Is there a formula for calculating the point equidistant from the start point and end point of an arc given:
1) An arc is defined as: A center point $P$, a radius $r$ from the center, a starting angle $sA$ and an ending angle $eA$ in $radians$ where the arc is defined from the starting angle to the ending angle in a counter-clockwise direction.
2) The start point $sP$ is calculated as: $sP\{Px + \cos sA \times r, Py + -\sin sA \times r\}$
3) The end point $eP$ is calculated as: $eP\{Px + \cos eA \times r, Py + -\sin eA \times r\}$
Give the above restrictions, is there a way to calculate the point that is halfway between the start and end angles and exactly $r$ units away from the center?
Best Answer
Had an epiphany just as I hit submit, would this work?
$cP \{ Px +$ $\cos (eA - sA) \over 2$ $\times r, Py +$ $-\sin (eA - sA) \over 2$ $\times r\}$
SOLVED:
Using the piece-wise function:
$ cP( Px +$ $\cos($ $sA + eA \over 2$ $ + n) \times r, Py +$ $-\sin($ $sA + eA \over 2$ $ + n) \times r) = \begin{cases} n = 0, & \text{if }eA - sA \text{ is } >= 0 \\ n = \pi, & \text{if }eA - sA \text{ is } < 0 \end{cases} $
For you computer science-y types here's some pseudo-code: