Improving your C# Skills

15. Line-circle intersection

Suppose the line is defined by the following parametric equations:

Here, p₀ = (p₀x, p₀y) is a point on the line and <vx, vy> is a vector pointing in the line's direction. If the second point on the line is p₁ = (p₁x, p₁y), then you can use <p₁x – p₀x, p₁y – p₀x> as the vector.

If the circle is centered at point (cx, cy) and has the radius r, then the following equation defines the circle:

If we plug the line's parametric ...