1 using System; 2 3 using System.Collections.Generic; 4 5 using System.ComponentModel; 6 7 using System.Data; 8 9 using System.Linq; 10 11 using System.Text; 12 13 using System.Windows.Forms; 14 15 using System.Drawing; 16 17 using System.Drawing.Drawing2D; 18 19 20 21 namespace Bresenham 22 23 { 24 25 public partial class Form1 : Form 26 27 { 28 29 Graphics g; 30 31 const int CellSize = 20; 32 33 int iclick = 0; 34 35 int Cols, Rows; 36 37 Point A,B; 38 39 40 41 public Form1() 42 43 { 44 45 InitializeComponent(); 46 47 g = CreateGraphics(); 48 49 Rows = this.Height / 20; 50 51 Cols = this.Width / 20; 52 53 } 54 55 56 57 private void Form1_Load(object sender, EventArgs e) 58 59 { 60 61 } 62 63 64 65 private void Form1_Paint(object sender, PaintEventArgs e)//程序启动时调用一次DrawSence() 66 67 { 68 69 DrawSence(); 70 71 } 72 73 74 75 private void DrawSence()//绘制背景网格 76 77 { 78 79 int i, j; 80 81 Point M, N; 82 83 Pen p = new Pen(Brushes.Black, 1); 84 85 g.Clear(Color.White); 86 87 for (i = 0; i < Rows 1; i ) 88 89 { 90 91 M = new Point(0, i * CellSize); 92 93 N = new Point(Width, i * CellSize); 94 95 g.DrawLine(p, M, N); 96 97 } 98 99 for (j = 0; j < Cols 1; j )100 101 {102 103 M = new Point(j * CellSize, 0);104 105 N = new Point(j * CellSize, Height);106 107 g.DrawLine(p, M, N);108 109 } 110 111 }112 113 114 115 private void Form1_MouseClick(object sender, MouseEventArgs e)//记录鼠标坐标，并绘制位置116 117 {118 119 switch (iclick)120 121 {122 123 case 0:124 125 {126 127 A = new Point(e.X / CellSize, e.Y / CellSize);128 129 DrawSence();130 131 g.FillEllipse(Brushes.Red, A.X * CellSize, A.Y * CellSize, CellSize, CellSize);132 133 iclick = 1;134 135 break;136 137 }138 139 case 1:140 141 {142 143 B = new Point(e.X / CellSize, e.Y / CellSize);144 145 DoBresenham(A,B);146 147 g.FillEllipse(Brushes.Red, B.X * CellSize, B.Y * CellSize, CellSize, CellSize);148 149 g.FillEllipse(Brushes.Red, A.X * CellSize, A.Y * CellSize, CellSize, CellSize);150 151 iclick = 0;152 153 break;154 155 }156 157 }158 159 }160 161 private void DoBresenham(Point p1,Point p2)//实现Bresenham算法，绘制离散像素点162 163 {164 165 int dx = p2.X - p1.X;166 167 int dy = p2.Y - p1.Y;168 169 int stepX = 0, stepY = 0;170 171 if (dx < 0)172 173 {174 175 dx = -dx;176 177 stepX = -1;178 179 }180 181 else182 183 stepX = 1;184 185 if (dy < 0)186 187 {188 189 dy = -dy;190 191 stepY = -1;192 193 }194 195 else196 197 stepY = 1;198 199 200 201 if (dx > dy)202 203 {204 205 int y = p1.Y;206 207 int d = 2 * dy - dx;208 209 for (int i = p1.X; i != p2.X; i = stepX)210 211 {212 213 g.FillEllipse(Brushes.Blue, i * CellSize, y * CellSize, 20, 20);214 215 d = d 2 * dy;216 217 if (d >= 0)218 219 {220 221 y = stepY;222 223 d = d - 2 * dx;224 225 }226 227 }228 229 }230 231 else232 233 {234 235 int x = p1.X;236 237 int d = 2 * dx - dy;238 239 for (int i = p1.Y; i != p2.Y; i = stepY)240 241 {242 243 g.FillEllipse(Brushes.Blue, x * CellSize, i * CellSize, 20, 20);244 245 d = d 2 * dx;246 247 if (d >= 0)248 249 {250 251 x = stepX;252 253 d = d - 2 * dy;254 255 }256 257 }258 259 } 260 261 }262 263 }264 265 }