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AboutAll PostsWarningRandom

squigs

  1. const canvas = document.body.appendChild(document.createElement("canvas"));
  2. const c = canvas.getContext("2d");
  3. document.body.style.margin = 0;
  4.  
  5. function resize() {
  6.   canvas.width = innerWidth * 2;
  7.   canvas.height = innerHeight * 2;
  8.   canvas.style.width = innerWidth + "px";
  9.   canvas.style.height = innerHeight + "px";
  10. }
  11. addEventListener("resize", resize);
  12. resize();
  13.  
  14. const PAD = 50;
  15. const RAD = 2;
  16. const SPEED = 40;
  17. const TWO_PI = Math.PI * 2;
  18.  
  19. let mode = "draw";
  20.  
  21. let t = Math.random() * TWO_PI,
  22.   x = innerWidth,
  23.   y = innerHeight,
  24.   vx = 0,
  25.   vy = 0,
  26.   ta = 0,
  27.   w = 10,
  28.   h = 1,
  29.   hue = 20;
  30.  
  31. function loop() {
  32.   c.globalAlpha = 1;
  33.   if (Math.random() < 0.12) {
  34.     let alpha = 0.02;
  35.     if (Math.random() < 0.1) alpha = 0.1;
  36.     c.fillStyle = `rgba(255, 255, 255, ${alpha})`;
  37.     c.fillRect(0, 0, canvas.width, canvas.height);
  38.   }
  39.   for (var i = 0; i < SPEED; i++) {
  40.     t = Math.sin(ta) * TWO_PI;
  41.     vx = RAD * Math.cos(t);
  42.     vy = RAD * Math.sin(t);
  43.     ta += Math.random() * 0.1 - 0.05;
  44.     x += vx;
  45.     y += vy;
  46.  
  47.     if (Math.random() < 0.005) {
  48.       mode = "no draw";
  49.       hue = [200, 20, 10, 40][~~(Math.random() * 4)];
  50.       if (Math.random() < 0.5) {
  51.         w = Math.random() * 200;
  52.         h = Math.random() * Math.random() * 10;
  53.       } else {
  54.         w = Math.random() * 20;
  55.         h = Math.random() * Math.random() * 200;
  56.       }
  57.     } else if (Math.random() < 0.005) {
  58.       mode = "draw";
  59.     }
  60.  
  61.     if (mode === "draw") {
  62.       c.shadowColor = "rgba(0, 205, 205, 0.2)";
  63.       c.shadowBlur = 5;
  64.       c.fillStyle = `hsl(${hue}, 100%, 50%)`;
  65.       c.fillRect(x, y, w, h);
  66.  
  67.       c.shadowColor = null;
  68.       c.shadowBlur = 0;
  69.     }
  70.  
  71.     if (x < -PAD) {
  72.       x = innerWidth + PAD;
  73.     } else if (x > canvas.width + PAD) {
  74.       x = -PAD;
  75.     }
  76.     if (y < -PAD) {
  77.       y = innerHeight + PAD;
  78.     } else if (y > canvas.height + PAD) {
  79.       y = -PAD;
  80.     }
  81.   }
  82.   c.globalAlpha = 0.9;
  83.   c.drawImage(canvas, -2, -1, canvas.width + 3, canvas.height + 4);
  84.  
  85.   requestAnimationFrame(loop);
  86. }
  87. loop();

More fun speed coding for some recent youtube shorts…

// canvas // curves // filters // hacks // hex // javascript // math // random // speedcoding // tricks

Simple Way to Validate CSS Colors

  1. function isColor(col) {
  2.   const cache = isColor[col]
  3.   if (cache != null) {
  4.     console.log('- reading cache')
  5.     return cache
  6.   }
  7.   isColor.el.style = ''
  8.   isColor.el.style.color = col
  9.   return isColor[col] = !!isColor.el.style.color
  10. }
  11. isColor.el = document.createElement('div')
  12.  
  13.  
  14. console.log('is "red" a color?', isColor('red'))
  15. console.log('from the cache: ', isColor('red'))
  16.  
  17. console.log('is "rgbx(1, 2, 3)" a color?', isColor('rgbx(1, 2, 3)'))
  18.  
  19. console.log('is "#0f0" a color?', isColor('#0f0'))
  20.  
  21. console.log('is "hsl(192, 50%, 50%)" a color?', isColor('hsl(192, 50%, 50%)'))
  22. console.log('from the cache: ', isColor('hsl(192, 50%, 50%)'))
  23.  
  24. console.log('is "lab(2000.1337% -8.6911 -159.131231 / .987189732)" ?',
  25.   isColor('lab(2000.1337% -8.6911 -159.131231 / .987189732)'))
  26.  
  27. console.log('is "snippetZone" ?', isColor('snippetZone'))

I find this technique is usually good enough to validate colors…

// color // css // dom // graphics // hacks // hex // html // javascript // tricks

Super Simple Seeded Random

  1. let _seed = 1234567;
  2.  
  3. // Deterministic pseudo-random float in the interval [ 0, 1 ]
  4. function seededRandom( s ) {
  5.   if ( s !== undefined ) _seed = s % 2147483647;
  6.  
  7.   // Park-Miller algorithm
  8.   _seed = _seed * 16807 % 2147483647;
  9.   return ( _seed - 1 ) / 2147483646;
  10. }

Straight from the THREE.js source code – a fun and simple seeded random. The best libraries are always filled with gems like this…

If I were going to use this I would do a couple things out of pure preference:

  1. let seed = 1234567;
  2.  
  3. const setSeed = newSeed => seed = newSeed
  4. function seededRand() {
  5.   // Park-Miller algorithm
  6.   seed *= 16807 % 0x7fffffff;
  7.   return (seed - 1) / 0x7fffffff;
  8. }
  9.  
  10. // try it out:
  11.  
  12. console.log('one', seededRand());
  13. console.log('two', seededRand());
  14. console.log('three', seededRand());
  15.  
  16. seed = 9999
  17. console.log('one new seed', seededRand());
  18. console.log('one new seed', seededRand());
  19.  
  20. seed = 1234567;
  21. console.log('one old seed', seededRand());

If you’re wondering about what this is doing… read more about it here.

// hex // javascript // math // oldschool // tricks

Easy Hex Color Invert

  1. let color = 0xFFFF00;
  2.  
  3. function toHexString(col) { 
  4.   return '#' + ('000000' + col.toString(16)).substr(-6);
  5. }
  6.  
  7. function onClick() {
  8.   // invert the color
  9.   color ^= 0xFFFFFF;
  10.   document.body.style.background = toHexString(color);
  11. }
  12.  
  13. onClick();
  14.  
  15. document.addEventListener('click', onClick);
  16.  
  17. console.log('try a different initial color');
  18. console.log('click anywhere to invert background...');

Easily invert a hex color. Expanding on yesterdays post – just one of many reasons you may want to work with colors in their integer form.

// color // hex // javascript // math // tricks

Integers to Colors

  1. function toHexString(col) { 
  2.   return '#' + ('000000' + col.toString(16)).substr(-6);
  3. }
  4.  
  5. document.body.style.background = toHexString(0x275ba1);
  6.  
  7. console.log("#275ba1 as an integer:", 0x275ba1);
  8. console.log("#ff0000 as an integer:", 0xff0000);

Convert an integer in hex (like 0xff0000) to a usable hex string "#ff0000".

// color // hex // javascript // math
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