圍繞原點旋轉三角形

Question

圍繞中心點旋轉三角形時遇到麻煩，三角形在嘗試旋轉時會扭曲並超過其通常的大小。

這就是我的工作

     x1r = ((x1 - s.x) * cos(radians)) - ((s.y - y1) * sin(radians)) + s.x;
     y1r = ((s.y - y1) * cos(radians)) + ((x1 - s.x) * sin(radians)) + s.y;
     x2r = ((x2 - s.x) * cos(radians)) - ((s.y - y2) * sin(radians)) + s.x;
     y2r = ((s.y - y2) * cos(radians)) + ((x2 - s.x) * sin(radians)) + s.y;
     x3r = ((x3 - s.x) * cos(radians)) - ((s.y - y3) * sin(radians)) + s.x;
     y3r = ((s.y - y3) * cos(radians)) + ((x3 - s.x) * sin(radians)) + s.y;

任何指導將不勝感激！

Answer 1

用於旋轉3點的公式不正確。 參考

//x1r = ((x1 - s.x) * cos(radians)) - ((s.y - y1) * sin(radians)) + s.x;
//y1r = ((s.y - y1) * cos(radians)) + ((x1 - s.x) * sin(radians)) + s.y;
  x1r = ((x1 - s.x) * cos(radians)) - ((y1 - s.y) * sin(radians)) + s.x;
  y1r = ((y1 - s.y) * cos(radians)) + ((x1 - s.x) * sin(radians)) + s.y;