import com.jogamp.opengl.GL;
import com.jogamp.opengl.GL2;
import com.jogamp.opengl.GLAutoDrawable;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.GLEventListener;
import com.jogamp.opengl.awt.GLCanvas;
import com.jogamp.opengl.GLProfile;
import com.jogamp.opengl.fixedfunc.GLMatrixFunc;
import javax.swing.JFrame;

import com.jogamp.opengl.util.Animator;

public class MainFrame extends JFrame implements GLEventListener {

  private GLCanvas canvas;
  private Animator animator;

  // For specifying the positions of the clipping planes (increase/decrease the distance) modify this variable.
  // It is used by the glOrtho method.
  private double v_size = 2.0;

  // Application main entry point
  public static void main(String args[]) {
    new MainFrame();
  }

  // Default constructor
  public MainFrame() {
    super("Java OpenGL");

    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    this.setSize(800, 600);

    this.initializeJogl();

    this.setVisible(true);
  }

  private void initializeJogl() {
    // Creating a new GL profile.
    GLProfile glprofile = GLProfile.getDefault();
    // Creating an object to manipulate OpenGL parameters.
    GLCapabilities capabilities = new GLCapabilities(glprofile);

    // Setting some OpenGL parameters.
    capabilities.setHardwareAccelerated(true);
    capabilities.setDoubleBuffered(true);

    // Try to enable 2x anti aliasing. It should be supported on most hardware.
    capabilities.setNumSamples(2);
    capabilities.setSampleBuffers(true);

    // Creating an OpenGL display widget -- canvas.
    this.canvas = new GLCanvas(capabilities);

    // Adding the canvas in the center of the frame.
    this.getContentPane().add(this.canvas);

    // Adding an OpenGL event listener to the canvas.
    this.canvas.addGLEventListener(this);

    // Creating an animator that will redraw the scene 40 times per second.
    this.animator = new Animator(this.canvas);

    // Starting the animator.
    this.animator.start();
  }

  public void init(GLAutoDrawable canvas) {
    // Obtaining the GL instance associated with the canvas.
    GL2 gl = canvas.getGL().getGL2();

    // Setting the clear color -- the color which will be used to erase the canvas.
    gl.glClearColor(0, 0, 0, 0);

    // Selecting the modelview matrix.
    gl.glMatrixMode(GLMatrixFunc.GL_MODELVIEW);

  }

  public double cy = 0.001;

  double px = -0.5d;
  double py = -0.5d;
  double qx = 0.5d;
  double qy = 0.5d;
  double pas = 0.005;

  double pqy = qy - py;
  double pqx = qx - px;

  public void display(GLAutoDrawable canvas) {

    GL2 gl = canvas.getGL().getGL2();
    gl.glClear(GL.GL_COLOR_BUFFER_BIT);

    gl.glPointSize(10);
    gl.glBegin(GL2.GL_POINTS);
    gl.glVertex2d(px, py);
    gl.glVertex2d(qx, qy);

    gl.glEnd();
    gl.glFlush();
    px = px + pqx * pas;
    py = py + pqy * pas;
  }

  public void reshape(GLAutoDrawable canvas, int left, int top, int width, int height) {
    GL2 gl = canvas.getGL().getGL2();

    // Selecting the viewport -- the display area -- to be the entire widget.
    gl.glViewport(0, 0, width, height);

    // Determining the width to height ratio of the widget.
    double ratio = (double) width / (double) height;

    // Selecting the projection matrix.
    gl.glMatrixMode(GLMatrixFunc.GL_PROJECTION);

    gl.glLoadIdentity();

    // Selecting the view volume to be x from 0 to 1, y from 0 to 1, z from -1 to 1.
    // But we are careful to keep the aspect ratio and enlarging the width or the height.
    if (ratio < 1) {
      gl.glOrtho(-v_size, v_size, -v_size, v_size / ratio, -1, 1);
    } else {
      gl.glOrtho(-v_size, v_size * ratio, -v_size, v_size, -1, 1);
    }

    // Selecting the modelview matrix.
    gl.glMatrixMode(GLMatrixFunc.GL_MODELVIEW);
  }

  public void displayChanged(GLAutoDrawable canvas, boolean modeChanged, boolean deviceChanged) {
    return;
  }

  @Override public void dispose(GLAutoDrawable arg0) {
    // TODO Auto-generated method stub
  }
}