getNumControlPoints()]
                                      [v.getNumControlPoints()];
        for (int i=0; i<u.getNumControlPoints(); i++) {
            for (int j=0; j<v.getNumControlPoints(); j++) {
                // Creates the Point4 objects and initializes them
                int index = 4*(j + i*v.getNumControlPoints());
                points[i][j] = new Point4(controlPoints.get1Value(index+0),
                                          controlPoints.get1Value(index+1),
                                          controlPoints.get1Value(index+2),
                                          controlPoints.get1Value(index+3));
            }
        }
        ControlNet controlNet = new ControlNet(u.getNumControlPoints(),
                                               v.getNumControlPoints(), points);

        if (debug.getValue()) {
            System.err.print("Control Points = [ ");
            for (int i=0; i<controlPoints.getSize(); i+=4) {
                System.err.print(controlPoints.get1Value(i+0) + " ");
                System.err.print(controlPoints.get1Value(i+1) + " ");
                System.err.print(controlPoints.get1Value(i+2) + " ");
                System.err.println(controlPoints.get1Value(i+3) + ", ");
            }
            System.err.println("]");
        }

        //
        // Finally we can construct the NURBS
        //
        Nurbs  shape    = new Nurbs(u, v, controlNet);

        //
        // Now tessellate to desired smoothness
        //
        Nurbs  temp     = shape.tessellate(uSegments.getValue(),
                                           vSegments.getValue() );
        String newCOORD = temp.toVRMLCoordinateNode();
        int[]  newINDEX = temp.toVRMLCoordIndex();
        if (debug.getValue()) {
            System.err.println(newCOORD);
            System.err.print("coordIndex [ ");
            for (int i=0; i<newINDEX.length; i++) {
                System.err.print(newINDEX[i] + ", ");
            }
            System.err.println("]");
        }

        //
        // Send the eventOuts to the Script node
        //
        try {
            coord_changed.setValue(getBrowser().createVrmlFromString(newCOORD)[0]);
            coordIndex_changed.setValue(newINDEX);
        }
        catch (InvalidVRMLSyntaxException e) {}
    }
}