/*
 *      @(#)Walk.java 1.0 99/02/14 23:00:00
 *
 * Copyright (c) 1999. All Rights Reserved.
 *
 * 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. WE 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.
 *
 * @Author: Dr. Richard Parent
 * @Author: Kovalan Muniandy
 */

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import com.sun.j3d.utils.geometry.ColorCube;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.universe.*;
import com.sun.j3d.utils.behaviors.mouse.MouseRotate;
import com.sun.j3d.utils.behaviors.mouse.MouseZoom;
import com.sun.j3d.utils.behaviors.mouse.MouseTranslate;
import javax.media.j3d.*;
import javax.vecmath.*;
import java.net.URL;
import java.net.MalformedURLException;

import com.sun.j3d.loaders.vrml97.VrmlLoader;
import com.sun.j3d.loaders.Scene;

public class Walk extends Applet implements ActionListener {
    public static void main(String[] args) {
        String locString = null;

        if (args.length == 0) {
            locString = "./tc2.wrl";
        }
        else {
            if (args.length != 1) {
                System.out.println("Usage: Walk [pathname|URL]");
                System.exit(0);
            }
            else {
                locString = args[0];
            }
        }

        new MainFrame(new Walk(locString), 330, 220);
    }

    String              location;
    Canvas3D            canvas;
    SimpleUniverse      universe;
    TransformGroup      vpTransGroup;
    VrmlLoader          loader;
    View                view;
    Panel               panel;
    Label               label;
    BranchGroup         sceneRoot;
    TransformGroup      examineGroup;
    BranchGroup         sceneGroup;
    BoundingSphere      sceneBounds;
    DirectionalLight    headLight;
    AmbientLight        ambLight;
    TextField           textField;
    Cursor              waitCursor;
    Cursor              handCursor;

    Thread animator = null;
    Transform3D initTrans;
    
    Walk(String initLocation) {
        setLayout(new BorderLayout());

        canvas = new Canvas3D( null );
        add("Center",canvas);

        Panel panel = new Panel( new FlowLayout( FlowLayout.LEFT ) );
        add( "South", panel );
        setupWalkPanel( panel );

        waitCursor = new Cursor(Cursor.WAIT_CURSOR);
        handCursor = new Cursor(Cursor.HAND_CURSOR);

        universe = new SimpleUniverse(canvas);
        ViewingPlatform viewingPlatform = universe.getViewingPlatform();
        vpTransGroup = viewingPlatform.getViewPlatformTransform();
        Viewer viewer = universe.getViewer();
        view = viewer.getView();
        view.setFrontClipDistance( view.getFrontClipDistance() - 0.095 );

        setupBehavior();

        loader = new VrmlLoader();

        gotoLocation(initLocation);

        setupInitialTransformation();
    }
    
    Button xleft = new Button( "<< x" );
    Button xright = new Button( "x >>" );
    Button ydown = new Button( "\\/ y" );
    Button yup = new Button( "y /\\" );
    Button zin = new Button( "- z" ); 
    Button zout = new Button( "z +" );
    Checkbox rotate = new Checkbox( "turn" );
    TextField deltaField = new TextField( "0.5" );

    void setupWalkPanel( Panel panel ) {
        panel.add( xleft );
        panel.add( xright );
        panel.add( ydown );
        panel.add( yup );
        panel.add( zin );
        panel.add( zout );
        panel.add( rotate );
        panel.add( deltaField );

        xleft.addActionListener( this );
        xright.addActionListener( this );
        yup.addActionListener( this );
        ydown.addActionListener( this );
        zin.addActionListener( this );
        zout.addActionListener( this );
    }

    public void actionPerformed(ActionEvent ae) {
        try {
    		Button button = (Button)ae.getSource();
            if ( button instanceof Button ) {
                String deltaText = deltaField.getText();
                double delta = Double.valueOf( deltaText ).doubleValue();
                double x=0.0, y=0.0, z=0.0;
                
                if ( xleft == button )
                    x = -delta;
                else if ( xright == button )
                    x = delta;
                else if ( ydown == button )
                    y = -delta;
                else if ( yup == button )
                    y = delta;
                else if ( zin == button )
                    z = -delta;
                else if ( zout == button )
                    z = delta;

                if ( rotate.getState() )
                    rotate( x, y, z );
                else
                    translate( x, y, z );
            }
        }
        catch ( Throwable tt ) {
            tt.toString();
        }
    }

    Transform3D xf = new Transform3D();

    void translate( double x, double y, double z ) {
        xf.setIdentity();
        xf.setTranslation( new Vector3d( x, y, z ) );
        initTrans.mul( xf );

        // view using the initial transformation
        vpTransGroup.setTransform( initTrans );
    }

    void rotate( double x, double y, double z ) {
        if ( 0.0 != x ) {
            xf.setIdentity();
            xf.rotX( (x/180.0) * Math.PI );
            initTrans.mul( xf );
        }

        if ( 0.0 != y ) {
            xf.setIdentity();
            xf.rotY( (y/180.0) * Math.PI );
            initTrans.mul( xf );
        }
        
        if ( 0.0 != z ) {
            xf.setIdentity();
            xf.rotZ( (z/180.0) * Math.PI );
            initTrans.mul( xf );
        }

        // view using the initial transformation
        vpTransGroup.setTransform( initTrans );
    }

    void setupInitialTransformation() {
        // Set initial view transform
        initTrans = new Transform3D();
	    Transform3D viewTrans = initTrans;
	    Transform3D eyeTrans = new Transform3D();

	    // point the view at the center of the object
	    Point3d center = new Point3d();
	    sceneBounds.getCenter(center);
	    double radius = sceneBounds.getRadius();
	    Vector3d temp = new Vector3d(center);
	    viewTrans.set(temp);

	    // pull the eye back far enough to see the whole object
	    double eyeDist = 2.5*radius / Math.tan(view.getFieldOfView() / 2.0);
        view.setBackClipDistance( eyeDist );
        temp.x = 0.0;
	    temp.y = 0.0;
	    temp.z = eyeDist;
	    eyeTrans.set(temp);
	    viewTrans.mul(eyeTrans);

	    // set the view transform 
	    vpTransGroup.setTransform(viewTrans);
    }

    void gotoLocation(String location) {
        canvas.setCursor(waitCursor);

        if (sceneGroup != null) {
            sceneGroup.detach();
        }

        Scene scene = null;

        try {
            URL loadUrl = new URL(location);
            try {
                // load the scene
                scene = loader.load( loadUrl );
            }
            catch (Exception e) {
                System.out.println("Exception loading URL:" + e);
            }
        }
        catch (MalformedURLException badUrl) {
            // location may be a path name
            try {
                  // load the scene
                  scene = loader.load(location);
            }
            catch (Exception e) {
                  System.out.println("Exception loading file from path:" + e);
            }
        }

        if (scene != null) {
            // get the scene group
            sceneGroup = scene.getSceneGroup();
            sceneGroup.setCapability(BranchGroup.ALLOW_DETACH);
            sceneGroup.setCapability(BranchGroup.ALLOW_BOUNDS_READ);

            // add the scene group  to the scene
            examineGroup.addChild(sceneGroup);
            
            // now that the scene group is "live" we can inquire the bounds
            sceneBounds = (BoundingSphere)sceneGroup.getBounds();
        }

        canvas.setCursor(handCursor);
    }

    private void setupBehavior() {
        sceneRoot = new BranchGroup();
        examineGroup = new TransformGroup();
        examineGroup.setCapability(TransformGroup.ALLOW_CHILDREN_EXTEND);
        examineGroup.setCapability(TransformGroup.ALLOW_CHILDREN_READ);
        examineGroup.setCapability(TransformGroup.ALLOW_CHILDREN_WRITE);
        examineGroup.setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
        examineGroup.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        sceneRoot.addChild(examineGroup);

        BoundingSphere behaviorBounds = new BoundingSphere(new Point3d(),
              Double.MAX_VALUE);

        MouseRotate mr = new MouseRotate();
        mr.setTransformGroup(examineGroup);
        mr.setSchedulingBounds(behaviorBounds);
        sceneRoot.addChild(mr);

        MouseTranslate mt = new MouseTranslate();
        mt.setTransformGroup(examineGroup);
        mt.setSchedulingBounds(behaviorBounds);
        sceneRoot.addChild(mt);

        MouseZoom mz = new MouseZoom();
        mz.setTransformGroup(examineGroup);
        mz.setSchedulingBounds(behaviorBounds);
        sceneRoot.addChild(mz);

        BoundingSphere lightBounds =
            new BoundingSphere(new Point3d(), Double.MAX_VALUE);

        ambLight = new AmbientLight(true, new Color3f(1.0f, 1.0f, 1.0f));
        ambLight.setInfluencingBounds(lightBounds);
        ambLight.setCapability(Light.ALLOW_STATE_WRITE);
        sceneRoot.addChild(ambLight);
        headLight = new DirectionalLight();
        headLight.setCapability(Light.ALLOW_STATE_WRITE);
        headLight.setInfluencingBounds(lightBounds);
        sceneRoot.addChild(headLight);

        universe.addBranchGraph(sceneRoot);
    }
}