C# 实现Bresenham算法（vs2010）

 using System;

 using System.Collections.Generic;

 using System.ComponentModel;

 using System.Data;

 using System.Linq;

 using System.Text;

 using System.Windows.Forms;

 using System.Drawing;

 using System.Drawing.Drawing2D;

 namespace Bresenham

 {

     public partial class Form1 : Form

     {

         Graphics g;

         const int CellSize = ;

         int iclick = ;

         int Cols, Rows;

         Point A,B;

         public Form1()

         {

             InitializeComponent();

             g = CreateGraphics();

             Rows = this.Height / ;

             Cols = this.Width / ;

         }

         private void Form1_Load(object sender, EventArgs e)

         {

         }

         private void Form1_Paint(object sender, PaintEventArgs e)//程序启动时调用一次DrawSence()

         {

             DrawSence();

         }

         private void DrawSence()//绘制背景网格

         {

             int i, j;

             Point M, N;

             Pen p = new Pen(Brushes.Black, );

             g.Clear(Color.White);

             for (i = ; i < Rows   ; i )

             {

                 M = new Point(, i * CellSize);

                 N = new Point(Width, i * CellSize);

                 g.DrawLine(p, M, N);

             }

             for (j = ; j < Cols   ; j )

             {

                 M = new Point(j * CellSize, );

                 N = new Point(j * CellSize, Height);

                 g.DrawLine(p, M, N);

             }                        

         }

         private void Form1_MouseClick(object sender, MouseEventArgs e)//记录鼠标坐标，并绘制位置

         {

             switch (iclick)

             {

                 case :

                     {

                         A = new Point(e.X / CellSize, e.Y / CellSize);

                         DrawSence();

                         g.FillEllipse(Brushes.Red, A.X * CellSize, A.Y * CellSize, CellSize, CellSize);

                         iclick = ;

                         break;

                     }

                 case :

                     {

                         B = new Point(e.X / CellSize, e.Y / CellSize);

                         DoBresenham(A,B);

                         g.FillEllipse(Brushes.Red, B.X * CellSize, B.Y * CellSize, CellSize, CellSize);

                         g.FillEllipse(Brushes.Red, A.X * CellSize, A.Y * CellSize, CellSize, CellSize);

                         iclick = ;

                         break;

                     }

             }

         }

         private void DoBresenham(Point p1,Point p2)//实现Bresenham算法，绘制离散像素点

         {

             int dx = p2.X - p1.X;

             int dy = p2.Y - p1.Y;

             int stepX = , stepY = ;

             if (dx < )

             {

                 dx = -dx;

                 stepX = -;

             }

             else

                 stepX = ;

             if (dy < )

             {

                 dy = -dy;

                 stepY = -;

             }

             else

                 stepY = ;

             if (dx > dy)

             {

                 int y = p1.Y;

                 int d =  * dy - dx;

                 for (int i = p1.X; i != p2.X; i  = stepX)

                 {

                     g.FillEllipse(Brushes.Blue, i * CellSize, y * CellSize, , );

                     d = d    * dy;

                     if (d >= )

                     {

                         y  = stepY;

                         d = d -  * dx;

                     }

                 }

             }

             else

             {

                 int x = p1.X;

                 int d =  * dx - dy;

                 for (int i = p1.Y; i != p2.Y; i  = stepY)

                 {

                     g.FillEllipse(Brushes.Blue, x * CellSize, i * CellSize, , );

                     d = d    * dx;

                     if (d >= )

                     {

                         x  = stepX;

                         d = d -  * dy;

                     }

                 }

             }                                       

         }

     }

 }