/*
 *  clip.java
 *  This program demonstrates arbitrary clipping planes.
 */

import java.awt.Frame;
import java.io.IOException;
import java.lang.String;
import java.lang.System;

import jgl.GL;
import jgl.GLCanvas;

public class clip extends GLCanvas {

    private void myinit () {
    	myGL.glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
	myGL.glShadeModel (GL.GL_FLAT);
    }

    public void display () {
    	double eqn [] = {0.0, 1.0, 0.0, 0.0};
	double eqn2 [] = {1.0, 0.0, 0.0, 0.0};

	myGL.glClear (GL.GL_COLOR_BUFFER_BIT);

	myGL.glColor3f (1.0f, 1.0f, 1.0f);
	myGL.glPushMatrix ();
	myGL.glTranslatef (0.0f, 0.0f, -5.0f);

	/*    clip lower half -- y < 0          */
	myGL.glClipPlane (GL.GL_CLIP_PLANE0, eqn);
	myGL.glEnable (GL.GL_CLIP_PLANE0);
	/*    clip left half -- x < 0           */
	myGL.glClipPlane (GL.GL_CLIP_PLANE1, eqn2);
	myGL.glEnable (GL.GL_CLIP_PLANE1);

	myGL.glRotatef (90.0f, 1.0f, 0.0f, 0.0f);
	myUT.glutWireSphere (1.0, 20, 16);
	myGL.glPopMatrix ();

	myGL.glFlush ();
    }

    public void myReshape (int w, int h) {
        myGL.glViewport (0, 0, w, h);
        myGL.glMatrixMode (GL.GL_PROJECTION);
        myGL.glLoadIdentity ();
	myGLU.gluPerspective (60.0, (float)w/(float)h, 1.0, 20.0);
        myGL.glMatrixMode (GL.GL_MODELVIEW);
    }

    /* ARGSUSED1 */
    public void keyboard (char key, int x, int y) {
	switch (key) {
	    case 27:
		System.exit(0);
	    default:
		break;
	}
    }

    public void init () {
	myUT.glutInitWindowSize (500, 500);
	myUT.glutInitWindowPosition (0, 0);
	myUT.glutCreateWindow (this);
	myinit ();
	myUT.glutDisplayFunc ("display");
	myUT.glutReshapeFunc ("myReshape");
	myUT.glutKeyboardFunc ("keyboard");
	myUT.glutMainLoop ();
    }

    static public void main (String args[]) throws IOException {
	Frame mainFrame = new Frame ();
	mainFrame.setSize (508, 527);
	clip mainCanvas = new clip ();
	mainCanvas.init();
	mainFrame.add (mainCanvas);
	mainFrame.setVisible (true);
    }

}