/*
 *  colormat.java
 *  After initialization, the program will be in
 *  ColorMaterial mode.  Interaction:  pressing the 
 *  mouse buttons will change the diffuse reflection values.
 */

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

import jgl.GL;
import jgl.GLUT;
import jgl.GLCanvas;

public class colormat extends GLCanvas {

    private float diffuseMaterial [] = {0.5f, 0.5f, 0.5f, 1.0f};

    /*
     *  Initialize material property, light source, lighting model,
     *  and depth buffer.
     */
    private void myinit () {
	float mat_specular[] = {1.0f, 1.0f, 1.0f, 1.0f};
	float light_position[] = {1.0f, 1.0f, 1.0f, 0.0f};

	myGL.glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
	myGL.glShadeModel (GL.GL_SMOOTH);
	myGL.glEnable (GL.GL_DEPTH_TEST);
	myGL.glMaterialfv (GL.GL_FRONT, GL.GL_DIFFUSE, diffuseMaterial);
	myGL.glMaterialfv (GL.GL_FRONT, GL.GL_SPECULAR, mat_specular);
	myGL.glMaterialf (GL.GL_FRONT, GL.GL_SHININESS, 25.0f);
	myGL.glLightfv (GL.GL_LIGHT0, GL.GL_POSITION, light_position);
	myGL.glEnable (GL.GL_LIGHTING);
	myGL.glEnable (GL.GL_LIGHT0);

	myGL.glColorMaterial (GL.GL_FRONT, GL.GL_DIFFUSE);
	myGL.glEnable (GL.GL_COLOR_MATERIAL);
    }
    
    public void display () {
	myGL.glClear (GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
	myUT.glutSolidSphere (1.0, 20, 16);
	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 (-1.5f,  1.5f, 
	    		  -1.5f*(float)h/(float)w, 
			   1.5f*(float)h/(float)w,
			 -10.0f, 10.0f);
        } else {
            myGL.glOrtho (-1.5f*(float)w/(float)h,
	    		   1.5f*(float)w/(float)h,
			  -1.5f,  1.5f,
			 -10.0f, 10.0f);
        }
        myGL.glMatrixMode (GL.GL_MODELVIEW);
	myGL.glLoadIdentity ();
    }
    
    /* ARGSUSED2 */
    public void mouse (int button, int state, int x, int y) {
	switch (button) {
	    case GLUT.GLUT_LEFT_BUTTON:
		if (state == GLUT.GLUT_DOWN) {
		    diffuseMaterial[0] += 0.1f;
		    if (diffuseMaterial[0] > 1.0f)
			diffuseMaterial[0] = 0.0f;
		    myGL.glColor4fv (diffuseMaterial);
		    myUT.glutPostRedisplay ();
		}
		break;
	    case GLUT.GLUT_MIDDLE_BUTTON:
		if (state == GLUT.GLUT_DOWN) {
		    diffuseMaterial[1] += 0.1f;
		    if (diffuseMaterial[1] > 1.0f)
			diffuseMaterial[1] = 0.0f;
		    myGL.glColor4fv (diffuseMaterial);
		    myUT.glutPostRedisplay ();
		}
		break;
	    case GLUT.GLUT_RIGHT_BUTTON:
		if (state == GLUT.GLUT_DOWN) {
		    diffuseMaterial[2] += 0.1f;
		    if (diffuseMaterial[2] > 1.0f)
			diffuseMaterial[2] = 0.0f;
		    myGL.glColor4fv (diffuseMaterial);
		    myUT.glutPostRedisplay ();
		}
		break;
	    default:
		break;
	}
    }

    /* 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.glutMouseFunc ("mouse");
	myUT.glutKeyboardFunc ("keyboard");
	myUT.glutMainLoop ();
    }

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

}