#JOGL A simple program to apply texture(image) to a polygon

A simple program in Java bindings for OpenGL where I apply a texture to a square(polygon). The texture is imported from an image file. The image is of a cartoon character Jerry whom i like very much. I like other characters too like tom and the dog.

Snapshot:

Here is the code.

#JOGL A simple Paddle Wheel

In this program, which the author David J Eck describes as a simple 3D program(chapter: Geometry) in his graphics book, a paddle wheel is being drawn. We can define a polygon in the x-y plane above the x axis and rotate it wrt the x axis each time with varying angles. Then to get a 3D look we tilt the paddle wheel by rotating about y axis.

Snapshot:

Here is the source.

#JOGL Simple program to draw a triangle using a display list

In this simple program a triangle is being drawn using a display list. The display list is identified by an integer. The integer is generated by call to glGenLists(). Then calls to glNewList() and glEndList() defines the list. Finally a call of glCallList() is made to draw whatever has been defined in the display list.
Snapshot:

Here is the source.

#JOGL Simple Program to draw a Triangle and rotate it about z-axis

Although the use of JPanel and calling repaint method on it is a good way to draw in Java Bindings for OpenGL I have followed the other method of creating a GLCanvas object and adding it to the JFrame object. In this program I have created a basic frame which sets the background color to red and clears the canvas and then draws a triangle. Each time the display is called by the FPSAnimator object the triangle is drawn at a new position after rotation by an angle. Angle is incremented in the display function itself.

Snapshot:

Here is the source in case you are interested to know.

Translate a Circle by pressing Swing Class JButton in #JOGL

This program translates the circle on pressing the translate button.

Here is the source:(online Viewing)


import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


import com.jogamp.opengl.GL2;
import com.jogamp.opengl.GLAutoDrawable;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.GLEventListener;
import com.jogamp.opengl.GLProfile;

import com.jogamp.opengl.glu.GLU;
import com.jogamp.opengl.awt.GLJPanel;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

class CircleTranslate extends GLJPanel implements GLEventListener,ActionListener {

/**
 * Interface to the GLU library.
 */
private GLU glu;
int x,y;
static JButton okButton;
/**
 * Take care of initialization here.
 */


CircleTranslate()
{
// super(g);
super( new GLCapabilities(null) ); // Makes a panel with default OpenGL "capabilities".
GLJPanel drawable = new GLJPanel();               // new GLJPanel inside GLJPanel
drawable.setPreferredSize(new Dimension(200,100));
setLayout(new BorderLayout());
add(drawable, BorderLayout.CENTER);
drawable.addGLEventListener(this); // Set up events for OpenGL drawing!
// drawable.addMouseListener(this);
//drawable.addMouseMotionListener(this);
//drawable.addActionListener(this);

}

public void actionPerformed(ActionEvent e) {
// System.exit(0);
x++;
repaint();
}
public void init(GLAutoDrawable gld) {
    GL2 gl = gld.getGL().getGL2();
    glu = new GLU();

    gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
//    gl.glViewport(-250, -150, 250, 150);
    gl.glMatrixMode(GL2.GL_PROJECTION);
    gl.glLoadIdentity();
    glu.gluOrtho2D(-250.0, 250.0, -150.0, 150.0);
    gl.glMatrixMode(GL2.GL_MODELVIEW);
    x=10;y=30;
    repaint();
}

/**
 * Take care of drawing here.
 */
public void display(GLAutoDrawable drawable) {
    GL2 gl = drawable.getGL().getGL2();
    gl.glClear(GL2.GL_COLOR_BUFFER_BIT);
    /*
     * put your code here
     */
   
    drawCircle(gl, x, y, 50);
}

public void reshape(GLAutoDrawable drawable, int x, int y, int width,
        int height) {
}


private void drawCircle(GL2 gl, int x1, int y1, int r) {
    gl.glPointSize(1.0f);
    gl.glBegin(GL2.GL_POINTS);
   
    int x=0,y=r,p=1-r;
    while(x<y)
    {
   
    if(p<0)
    p+=2*x+3;
    else {
    p+=2*(x-y)+5;
    y--;
    }
    x++;
    circleSymmetry(gl,x1,y1,x,y);

    }
    gl.glEnd();//end drawing of points

}
public void dispose(GLAutoDrawable arg0)
{
}
public void circleSymmetry(GL2 gl,int xc,int yc,int x,int y)
{
gl.glVertex2i(xc+x , yc+y );
gl.glVertex2i(xc-x , yc+y );
gl.glVertex2i(xc+x , yc-y );
gl.glVertex2i(xc-x , yc-y );
gl.glVertex2i(xc+y , yc+x );
gl.glVertex2i(xc+y , yc-x );
gl.glVertex2i(xc-y , yc+x );
gl.glVertex2i(xc-y , yc-x );
}
public static void main(String args[])
{
JFrame window = new JFrame("Circle Translate");
    // The canvas
    CircleTranslate panel = new CircleTranslate();
    panel.setPreferredSize(new Dimension(1000,1000));      
    okButton = new JButton("Translate");
    JPanel content = new JPanel();

content.setLayout(new BorderLayout());
content.add(panel, BorderLayout.CENTER);
content.add(okButton, BorderLayout.SOUTH);
    okButton.addActionListener(panel);
   
    window.setContentPane(content);
    window.pack();
    window.setLocation(0,0);
    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    window.setVisible(true);
    panel.requestFocusInWindow();
}
}

Thanks!!!

Simple program to create JFrame and add a JPanel to it and draw using Graphics class in Java

This program is self explanatory...

I have done this to demonstrate simple way of creating A window(using Java Swing) and display something inside a panel in it.

/* Program to display a rectangle, filled rectangle and a line all with different colors
 * and a text string
 */
import java.awt.Graphics;
import java.awt.Color;
//import java.awt.
import java.awt.event.*;
import javax.swing.JPanel;
import javax.swing.JFrame;
//import javax.swing.Timer;
public class FirstJavaGraphics extends JPanel
{
   
public static void main(String[] args)
{
    FirstJavaGraphics fjg=new FirstJavaGraphics();
    JFrame window=new JFrame("Hello Java Graphics");
    window.setSize(640, 480);
    window.add(fjg);
    window.setVisible(true);
}
public void paintComponent(Graphics g)
{
    super.paintComponent(g);
    setBackground(Color.RED);
    g.drawRect(100, 20, 30, 30);
    g.setColor(Color.GREEN);
    g.fillRect(200, 320, 40, 40);
    g.drawLine(100, 100, 200, 200);
    g.setColor(Color.BLUE);
    g.drawString("Hello WOrld", 100, 250);
}
FirstJavaGraphics()
{
}
}

Snapshot:

The next program will be to animate the scene using a Timer in the swing package.

#JOGL-Events- Mouse and Keyboard handling using (immediate mode) animator class

These two programs I consider basic in handling mouse and keyboard events. I looked up some programming sites and had to collate info from variety of sources. If you are new to JOGL then I suggest you this site where you can download a PDF of e-book on computer graphics by David J Eck.

The first program i made was to handle keyboard events:
Here it is:
import java.awt.*;
import java.awt.event.*;

import com.jogamp.opengl.util.Animator;
import com.jogamp.opengl.util.gl2.*;
import com.jogamp.opengl.GL2;
import com.jogamp.opengl.GLAutoDrawable;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.GLEventListener;
import com.jogamp.opengl.GLProfile;
import com.jogamp.opengl.awt.GLCanvas;
import com.jogamp.opengl.glu.GLU;

import javax.swing.JFrame;

class mykeyboardeventshandler implements KeyListener,GLEventListener
{
String msg="";
int x=10,y=20;
private GLU glu;
public void keyPressed(KeyEvent ke)
{
//showStatus("Key down");
}
public void keyReleased(KeyEvent ke)
{
//showStatus("Key released");
}
public void keyTyped(KeyEvent ke)
{
msg+=ke.getKeyChar();
//repaint();
}
/**
 * Take care of initialization here.
 */
public void init(GLAutoDrawable gld) {
    GL2 gl = gld.getGL().getGL2();
    glu = new GLU();

    gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    gl.glViewport(-250, -150, 250, 150);
    gl.glMatrixMode(GL2.GL_PROJECTION);
    gl.glLoadIdentity();
    glu.gluOrtho2D(-250.0, 250.0, -150.0, 150.0);
}

/**
 * Take care of drawing here.
 */
public void display(GLAutoDrawable drawable) {
    GL2 gl = drawable.getGL().getGL2();
    gl.glClear(GL2.GL_COLOR_BUFFER_BIT);
    /*
     * put your code here
     */
//    drawLine(gl, 0, 0, 100, 50);
    gl.glPushMatrix();
    GLUT glut = new GLUT();
    gl.glRasterPos2i(0,10);
  //  gl.glTranslatef(0, 0, 0);
    gl.glColor3f(1, 0, 0);
    glut.glutBitmapString(GLUT.BITMAP_HELVETICA_18, msg);
    gl.glPopMatrix();
    gl.glFlush();
}

public void reshape(GLAutoDrawable drawable, int x, int y, int width,
        int height) {
}
public void dispose(GLAutoDrawable arg0)
{
}
}
public class keyboardeventsdemo
{
    public static void main(String[] args)
    {
    //getting the capabilities object of GL2 profile
    final GLProfile profile=GLProfile.get(GLProfile.GL2);
    GLCapabilities capabilities=new GLCapabilities(profile);
    // The canvas
    final GLCanvas glcanvas=new GLCanvas(capabilities);
    final Animator animator = new Animator(glcanvas);
    mykeyboardeventshandler b=new mykeyboardeventshandler();
    glcanvas.addGLEventListener(b);
    glcanvas.addKeyListener(b);
    glcanvas.setSize(400, 400);
    //creating frame
    final JFrame frame=new JFrame("Basic frame");
    //adding canvas to frame
    frame.add(glcanvas);
    frame.setSize(640,480);
    frame.setResizable(false);
    frame.addWindowListener(new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
            animator.stop();
            frame.dispose();
            System.exit(0);
        }
});
    animator.start();
    frame.setVisible(true);
    glcanvas.requestFocus();
    }
}


Snapshot:

 
The second program i made is on handling mouse events. I made a separate class for handling mouse events and GLEvents called MyMouseEventsHandler. I instantiate it in the MouseEventsDemo class and them add event listeners to the frame using this object.

import com.jogamp.opengl.GL2;
import com.jogamp.opengl.GLAutoDrawable;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.GLEventListener;
import com.jogamp.opengl.GLProfile;
import com.jogamp.opengl.awt.GLCanvas;
import com.jogamp.opengl.glu.GLU;
import com.jogamp.opengl.util.gl2.GLUT;
import com.jogamp.opengl.util.Animator;
import java.awt.*;
import java.awt.event.*;

import javax.swing.JFrame;

class MyMouseEventsHandler implements MouseMotionListener, MouseListener,GLEventListener
{
String msg="hello";
int mouseX=0,mouseY=0;
private GLU glu;
public void init()
{
}
public void mouseClicked(MouseEvent me)
{
mouseX=0;
mouseY=10;
msg="mouse clicked";
//repaint();
}
public void mouseEntered(MouseEvent me)
{
mouseX=0;
mouseY=10;
msg="mouse Entered";
//repaint();
}
public void mouseExited(MouseEvent me)
{
mouseX=0;
mouseY=10;
msg="mouse Exited";
//repaint();
}
public void mousePressed(MouseEvent me)
{
mouseX=0;
mouseY=10;
msg="mouse Pressed";
//repaint();
}
public void mouseReleased(MouseEvent me)
{
mouseX=me.getX();
mouseY=me.getY();
msg="Mouse Released";
//repaint();
}
public void mouseMoved(MouseEvent me)
{
//showStatus("Moving mouse at "+me.getX()+" , "+me.getY());
}
public void mouseDragged(MouseEvent me)
{
mouseX=me.getX();
mouseY=me.getY();
msg="mouse dragged";
//repaint();
}
public void init(GLAutoDrawable gld)
{
    GL2 gl = gld.getGL().getGL2();
    glu = new GLU();

    gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    gl.glViewport(-250, -150, 250, 150);
    gl.glMatrixMode(GL2.GL_PROJECTION);
    gl.glLoadIdentity();
    glu.gluOrtho2D(-250.0, 250.0, -150.0, 150.0);
}
public void display(GLAutoDrawable gld)
{
    GL2 gl = gld.getGL().getGL2();
    gl.glClear(GL2.GL_COLOR_BUFFER_BIT);
    /*
     * put your code here
     */
//    drawLine(gl, 0, 0, 100, 50);
    gl.glPushMatrix();
    GLUT glut = new GLUT();
    gl.glRasterPos2i(0,10);
  //  gl.glTranslatef(0, 0, 0);
    gl.glColor3f(1, 0, 0);
    glut.glutBitmapString(GLUT.BITMAP_HELVETICA_18, msg);
    gl.glPopMatrix();
    gl.glFlush();
//    gld.swapBuffers();
}
public void reshape(GLAutoDrawable gld,int x,int y,int width,int height)
{
   
}
public void dispose(GLAutoDrawable gld)
{
   
}
}
public class MouseEventsDemo extends JFrame
{
    public static void main(String[] args)
    {
        final GLProfile profile=GLProfile.get(GLProfile.GL2);
        GLCapabilities capabilities=new GLCapabilities(profile);
        // The canvas
        final GLCanvas glcanvas=new GLCanvas(capabilities);
        MyMouseEventsHandler mmeh=new MyMouseEventsHandler();
        final Animator animator = new Animator(glcanvas);
//        glcanvas.addGLEventListener(mmeh);
        glcanvas.setSize(400, 400);
        //creating frame
        final JFrame frame=new JFrame("Basic frame");
        //adding canvas to frame
        frame.add(glcanvas);
        frame.setSize(640,480);
      
        frame.setResizable(false);
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                animator.stop();
                frame.dispose();
                System.exit(0);
            }
});
         glcanvas.addGLEventListener(mmeh);
        glcanvas.addMouseMotionListener(mmeh);
        glcanvas.addMouseListener(mmeh);
        animator.start();
        frame.setVisible(true);
      
        glcanvas.requestFocus();
      
    }
}
 Snapshot: