// Use OpenGL and JOGL to draw a simple cube
// with each face being a different color.  Rotations
// can be applied with the arrow keys, the page up
// key and the page down key.  The home key will set
// all rotations to 0.

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;

public class SimpleCube extends GLJPanel implements GLEventListener, KeyListener {

	public static void main(String[] args) {
		JFrame window = new JFrame("JOGL Scene");
		GLCapabilities caps = new GLCapabilities(null);
		SimpleCube panel = new SimpleCube(caps);
		window.setContentPane(panel);
		window.pack();
		window.setLocation(50,50);
		window.setResizable(false);
		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		window.setVisible(true);
		panel.requestFocusInWindow();
	}

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

	public SimpleCube(GLCapabilities capabilities) {
		super(capabilities);
		setPreferredSize( new Dimension(500,500) );
		addGLEventListener(this);
		addKeyListener(this);
		rotateX = 15;
		rotateY = 15;
		rotateZ = 0;
	}
	
	// ------------ methods of the KeyListener interface ------------

	public void keyPressed(KeyEvent e) {
		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_PAGE_UP )
			rotateZ += 15;
		else if ( key == KeyEvent.VK_PAGE_DOWN )
			rotateZ -= 15;
		else if ( key == KeyEvent.VK_HOME )
			rotateX = rotateY = rotateZ = 0;
		repaint();
	}

	public void keyReleased(KeyEvent e) { 
	}

	public void keyTyped(KeyEvent e) { 
	}
	
	// ----------------- define some drawing methods for this program ----------

	private void square(GL2 gl, float r, float g, float b) {
		gl.glColor3f(r,g,b);         // The color for the square.
		gl.glTranslatef(0,0,0.5f);    // Move square 0.5 units forward.
		gl.glNormal3f(0,0,1);        // Normal vector to square (this is actually the default).
		gl.glBegin(GL2.GL_TRIANGLE_FAN);
		gl.glVertex2f(-0.5f,-0.5f);    // Draw the square (before the
		gl.glVertex2f(0.5f,-0.5f);     //   the translation is applied)
		gl.glVertex2f(0.5f,0.5f);      //   on the xy-plane, with its
		gl.glVertex2f(-0.5f,0.5f);     //   at (0,0,0).
		gl.glEnd();
	}

	private void cube(GL2 gl) {

		gl.glPushMatrix();
		square(gl,1,0,0);        // front face is red
		gl.glPopMatrix();

		gl.glPushMatrix();
		gl.glRotatef(180,0,1,0); // rotate square to back face
		square(gl,0,1,1);        // back face is cyan
		gl.glPopMatrix();

		gl.glPushMatrix();
		gl.glRotatef(-90,0,1,0); // rotate square to left face
		square(gl,0,1,0);        // left face is green
		gl.glPopMatrix();

		gl.glPushMatrix();
		gl.glRotatef(90,0,1,0); // rotate square to right face
		square(gl,1,0,1);       // right face is magenta
		gl.glPopMatrix();

		gl.glPushMatrix();
		gl.glRotatef(-90,1,0,0); // rotate square to top face
		square(gl,0,0,1);        // top face is blue
		gl.glPopMatrix();

		gl.glPushMatrix();
		gl.glRotatef(90,1,0,0); // rotate square to bottom face
		square(gl,1,1,0);        // bottom face is yellow
		gl.glPopMatrix();

	}
	
	// ---------------  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(0,0,0,0);
		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(-1,1,-1,1,-2,2);
		gl.glMatrixMode(GL2.GL_MODELVIEW);

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

		cube(gl);

	}

	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);
		gl.glEnable(GL2.GL_LIGHTING);
		gl.glEnable(GL2.GL_LIGHT0);
		gl.glEnable(GL2.GL_COLOR_MATERIAL);
	}

	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
	}

}