Blitter and direct access to Silverlight frame buffer
Can Silverlight be used for serious game development?
Some time ago I found interesting project, C# port of Quake engine optimized for Silverlight. Demo published by authors currently doesn’t work (dunno why), but videos show that they achieved fair 60fps with it.
I started wondering how was it done. Quake uses it’s own 100% software renderer. No hardware acceleration was supported at that time. So, to port it to C# and Silverlight developers needed just very fast blitter and/or access to frame buffer (window pixel table or memory pointer equivalent).
One of Silverlight MVPs, Bill Reiss , actually has developed a library that solves all of these problems. Library is called: SilverSprite and you can check its sources on Codeplex. It’s really interesting project, because its API is very close to Xna API developed by Microsoft. Bill gives several examples how to easily port Xna game to Silverlight. He also spoke for Channel 9 on this topic. Whole that coverage is really awesome.
I checked above resources by myself and Silverlight triggered my curiosity as for serious game development. I wanted to investigate and find answer to that original question on blitter/frame buffer. I’ve written a simple implementation of WriteableBitmap based routines to build some benchmark.
You can run this benchmark by yourself too:
* Silverlight 4.0 compatible
* Silverlight 3.0 compatible
I used direct pixel table access to clear the screen and it does not slow down Silverlight a bit. I added also a Blit method that is able to render any UIElement that Silverlight supports (or you create). This is first bottleneck I found. Rendering UIElements can slow down Silverlight heavily. Mixing these two techniques (Pixel Table and UIElements) is definitely an area for further analysis and optimization, but WriteableBitmap looks like a direction, where you can go and check if you can make software renderer (real-time ray-tracer) by yourself. Another interesting aspect of this simple test is performance comparison between SL3 and SL4. Silverligh 4.0 seems to work faster so I assume that SL team might have actually optimized WritableBitmap.Render() routine between these two versions.