Snippet Zone

Airbrush-esque

const canvas = document.createElement('canvas');

```
const c = canvas.getContext('2d');
```
```
 
```

const brush = document.createElement('canvas');

```
const brushC = brush.getContext('2d');
```
```
 
```
```
canvas.width = innerWidth;
```
```
canvas.height = innerHeight;
```
```
brush.width = innerWidth;
```
```
brush.height = innerHeight;
```
```
 
```
```
document.body.appendChild(canvas);
```
```
 
```
```
c.fillStyle = 'black'
```

c.fillRect(0, 0, canvas.width, canvas.height);

```
 
```
```
let brushSize = 50;
```
```
let featherSize = .1;
```

let featherSteps = Math.floor(brushSize * featherSize) + 1;

```
let st = brushSize - featherSteps;
```
```
 
```
```
let a = 0;
```
```
if (st < 1) st = 1;
```
```
for (let i = 0; i < st; i++) {
```
```
  a = 1 / (st - i)
```

  c.strokeStyle = `rgba(255, 255, 255, ${a})`;

```
  console.log(c.strokeStyle)
```
```
  c.lineWidth = brushSize - i;
```
```
  c.lineJoin = 'round'
```
```
  c.lineCap = 'round'
```
```
  c.beginPath();
```
```
  c.moveTo(50, 50);
```
```
  c.lineTo(200, 200);
```

  c.bezierCurveTo(300, 200, 400, 200, 300, 400);

```
  c.stroke();
```
```
}
```

January 27, 2022

// canvas // javascript

Alphabet Array Golfed

```
l=[]
```
```
for(i=26;i--;)l[i]=(10+i).toString(36)
```
```
console.log(l)
```

A nasty golfed way to fill an array with letters a-z.

I usually do (as seen in another post):

let letters = 'abcdefghijklmopqrstuvwxyz'.split``

January 25, 2022

// codegolf // javascript // speedcoding // strings

Drag Svg Circles

document.addEventListener('touchmove', (e) => e.preventDefault(), {

```
  passive: false,
```
```
});
```
```
 
```

// this is just lazy - obviously goes in your stylesheet.... :P

```
document.body.innerHTML += `
```
```
<style>
```
```
  body, html {
```
```
    padding: 0;
```
```
    height: 100%;
```
```
    margin: 0;
```
```
  }
```
```
</style>
```
```
`;
```
```
 
```

const temp = document.createElement('div');

temp.innerHTML = `<svg width="100%" height="100%" viewBox="0 0 500 500"></svg>`;

```
 
```

const svg = document.body.appendChild(temp.querySelector('svg'));

```
 
```
```
const CIRCLE_NUM = 4;
```
```
 
```

// make some randomly positioned circles

```
for (let i = 0; i < CIRCLE_NUM; i++) {
```
```
  const x = Math.random() * 150 + 150;
```
```
  const y = Math.random() * 150 + 150;
```
```
  svg.innerHTML += `<circle 
```
```
    cx="${x}" cy="${y}" r="60" 
```

    stroke="#000" fill="rgba(81, 121, 200, 0.3)"

```
    style="cursor:pointer" />`;
```
```
}
```
```
 
```
```
function touch(e) {
```
```
  const pt = svg.createSVGPoint();
```
```
  pt.x = e.clientX;
```
```
  pt.y = e.clientY;
```

  return pt.matrixTransform(svg.getScreenCTM().inverse());

```
}
```
```
 
```
```
let down, ox, oy, curr;
```

document.addEventListener('pointerdown', (e) => {

```
  down = true;
```
```
  if (e.target.tagName === 'circle') {
```
```
    curr = e.target;
```
```
    const { x, y } = touch(e);
```
```
    ox = curr.cx.baseVal.value - x;
```
```
    oy = curr.cy.baseVal.value - y;
```
```
  }
```
```
});
```
```
 
```

document.addEventListener('pointermove', (e) => {

```
  if (down && curr) {
```
```
    const { x, y } = touch(e);
```
```
    curr.cx.baseVal.value = x + ox;
```
```
    curr.cy.baseVal.value = y + oy;
```
```
  }
```
```
});
```
```
 
```

document.addEventListener('pointerup', (e) => {

```
  down = false;
```
```
  curr = null;
```
```
});
```

Drag some svg circles on mobile and desktop…

January 23, 2022

// javascript // svg // ui

Speed-coded Eye

```
d = document
```
```
b = d.body
```
```
b.style.margin = 0
```
```
with(Math) {
```

  S = min(innerHeight * 2, innerWidth * 2)

```
  hs = S / 2
```
```
 
```
```
  with(
```
```
    b.appendChild(Object.assign(
```
```
      d.createElement`canvas`, {
```
```
        width: S,
```
```
        height: S
```
```
      })).getContext`2d`) {
```
```
 
```

    // array of xy coords, closed boolean

    function bezierSkin(bez, closed = true) {

```
      const avg = calcAvgs(bez);
```
```
      const leng = bez.length;
```
```
      let i, n;
```
```
 
```
```
      if (closed) {
```
```
        moveTo(avg[0], avg[1]);
```
```
        for (i = 2; i < leng; i += 2) {
```
```
          n = i + 1;
```

          quadraticCurveTo(bez[i], bez[n], avg[i], avg[n]);

```
        }
```

        quadraticCurveTo(bez[0], bez[1], avg[0], avg[1]);

```
      } else {
```
```
        moveTo(bez[0], bez[1]);
```
```
        lineTo(avg[0], avg[1]);
```

        for (i = 2; i < leng - 2; i += 2) {

```
          n = i + 1;
```

          quadraticCurveTo(bez[i], bez[n], avg[i], avg[n]);

```
        }
```

        lineTo(bez[leng - 2], bez[leng - 1]);

```
      }
```
```
    }
```
```
 
```

    // create anchor points by averaging the control points

```
    function calcAvgs(p) {
```
```
      const avg = [];
```
```
      const leng = p.length;
```
```
      let prev;
```
```
      for (var i = 2; i < leng; i++) {
```
```
        prev = i - 2;
```
```
        avg.push((p[prev] + p[i]) / 2);
```
```
      }
```
```
      // close
```

      avg.push((p[0] + p[leng - 2]) / 2);

      avg.push((p[1] + p[leng - 1]) / 2);

```
      return avg;
```
```
    }
```
```
 
```
```
 
```

    canvas.style.transformOrigin = '0 0'

    canvas.style.transform = 'scale(.4)'

```
 
```
```
    rinit = _ => {
```
```
      t = 0
```
```
      tinc = .1
```
```
      rad = hs * .8
```
```
      pupil = random() * .25
```
```
      radA = pupil + random() * .25
```
```
 
```
```
    }
```
```
    dx = dy = hs
```
```
    cx = cy = hs
```
```
 
```
```
    rinit()
```
```
 
```
```
    fillStyle = 'black'
```
```
    fillRect(0, 0, S, S);
```
```
    fillStyle = 'white'
```
```
    beginPath()
```
```
    moveTo(hs, hs)
```
```
    arc(hs, hs, rad, 0, 7)
```
```
    fill()
```
```
 
```
```
    outer = _ => {
```
```
      dx = cx + rad * cos(t)
```
```
      dy = cy + rad * sin(t)
```
```
 
```
```
      if (t > 7 && random() < .3) {
```
```
        fnIdx++
```
```
      }
```
```
    }
```
```
 
```

    shutter = () => hs * radA + random() * hs * (.6 - pupil)

```
 
```
```
    innerA = _ => {
```
```
      tinc = .05
```
```
      rad = shutter()
```
```
      dx = cx + rad * cos(t)
```
```
      dy = cy + rad * sin(t)
```
```
 
```
```
      if (t > 21 && random() < .3) {
```
```
        fnIdx++
```
```
      }
```
```
    }
```
```
 
```
```
    oa = 7 * 3
```
```
 
```
```
    innerB = _ => {
```
```
      tinc = .05
```
```
      T = t * random();
```
```
      dx = cx + hs * radA * cos(T)
```
```
      dy = cy + hs * radA * sin(T)
```

      if (t > 28 + oa && random() < .3) {

```
        rad = hs * .8
```
```
        fnIdx++
```
```
      }
```
```
    }
```
```
 
```
```
    outerA = _ => {
```

      R = (rad - hs * .1) + random() * hs * .1;

```
      dx = cx + R * cos(t)
```
```
      dy = cy + R * sin(t)
```

      if (t > 35 + oa && random() < .3) {

```
        fnIdx++
```
```
      }
```
```
    }
```
```
 
```
```
    outerB = _ => {
```
```
      tinc = .01;
```
```
      R = rad
```
```
      if (random() < .5) R = shutter()
```
```
      dx = cx + R * cos(t)
```
```
      dy = cy + R * sin(t)
```
```
 
```

      if (t > 42 + oa && random() < .3) {

```
        fnIdx++
```
```
        ct = t
```
```
      }
```
```
    }
```
```
 
```
```
 
```
```
    t2 = 0
```
```
    outerC = _ => {
```
```
      tinc = .1;
```
```
      t2 += .01;
```
```
      R = hs * .3
```
```
      RR = (R + t2 + random() * 10);
```
```
      dx = cx + R * .84 + RR * cos(t)
```
```
      dy = cy - R * .84 + RR * sin(t)
```
```
 
```

      if (t > 70 + oa && random() < .3) {

```
        fnIdx++
```
```
      }
```
```
    }
```
```
 
```
```
    outerD = _ => {
```
```
      tinc = .1;
```
```
      t2 += .01;
```
```
      R = hs * .1
```
```
      RR = (R + t2 + random() * 10);
```
```
      dx = cx + hs * .3 + RR * cos(t)
```
```
      dy = cy + R * .84 + RR * sin(t)
```
```
 
```

      if (t > 91 + oa && random() < .3) {

```
        fnIdx++
```
```
      }
```
```
    }
```
```
 
```
```
    outerE = _ => {
```
```
      tinc = .1;
```
```
 
```
```
      rad -= random() * .1;
```
```
      dx = cx + rad * cos(t)
```
```
      dy = cy + rad * sin(t)
```
```
 
```

      if (t > 112 + oa && random() < .3) {

```
        fnIdx++
```
```
      }
```
```
    }
```
```
    count = 0
```
```
    last = _ => {
```
```
      done = true;
```
```
 
```
```
      fillStyle = 'black'
```
```
      fillRect(0, 0, S, S);
```
```
      fillStyle = 'white'
```
```
      beginPath()
```
```
      moveTo(hs, hs)
```
```
      arc(hs, hs, hs * .8, 0, 7)
```
```
      fill()
```
```
 
```
```
      beginPath();
```
```
      moveTo(0, 0);
```
```
      bezierSkin(pnts, false)
```
```
      stroke()
```
```
 
```
```
 
```
```
      return
```
```
      count++
```
```
      if (count < 1) {
```
```
        rinit()
```
```
        setOff()
```
```
        t = 0
```
```
        fnIdx = 0
```
```
      }
```
```
    }
```
```
 
```

    fns = [outer, innerA, innerB, outerA, outerB, outerC, outerD, outerE, last]

```
    fnIdx = 0
```
```
 
```
```
    outer()
```
```
    drawX = dx
```
```
    drawY = dy
```
```
    pDrawX = 0
```
```
    pDrawY = 0
```
```
 
```
```
    strokeStyle = 'rgba(0, 0, 0, 0.8)'
```
```
    lineWidth = 1;
```
```
    tt = 0
```
```
 
```
```
    ox = 0;
```
```
    oy = 0;
```
```
    setOff = _ => {
```
```
      return
```
```
      ox = S * 1.2 * random() - S / 2
```
```
      oy = S * 1.2 * random() - S / 2
```
```
      sl = .1 + random() * .9;
```
```
    }
```
```
 
```
```
    sl = 1
```
```
    pnts = []
```
```
    done = false
```
```
    loop = _ => {
```
```
 
```
```
      if (done) {
```
```
        return;
```
```
      }
```

      shadowColor = 'rgba(155, 255, 255, .5)';

```
      shadowBlur = 15;
```
```
 
```
```
      save()
```
```
      scale(1, 1)
```
```
      lineWidth = 2;
```
```
      for (i = 0; i < 20; i++) {
```
```
        t += tinc / 2
```
```
        fns[fnIdx]()
```
```
 
```

        drawX += ((dx + ox) * sl - drawX) / 2;

        drawY += ((dy + oy) * sl - drawY) / 2;

```
 
```
```
        if (drawX != 0 && pDrawX) {
```
```
          beginPath()
```
```
          moveTo(pDrawX, pDrawY);
```
```
          lineTo(drawX, drawY);
```
```
          pnts.push(drawX, drawY);
```
```
          stroke()
```
```
        }
```
```
 
```
```
        pDrawX = drawX
```
```
        pDrawY = drawY
```
```
      }
```
```
 
```
```
      restore()
```
```
      requestAnimationFrame(loop)
```
```
    }
```
```
    loop()
```
```
  }
```
```
}
```

Another thing for #genuary2022… a single curve…

January 21, 2022

// animation // canvas // javascript

Raphaël Easing Equations How To

```
const { pow, PI } = Math;
```
```
 
```
```
// mostly unedited code from Raphaël
```
```
var ef = {
```
```
  linear: function(n) {
```
```
    return n;
```
```
  },
```
```
  '<': function(n) {
```
```
    return pow(n, 1.7);
```
```
  },
```
```
  '>': function(n) {
```
```
    return pow(n, 0.48);
```
```
  },
```
```
  '<>': function(n) {
```
```
    var q = 0.48 - n / 1.04,
```
```
      Q = Math.sqrt(0.1734 + q * q),
```
```
      x = Q - q,
```

      X = pow(abs(x), 1 / 3) * (x < 0 ? -1 : 1),

```
      y = -Q - q,
```

      Y = pow(abs(y), 1 / 3) * (y < 0 ? -1 : 1),

```
      t = X + Y + 0.5;
```

    return (1 - t) * 3 * t * t + t * t * t;

```
  },
```
```
  backIn: function(n) {
```
```
    var s = 1.70158;
```
```
    return n * n * ((s + 1) * n - s);
```
```
  },
```
```
  backOut: function(n) {
```
```
    n = n - 1;
```
```
    var s = 1.70158;
```

    return n * n * ((s + 1) * n + s) + 1;

```
  },
```
```
  elastic: function(n) {
```
```
    if (n == !!n) {
```
```
      return n;
```
```
    }
```

    return pow(2, -10 * n) * Math.sin(((n - 0.075) * (2 * PI)) / 0.3) + 1;

```
  },
```
```
  bounce: function(n) {
```
```
    var s = 7.5625,
```
```
      p = 2.75,
```
```
      l;
```
```
    if (n < 1 / p) {
```
```
      l = s * n * n;
```
```
    } else {
```
```
      if (n < 2 / p) {
```
```
        n -= 1.5 / p;
```
```
        l = s * n * n + 0.75;
```
```
      } else {
```
```
        if (n < 2.5 / p) {
```
```
          n -= 2.25 / p;
```
```
          l = s * n * n + 0.9375;
```
```
        } else {
```
```
          n -= 2.625 / p;
```
```
          l = s * n * n + 0.984375;
```
```
        }
```
```
      }
```
```
    }
```
```
    return l;
```
```
  }
```
```
};
```
```
ef.easeIn = ef['ease-in'] = ef['<'];
```
```
ef.easeOut = ef['ease-out'] = ef['>'];
```

ef.easeInOut = ef['ease-in-out'] = ef['<>'];

```
ef['back-in'] = ef.backIn;
```
```
ef['back-out'] = ef.backOut;
```
```
 
```
```
// create a dot
```
```
function dot(x, y, radius, color) {
```

  const el = document.createElement('div');

```
  const size = `${radius * 2}px`;
```
```
  Object.assign(el.style, {
```
```
    position: 'absolute',
```
```
    left: `${x}px`,
```
```
    top: `${y}px`,
```
```
    width: size,
```
```
    height: size,
```

    transform: `translate(${-radius}px, ${-radius}px)`,

```
    borderRadius: '50%',
```
```
    background: color
```
```
  });
```
```
  el.classList.add('dot');
```
```
  document.body.appendChild(el);
```
```
  return el;
```
```
}
```
```
 
```
```
const elA = dot(0, 40, 30, 'red');
```
```
const elB = dot(0, 110, 30, 'blue');
```
```
const elC = dot(0, 160, 20, 'green');
```
```
 
```
```
// how to use the easing equations:
```
```
let t = 0;
```
```
 
```
```
let start = Date.now();
```
```
let time = 0;
```
```
let duration = 2; // 2 seconds
```
```
function loop() {
```
```
  // frame based
```

  elA.style.left = `${ef.elastic(t) * 50}%`;

```
  t += 0.005;
```
```
 
```
```
  // time based
```
```
  if (time <= duration) {
```
```
    time = (Date.now() - start) / 1000;
```
```
    const param = time / duration;
```

    elB.style.left = `${ef.elastic(param) * 50}%`;

```
 
```
```
    // green bounce example
```

    elC.style.left = `${ef.bounce(param) * 50}%`;

```
  }
```
```
 
```
```
  requestAnimationFrame(loop);
```
```
}
```
```
loop();
```

I realized it might not be obvious how to use Raphaël’s easing equations. So I speed coded this example.

If you’d like to learn more about this kind of thing gsap is a great place to start… it is amazing… I highly recommend browsing the source.

January 18, 2022

// animation // javascript // oldschool // speed-coded // tricks

Older Posts

Newer Posts

Airbrush-esque

Alphabet Array Golfed

Drag Svg Circles

Speed-coded Eye

Raphaël Easing Equations How To

Recent

Archive