Grafika - Hermit görbe

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace hermit_gorbe
{
    public partial class Form1 : Form
    {
        Graphics g;
        List<Point> points = new List<Point>();
        List<HermitPoints> hermits = new List<HermitPoints>();

        public Form1()
        {
            InitializeComponent();
            g = CreateGraphics();
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
            MouseClick += new MouseEventHandler(Form1_MouseClick);
        }

        void Form1_MouseClick(object sender, MouseEventArgs e)
        {
            if (points.Count < 4)
            {
                points.Add(e.Location);
                DrawPoints();
                if (points.Count == 4)
                {
                    hermits.Add(new HermitPoints(points[0], points[1], points[2], points[3]));
                    for (int i = 0; i < 3; i++)
                    {
                        points.RemoveAt(0);
                    }
                }
            }
            else
            {
                MessageBox.Show("4 pontot tehetsz!");
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (hermits.Count < 1)
            {
                MessageBox.Show("Legalább 4 pont kell a hermit görbéhez! Neked csak " + points.Count + " pontod van.");
            }
            else
            {
                Invalidate();
                Update();
                DrawPoints();
                DrawHermit();
            }
        }

        public void DrawHermit()
        {
            for (int i = 0; i < hermits.Count; i++)
            {
                for (float u = 0; u <= 1; u = u + 0.01f)
                {
                    double x = CalculateHermit(hermits[i].Start.X, hermits[i].End.X, hermits[i].startDirection.X - hermits[i].Start.X, hermits[i].End.X - hermits[i].endDirection.X, u);
                    double y = CalculateHermit(hermits[i].Start.Y, hermits[i].End.Y, hermits[i].startDirection.Y - hermits[i].Start.Y, hermits[i].End.Y - hermits[i].endDirection.Y, u);
                    g.FillEllipse(Brushes.Black, Convert.ToInt32(x - 2), Convert.ToInt32(y - 2), 4, 4);
                }
            }
            points.Clear();
            hermits.Clear();
        }

        public double CalculateHermit(float a0, float a1, float a2, float a3, float u)
        {
            return (2 * Math.Pow(u, 3) - 3 * Math.Pow(u, 2) + 1) * a0 + (-2 * Math.Pow(u, 3) + 3 * Math.Pow(u, 2)) * a1 + (Math.Pow(u, 3) - 2 * Math.Pow(u, 2) + u) * a2 + (Math.Pow(u, 3) - Math.Pow(u, 2)) * a3;
        }

        public void DrawPoints()
        {
            foreach (var p in points)
            {
                g.DrawEllipse(Pens.Blue, p.X - 5, p.Y - 5, 10, 10);
                g.FillEllipse(Brushes.Red, p.X - 5, p.Y - 5, 10, 10);
            }
            foreach (var h in hermits)
            {
        // NINCS KÉSZ MÉG
                g.DrawEllipse(Pens.Blue, h.Start.X - 5, h.Start.Y - 5, 10, 10);
                g.FillEllipse(Brushes.Red, h.Start.X - 5, h.Start.Y - 5, 10, 10);

                g.DrawEllipse(Pens.Blue, h.Start.X - 5, h.Start.Y - 5, 10, 10); // startdirection
                g.FillEllipse(Brushes.Red, h.Start.X - 5, h.Start.Y - 5, 10, 10);

                g.DrawEllipse(Pens.Blue, h.Start.X - 5, h.Start.Y - 5, 10, 10); // enddirection
                g.FillEllipse(Brushes.Red, h.Start.X - 5, h.Start.Y - 5, 10, 10);

                g.DrawEllipse(Pens.Blue, h.Start.X - 5, h.Start.Y - 5, 10, 10);
                g.FillEllipse(Brushes.Red, h.Start.X - 5, h.Start.Y - 5, 10, 10); // end
            }
        }
    }
}