电の岁月---点滴记忆

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        Point[] pt;
        int puint = 70;
        Point ptmouse;
        bool move = false;
        bool mouseup = false;
        bool rot = false;
        double x0, y0;
        public Form1()
        {
            InitializeComponent();
            pt = new Point[] { new Point(64, 23), new Point(64, 4 * puint + 23), new Point(64 + 2 * puint, 23 + puint * 2) };
        }

        public bool ptinchip(Point pt0,Point[] pts)
        {
            GraphicsPath path = new GraphicsPath();
            path.AddLines(pts);
            Region rg = new Region(path);
            return rg.IsVisible(pt0);
        }

        public void rotation()
        {
            double dx,dy;
            for (int i = 0; i < pt.Length; i++)
            {
                dx = pt[i].X - x0;
                dy = pt[i].Y - y0;
                pt[i].X = (int)(x0 + dx * 0.7071 - dy * 0.7071);
                pt[i].Y = (int)(y0 + dx * 0.7071 + dy * 0.7071);
                Invalidate(false);
            }
        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        { 
            
            Graphics gp = e.Graphics;
            GraphicsPath path1 = new GraphicsPath(); 
            path1.AddLines(pt);
            gp.FillPath(Brushes.Red, path1);
            RectangleF rf = path1.GetBounds();
            x0 = rf.Left + rf.Width / 2;
            y0 = rf.Top + rf.Height / 2;
        }

        private void Form1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                mouseup = false;
                ptmouse = new Point(e.X, e.Y);
                if (ptinchip(ptmouse, pt))
                {
                    move = true;
                }
                else
                    move = false;
            }
            else if (e.Button == MouseButtons.Right)
            {
                ptmouse = new Point(e.X, e.Y);
                if (ptinchip(ptmouse, pt))
                {
                    rot = true;
                }
                else
                    rot = false;
            }
        }

        private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            Point pt0 = new Point(e.X, e.Y);
            if (ptinchip(pt0, pt))
            {
                this.Cursor = Cursors.Hand;
            }
            else
                this.Cursor = Cursors.Arrow;
            if (move&&!mouseup)
            {
                Point offpt = new Point(pt0.X - ptmouse.X, pt0.Y - ptmouse.Y);
                for (int i = 0; i < pt.Length; i++)
                {
                    pt[i].Offset(offpt);
                }
                Invalidate(false);
            }
        }

        private void Form1_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                mouseup = true;
            }
            else if (e.Button == MouseButtons.Right&&rot)
            {
                rotation();
            }
        }
    }
}