I built an aviation mapping engine that used fixed point math for lat/lon representation. It basically used an entire 32bit signed int and gave a guaranteed minimal resolution of 3 feet. It would quite often go to the ragged edge of what you can fit in a 32 bit quantity.
The fun bit was that you had to use 2 combined registers (ARM) to represent a 64bit quantity so you could do multiplication and keep all your precision.
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I built an aviation mapping engine that used fixed point math for lat/lon representation. It basically used an entire 32bit signed int and gave a guaranteed minimal resolution of 3 feet. It would quite often go to the ragged edge of what you can fit in a 32 bit quantity.
The fun bit was that you had to use 2 combined registers (ARM) to represent a 64bit quantity so you could do multiplication and keep all your precision.
Oh, for the luxury of a FPU...