The post is up. I tried answering your questions with high abstractions. I would rather give you the information so that you can come to your own conclusion instead
of forcing my views on you.
To give you might view on each of your statements:
1. It might not be faster. It is hard to say what is faster: fixed point math or floating point. It really depends on the application in which it is used. Simple algorithms might benefit a lot from fixed point math, but more advanced algorithms can benefit
more from floating point. I'm talking performance only here.
2. Indeed. The Xbox 360 could benefit a lot from fixed point - problem is that it is not easy to create a transparent solution that works with both fixed and floating point math. I will make some performance tests in the future and try to create a transparent
solution and post my results.
3. Same as Xbox 360. The floating point performance on Zune HD is really low and it could benefit a lot from fixed point math.
4. Indeed. Having no inconsistencies across platforms in the calculations is a huge improvement over floating point. There are a lot of things to consider when using floats: rounding methods, accuracy and implementations (and instruction sets). Fixed point
guarantees you a deterministic simulation.
5. As point number 4, you have more consistent accuracy using fixed point. You will suffer from lower range of values if you use 32bit integers only. I've seen space games that hit the roof quite fast and overflowed. There were better off using 64bit integers
or floating point.
As for Farseer Physics and fixed point. I've considered creating a fixed point version of Farseer Physics 3.0 and test it out. There are a lot of algorithms that needs to be rebuild using fixed point, but that is a one-time job only. Paul sent me a great
fixed point math implementation in C# some time ago. Once 3.0 is up and running I will include it and test it out.