<!DOCTYPE html>
<html>
  <!-- ahhh -->

  <body style="margin: 0; overflow: hidden">
    <canvas
      id="myCanvas"
      width="10"
      height="10"
      style="display: block; box-sizing: border-box"
    >
      Browser does not support the HTML5 canvas tag</canvas
    >
    <script>
      let c = document.getElementById("myCanvas");
      let ctx = c.getContext("2d");
      ctx.canvas.width = window.innerWidth;
      ctx.canvas.height = window.innerHeight;

      //increase deg_per_sec to rotation speed
      let deg_per_sec = 1/200 /// 200;
      let time = 99999999; //set this to stop the animation after x seconds (stops it running in background)
      let fps = 60;
      let leafWidth = 200; //leaf height is just half width
    //   let leafHeight = 100;
      centerX = ctx.canvas.width / 2;
      centerY = ctx.canvas.height / 2;

      rotation = 0; //was = j = angle
      currentFrame = 0; //was = i

      let colour1 = [45, 129, 252];
      // let colour2 = [0, 0, 0];
      let colour2 = [252, 3, 98];
      let lerpedColours = [];

      //270 specifically bc of Math.cos(i/1.5)
      //e.g. 360 would be Math.cos(i)
      //just so the colours loop back
      for (let i = 0; i < 270; i++) {
        let ncolour = LerpRGB(colour1, colour2, Math.cos(rad(i/1.5)));
        lerpedColours.push(colourToText(ncolour))
      }
      console.log(lerpedColours)

      function render() {
        if (currentFrame < time / (1 / fps)) {
          setTimeout(() => {
            render();
            render_clear();

            // Draw_Phyllotaxis(rotation);
            Draw_FloralPhyllo(rotation+.5);
            // Draw_Phyllotaxis(rotation + 1.5);
            // Draw_Phyllotaxis(rotation + 4.8);
            // Draw_Phyllotaxis(Math.PI/4);
            // Draw_Phyllotaxis(1.5);
            // Draw_center(50); //Debugging

            //just moving the last colour to the start, makes the gradient flow
            //through all the items
            lerpedColours.unshift(lerpedColours[lerpedColours.length-1])
            lerpedColours.pop()

          }, 1000 / fps);
          rotation += deg_per_sec / fps; // was = j = angle, now = rotation
          currentFrame += 1; // was = i
        }
      }

      render();

      function Draw_FloralPhyllo(angle) {
        // var c = 24; //something to do with width. but not width
        var c = 1; //something to do with width. but not width

        //dont make larger than 270 unless altering the number of colours in lerpedColours
        for (let n = 200; n > 0; n -= 1) {
          let a = n * angle; //137.5;
          let r = c * Math.sqrt(n);
          let x = r * Math.cos(a) + centerX;
          let y = r * Math.sin(a) + centerY;

          drawEyelid(n * 2.4 + 40, x, y, lerpedColours[n]);
        }
      }
      function rad(degrees) {
        var pi = Math.PI;
        return degrees * (pi / 180);
      }

      function LerpRGB(a, b, t) {
        if (t < 0) {
          t *= -1;
        }
        var newColor = [0, 0, 0];
        newColor[0] = a[0] + (b[0] - a[0]) * t;
        newColor[1] = a[1] + (b[1] - a[1]) * t;
        newColor[2] = a[2] + (b[2] - a[2]) * t;
        return newColor;
      }

      function colourToText(colour) {
        return "rgb(" + colour[0] + "," + colour[1] + "," + colour[2] + ")";
      }

      function render_clear() {
        ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
        ctx.fillStyle = "black";
        ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
      }

      function drawEyelid(width, x1, y1, colour) {
        x1 -= centerX;
        y1 -= centerY;

        let angle = Math.atan2(y1, x1);
        let cosAngle = Math.cos(angle);
        let sinAngle = Math.sin(angle);

        let x2Old = 0 + width;
        let y2Old = 0;

        let x3Old = 0 + width / 2;
        let y3Old = 0 + width / 2;

        let x4Old = 0 + width / 2;
        let y4Old = 0 - width / 2;

        let x2 = cosAngle * width;
        let y2 = sinAngle * width;
        let x3 = x3Old * cosAngle - y3Old * sinAngle;
        let y3 = x3Old * sinAngle + y3Old * cosAngle;

        let x4 = x4Old * cosAngle - y4Old * sinAngle;
        let y4 = x4Old * sinAngle + y4Old * cosAngle;

        x1 += centerX;
        y1 += centerY;
        x2 += x1;
        y2 += y1;
        x3 += x1;
        y3 += y1;
        x4 += x1;
        y4 += y1;

        ctx.beginPath();
        ctx.moveTo(x1, y1);
        ctx.quadraticCurveTo(x3, y3, x2, y2);

        ctx.moveTo(x1, y1);
        ctx.quadraticCurveTo(x4, y4, x2, y2);
        ctx.fillStyle = colour;
        ctx.fill();

        ctx.lineWidth = 2;
        ctx.strokeStyle = "black";
        ctx.stroke();
      }
      function drawEyelid2(x1, y1) {
        x1 -= centerX;
        y1 -= centerY;
        let angle = Math.atan(y1 / x1);

        let localLeafCenterX = -(leafWidth * Math.cos(Math.PI - angle)) / 2;
        let localLeafCenterY = (leafWidth * Math.sin(Math.PI - angle)) / 2;

        let x2 = x1 - leafWidth * Math.cos(Math.PI - angle);
        let y2 = y1 + leafWidth * Math.sin(Math.PI - angle);

        let alpha = Math.atan(leafHeight / (leafWidth / 2));
        let x3 = x1 + localLeafCenterX + leafHeight * Math.sin(alpha);
        let y3 = y1 + localLeafCenterY - leafHeight * Math.cos(alpha);

        let x4 = x1 + localLeafCenterX - leafHeight * Math.sin(alpha);
        let y4 = y1 + localLeafCenterY + leafHeight * Math.cos(alpha);

        x1 += centerX;
        y1 += centerY;
        x2 += centerX;
        y2 += centerY;
        x3 += centerX;
        y3 += centerY;
        x4 += centerX;
        y4 += centerY;
        ctx.beginPath();
        ctx.moveTo(x1, y1);
        ctx.quadraticCurveTo(x3, y3, x2, y2);

        ctx.moveTo(x1, y1);
        ctx.quadraticCurveTo(x4, y4, x2, y2);
        ctx.fillStyle = "black";
        ctx.fill();

        ctx.lineWidth = 1;
        ctx.beginPath();
        ctx.moveTo(x1, y1);
        ctx.quadraticCurveTo(x3, y3, x2, y2);

        ctx.moveTo(x1, y1);
        ctx.quadraticCurveTo(x4, y4, x2, y2);
        ctx.strokeStyle = "orange";
        ctx.stroke();
      }
      

      function Draw_center(width) {
        ctx.beginPath();
        ctx.moveTo(centerX - width / 2, centerY);
        ctx.lineTo(centerX + width / 2, centerY);
        ctx.moveTo(centerX, centerY - width / 2);
        ctx.lineTo(centerX, centerY + width / 2);
        ctx.strokeStyle = "pink";
        ctx.lineWidth = 2;
        ctx.stroke();
      }
    </script>
  </body>
</html>