createCanvas(400, 400);

  strokeWeight(3);

  //noFill();

}

​

function draw() {

  const r = 100;

  background(220);

  push();

  translate(width/2 + r/2+r/10, height/2);

  draw_leaf(r);

  pop();

  push();

  translate(width/2 - r/2-r/10, height/2);

  scale(-1,1);

  draw_leaf(r);

  pop();

  noLoop();

}

​

  //葉っぱを描く

function draw_leaf(r) {

  push();

  beginShape();

  translate(-r/2, -r/2);

  let points = [];

  let num = 10;

  let angle = 360 / num;

  const a = 3;

  let testX = [];

  let testY = [];

  for (let i = 0; i < 60; i++) {

    x = (r / 3) * a * pow(cos(radians(i * 2)), 3);

    y = (r / 3) * a * pow(sin(radians(i * 1.5)), 3);

    points.push(new p5.Vector(x, y));

    testX.push(x);

    testY.push(y);

    vertex(x, y);

  }

    //pointsで一番小さい点と大きい点を割り出す

  const middleX = map(0.5, 0, 1.0, Math.min(...testX), Math.max(...testX));

  const middleY = map(0.5, 0, 1.0, Math.min(...testY), Math.max(...testY));

  //point(middleX, middleY); //回転する中心座標

​

  for (let i = 0; i < 60; i++) {

    const afin = afin_rotate(radians(180), points[i].x, points[i].y, middleX, middleY);

    vertex(afin[0], afin[1]);

  }

  endShape(CLOSE);

  pop();

}

​

//行列計算

function afin(a, b) {

  let x;

  let y;

  for (let k = 0; k < 3; k++) {

    let a0 = a[k][0] * b[0];

    let a1 = a[k][1] * b[1];

    let a2 = a[k][2] * b[2];

    if (k == 0) {

      x = a0 + a1 + a2;

    } else if (k == 1) {

      y = a0 + a1 + a2;

    }

  }

  return [x, y];

}

​

  //回転

function afin_rotate(shita, x, y, tx, ty) {

  let a = [

      [cos(shita), -sin(shita), tx - tx * cos(shita) + ty * sin(shita)],

      [sin(shita), cos(shita), ty - tx * sin(shita) - ty * cos(shita)],

      [0, 0, 1],

    ];

  let b = [x, y, 1];

  return afin(a, b);

}