用JOGL画出屏幕

import javax.media.opengl.*;
import javax.media.opengl.awt.*;
import javax.media.opengl.glu.*;
import com.sun.opengl.util.*;
import com.sun.opengl.util.gl2.*;

public class JOGLExample implements GLEventListener {
    private GLCanvas canvas;

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

    public void run() {
        GLProfile profile = GLProfile.getDefault();
        GLCapabilities capabilities = new GLCapabilities(profile);
        canvas = new GLCanvas(capabilities);
        canvas.addGLEventListener(this);
        Frame frame = new Frame("JOGL Example");
        frame.add(canvas);
        frame.setSize(640, 480);
        frame.setVisible(true);
    }

    public void init(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();
        gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    }

    public void display(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();
        gl.glClear(GL2.GL_COLOR_BUFFER_BIT);
        gl.glColor3f(1.0f, 1.0f, 1.0f);
        gl.glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
        gl.glBegin(GL2.GL_TRIANGLES);
        gl.glVertex2f(-0.5f, -0.5f);
        gl.glVertex2f(0.5f, -0.5f);
        gl.glVertex2f(0.0f, 0.5f);
        gl.glEnd();
        gl.glFlush();
    }

    public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
    }

    public void dispose(GLAutoDrawable drawable) {
    }
}