exbackgroundimage.java

详细介绍Java 3D编程的一本电子书

//
//  CLASS
//    ExBackgroundImage  -  illustrate use of background images
//
//  LESSON
//    Add a Background node to place an background image behind geometry.
//
//  SEE ALSO
//    ExBackgroundColor
//    ExBackgroundGeometry
//
//  AUTHOR
//    David R. Nadeau / San Diego Supercomputer Center
//

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.net.*;
import javax.media.j3d.*;
import javax.vecmath.*;
import com.sun.j3d.utils.image.*;

public class ExBackgroundImage
	extends Example
{
	//--------------------------------------------------------------
	//  SCENE CONTENT
	//--------------------------------------------------------------

	//
	//  Nodes (updated via menu)
	//
	private Background background = null;

	//
	//  Build scene
	//
	public Group buildScene( )
	{
		// Get the current image
		ImageComponent2D image = imageComponents[currentImage];

		// Turn off the example headlight
		setHeadlightEnable( false );

		// Default to walk navigation
		setNavigationType( Walk );

		// Build the scene root
		Group scene = new Group( );


	// BEGIN EXAMPLE TOPIC
		// Create application bounds
		BoundingSphere worldBounds = new BoundingSphere(
			new Point3d( 0.0, 0.0, 0.0 ),  // Center
			1000.0 );                      // Extent

		// Set the background color and its application bounds
		background = new Background( );
		background.setImage( image );
		background.setCapability( Background.ALLOW_IMAGE_WRITE );
		background.setApplicationBounds( worldBounds );
		scene.addChild( background );
	// END EXAMPLE TOPIC


		// Build foreground geometry
		scene.addChild( new TowerScene( this ) );

		return scene;
	}



	//--------------------------------------------------------------
	//  USER INTERFACE
	//--------------------------------------------------------------

	//
	//  Main
	//
	public static void main( String[] args )
	{
		ExBackgroundImage ex = new ExBackgroundImage( );
		ex.initialize( args );
		ex.buildUniverse( );
		ex.showFrame( );
	}


	//  Image menu choices
	private NameValue[] images = {
		new NameValue( "None",         null ),
		new NameValue( "Stars",        "stars2.jpg" ),
		new NameValue( "Red Clouds",   "oddclouds.jpg" ),
		new NameValue( "White Clouds", "clouds.jpg" ),
	};
	private int currentImage = 0;
	private ImageComponent2D[] imageComponents = null;
	private CheckboxMenu imageMenu = null;


	//
	//  Initialize the GUI (application and applet)
	//
	public void initialize( String[] args )
	{
		// Initialize the window, menubar, etc.
		super.initialize( args );
		exampleFrame.setTitle( "Java 3D Background Image Example" );


		//
		//  Add a menubar menu to change node parameters
		//    Image -->
		//

		Menu m = new Menu( "Background" );

		imageMenu = new CheckboxMenu( "Image", images,
			currentImage, this );
		m.add( imageMenu );

		exampleMenuBar.add( m );


		// Preload the background images
		//   Use the texture loading utility to read in the image
		//   files and process them into an ImageComponent2D
		//   for use in the Background node.
		if ( debug ) System.err.println( "  background images..." );
		TextureLoader texLoader = null;
		String value = null;
		imageComponents = new ImageComponent2D[images.length];

		for ( int i = 0; i < images.length; i++ )
		{
			value = (String)images[i].value;
			if ( value == null )
			{
				imageComponents[i] = null;
				continue;
			}
			texLoader = new TextureLoader( value, this );
			imageComponents[i] = texLoader.getImage( );
			// Component could be null if image couldn't be loaded
		}
	}


	//
	//  Handle checkboxes and menu choices
	//
	public void checkboxChanged( CheckboxMenu menu, int check )
	{
		if ( menu == imageMenu )
		{
			// Change the background image
			currentImage = check;
			ImageComponent2D image = imageComponents[check];
			background.setImage( image );
			return;
		}

		// Handle all other checkboxes
		super.checkboxChanged( menu, check );
	}
}