Maths

A vanilla JS class with Math functions not included in the JS standard library Math object. This repo also contians a couple of example pages for how to use the randomness mthods as well as the easing mthods.

Maths.norm(value, min, max)
Maths.clamp(value, min, max)
Maths.lerp(valueA, valueB, t)
Maths.map(value, sourceMin, sourceMax, destMin, destMax)

Maths.dist(p1x, p1y, p2x, p2y)
Maths.angleBtw(p1x, p1y, p2x, p2y)

Maths.radToDeg(radians)
Maths.degToRad(degrees)
Maths.cartesianToPolar(x, y)
Maths.polarToCartesian(distance, angle)

Maths.shuffle(array)
Maths.randomInt(min, max)
Maths.randomFloat(min, max)
Maths.random(val, val2)
Maths.perlin()

Maths.easeInQuad(t)
Maths.easeOutQuad(t)
Maths.easeInOutQuad(t)
Maths.easeInCubic(t)
Maths.easeOutCubic(t)
Maths.easeInOutCubic(t)
Maths.easeInQuart(t)
Maths.easeOutQuart(t)
Maths.easeInOutQuart(t)
Maths.easeInQuint(t)
Maths.easeOutQuint(t)
Maths.easeInOutQuint(t)
Maths.easeInSine(t)
Maths.easeOutSine(t)
Maths.easeInOutSine(t)
Maths.easeInCirc(t)
Maths.easeOutCirc(t)
Maths.easeInOutCirc(t)
Maths.easeInElastic(t)
Maths.easeOutElastic(t)
Maths.easeInOutElastic(t)
Maths.easeInExpo(t)
Maths.easeOutExpo(t)
Maths.easeInOutExpo(t)
Maths.easeInBack(t)
Maths.easeOutBack(t)
Maths.easeInOutBack(t)
Maths.easeInBounce(t)
Maths.easeOutBounce(t)

the easing methods are pretty "raw", so any timing or higher level logic is up to u, for ex:

// example of using one of the easing functions to get a tweened scrolling effect
function tween (from, to, i = 0) {
  if (this.tweenTimer) clearTimeout(this.tweenTimer)
  const dur = 2 // duration in seconds
  const fps = 1000 / 30 // 30 frames per second
  const inc = 1 / dur / fps
  i += inc
  if (i >= 1) return
  const pos = Maths.easeInOutQuart(i)
  const Y = Maths.map(pos, 0, 1, from, to)
  window.scrollTo(0, Y)
  this.tweenTimer = setTimeout(() => tween(from, to, i), fps)
}

tween(0, 100) // scroll from 0 to 1000 w/an easeInOutQuart

the perlin method returns a perlinNoise object, which first needs to be seeded && then can be used to return 1 or 2 dimensional noise from -1 to 1, for ex:

// assuming we've got a canvas && ctx...
const perlin = Maths.perlin()
perlin.seed()
for (let x = 0; x < canvas.width; x++) {
  let y = perlin.get(x * 0.1)
  y = Maths.map(y, -1, 1, 0, canvas.height)
  ctx.lineTo(x, y)
}
ctx.stroke()