using System;

public class Program

{

    public delegate float Bezier(float p1, float p2, float c1, float c2, float t);

    public static void Main()

    {

        Console.WriteLine("Bezier1: " + Bezier1(-1, 4, 0, 3, 0.2f)); // 0.26s @ 10000000 iterations ()

        Console.WriteLine("Bezier2: " + Bezier2(-1, 4, 0, 3, 0.2f)); // 0.33s @ 10000000 iterations

        Console.WriteLine("Bezier3: " + Bezier3(-1, 4, 0, 3, 0.2f)); // 0.51s @ 10000000 iterations

        Console.WriteLine("Bezier4: " + Bezier4(-1, 4, 0, 3, 0.2f)); // 0.30s @ 10000000 iterations

​

        TimeBezier(Bezier4, 10000000);

​

        Console.WriteLine("Done");

    }

​

    public static void TimeBezier(Bezier bezier, float iterations)

    {

        var rand = new Random();

        for (var i = 0; i < iterations; i++)

        {

            var t = (float)rand.NextDouble();

            bezier.Invoke(-1, 4, 0, 3, t);

        }

    }

​

    public static float Bezier1(float p1, float p2, float c1, float c2, float t)

    {

        return p1 + 2f*t*(c1 - p1 + t*((p1 + p2)/2f - 2f*c1 + c2 + t*(c1 - c2)));

    }

​

    public static float Bezier2(float p1, float p2, float c1, float c2, float t)

    {

        var t2 = t*t;

        var t3 = t2*t;

        return 2f*(c1*t3 - c2*t3 - 2*c1*t2 + c2*t2 + (p1*t2 + p2*t2)/2f - p1*t + c1*t + p1/2f);

    }

​

    public static float Bezier3(float p1, float p2, float c1, float c2, float t)

    {

        var l1 = Lerp(c1, c2, t);

        var l2 = Lerp(p1, l1, t);

        var l3 = Lerp(l1, p2, t);

        return Lerp(l2, l3, t);

    }

​

    public static float Bezier4(float p1, float p2, float c1, float c2, float t)

    {

        var l1 = c1 + t*(c2 - c1);

        var l2 = p1 + t*(l1 - p1);

        var l3 = l1 + t*(p2 - l1);

        return l2 + t*(l3 - l2);

    }

​

    public static float Lerp(float a, float b, float c)

    {

        return a + c*(b - a);

    }

}