MFC(2)

绘制万花筒
在头文件添加#include
在OnDraw中添加代码

int n = 2;
 int r1 = 300 / n;
 int r2 = 100 / n;
 int w = 400 / n;
 int h = 300 / n;
 int s = 10;
 int tmpx = w - (r1 - r2 + s);
 int tmpy = h;
 CString str;
 str = "s=10";
 //str.Format(s);
 pDC->TextOutW(600,50,str );
 CPen pen(PS_SOLID, 1, RGB(255, 0, 0));
 CPen *oldpen = pDC->SelectObject(&pen);
 int a1, a2, xt, yt;
 for (int i = 1;i < 20000;i++)
 {
  a1 = (int)(3.14 / 30 * i);
  a2 = (int)(r1 / r2 * a1);
  xt = -(r1 - r2)*cos(a1) - s * cos(a2 - a1) + w;
  yt = (r1 - r2)*sin(a1) - s * cos(a2 - a1) + h;
  pDC->MoveTo(tmpx, tmpy);
  pDC->LineTo(xt, yt);
  tmpx = xt;
  tmpy = yt;

运行结果