Paint2/Paint_2/BezierPencil.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//[DEBUG]
using System.Windows.Forms;

namespace Paint_2
{
    internal class BezierPencil : PaintTool
    {
        private List<List<Point>> _drawings;
        private List<List<Point>> _drawingsRedo;
        private PaintToolUtils Utils;
        private List<Color> _colors;
        private List<Color> _colorsRedo;
        private List<int> _widths;
        private List<int> _widthsRedo;
        private Color _color;
        private string _name;
        private int _width;

        public List<List<Point>> Drawings { get => _drawings; set => _drawings = value; }
        public List<List<Point>> DrawingsRedo { get => _drawingsRedo; set => _drawingsRedo = value; }
        public List<Color> Colors { get => _colors; set => _colors = value; }
        public List<Color> ColorsRedo { get => _colorsRedo; set => _colorsRedo = value; }
        public List<int> Widths { get => _widths; set => _widths = value; }
        public List<int> WidthsRedo { get => _widthsRedo; set => _widthsRedo = value; }
        public Color Color { get => _color; set => _color = value; }
        public string Name { get => _name; set => _name = value; }
        public int Width { get => _width; set => _width = value; }

        public BezierPencil(string name)
        {
            Drawings = new List<List<Point>>();
            DrawingsRedo = new List<List<Point>>();
            Colors = new List<Color>();
            ColorsRedo = new List<Color>();
            Widths = new List<int>();
            WidthsRedo = new List<int>();
            Name = name;

            Utils = new PaintToolUtils(this);
        }
        public void Add(Point point)
        {
            if (Drawings[Drawings.Count - 1].Count == 0)
            {
                Drawings[Drawings.Count - 1].Add(point);
            }
        }

        public void Clear()
        {
            Utils.StandartClear();
        }

        public List<Color> GetLastColors(int colorNumber)
        {
            return Utils.SandartGetLastColors(colorNumber);
        }
        public void Paint(Bitmap canvas)
        {
            Graphics gr = Graphics.FromImage(canvas);
            int drawingCounter = 0;
            Size pointSize;

            List<Point> points = new List<Point>();
            foreach (List<Point> drawing in Drawings)
            {
                if (drawing.Count > 0)
                {
                    points.Add(drawing[0]);
                }
            }
            if (points.Count > 0)
            {

                for (int i = 1; i <= points.Count; i++)
                {

                    pointSize = new Size(Widths[0], Widths[0]);
                    gr.FillEllipse(new SolidBrush(Colors[i - 1]), new Rectangle(new Point(points[i - 1].X - pointSize.Width / 2, points[i - 1].Y - pointSize.Height / 2), pointSize));
                    ContinuousBezierGenerator(gr, points, i);
                }
            }
        }
        private void ContinuousBezierGenerator(Graphics gr, List<Point> points, int i)
        {
            if (points.Count >= 4 && points.Count % 2 == 0)
            {
                float precision = 0.01f;
                for (float t = 0; t <= 1; t += precision)
                {
                    List<Point> DumpList = new List<Point>();
                    List<Point> WorkingList = new List<Point>(points);

                    while (WorkingList.Count != 1)
                    {
                        if (WorkingList.Count > 2)
                        {
                            for (int pos = 0; pos < WorkingList.Count - 1; pos++)
                            {
                                DumpList.Add(Utils.Lerp(WorkingList[pos], WorkingList[pos + 1], t));
                            }
                        }
                        else
                        {
                            DumpList.Add(Utils.Lerp(WorkingList[0], WorkingList[1], precision));
                        }
                        WorkingList = new List<Point>(DumpList);
                        DumpList = new List<Point>();
                    }
                    gr.FillEllipse(new SolidBrush(GetRandomColor()), new Rectangle(WorkingList[0].X - Widths[0] / 2, WorkingList[0].Y - Widths[0] / 2, Widths[0], Widths[0]));
                }
            }
        }
        private void BezierGenerator(Graphics gr, Point p1, Point p2, Point p3, Point p4, int i)
        {
            gr.DrawLine(new Pen(Colors[i - 4], Widths[i - 4]), p1, p2);
            gr.DrawLine(new Pen(Colors[i - 3], Widths[i - 3]), p2, p3);
            gr.DrawLine(new Pen(Colors[i - 2], Widths[i - 2]), p3, p4);

            //float t = 0.5f;
            float precision = 0.01f;

            for (float t = 0; t <= 1; t += precision)
            {
                Point p1_2 = Utils.Lerp(p1, p2, t);
                Point p2_2 = Utils.Lerp(p2, p3, t);
                Point p3_2 = Utils.Lerp(p3, p4, t);

                //gr.DrawLine(new Pen(GetRandomColor(), Widths[0]), p1_2, p2_2);
                //gr.DrawLine(new Pen(GetRandomColor(), Widths[0]), p2_2, p3_2);

                //Drawing the second step of the curve
                Point p1_3 = Utils.Lerp(p1_2, p2_2, t);
                Point p2_3 = Utils.Lerp(p2_2, p3_2, t);

                //gr.DrawLine(new Pen(GetRandomColor(), Widths[0]), p1_3, p2_3);

                //Drawing the Bezier Point
                Point p1_4 = Utils.Lerp(p1_3, p2_3, t);

                gr.FillEllipse(new SolidBrush(GetRandomColor()), new Rectangle(p1_4.X - Widths[0] / 2, p1_4.Y - Widths[0] / 2, Widths[0], Widths[0]));
            }
        }
        private Color GetRandomColor()
        {
            Random rnd = new Random();
            return Color.FromArgb(rnd.Next(0, 256), rnd.Next(0, 256), rnd.Next(0, 256));
        }
        public void Start(Color color, int width)
        {
            Utils.StandartStart(color,width);
        }

        public void Stop()
        {
            //Empty
        }

        public override string ToString()
        {
            return Name;
        }

        public void Undo()
        {
            Utils.StandartUndo();
        }

        public void Redo()
        {
            Utils.StandartRedo();
        }

        public Bitmap Stop(Bitmap bmp)
        {
            return bmp;
        }
    }
}