import jgl.GL;
import jgl.GLApplet;

public class tea extends GLApplet {

    /* Initialize light source. */
    private void myinit () {
	float light_ambient[] = { 0.0f, 0.0f, 0.0f, 1.0f };
	float light_diffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
	float light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
	/* light_position is NOT default value */
	float light_position[] = { 1.0f, 1.0f, 1.0f, 0.0f };

	myGL.glLightfv (GL.GL_LIGHT0, GL.GL_AMBIENT, light_ambient);
	myGL.glLightfv (GL.GL_LIGHT0, GL.GL_DIFFUSE, light_diffuse);
	myGL.glLightfv (GL.GL_LIGHT0, GL.GL_SPECULAR, light_specular);
	myGL.glLightfv (GL.GL_LIGHT0, GL.GL_POSITION, light_position);
    
	myGL.glFrontFace (GL.GL_CW);
	myGL.glEnable (GL.GL_LIGHTING);
	myGL.glEnable (GL.GL_LIGHT0);
	myGL.glEnable (GL.GL_AUTO_NORMAL);
	myGL.glEnable (GL.GL_NORMALIZE);
	myGL.glDepthFunc (GL.GL_LESS);
	myGL.glEnable (GL.GL_DEPTH_TEST);
    }

    public void display () {
	double eqn[] = { 1.0, 0.0, -1.0, 1.0 };
	boolean two_side_on[] = { GL.GL_TRUE };
	boolean two_side_off[] = { GL.GL_FALSE };
	float mat_diffuse[] = { 0.8f, 0.8f, 0.8f, 1.0f };
	float back_diffuse[] = { 0.8f, 0.2f, 0.8f, 1.0f };

	myGL.glClear (GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);

	myGL.glPushMatrix ();
	myGL.glClipPlane (GL.GL_CLIP_PLANE0, eqn);  /* slice objects */
	myGL.glEnable (GL.GL_CLIP_PLANE0); 

	myGL.glPushMatrix ();
	myGL.glTranslatef (0.0f, 2.0f, 0.0f);
	myUT.glutSolidTeapot(1.0);		/* one-sided lighting */
	myGL.glPopMatrix ();

	/* two-sided lighting, but same material */
	myGL.glLightModeli (GL.GL_LIGHT_MODEL_TWO_SIDE, GL.GL_TRUE);
	myGL.glMaterialfv (GL.GL_FRONT_AND_BACK, GL.GL_DIFFUSE, mat_diffuse);
	myGL.glPushMatrix ();
	myGL.glTranslatef (0.0f, 0.0f, 0.0f);
	myUT.glutSolidTeapot(1.0);
	myGL.glPopMatrix ();

	/* two-sided lighting, two different materials */
	myGL.glMaterialfv (GL.GL_FRONT, GL.GL_DIFFUSE, mat_diffuse);
	myGL.glMaterialfv (GL.GL_BACK, GL.GL_DIFFUSE, back_diffuse);
	myGL.glPushMatrix ();
	myGL.glTranslatef (0.0f, -2.0f, 0.0f);
	myUT.glutSolidTeapot(1.0);
	myGL.glPopMatrix ();

	myGL.glLightModeli (GL.GL_LIGHT_MODEL_TWO_SIDE, GL.GL_FALSE);
	myGL.glDisable (GL.GL_CLIP_PLANE0);
	myGL.glPopMatrix ();
	myGL.glFlush();
    }

    public void myReshape (int w, int h) {
        myGL.glViewport (0, 0, w, h);
        myGL.glMatrixMode (GL.GL_PROJECTION);
        myGL.glLoadIdentity ();
        if (w <= h) {
            myGL.glOrtho (-4.0f, 4.0f,
                          -4.0f*(float)h/(float)w, 
                           4.0f*(float)h/(float)w, 
                         -10.0f, 10.0f);
        } else {
            myGL.glOrtho (-4.0f*(float)w/(float)h, 
                           4.0f*(float)w/(float)h, 
                          -4.0f,  4.0f,
                         -10.0f, 10.0f);
        }
        myGL.glMatrixMode (GL.GL_MODELVIEW);
    }

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

}