INdex 2D

Coord.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace run2d
{
    public class ComplexComparer : IComparer<Coord>
    {
        public int Compare(Coord c1, Coord c2)
        {
            if (c1.bits < c2.bits) return -1;
            else if (c1.bits > c2.bits) return 1;
            else return 0;
        }
    }
    public class Coord
    {
        internal int x, y;
        internal long bits = 0;
        private void DivideRangeEncode(int value, int[] range)
        {
            int mid = (range[0] + range[1]) / 2;
            bits <<= 1;
            if (value >= mid)
            {
                bits = bits | 0x1;
                range[0] = mid;
            }
            else
            {
                range[1] = mid;
            }
        }

        private void DivideRangeDecode(ref int bits, bool b)
        {
            bits <<= 1;
            if (b)
            {
                bits = bits | 0x1;
            }
        }

        public Coord(long bits)
        {
            this.bits = bits;
            bool isEvenBit = true;
            long mask = 1<<15;
            for (int i = 0; i < 16; i++)
            {
                if (isEvenBit)
                {
                    DivideRangeDecode(ref x, (bits & mask) != 0);
                }
                else
                {
                    DivideRangeDecode(ref y, (bits & mask) != 0);
                }
                isEvenBit = !isEvenBit;
                mask >>= 1;
            }
        }

        public Coord(int x, int y)
        {
            this.x = x;
            this.y = y;
            bits = 0;
            int[] rangeX = { 0, 256 };
            int[] rangeY = { 0, 256 };
            bool isEvenBit = true;
            for (int i = 0; i < 16; i++)
            {
                if (isEvenBit)
                {
                    DivideRangeEncode(x, rangeX);
                }
                else
                {
                    DivideRangeEncode(y, rangeY);
                }
                isEvenBit = !isEvenBit;
            }
        }
    }
}

Form1.cs

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

namespace run2d
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        List<Coord> list = new List<Coord>();
        ComplexComparer comparer = new ComplexComparer();
        private void button1_Click(object sender, EventArgs e)
        {                    
            Bitmap drawBitmap;
            drawBitmap = new Bitmap(pictureBox1.Width, pictureBox1.Height);            
            pictureBox1.Image = drawBitmap;
            Graphics g = Graphics.FromImage(pictureBox1.Image);
            g.Dispose();
            foreach (Coord c in list)
            {
                drawBitmap.SetPixel(c.x, c.y,Color.Red);
         //       Thread.Sleep(1);
                pictureBox1.Refresh();
            }
        }

        private void SetPoint(int x,int y)
        {
            Bitmap drawBitmap;
            drawBitmap = new Bitmap(pictureBox1.Width, pictureBox1.Height);
            pictureBox1.Image = drawBitmap;
            Graphics g = Graphics.FromImage(pictureBox1.Image);
            g.Dispose();
            Coord cleft = new Coord(x - 10, y);
            Coord cright = new Coord(x + 10, y);
            Coord ctop = new Coord(x, y-10);
            Coord cbot = new Coord(x, y + 10);
            Coord cc = new Coord(x, y);
            Coord cfirst;
            if (cleft.bits < ctop.bits) cfirst = cleft; else cfirst = ctop;
            Coord clast;
            if (cright.bits > cbot.bits) clast = cright; else clast = cbot;
            int istart = list.BinarySearch(cfirst, comparer);
            int iend = list.BinarySearch(clast, comparer);
            for (long i=istart; i<= iend; i++)
            {
                Coord c = list[(int)i];
                if (c.bits==cc.bits)
                    drawBitmap.SetPixel(c.x, c.y, Color.Yellow);
                else
                    drawBitmap.SetPixel(c.x, c.y, Color.Red);                
            }
        }

        private void SetPointSimple(int x, int y)
        {            
            Bitmap drawBitmap;
            drawBitmap = new Bitmap(pictureBox1.Width, pictureBox1.Height);
            pictureBox1.Image = drawBitmap;
            Graphics g = Graphics.FromImage(pictureBox1.Image);
            g.Dispose();            
            Coord cc = new Coord(x, y);
            Coord cfirst = new Coord(Math.Max(cc.bits - 256,0));
            Coord clast = new Coord(Math.Min(cc.bits + 256,65535));
            int istart = list.BinarySearch(cfirst, comparer);
            int iend = list.BinarySearch(clast, comparer);
            for (long i = istart; i <= iend; i++)
            {
                Coord c = list[(int)i];
                if (c.bits == cc.bits)
                    drawBitmap.SetPixel(c.x, c.y, Color.Yellow);
                else
                    drawBitmap.SetPixel(c.x, c.y, Color.Red);                
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Random rand = new Random();
            SetPoint(rand.Next(256), rand.Next(256));
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            for (int y = 0; y < 256; y++)
                for (int x = 0; x < 256; x++)
                {
                    Coord c = new Coord(x, y);
                    list.Add(c);
                }
            list.Sort(comparer);
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Random rand = new Random();
            SetPointSimple(rand.Next(256), rand.Next(256));
        }
    }
}

Form1.Designer.cs

namespace run2d
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.button3 = new System.Windows.Forms.Button();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // pictureBox1
            // 
            this.pictureBox1.Location = new System.Drawing.Point(12, 12);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(256, 256);
            this.pictureBox1.TabIndex = 0;
            this.pictureBox1.TabStop = false;
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(280, 23);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 1;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(280, 65);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(75, 23);
            this.button2.TabIndex = 2;
            this.button2.Text = "button2";
            this.button2.UseVisualStyleBackColor = true;
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // button3
            // 
            this.button3.Location = new System.Drawing.Point(280, 103);
            this.button3.Name = "button3";
            this.button3.Size = new System.Drawing.Size(75, 23);
            this.button3.TabIndex = 3;
            this.button3.Text = "button3";
            this.button3.UseVisualStyleBackColor = true;
            this.button3.Click += new System.EventHandler(this.button3_Click);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(367, 289);
            this.Controls.Add(this.button3);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.pictureBox1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.PictureBox pictureBox1;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.Button button3;
    }
}