cuboid.java

《Java 3D编程》的源代码

// Based on Sun's Box.java 1.13 98/11/23 10:23:02
// Work around for the Box bug when rendered in Wireframe mode.

package org.selman.java3d.book.cuboidtest;

import com.sun.j3d.utils.geometry.*;
import javax.media.j3d.*;
import javax.vecmath.*;

/**
 * Cuboid is a geometry primitive created with a given length, width, and height.
 * It is centered at the origin. By default, it lies within the bounding 
 * Cuboid, [-1,-1,-1] and [1,1,1].
 *
 * When a texture is applied to a Cuboid, it is map CCW like on a Cylinder.
 * A texture is mapped CCW from the back of the
 * body. The top and bottom faces are mapped such that the texture appears
 * front facing when the faces are rotated 90 toward the viewer.
 */

public class Cuboid extends Primitive {

	protected int numTris = 0;
	protected int numVerts = 0;

	/**
	* Primitive flags.
	*/
	protected int flags;

	/**
	* Used to designate the front side of the Cuboid when using
	* getShape().
	*
	* @see Cuboid#getShape
	*/
	public static final int FRONT = 0;

	/**
	* Used to designate the back side of the Cuboid when using
	* getShape().
	*
	* @see Cuboid#getShape
	*/
	public static final int BACK = 1;

	/**
	* Used to designate the right side of the Cuboid when using
	* getShape().
	*
	* @see Cuboid#getShape
	*/
	public static final int RIGHT = 2;

	/**
	* Used to designate the left side of the Cuboid when using
	* getShape().
	*
	* @see Cuboid#getShape
	*/
	public static final int LEFT = 3;

	/**
	* Used to designate the top side of the Cuboid when using
	* getShape().
	*
	* @see Cuboid#getShape
	*/
	public static final int TOP = 4;

	/**
	* Used to designate the bottom side of the Cuboid when using
	* getShape().
	*
	* @see Cuboid#getShape
	*/
	public static final int BOTTOM = 5;

	float xDim, yDim, zDim;

	/**
	* Constructs a default Cuboid of 1.0 in all dimensions. 
	*/

	public Cuboid( )
	{
		this( 1.0f, 1.0f, 1.0f, GENERATE_NORMALS, null );
	}

	public Appearance getAppearance( int index )
	{
		return null;
	}

	/** 
	* Constructs a Cuboid of a given dimension and appearance.
	*
	* @param xdim X-dimension size.
	* @param ydim Y-dimension size.
	* @param zdim Z-dimension size.
	* @param ap Appearance
	*/

	public Cuboid( float xdim, float ydim, float zdim, Appearance ap )
	{
		this( xdim, ydim, zdim, GENERATE_NORMALS, ap );
	}

	/** 
	* Constructs a Cuboid of a given dimension, flags, and appearance.
	*
	* @param xdim X-dimension size.
	* @param ydim Y-dimension size.
	* @param zdim Z-dimension size.
	* @param primflags primitive flags.
	* @param ap Appearance
	*/

	public Cuboid( float xdim, float ydim, float zdim, int primflags,
		Appearance ap )
	{
		int i;
		double sign;

		xDim = xdim;
		yDim = ydim;
		zDim = zdim;
		flags = primflags;

		//Depending on whether normal inward bit is set.
		if ((flags & GENERATE_NORMALS_INWARD) != 0)
			sign = -1.0;
		else sign = 1.0;

		TransformGroup objTrans = new TransformGroup( );
		objTrans.setCapability( ALLOW_CHILDREN_READ );
		this.addChild( objTrans );

		Shape3D shape[] = new Shape3D[6];

		for (i = FRONT; i <= BOTTOM; i++)
		{
			OldGeomBuffer gbuf = new OldGeomBuffer( 4 );

			gbuf.begin( OldGeomBuffer.QUAD_STRIP );
			for (int j = 0; j < 2; j++)
			{
				gbuf.normal3d( (double) normals[i].x*sign, 
					(double) normals[i].y*sign, 
					(double) normals[i].z*sign );
				gbuf.texCoord2d( tcoords[i*8 + j*2], tcoords[i*8 + j*2 + 1] );
				gbuf.vertex3d( (double) verts[i*12 + j*3]*xdim, 
					(double) verts[i*12+ j*3 + 1]*ydim,
					(double) verts[i*12+ j*3 + 2]*zdim );
			}
			for (int j = 3; j > 1; j--)
			{
				gbuf.normal3d( (double) normals[i].x*sign, 
					(double) normals[i].y*sign, 
					(double) normals[i].z*sign );
				gbuf.texCoord2d( tcoords[i*8 + j*2], tcoords[i*8 + j*2 + 1] );
				gbuf.vertex3d( (double) verts[i*12 + j*3]*xdim, 
					(double) verts[i*12+ j*3 + 1]*ydim,
					(double) verts[i*12+ j*3 + 2]*zdim );
			}
			gbuf.end( );
			shape[i] = new Shape3D( gbuf.getGeom( flags ) );
			numVerts = gbuf.getNumVerts( );
			numTris = gbuf.getNumTris( );

			if ((flags & ENABLE_APPEARANCE_MODIFY) != 0)
			{
				(shape[i]).setCapability( Shape3D.ALLOW_APPEARANCE_READ );
				(shape[i] ).setCapability( Shape3D.ALLOW_APPEARANCE_WRITE );
			}

			objTrans.addChild( shape[i] );
		}

		if (ap == null)
		{
			setAppearance( );
		}
		else setAppearance( ap );
	}

	/**
	*  Gets one of the faces (Shape3D) from the Cuboid that contains the
	*  geometry and appearance. This allows users to modify the 
	*  appearance or geometry of individual parts. 
	* @param partId The part to return.
	* @return The Shape3D object associated with the partID.  If an
	* invalid partId is passed in, null is returned.
	*/

	public Shape3D getShape( int partId )
	{
		if ((partId >= FRONT) && (partId <= BOTTOM))
			return ( Shape3D )(((Group)getChild( 0 )).getChild( partId ));
		return null;
	}

	/**
	*  Sets appearance of the Cuboid. This will set each face of the
	*  Cuboid to the same appearance. To set each face's appearance 
	*  separately, use getShape(partId) to get the
	*  individual shape and call shape.setAppearance(ap). 
	*/

	public void setAppearance( Appearance ap )
	{
		((Shape3D)((Group)getChild( 0 )).getChild( TOP )).setAppearance( ap );
		((Shape3D)((Group)getChild( 0 )).getChild( LEFT )).setAppearance( ap );
		((Shape3D)((Group)getChild( 0 )).getChild( RIGHT )).setAppearance( ap );
		((Shape3D)((Group)getChild( 0 )).getChild( FRONT )).setAppearance( ap );
		((Shape3D)((Group)getChild( 0 )).getChild( BACK )).setAppearance( ap );
		((Shape3D)((Group)getChild( 0 )).getChild( BOTTOM )).setAppearance( ap );
	}

	private static final float[] verts = {
    // front face
    1.0f, -1.0f,  1.0f,
    1.0f,  1.0f,  1.0f,
-1.0f,  1.0f,  1.0f,
-1.0f, -1.0f,  1.0f,
    // back face
-1.0f, -1.0f, -1.0f,
-1.0f,  1.0f, -1.0f,
    1.0f,  1.0f, -1.0f,
    1.0f, -1.0f, -1.0f,
    // right face
    1.0f, -1.0f, -1.0f,
    1.0f,  1.0f, -1.0f,
    1.0f,  1.0f,  1.0f,
    1.0f, -1.0f,  1.0f,
    // left face
-1.0f, -1.0f,  1.0f,
-1.0f,  1.0f,  1.0f,
-1.0f,  1.0f, -1.0f,
-1.0f, -1.0f, -1.0f,
    // top face
    1.0f,  1.0f,  1.0f,
    1.0f,  1.0f, -1.0f,
-1.0f,  1.0f, -1.0f,
-1.0f,  1.0f,  1.0f,
    // bottom face
-1.0f, -1.0f,  1.0f,
-1.0f, -1.0f, -1.0f,
    1.0f, -1.0f, -1.0f,
    1.0f, -1.0f,  1.0f,
  };

	private static final double[] tcoords = {
    // front
    1.0, 0.0,
    1.0, 1.0,
    0.0, 1.0,
    0.0, 0.0,
    // back
    1.0, 0.0,
    1.0, 1.0,
    0.0, 1.0,
    0.0, 0.0,
    //right
    1.0, 0.0,
    1.0, 1.0,
    0.0, 1.0,
    0.0, 0.0,
    // left
    1.0, 0.0,
    1.0, 1.0,
    0.0, 1.0,
    0.0, 0.0,
    // top
    1.0, 0.0,
    1.0, 1.0,
    0.0, 1.0,
    0.0, 0.0,
    // bottom
    0.0, 1.0,
    0.0, 0.0,
    1.0, 0.0,
    1.0, 1.0
  };


	private static final Vector3f[] normals = {
    new Vector3f( 0.0f,  0.0f,  1.0f),	// front face
    new Vector3f( 0.0f,  0.0f, -1.0f),	// back face
    new Vector3f( 1.0f,  0.0f,  0.0f),	// right face
    new Vector3f(-1.0f,  0.0f,  0.0f),	// left face
    new Vector3f( 0.0f,  1.0f,  0.0f),	// top face
    new Vector3f( 0.0f, -1.0f,  0.0f),	// bottom face
  };


	/**
	* Used to create a new instance of the node.  This routine is called
	* by <code>cloneTree</code> to duplicate the current node.
	* <code>cloneNode</code> should be overridden by any user subclassed
	* objects.  All subclasses must have their <code>cloneNode</code>
	* method consist of the following lines:
	* <P><blockquote><pre>
	*     public Node cloneNode(boolean forceDuplicate) {
	*         UserSubClass usc = new UserSubClass();
	*         usc.duplicateNode(this, forceDuplicate);
	*         return usc;
	*     }
	* </pre></blockquote>
	* @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.
	*
	* @see Node#cloneTree
	* @see Node#duplicateNode
	* @see NodeComponent#setDuplicateOnCloneTree
	*/
	public Node cloneNode( boolean forceDuplicate )
	{
		Cuboid b = new Cuboid( xDim, yDim, zDim, flags, getAppearance( ) );
		b.duplicateNode( this, forceDuplicate );
		return b;
	}

	/**
	* Copies all node 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>
	* For any <i>NodeComponent</i> objects
	* contained by the object being duplicated, each <i>NodeComponent</i>
	* object's <code>duplicateOnCloneTree</code> value is used to determine
	* whether the <i>NodeComponent</i> should be duplicated in the new node
	* or if just a reference to the current node should be placed in the
	* new node.  This flag can be overridden by setting the
	* <code>forceDuplicate</code> parameter in the <code>cloneTree</code>
	* method to <code>true</code>.
	*
	* @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.
	*
	* @see Node#cloneTree
	* @see Node#cloneNode
	* @see NodeComponent#setDuplicateOnCloneTree
	*/
	public void duplicateNode( Node originalNode, boolean forceDuplicate )
	{
		super.duplicateNode( originalNode, forceDuplicate );
	}

}