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comment Lat/Lon/Alt to spherical or cartesian coordinates
@whuber: These errors are tolerable.
Dec
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Dec
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answered Find the best path along raster
Dec
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comment Quick way to determine if facing a given lat/lon pair with a heading
Actually, I created a second question for this, because it sounds like a good optimisation: gis.stackexchange.com/questions/4147/…
Dec
3
asked Lat/Lon/Alt to spherical or cartesian coordinates
Dec
3
comment Quick way to determine if facing a given lat/lon pair with a heading
Do you have any tips on converting the coordinates? The position of the viewer may move so these would have to be updated, but if the cost is only a few sin or cos calculations when the coordinates change it would probably be worth it.
Dec
3
comment Quick way to determine if facing a given lat/lon pair with a heading
@whuber: Yep, it's probably a better idea because the fixed point library also uses the 40-bit accumulators which support add, subtract, multiply, multiply-accumulate, euclidean distance etc. But these are only available on the dsPIC33F processors and I'm hoping to migrate to PIC24 after a while, which doesn't have these accumulators. So I might have to stick with floating point for now. It renders at about 20-30 frames per second, which is fast enough for me.
Dec
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comment Quick way to determine if facing a given lat/lon pair with a heading
@whuber: My MCU manufacturer (Microchip) have a software fixed point Q16 library. I was considering using it; it might be faster. It has most trig functions.
Dec
3
comment Quick way to determine if facing a given lat/lon pair with a heading
@whuber Don't have Excel, but I think OpenOffice.org Calc has a solver like function. Or I could use Python.