回転する三角形

/**
* triangles 
*
* @author aa_debdeb
* @date 2016/12/20
*/

int LOOP = 200;
float radius = 70;

void setup(){
  size(500, 500);
  stroke(200);
  strokeWeight(3);
  fill(204, 204, 0);
}

void draw(){
  background(0, 0, 30);
  translate(width / 2.0, height / 2.0);
  for(int i = 0; i < 3; i++){
    pushMatrix();
    float angle = radians(120 * i);
    rotate(angle);
    translate(radius * cos(radians(-30)), radius * sin(radians(-30)));
    rotate(map(calcQuad(float(frameCount % LOOP) / LOOP), 0, 1.0, 0, radians(240)));
    float edge = radius * sqrt(3);
    triangle(0, 0, -edge / 2, -edge * sqrt(3) / 2, -edge, 0); 
    popMatrix();
  }
}

float calcQuad(float v){
  if(v < 0.5){
    return 2.0 * v * v;
  } else {
    return -2.0 * (v - 1.0) * (v - 1.0) + 1.0;
  }
}