How I can calculate the distance between a point and a line?

Ah, I love math like that. Google of course can give you the formula, but it’s fun to derive it.

Two points on the line

X0,y0

X1,y1

The point to get the distance of

Px,py

Dist = ((x0-x1)*(py-y1)-(y0-y1)*(px-x1))/distance(x0,y0,x1,y1)

Anyways that’ll give you the signed distance. It will be negative on one side of the line. Use abs() to make it positive.

Wonderful!! But, I wonder if it has some error because the closer it gets to x0, the larger the resulting distance gets. My math is horrible. Anyway, if I can make progress on this I will be able to find the intersection point between the line and the perpendicular.