quad.java

来自「java 3d game jme 工程开发源代码」· Java 代码 · 共 162 行

/*
 * Copyright (c) 2003-2009 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
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 *   may be used to endorse or promote products derived from this software 
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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// $Id: Quad.java 4091 2009-01-21 19:01:20Z joshua.j.ellen $
package com.jme.scene.shape;

import java.nio.FloatBuffer;

import com.jme.math.Vector3f;
import com.jme.scene.TexCoords;
import com.jme.scene.TriMesh;
import com.jme.util.geom.BufferUtils;

/**
 * A four sided, two dimensional shape (a quadrilateral).
 * <p>
 * The local height of the {@code Quad} defines it's size about the y-axis,
 * while the width defines the x-axis. The z-axis will always be 0.
 * 
 * @author Mark Powell
 * @version $Revision: 4091 $, $Date: 2009-01-22 03:01:20 +0800 (星期四, 22 一月 2009) $
 */
public class Quad extends TriMesh {

    private static final long serialVersionUID = 1L;

    protected float width = 0;
    
    protected float height = 0;

    public Quad() {
    }

    /**
     * Constructor creates a new <code>Quad</code> object. That data for the
     * <code>Quad</code> is not set until a call to <code>initialize</code>
     * is made.
     * 
     * @param name
     *            the name of this <code>Quad</code>.
     */
    public Quad(String name) {
        this(name, 1, 1);
    }

    /**
     * Constructor creates a new <code>Quade</code> object with the provided
     * width and height.
     * 
     * @param name
     *            the name of the <code>Quad</code>.
     * @param width
     *            the width of the <code>Quad</code>.
     * @param height
     *            the height of the <code>Quad</code>.
     */
    public Quad(String name, float width, float height) {
        super(name);
        updateGeometry(width, height);
    }

    /**
     * <code>getCenter</code> returns the center of the <code>Quad</code>.
     * 
     * @return Vector3f the center of the <code>Quad</code>.
     */
    public Vector3f getCenter() {
        return worldTranslation;
    }

    public float getHeight() {
        return height;
    }

    public float getWidth() {
        return width;
    }

    /**
     * <code>initialize</code> builds the data for the <code>Quad</code>
     * object.
     * 
     * @param width
     *            the width of the <code>Quad</code>.
     * @param height
     *            the height of the <code>Quad</code>.
     * @deprecated Use {@link #updateGeometry(float,float)} instead
     */
    public void initialize(float width, float height) {
        updateGeometry(width, height);
    }

    /**
     * <code>resize</code> changes the width and height of the given quad by
     * altering its vertices.
     * 
     * @param width
     *            the new width of the <code>Quad</code>.
     * @param height
     *            the new height of the <code>Quad</code>.
     */
    public void resize(float width, float height) {
        this.width = width;
        this.height = height;
        getVertexBuffer().clear();
        getVertexBuffer().put(-width / 2f).put(height / 2f).put(0);
        getVertexBuffer().put(-width / 2f).put(-height / 2f).put(0);
        getVertexBuffer().put(width / 2f).put(-height / 2f).put(0);
        getVertexBuffer().put(width / 2f).put(height / 2f).put(0);
    }

    /**
     * Rebuild this quad based on a new set of parameters.
     * 
     * @param width the width of the quad.
     * @param height the height of the quad.
     */
    public void updateGeometry(float width, float height) {
        this.width = width;
        this.height = height;
        setVertexCount(4);
        setVertexBuffer(BufferUtils.createVector3Buffer(getVertexCount()));
        setNormalBuffer(BufferUtils.createVector3Buffer(getVertexCount()));
        FloatBuffer tbuf = BufferUtils.createVector2Buffer(getVertexCount());
        setTextureCoords(new TexCoords(tbuf));
        setTriangleQuantity(2);
        setIndexBuffer(BufferUtils.createIntBuffer(getTriangleCount() * 3));
        resize(width, height);
        getNormalBuffer().put(new float[] { 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1 });
        tbuf.put(new float[] { 0, 1, 0, 0, 1, 0, 1, 1 });
        getIndexBuffer().put(new int[] { 0, 1, 2, 0, 2, 3 });
    }

}