import java.awt.event.*;
import javax.swing.*;

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

public class Clip//
        extends glskeleton//
        implements GLEventListener//
        , KeyListener//
{
    private GLU glu;
    private GLUT glut;
    
    //
    public Clip() {
    }
    
    public static void main(String[] args) {
        GLCapabilities caps = new GLCapabilities();
        GLJPanel canvas = new GLJPanel(caps);
        Clip demo = new Clip();
        canvas.addGLEventListener(demo);
        demo.setCanvas(canvas);
        demo.setDefaultListeners(demo);
        JFrame frame = new JFrame("Clip");
        frame.getContentPane().add(canvas);
        frame.setSize(500, 500);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        frame.getContentPane().add(canvas);
        frame.setVisible(true);
        canvas.requestFocusInWindow();
    }
    
    public void init(GLAutoDrawable drawable) {
        GL gl = drawable.getGL();
        glu = new GLU();
        glut = new GLUT();
        gl.glClearColor(0, 0, 0, 0);
        gl.glShadeModel(GL.GL_FLAT);
    }
    
    public void display(GLAutoDrawable drawable) {
        GL gl = drawable.getGL();
	// change the equation to see the effect
        /* clip lower half -- y < 0 */
        double eqn[] = { 0.0, 1.0, 0.0, 0.0 };
        /* clip left half -- x < 0 */
        double eqn2[] = { 1.0, 0.0, 0.0, 0.0 };
        
        gl.glClear(GL.GL_COLOR_BUFFER_BIT);
        gl.glColor3f(1.0f, 1.0f, 1.0f);
        gl.glPushMatrix();
        gl.glTranslatef(0.0f, 0.0f, -5.0f);

        gl.glClipPlane(GL.GL_CLIP_PLANE0, eqn, 0);
	gl.glEnable(GL.GL_CLIP_PLANE0);

        gl.glClipPlane(GL.GL_CLIP_PLANE1, eqn2, 0);
        gl.glEnable(GL.GL_CLIP_PLANE1);
        
//	gl.glRotatef(90.0f, 1.0f, 0.0f, 0.0f);
        glut.glutWireSphere(1.0, 20, 16);
        gl.glPopMatrix();
        
        gl.glFlush();
    }
    
    public void reshape(GLAutoDrawable drawable, int x, int y, 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);
	glu.gluLookAt(0,0,0,
		      0,0,-5,
		      0,1,0);
        gl.glMatrixMode(GL.GL_MODELVIEW);
    }
    
    public void displayChanged(GLAutoDrawable drawable, boolean modeChanged,
            boolean deviceChanged) {
    }
    
    public void keyTyped(KeyEvent key) {
    }
    
    public void keyPressed(KeyEvent key) {
        
        switch (key.getKeyCode()) {
            case KeyEvent.VK_ESCAPE:
                super.runExit();
                break;
                
            default:
                break;
        }
    }
    
    public void keyReleased(KeyEvent key) {
        // TODO Auto-generated method stub
    }
}