JOGL

Lecture 1

What is OpenGL?

· OpenGL is a Graphics rendering API

• Produces high-quality color images composed of geometric and image primitives
• Is window system independent
• Is operating system independent

OpenGL as a Renderer

• Geometric primitives
• points, lines and polygons

• Image Primitives
• images and bitmaps
• separate pipeline for images and geometry
• linked through texture mapping

• Rendering depends on state
• colors, materials, light sources, etc

Related APIs

• AGL, GLX, WGL
• glue between OpenGL and windowing systems

• GLU (OpenGL Utility Library)
• part of OpenGL
• NURBS, tessellators, quadric shapes, etc.

• GLUT (OpenGL Utility Toolkit)
• portable windowing API
• not officially part of OpenGL

What is JOGL

JOGL is a Java package that provides bindings to the OpenGL libraries for the Java Virtual Machine.

OpenGL Resources

• OpenGL.org
• The Red Book – Intro to OpenGL
• JOGL Examples
• JOGL User Manual
• Jumping into JOGL
• NeHe Productions: OpenGL Lessons – with JOGL Sample Code.

How to Install JOGL

1. JOGL requires the JAVA SDK J2SDK 1.4.2 and JOGL binaries. Make sure J2SDK 1.4.2 has been installed on your machine.

2. Download the JOGL Windows binaries (jogl-win32.zip) and JOGL Docs (javadoc_public.zip)

3. Unzip jogl-win32.zip into 3 files - jogl.dll , jogl_cg.dll and jogl.jar.

4. Find the Java SDK or JRE installation on your machine. Usually they are found at "C:\" or "C:\Program Files\Java\".

5. Copy the DLLs jogl.dll and jogl_cg.dll into the "\bin" directory for the Java SDK or JRE installed on your machine

e.g.

C:\[jre_location]\bin\jogl.dll

C:\[jre_location]\bin\jogl_cg.dll

6. Copy jogl.jar into the "\lib\ext" directory for the Java SDK or JRE installed on your machine

e.g.

C:\[jre_location]\lib\ext\jogl.jar

JOGL “Hello World”

import java.awt.*;

import java.awt.event.*;

import net.java.games.jogl.*;

public class Lesson0 {

public static void main(String[] args){

Frame frame = new Frame("Hello World");

GLCanvas canvas = GLDrawableFactory.getFactory().createGLCanvas(new GLCapabilities());

frame.add(canvas);

frame.setSize(400, 400);

frame.setBackground(Color.white);

frame.addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{

System.exit(0);

}

});

frame.show();

}

}

GLUT Basics

Application Structure

1. Configure and open window

2. Initialize OpenGL state

3. Register input callback functions

4. render

5. resize

6. input: keyboard, mouse, etc.

7. Enter event processing loop

import java.awt.*;

import java.awt.event.*;

import net.java.games.jogl.*;

/** Port of the NeHe OpenGL Tutorial (Lesson 1)

* to Java using the Jogl interface to OpenGL. Jogl can be obtained

* at http://jogl.dev.java.net/

*

* @author Kevin Duling (jattier@hotmail.com)

*/

public class Lesson01

{

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(GLDrawable gLDrawable)

{

final GL gl = gLDrawable.getGL();

gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);

gl.glLoadIdentity();

}

/** 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(GLDrawable 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(GLDrawable gLDrawable)

{

final GL gl = gLDrawable.getGL();

gl.glShadeModel(GL.GL_SMOOTH); // Enable Smooth Shading

gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background

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(GLDrawable gLDrawable, int x, int y, int width, int height)

{

final GL gl = gLDrawable.getGL();

final GLU glu = gLDrawable.getGLU();

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) {}

}

/** Program's main entry point

* @param args command line arguments.

*/

public static void main(String[] args)

{

Frame frame = new Frame("Lesson 1: An OpenGL Window");

GLCanvas canvas = GLDrawableFactory.getFactory().createGLCanvas(new GLCapabilities());

canvas.addGLEventListener(new Renderer());

frame.add(canvas);

frame.setSize(640, 480);

frame.addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{

System.exit(0);

}

});

frame.show();

canvas.requestFocus();

}

}