sunday, 3 may 2009

posted at 22:49

Long ago I wrote a SDL driver for AROS hosted. Back then I wrote about it being slow because of deficiencies in the driver interface that require flushing the output to the screen for every pixel plotted by software fallbacks. Go and read that first.

I never did finish my implementation originally, but in the last week I've resurrected the branch and completed it. Its taken adding an UpdateRect method to the bitmap class and then modifying graphics.library to call it after ever operation. If its running a tight loop to paint a rectangle or something, it will call this once when its finished to push its output.

To test, I removed all the "accelerated" methods in the SDL bitmap class, leaving only GetPixel and PutPixel. Back when I first writing sdl.hidd this was all I had implemented, and it worked fine, but was slow enough that you could watch the individual pixels appear on the screen. With the UpdateRect stuff its now very usable. Its not blinding fast, but its snappy enough to be comfortable.

And the best thing is that no changes are required to existing graphics drivers. For those, the call to UpdateRect will just use the baseclass version, which is a no-op. I've confirmed this is actually the case with the X11 driver, so yay.

I'm not sure what's next for my hacking. I'm really just studying graphics.library and graphics.hidd at the moment, trying to get my head around how it all fits together. Something big is coming, I'm just not sure what it looks like yet :)

tuesday, 28 april 2009

posted at 08:39
tags:

It would appear I'm back in the AROS game for a little while. I got a nice email asking for some help with fat.handler so I decided that I'd look into it. In the last 18 months a few things have been broken in things that I care about which were causing my particular configuration to fail to build, so I had to get into the code to fix them. While doing this I started to remember that I actually quite like hacking on AROS and miss it. That and my brain seems ready for a challenge again.

Of course this time around, I'd like to avoid the frustrations that contributed to me quitting last time. So this is my plan:

  • I will only work on things that interest me
  • I will not work for money
  • I will not take on significant commitments (ie "sure, I can take a look at that bug" is ok, but "sure, I'll write you a browser" is not)
  • I will not get involved in any political stuff like arguments about project governance, goals (backward compatibility) or anything else

The last point is key. There was a few times previously that I had to do things the wrong way just so that backwards compatibility would be maintained, a goal that I never agreed with. This time, I won't be arguing about it, I'll just be doing what I want to do. Its a light fork, if you like.

I've got a new repository set up over at repo.or.cz. "cake" is what I'm calling my mini-project for now. I'll be committing everything I do there, as well as keeping the AROS mainline there (manually updated as necessary). I will commit things to the AROS Subversion repository as appropriate, but when I do something that causes significant breakage then it will live here. In true open source fashion, anyone who wants my stuff can get it from me and build their own, or if demand gets high, maybe I'll provide some builds or something. We'll see.

So here we go, the brave new world. I'm great at changing my mind, so we'll see how long this lasts :)