Box2D.Collision.Shapes.CircleShape.Raycast C# (CSharp) Method

        public override bool Raycast(RayCastOutput output, RayCastInput input, Transform transform, int childIndex)
        {
            Vec2 position = pool1;
            Vec2 s = pool2;
            Vec2 r = pool3;

            Rot.MulToOutUnsafe(transform.Q, P, position);
            position.AddLocal(transform.P);
            s.Set(input.P1).SubLocal(position);
            float b = Vec2.Dot(s, s) - Radius * Radius;

            // Solve quadratic equation.
            r.Set(input.P2).SubLocal(input.P1);
            float c = Vec2.Dot(s, r);
            float rr = Vec2.Dot(r, r);
            float sigma = c * c - rr * b;

            // Check for negative discriminant and short segment.
            if (sigma < 0.0f || rr < Settings.EPSILON)
            {
                return false;
            }

            // Find the point of intersection of the line with the circle.
            float a = -(c + MathUtils.Sqrt(sigma));

            // Is the intersection point on the segment?
            if (0.0f <= a && a <= input.MaxFraction * rr)
            {
                a /= rr;
                output.Fraction = a;
                output.Normal.Set(r).MulLocal(a);
                output.Normal.AddLocal(s);
                output.Normal.Normalize();
                return true;
            }

            return false;
        }