I am using a small microcontroller, which has limited processing resources. I need to calculate the three tangents:
tan(theta) tan(hdg + theta) tan(90 - hdg + theta)
theta
is virtually constant (it is a field of view); hdg
may change. tan(theta)
is provided by doing sin(theta)/cos(theta)
(in my library), so that all tangents in total incur six trig function calls... which slows it down a lot.
Is it possible to calculate all of these at once?