Spiral

float radius = 10;
int segment = 10;
float centerX;
float centerY;

void setup(){
 size(600,600);
}

void draw(){
  centerX = mouseX;
  centerY = mouseY;
  spiral(centerX,centerY,radius,segment);
}
void spiral(float x_c,float y_c, float r, int seg){
    for(int i =0;i<=seg;i++){
      float x = x_c+cos(i*2*PI/seg)*r;  //算出x的位置
      float y = y_c+sin(i*2*PI/seg)*r;  //算出y的位置
      point(x,y);  // 畫出點，也能用其他形狀
    }
}