OpenCV, C++: Distance between two points

Question

For a group project, we are attempting to make a game, where functions are executed whenever a player forms a set of specific hand gestures in front of a camera. To process

Answer 1

This ought to a comment, but I haven't enough rep (50?) |-( so I post it as an answer.

What the guys are trying to tell you in the comments of your questions is that if it's only about comparing distances, then you can simply use d=(dx*dx+dy*dy) = (x1-x2)(x1-x2) + (y1-y2)(y1-y2) thus avoiding the square root. But you can't of course skip the square elevation.