//Copyright (c) 2002, Art Gittleman
//This example is provided WITHOUT ANY WARRANTY
//either expressed or implied.

/*  Start with the seven polygons forming
 *  a square. Drag them with the mouse, and rotate
 *  them with the F and B keys to form other shapes.
 */

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
public class TangramSolver : Form {
  private PointF[][] vertices = new PointF[7][];
  private Brush[] color = {Brushes.Red,Brushes.Blue,Brushes.Yellow,
            Brushes.Magenta,Brushes.Cyan,Brushes.Pink,Brushes.Orange};
  private GraphicsPath[] polygon = new GraphicsPath[7];
  private Region[] region = new Region[7];
  private float[] oldX = new float[7];
  private float[] oldY = new float[7];
  private int index;

  public TangramSolver() {
    Size = new Size(500,500);
    Text = "Tangram Solver";
    BackColor = Color.White;
    vertices[0] = new PointF[3]
       {new PointF(0,200), new PointF(100,100),
                                     new PointF(200,200)};
    vertices[1] = new PointF[3]
      {new PointF(100,100), new PointF(200,0),
                                     new PointF(200,200)};
    vertices[2] = new PointF[3]
      {new PointF(0,0), new PointF(100,0), new Point(0,100)};
    vertices[3] = new PointF[3]
      {new PointF(0,100), new PointF(50,150),
                                   new PointF(0,200)};
    vertices[4] = new PointF[3]
      {new PointF(50,50), new PointF(150,50),
                                  new PointF(100,100)};
    vertices[5] = new PointF[4]
      {new PointF(0,100), new PointF(50,50),
                 new PointF(100,100), new PointF(50,150)};
    vertices[6] = new PointF[4]
      {new PointF(100,0), new PointF(200,0),
                 new PointF(150,50), new PointF(50,50)};
    for (int i = 0; i < vertices.Length; i++) {
      polygon[i] = new GraphicsPath();
      polygon[i].AddPolygon(vertices[i]);
      region[i] = new Region(polygon[i]);
    }
  }
  protected override void OnMouseDown(MouseEventArgs e) {
    bool found = false;
    int i = 0;
    while(!found && i < region.Length){
      RectangleF[] scans =
               region[i].GetRegionScans(new Matrix());
      int j = 0;
      while(!found && j < scans.Length){
        if (scans[j].Contains(e.X, e.Y)){
          oldX[i] = e.X;
          oldY[i] = e.Y;
          index = i;
          found = true;
        }
        j++;
      }
      i++;
    }
    base.OnMouseDown(e);
  }
  protected override void OnMouseUp(MouseEventArgs e) {
    region[index].Translate(e.X-oldX[index], e.Y-oldY[index]);
    oldX[index] = e.X;
    oldY[index] = e.Y;
    Invalidate();
    base.OnMouseUp(e);
  }
  protected override void OnPaint(PaintEventArgs e) {
    Graphics g = e.Graphics;
    for (int i = 0; i < region.Length; i++)
      g.FillRegion(color[i], region[i]);
    base.OnPaint(e);
  }
  protected override void OnKeyPress(KeyPressEventArgs e) {
    float angle = 0;
    switch(e.KeyChar){
      case 'b'    : angle = -3;
                    break;
      case 'B'    : angle = -30;
                    break;
      case 'f'    : angle =  3;
                    break;
      case 'F'    : angle =  30;
                    break;
    }
    Matrix m = new Matrix();
    m.RotateAt(angle, new PointF(oldX[index], oldY[index]));
    if (e.KeyChar == 'R') {  }
    region[index].Transform(m);
    Invalidate();
    base.OnKeyPress(e);
  }
  public static void Main() {
    Application.Run(new TangramSolver());
  }
}