1. Re: Trig and the ...
Pete Eberlein wrote:
> speed = sqrt((xv*xv)+(yv*yv))
> if speed > maxspeed then
> xv = xv* maxspeed / speed
> yv = yv * maxspeed / speed
> end if
This is nice, straight forward and accurate. The square root operation
is usually quite expensive, so I'll show you slightly faster, but more
complicated way of calculating the scaling factor with sufficient
accuracy. Instead of Pete's
f = maxspeed / sqrt(xv*xv+yv*yv)
you can try
vvmax = maxspeed * maxspeed -- known, can be pre-calculated
vv = xv*xv + yv*yv -- speed squared
f = (vvmax+vv) / (vv+vv)
I shall not bore you with the mathematics of it - unless, of course,
you insist. Jiri
