using System;
using System.Drawing;
using System.Windows.Forms;
class Spiral: Form
{
public static void Main()
{
Application.Run(new Spiral());
}
public Spiral()
{
ResizeRedraw = true;
}
protected override void OnPaint(PaintEventArgs pea)
{
DoPage(pea.Graphics, ForeColor,ClientSize.Width, ClientSize.Height);
}
protected void DoPage(Graphics grfx, Color clr, int cx, int cy)
{
const int iNumRevs = 20;
int iNumPoints = iNumRevs * 2 * (cx + cy);
PointF[] aptf = new PointF[iNumPoints];
float fAngle, fScale;
for (int i = 0; i < iNumPoints; i++)
{
fAngle = (float)(i * 2 * Math.PI /(iNumPoints / iNumRevs));
fScale = 1 - (float)i / iNumPoints;
aptf[i].X = (float)(cx / 2 * (1 + fScale * Math.Cos(fAngle)));
aptf[i].Y = (float)(cy / 2 * (1 + fScale * Math.Sin(fAngle)));
}
grfx.DrawLines(new Pen(clr), aptf);
}
}