import javax.media.opengl.*;
import java.awt.Dimension;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.media.opengl.awt.GLJPanel;

/**
 * This is a template for a very basic OpenGL program that shows a static
 * scene.  The arrow keys can be used to rotate the view of the scene, and
 * the Home key will set the view rotations to zero.  The ranges of x, y,
 * and z that are visible in the scene are determined by a "scale" property;
 * The scale variable is used in the display function to set up the projection.
 * It determines the range of x, y, and z that are visible in the scene.
 * x and y range from -scale to scale; z ranges from -2*scale to 2*scale. 
 * Note that lighting is NOT enabled in this template; to enable it, 
 * uncomment the three commented lines in the init() method.
 */
public class JoglBasic extends GLJPanel implements GLEventListener, KeyListener {

	public static void main(String[] args) {
		JFrame window = new JFrame("JOGL Scene");
		GLCapabilities caps = new GLCapabilities(null);
		JoglBasic panel = new JoglBasic(caps);
		window.setContentPane(panel);
		window.pack();
		window.setLocation(50,50);
		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		window.setVisible(true);
		panel.requestFocusInWindow(); // to set up key events to go to the panel
	}
	
	private double scale = 5;  // determines the range of visible x, y, and z

	private float rotateX, rotateY;   // rotation amounts about axes, controlled by keyboard

	public JoglBasic(GLCapabilities capabilities) {
		super(capabilities);
		setPreferredSize( new Dimension(500,500) ); // set size of viewing area
		addGLEventListener(this);
		addKeyListener(this);
		rotateX = 15;   // start with rotations of 15 degrees about each axis
		rotateY = 15;
	}

	// ------------ methods of the KeyListener interface ------------

	public void keyPressed(KeyEvent e) {
		   // responds to arrow and home keys by changing rotation amounts
		int key = e.getKeyCode();
		if ( key == KeyEvent.VK_LEFT )
			rotateY -= 15;
		else if ( key == KeyEvent.VK_RIGHT )
			rotateY += 15;
		else if ( key == KeyEvent.VK_DOWN)
			rotateX += 15;
		else if ( key == KeyEvent.VK_UP )
			rotateX -= 15;
		else if ( key == KeyEvent.VK_HOME )
			rotateX = rotateY = 0;
		repaint();
	}

	public void keyReleased(KeyEvent e) { 
	}

	public void keyTyped(KeyEvent e) { 
	}


	// ---------------  Methods of the GLEventListener interface -----------

	public void display(GLAutoDrawable drawable) {	
		    // called when the panel needs to be drawn

		GL2 gl = drawable.getGL().getGL2();
		gl.glClearColor(0,0,0,1);
		gl.glClear( GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT );

		gl.glMatrixMode(GL2.GL_PROJECTION);  // Set up the projection.
		gl.glLoadIdentity();
		gl.glOrtho(-scale,scale,-scale,scale,-2*scale,2*scale);
		gl.glMatrixMode(GL2.GL_MODELVIEW);

		gl.glLoadIdentity();             // Set up modelview transform. 
		gl.glRotatef(rotateY,0,1,0);
		gl.glRotatef(rotateX,1,0,0);

		// TODO:  Add drawing code!

	}

	public void init(GLAutoDrawable drawable) {
		    // called when the panel is created
		GL2 gl = drawable.getGL().getGL2();
		gl.glClearColor(0.8F, 0.8F, 0.8F, 1.0F);
		gl.glEnable(GL.GL_DEPTH_TEST);
		
		// To enable lighting, uncomment the next four lines
//		gl.glEnable(GL2.GL_LIGHTING);
//		gl.glEnable(GL2.GL_LIGHT0);
//		gl.glEnable(GL2.GL_COLOR_MATERIAL);
//      gl.glEnable(GL2.GL_NORMALIZE);
	}

	public void dispose(GLAutoDrawable drawable) {
		// called when the panel is being disposed
	}

	public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
		// called when user resizes the window
	}

}