import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.media.opengl.GL;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLCanvas;
import javax.media.opengl.GLCapabilities;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.glu.GLU;
import javax.swing.Timer;



public class DegradeBleu  {
    
    static class Renderer
            implements GLEventListener,
            KeyListener {
        /** Called by the drawable to initiate OpenGL rendering by the client.
         * After all GLEventListeners have been notified of a display event, the
         * drawable will swap its buffers if necessary.
         * @param gLDrawable The GLDrawable object.
         */
        public void display(GLAutoDrawable gLDrawable) {
            final GL gl = gLDrawable.getGL();
            gl.glClearColor(0.0f, 0.0f, (float)(i/255.), 0.0f);
            gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
            gl.glLoadIdentity();
            gl.glTranslatef(-1.5f, 0.0f, -6.0f);
            gl.glBegin(GL.GL_TRIANGLES);		// Drawing Using Triangles
            gl.glColor3f(1,0,0);
            gl.glVertex3f( 0.0f, 1.0f, 0.0f);	// Top
            gl.glColor3f(0,1,0);
            gl.glVertex3f(-1.0f,-1.0f, 0.0f);	// Bottom Left
            gl.glColor3f(0,0,1);
            gl.glVertex3f( 1.0f,-1.0f, 0.0f);	// Bottom Right
            gl.glEnd();				// Finished Drawing The Triangle
            gl.glTranslatef(3.0f, 0.0f, 0.0f);
            gl.glBegin(GL.GL_QUADS);           	// Draw A Quad
            gl.glColor3f(0,0,1);
            gl.glVertex3f(-1.0f, 1.0f, 0.0f);	// Top Left
            gl.glColor3f(1,0,0);
            gl.glVertex3f( 1.0f, 1.0f, 0.0f);	// Top Right
            gl.glColor3f(0,0,1);
            gl.glVertex3f( 1.0f,-1.0f, 0.0f);	// Bottom Right
            gl.glColor3f(1,0,0);
            gl.glVertex3f(-1.0f,-1.0f, 0.0f);	// Bottom Left
            gl.glEnd();				// Done Drawing The Quad
            gl.glFlush();
        }
        
        
        /** Called when the display mode has been changed.  <B>!! CURRENTLY UNIMPLEMENTED IN JOGL !!</B>
         * @param gLDrawable The GLDrawable object.
         * @param modeChanged Indicates if the video mode has changed.
         * @param deviceChanged Indicates if the video device has changed.
         */
        public void displayChanged(GLAutoDrawable gLDrawable, boolean modeChanged, boolean deviceChanged) {
        }
        
        /** Called by the drawable immediately after the OpenGL context is
         * initialized for the first time. Can be used to perform one-time OpenGL
         * initialization such as setup of lights and display lists.
         * @param gLDrawable The GLDrawable object.
         */
        public void init(GLAutoDrawable gLDrawable) {
            final GL gl = gLDrawable.getGL();
            gl.glClearColor(0.0f, 0.0f, (float)(i/255.), 0.0f);
            gl.glShadeModel(GL.GL_SMOOTH);
            gLDrawable.addKeyListener(this);
        }
        
        
        /** Called by the drawable during the first repaint after the component has
         * been resized. The client can update the viewport and view volume of the
         * window appropriately, for example by a call to
         * GL.glViewport(int, int, int, int); note that for convenience the component
         * has already called GL.glViewport(int, int, int, int)(x, y, width, height)
         * when this method is called, so the client may not have to do anything in
         * this method.
         * @param gLDrawable The GLDrawable object.
         * @param x The X Coordinate of the viewport rectangle.
         * @param y The Y coordinate of the viewport rectanble.
         * @param width The new width of the window.
         * @param height The new height of the window.
         */
        public void reshape(GLAutoDrawable gLDrawable, int x, int y, int width, int height) {
            final GL gl = gLDrawable.getGL();
            //final GLU glu = gLDrawable.getGLU();
            final GLU glu = new GLU();
            
            if (height <= 0) // avoid a divide by zero error!
                height = 1;
            final float h = (float)width / (float)height;
            gl.glViewport(0, 0, width, height);
            gl.glMatrixMode(GL.GL_PROJECTION);
            gl.glLoadIdentity();
            glu.gluPerspective(45.0f, h, 1.0, 20.0);
            gl.glMatrixMode(GL.GL_MODELVIEW);
            gl.glLoadIdentity();
        }
        
        /** Invoked when a key has been pressed.
         * See the class description for {@link KeyEvent} for a definition of
         * a key pressed event.
         * @param e The KeyEvent.
         */
        public void keyPressed(KeyEvent e) {
            if (e.getKeyCode() == KeyEvent.VK_ESCAPE)
                System.exit(0);
        }
        
        /** Invoked when a key has been released.
         * See the class description for {@link KeyEvent} for a definition of
         * a key released event.
         * @param e The KeyEvent.
         */
        public void keyReleased(KeyEvent e) {}
        
        /** Invoked when a key has been typed.
         * See the class description for {@link KeyEvent} for a definition of
         * a key typed event.
         * @param e The KeyEvent.
         */
        public void keyTyped(KeyEvent e) {}
        
        int i=0;
        
        public void ticI(int step) {
            this.i=this.i+step;
            if (i>255) i=0;
        }
        
    }
    
    /** Program's main entry point
     * @param args command line arguments.
     */
    public static void main(String[] args) {
        Frame frame = new Frame("Lesson 2: Your First Polygon");
        final GLCanvas canvas = new GLCanvas();
        
        final Renderer renderer=new Renderer();
        canvas.addGLEventListener(renderer);
        frame.add(canvas);
        frame.setSize(640, 480);
        
        final Timer time=new Timer(0,new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                renderer.ticI(5);
                canvas.repaint();
            }
        });
        
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                time.stop();
                System.exit(0);
            }
        });
        
        time.start();
        
        frame.show();
        canvas.requestFocus();
    }
    
}