Santiance » C

Compiz Documentation Update

Kristopher Ives — Mon, 29 Mar 2010 20:33:36 +0000

As the release for Compiz 0.9.0 gets closer, now is a good time to let everyone know what I’ve been most involved with: Documenting the API. Until recently, there was no API documentation for Compiz. You really have to admire the amount of time the core developers and others have spent working with a system that had no reference.

We’re now on the path to having a fully documented API. You can view the most recent documentation from the master branch here:

Compiz API Reference

I thought I would take a minute to thank all the developers involved and give much due credit:

Guillaume Seguin (iXce) hooked together Doxygen and git as a post-commit hook to master, so you’ll always see the most up-to-date API reference at docs.compiz.org

Sam Spilsbury (smspillaz) helped merge my staging branch into master and helped me with git, since I appear to be handicapped with it

Of course this documentation is for the 0.0.9 version that should be getting released soon, and the old 0.8.x (and before) code will remain likely remain undocumented. The new C++ architecture is much cleaner, and I’m expecting a surge in new plugins now that we have a simpler and better documented system.

If you’re a Compiz developer and you see a TODO laying around in a doc tag, help out and fill it in. Looking at the commit log, it appears this should work out nicely!

Compiz Fusion Plugin Development

Kristopher Ives — Sun, 18 Oct 2009 23:55:18 +0000

In between the massive changes to the site (see my twitter) and setting up new developer relationships, I was inspired to work with Compiz Fusion – or what most now just call Compiz. I’ve always wanted to do some plugins, but the problem is jumping into their largely undocumented API. That’s changing a bit now, since there seems to be a better effort and they’ve got a nice start with the Compiz Wiki. Doesn’t it always seem you can just throw MediaWiki (or in this case MoinMoin) at something and it appears to fix itself.

In the past we’ve all pimped out Compiz to the point where we’re basically expecting a Spinner Rims plug-in, but I want to change that a bit. Firstly I think that many effects use too much blending with Opacity, which can be sluggish on older or low-performance hardware. Plus I think the Dodge focus effect, Show Desktop, and other effects that simply “move” windows look really clean.

A nice developer on the Compiz Forums helped me out in my post about modifying the animations plugins, which led me to this git repository:

git clone git://git.compiz.org/users/smspillaz/simple-animations

From there you can follow the thread on how I simply modified his Fly In effect to be capable of using the Minimize and other events. It doesn’t do exactly what I want, but the point is that the code is already integrated with Compiz, which is easily half the battle. I’m now in the process of doing a couple of neat things:

As I decrypt the inner workings of their plugin API I would like to document
The best way I can think of to document is to wrap it in Java and provide bindings. This kills two birds with one stone: Java bindings and it’s a lot nicer to use javadoc over something like doxygen. (see our doc/ archive)

The result so far was this:

Flash video haters can download an Ogg Video (1.5Mb)

Let me know what you think. I’m also looking for some help with building 32-bit packages. If you want my code it’s available here:

bzr branch http://santiance.com/bzr/compiz-fusion-plugins-simple

And just for kicks anyone with 64-bit can have this package that seem to be working rather nicely for me.

Update:

Anyone interested in compiz 0.9 docs (C++) see: http://santiance.com/doc/compiz/html/annotated.html

A better SDL wrapper for Java

Kristopher Ives — Thu, 15 Oct 2009 17:51:05 +0000

I’ve been using SDL for a long time in C++, and I’ve toyed sdljava, which are rather complete bindings for SDL for Java. While the bindings are rather complete, they where created using SWIG, which is a (great) code generator, but still the result is that these bindings are kinda clunky and rather bloated. For example, there are many intermediate classes that are prefixed with SWIG_. This motivated me to write my own, which I call SDLbits.

While it’s not as complete as sdljava, it’s much smaller and is hand written. While the idea of hand-writing lots of C wrapper code seems daunting, it was not much more than writing a class with many native methods, running javah and writing some simple glue. Here is quick rundown of what is supported:

Video functions including support for OpenGL bindings. We also provide our own very small GL bindings, GLbits.
Audio functions with support for callbacks to generate audio from Java.
Event functions (including SDL_SetEventFilter with a callback) and simple class system that allows for use of instanceof.
Joystick, Keyboard, and Mouse functions for polling device input.
Time functions like SDL_Delay and SDL_GetTicks incase their Java counterparts have undesired affects

However, it’s also important to note what wasn’t implemented:

Input/output (RWops) for files, since a java.io.File or java.nio.FileChannel (and variants) should be used instead.
Thread functions for SDL, since java.lang.Thread should be used instead.

While the code is not 100% complete, it can easily be thought of as at least 85% completed, and work will continue as warranted. It doesn’t hurt that the code is licensed under the LGPL, so anyone can modify and commit changes. Even though the code isn’t complete I compared the amount of both C and Java code between the projects: