分形算法->跳舞的小树

这里用的是GDI来绘图,采用双缓冲.

以下是Form窗体内的所有代码:

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Drawing.Drawing2D;
using System.Threading;
using System.IO;

namespace 分形
{
    /**//// <summary>
    /// Form1 的摘要说明。
    /// </summary>
    public class frmAction : System.Windows.Forms.Form
    {
        /**//// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.Container components = null;

        SolidBrush brush= new SolidBrush(Color.Black);
        private System.Windows.Forms.Button btnPlay;
        private System.Windows.Forms.Button btnStop;
        Pen pen;
        public frmAction()
        {
            //
            // Windows 窗体设计器支持所必需的
            //
            InitializeComponent();
            Init();
            //
            // TODO: 在 InitializeComponent 调用后添加任何构造函数代码
            //
        }

        /**//// <summary>
        /// 清理所有正在使用的资源。
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        Windows 窗体设计器生成的代码#region Windows 窗体设计器生成的代码
        /**//// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            this.btnPlay = new System.Windows.Forms.Button();
            this.btnStop = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // btnPlay
            // 
            this.btnPlay.Location = new System.Drawing.Point(80, 344);
            this.btnPlay.Name = "btnPlay";
            this.btnPlay.Size = new System.Drawing.Size(96, 24);
            this.btnPlay.TabIndex = 0;
            this.btnPlay.Text = "跳舞哦！";
            this.btnPlay.Click += new System.EventHandler(this.btnPlay_Click);
            // 
            // btnStop
            // 
            this.btnStop.Enabled = false;
            this.btnStop.Location = new System.Drawing.Point(320, 344);
            this.btnStop.Name = "btnStop";
            this.btnStop.Size = new System.Drawing.Size(88, 24);
            this.btnStop.TabIndex = 1;
            this.btnStop.Text = "停下来！";
            this.btnStop.Click += new System.EventHandler(this.btnStop_Click);
            // 
            // frmAction
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
            this.ClientSize = new System.Drawing.Size(480, 390);
            this.Controls.Add(this.btnStop);
            this.Controls.Add(this.btnPlay);
            this.Name = "frmAction";
            this.Text = "Form1";
            this.Closing += new System.ComponentModel.CancelEventHandler(this.frmAction_Closing);
            this.Load += new System.EventHandler(this.Form1_Load);
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
            this.ResumeLayout(false);

        }
        #endregion

        /**//// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main() 
        {
            Application.Run(new frmAction());
        }
        private void Form1_Load(object sender, System.EventArgs e)
        {             
        }

        private void RePaint()
        {
            while (true)
            {
                paint(this.CreateGraphics());
            }            
        }

        /**//// <summary>
        /// 画叶子
        /// </summary>
        /// <param name="g"></param>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <param name="L"></param>
        /// <param name="a"></param>
        /// <param name="B"></param>
        /// <param name="C"></param>
        public void DrawLeaf(Graphics g,double x,double y,
            double L, double a,float B,float C)
        {    
            double x1,x2,x1L,x2L,x2R,x1R,
                y1,y2,y1L,y2L,y2R,y1R;
       
            float s1 = 2;
            float s2 = 3;
            float s3 = 1.1f;

            if(L > s1)
            {
                x2 = x + L * Math.Cos(a * PI);
                y2 = y + L * Math.Sin(a * PI);
                x2R = x2 + L / s2 * Math.Cos((a + B) * PI);
                y2R = y2 + L / s2 * Math.Sin((a + B) * PI);
                x2L = x2 + L / s2 * Math.Cos((a - B) * PI);
                y2L = y2 + L / s2 * Math.Sin((a - B) * PI);
  
                x1 = x + L / s2 * Math.Cos(a * PI);
                y1 = y + L / s2 * Math.Sin(a * PI);
                x1L = x1 + L / s2 * Math.Cos((a - B) * PI);
                y1L = y1 + L / s2 * Math.Sin((a - B) * PI);
                x1R = x1 + L / s2 * Math.Cos((a + B) * PI);
                y1R = y1 + L / s2 * Math.Sin((a + B) * PI);
             
                g.DrawLine(pen,(int) x, (int) y, (int) x2, (int) y2);
                g.DrawLine(pen,(int) x2, (int) y2, (int) x2R, (int) y2R);
                g.DrawLine(pen,(int) x2, (int) y2, (int) x2L, (int) y2L);
                g.DrawLine(pen,(int) x1, (int) y1, (int) x1L, (int) y1L); 
                g.DrawLine(pen,(int) x1, (int) y1, (int) x1R, (int) y1R);
          
                DrawLeaf(g, x2, y2, L / s3, a + C,B,C);
                DrawLeaf(g, x2R, y2R, L / s2, a + B,B,C);
                DrawLeaf(g, x2L, y2L, L / s2, a - B,B,C);
                DrawLeaf(g, x1L, y1L, L / s2, a - B,B,C);
                DrawLeaf(g, x1R, y1R, L / s2, a + B,B,C);   
            }
        }

        /**//// <summary>
        /// 绘制图形
        /// </summary>
        /// <param name="g"></param>
        public void paint(Graphics g)
        {        
            if (dstatus) 
            {
                D += 0.2f;
                if (D>=10) dstatus = false;
            }
            else 
            {
                D -= 0.2f;
                if (D<=-10) dstatus = true;
            }

            if (K<60) K=K+0.2f;

            //清除缓冲内的图形
            offscreenbuffer.Clear(Color.White);
     
            //在offscreenbuffer中画树;
            DrawLeaf(offscreenbuffer,200, 300, 30,270,K,D);
            
            //将缓冲画出来
            g.DrawImage(offscreenimage,0,0);
        }

        public void Init()
        { 
//            //创建缓冲区内的图形
            offscreenimage= new Bitmap(this.Width,this.Height);

            //得到g;
            offscreenbuffer=Graphics.FromImage(offscreenimage);
            pen = new Pen(brush,1);
        }

        float D=-10;//树的弯曲角度C
        float K=40;//树杈的伸展角度B
        bool dstatus = true;
        public static readonly double PI = Math.PI / 180;
        Bitmap offscreenimage=null;    //缓冲区中的图形
        Graphics offscreenbuffer=null;  //缓存中的g
        MemoryStream stream = new MemoryStream();

        private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
        {
            
        }

        Thread thread;
        private void btnPlay_Click(object sender, System.EventArgs e)
        {
            thread = new Thread(new ThreadStart(RePaint));
            thread.Start();
            btnPlay.Enabled = false;
            btnStop.Enabled = true;
        }

        private void btnStop_Click(object sender, System.EventArgs e)
        {
            thread.Suspend();
            btnStop.Enabled = false;
            btnPlay.Enabled = true;
        }

        private void frmAction_Closing(object sender, System.ComponentModel.CancelEventArgs e)
        {
            if (thread.ThreadState==ThreadState.Running)
            {
                thread.Abort();
            }

            Application.ExitThread();
        }
    }
}