<!DOCTYPE html> <html> <!-- ahhh --> <body style="margin:0;"> <canvas id="myCanvas" width="10" height="10" style="display: block;box-sizing: border-box;"> Your 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; let deg_per_sec = 30; let time = 120; let fps = 60; centerX = ctx.canvas.width / 2; centerY = ctx.canvas.height / 2; rotation = 0; //was = j = angle currentFrame = 0; //was = i function render() { if (currentFrame < time / (1 / fps)) { setTimeout(() => { render(); render_clear(); DrawSquareTwist_angle(400,0,rotation,"red") }, 1000 / fps); rotation += deg_per_sec / fps; // was = j = innerRotation, now = rotation currentFrame += 1; // was = i } } render(); function DrawSquareTwist_angle(width, rotation,innerRotation, colour){ let out_angle = innerRotation; let widthMultiplier = 1 / (2 * Math.sin(Math.PI / 180 * (130 - out_angle + 90 * Math.floor(out_angle / 90))))+0.5 for (let i = 0; i < 25; i++) { drawSquare(innerRotation*i,width*widthMultiplier**i, colour) } } function drawSquare(angle,size, colour) { ctx.save(); ctx.translate(centerX, centerY)//-(Math.sin(rad(angle)) *centerX)); ctx.rotate(rad(angle + 180)); ctx.beginPath(); ctx.strokeStyle = colour; ctx.rect(-size/2, -size/2, size, size); ctx.stroke(); ctx.restore(); } function rad(degrees) { var pi = Math.PI; return degrees * (pi / 180); } 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); } </script> </body> </html>