/*
 *  planet.java
 *  This program shows how to composite modeling transformations
 *  to draw translated and rotated models.
 *  Interaction:  pressing the d and y keys (day and year)
 *  alters the rotation of the planet around the sun.
 */

import jgl.GL;
import jgl.GLApplet;

public class planet extends GLApplet {

    private static int year = 0, day = 0;

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

    public void display () {
	myGL.glClear (GL.GL_COLOR_BUFFER_BIT);
	myGL.glColor3f (1.0f, 1.0f, 1.0f);

	myGL.glPushMatrix ();
	    myUT.glutWireSphere(1.0, 20, 16);	/* draw sun */
	    myGL.glRotatef ((float)year, 0.0f, 1.0f, 0.0f);
	    myGL.glTranslatef (2.0f, 0.0f, 0.0f);
	    myGL.glRotatef ((float)day, 0.0f, 1.0f, 0.0f);
	    myUT.glutWireSphere(0.2, 10, 8);	/* draw smaller planet */
	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, (double)w/(double)h, 1.0, 20.0);
	myGL.glMatrixMode (GL.GL_MODELVIEW);
	myGL.glLoadIdentity ();
	myGLU.gluLookAt (0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
    }

    /* ARGSUSED1 */
    public void keyboard (char key, int x, int y) {
	switch (key) {
	    case 'd':
		day = (day + 10) % 360;
		myUT.glutPostRedisplay ();
		break;
	    case 'D':
		day = (day - 10) % 360;
		myUT.glutPostRedisplay ();
		break;
	    case 'y':
		year = (year + 5) % 360;
		myUT.glutPostRedisplay ();
		break;
	    case 'Y':
		year = (year - 5) % 360;
		myUT.glutPostRedisplay ();
		break;
	    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 ();
    }

}