Interface APIs

Last night I started the Java 3D Interfaces (J3DI) API. J3DI is an "interface API". An interface API provides interfaces for the concrete and abstract classes of another API. The purpose is to be able to program your applications to the interface API so that you can swap out the underlying implementation at compile-time or run-time without additional coding. Applications and libraries programmed to manipulate instances of the interfaces will work with any of the implementations. Wrapper classes are used to adapt implementations to the interface API. They also shield application code from changes in the implementation APIs as they evolve over time.

J3DI is based on the Java 3D scene graph API. Sun Microsystems provides a public source reference implementation. Xith is an Open Source implementation of the Java 3D API with a few deviations. I developed a COLLADA loader for the Xith API. I also created a multiplayer game prototype and a 3D browser based on Xith. I am modifying the COLLADA loader, the game, and the browser to work with J3DI instead so that they can use either Java 3D or Xith as the underlying implementation.

Using J3DI also gives me the flexibility to experiment with a new implementation under development while retaining compatibility with working implementations. I am toying with a J3DI implementation (JIMP) that will render using another interface API, JIGL. No wrapper classes will be needed as the concrete classes will implement the J3DI interfaces directly. You can take a look at what I have so far in the project source code repository for J3DI, JIMP, and JIGL.

JIGL demo

Please see the JIGL demo applet and documentation that I created today.

JIGL

I am having some success in creating a JOGL-compatible wrapper API for jGL, a pure Java implementation of OpenGL. I am calling it the Java Interface to OpenGL (JIGL) because it lets you "jiggle" between JOGL-based hardware rendering and jGL-based software rendering at run-time. You can see what I have so far by browsing the library and the test application in the CVS repository.

The purpose is to be able deploy Whoola Cyberspace as an unsigned applet and still have it run when the JOGL native libraries are not pre-installed. I do have a prototype where it is deployed as a signed applet with the native libraries installed on demand but this is less than satisfactory as it brings up a window requesting that the users grant the applet full access to their machines.

Multiverse

I am at the Austin Game Conference where the focus is on online and multiplayer games. The most exciting thing I have seen here is Multiverse, a website that provides you with the software to build your own massively multiplayer online game (MMOG). The really unique bit about it is that they only charge you to use their tools if you are charging your users to play. That means academicians and hobbyists can use it for free. Is this the beginning of the 3D equivalent to the blogosphere?