"The Lightweight Java Game Library (LWJGL) [...] provides developers access to high performance crossplatform libraries such as OpenGL (Open Graphics Library) [...]"
- The LWJGL homepage

In order to use OpenGL in Java wrappers, like the Lightweight Java Gaming Library (LWJGL), you obviously have to learn how to use both first. The de facto standard beginner book for OpenGL is the Redbook, the OpenGL Programming Guide. However, its examples are written in C. While I was learning from the book, I implemented its examples with the LWJGL in Java. These rewritten and ported examples are published here.

The use of OpenGL in the LWJGL is similar to how you use the native OpenGL libraries in C. Yet there are a few differences. These examples are a good way to get to know both OpenGL and the LWJGL.

All examples are based on revision 2 of the OpenGL Programming Guide. LWJGL 2 is used.

Differences to the book

The way this implementation is structured differs slightly from the original C examples. All examples extend a common Base class. It handles basic setup of OpenGL and the window used for display. Like in games, rendering is done in a continuous loop. There are several functions that can be overridden by examples. This has the advantage that examples contain almost only relevant code and keeps the original code identifiable. Such functions are:

• init(), contains OpenGL initialisation code and usually contains code from init() and reshape() (the window cannot be resized, so this only needs to be called once) of the original examples.
• render(), contains code from display(). It is called in a continuous loop due to slightly different semantics of the Display.
• logic(), handles animation or input via the mouse or keyboard.
• User input is being handled by LWJGL instead of GLUT. Part of this means that there is no need to write code (as in the C examples) that quits the program on ESC. This is already part of LWJGL functionality.

Another difference is that GLUT is not used. Window setups are defined in class Base. Examples in the book set up windows in the main() method. The Base class does this upon creation. A default window is used. Its properties can be set in the Base class. "Why not use GLUT?" you may ask. The answer is quite simple: GLUT does not exist in the LWJGL.

Implemented examples

Not all examples in the book are actually runnable. It is not sensible to run some of them as they are only a few incoherent lines of code. If an example has been implemented (i.e. there is a class named Example_ followed by the number of the example), it is stated in the Implemented column of the following table. Incomplete examples are either part of another example (and can be found in the other example's class) or not implemented at all.

Some of the original examples exist in C code and can be downloaded from the OpenGL homepage. If this is the case, the original file name containing the C code is given, too. I have also implemented many of the examples for which there is no C code.

Download the source

Updated 2010-05-29 to use LWJGL 2.5 and added a console output window to the launcher.

Download the source code of the examples: lwjgl_redbook_examples_src_2010-05-29.zip.

LWJGL 2.5 (at time of update, 2.5 was still in development/nightly, 2.4.2 works too) .jars are required in the classpath. You can download them here. In order to run them, you also have to use the parameter -Djava.library.path=C:/lwjgl/native/windows which should point to the native libraries for your system (Windows in this example).

Download the executable

There is also an executable distribution that includes a launcher to conveniently choose and run all examples: lwjgl_redbook_examples_bin_2010-05-29.zip.

No setup is needed. All required LWJGL-libraries are included for Windows, Mac OS X, Linux and Solaris. Just run the .jar file. The launcher requires Java 6 to run.

Screenshot of the launcher.