JOGL程式的基本架構

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package idv.sean;

import com.sun.opengl.util.FPSAnimator;
import com.sun.opengl.util.GLUT;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.media.opengl.GL;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLCanvas;
import javax.media.opengl.GLCapabilities;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.glu.GLU;
import javax.swing.JFrame;

/**
 *
 * @author sean
 */
public class OpenGLApp3 extends JFrame
        implements GLEventListener, KeyListener {

    static int year = 0, day = 0;
    private KeyEvent key;
    private GLCanvas canvas;
    private GLCapabilities caps;
    GLU glu = new GLU();
    GLUT glut = new GLUT();
    private FPSAnimator animator;

    public OpenGLApp3() {
        super("My Test");

        caps = new GLCapabilities();
        canvas = new GLCanvas(caps);
        //canvas.setIgnoreRepaint( true );
        canvas.addGLEventListener(this);
        canvas.addKeyListener(this);
        animator = new FPSAnimator( canvas, 60 );
        animator.setRunAsFastAsPossible(false);
        getContentPane().add(canvas);
    }

    public void run() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(512, 512);
        setLocationRelativeTo(null);
        setVisible(true);
        canvas.requestFocus();
        animator.start();
    }

    public static void main(String[] args) {
        new OpenGLApp3().run();
    }

    public void init(GLAutoDrawable drawable) {
        GL gl = drawable.getGL();
        gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
        gl.glShadeModel(GL.GL_FLAT);

    }

    public void display(GLAutoDrawable drawable) {
        GL gl = drawable.getGL();

        gl.glClear(GL.GL_COLOR_BUFFER_BIT);
        gl.glColor3f(1.0f, 1.0f, 1.0f);

        gl.glPushMatrix();
        glut.glutWireSphere(1.0, 20, 16);   /* draw sun */
        gl.glRotatef((float) year, 0.0f, 1.0f, 0.0f);
        gl.glTranslatef(2.0f, 0.0f, 0.0f);
        gl.glRotatef((float) day, 0.0f, 1.0f, 0.0f);
        glut.glutWireSphere(0.2, 10, 8);    /* draw smaller planet */
        gl.glPopMatrix();
        drawable.swapBuffers();

    }

    public void reshape(GLAutoDrawable drawable, int arg1, int arg2, int w, int h) {
        GL gl = drawable.getGL();

        gl.glViewport(0, 0, w, h);
        gl.glMatrixMode(GL.GL_PROJECTION);
        gl.glLoadIdentity();
        glu.gluPerspective(60.0, (float) w / (float) h, 1.0, 20.0);
        gl.glMatrixMode(GL.GL_MODELVIEW);
        gl.glLoadIdentity();
        glu.gluLookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

    }

    public void displayChanged(GLAutoDrawable arg0, boolean arg1, boolean arg2) {
    }

    public void keyTyped(KeyEvent e) {
    }

    public void keyPressed(KeyEvent key) {
        this.key = key;
        System.out.println(key.getKeyCode());
        switch (key.getKeyChar()) {

            case 'd':
                day = (day + 10) % 360;
                break;
            case 'D':
                day = (day - 10) % 360;
                break;
            case 'y':
                year = (year + 5) % 360;
                break;
            case 'Y':
                year = (year - 5) % 360;
                break;
            default:
                break;
        }

        canvas.display();
    }

    public void keyReleased(KeyEvent e) {
    }
}

JOGL的核心在於GLEventListener與GLAutoDrawable這兩個介面。GLAutoDrawable這個介面有兩個實作，一個是GLCanvas，另一個是GLJPanel。前者是AWT的元件，後者是Swing的元件，當你將AWT與Swing元件混用的時候會有一些問題，但是GLCanvas會直接與OpenGL互動，所以效率比較好，之間的取捨就看需求。

GLEventListner則是JOGL繪圖的核心，包含了init、display、reshape、dispose四個函式。init只會被呼叫一次，負責繪圖環境的建置。display相當於java2d的paintComponent，負責實際的繪圖動作。reshape則是在GLAutoDrawable改變大小時進行視點、Viewport的變化。dispose則是GLAutoDrawable物件消失時，負責資源回收的工作。