arrayPick Randomly pick a value from an array

arrayPick([1,2,3]) // 2

arrayShuffle Randomly shuffle an array

arrayShuffle([1, 2, 3]) // [2, 1, 3]

clamp Clamps a value between an upper and lower bound.

const value = 100;
clamp(value, 0, 10) // 10

damp Framerate independent lerp

const value = 10;
damp(value, 50, 0.4, deltaTime) // 26

debounce Will only trigger function when it has not been invoked in given timeframe

const onResize = () => { console.log(window.innerWidth) }
document.addEventListener("resize", debounce(onResize, 250)) // Will be called on resize every 250ms

distance Distance between two points using pythagoras theorem

distance({ x: 0, y: 2 }, { x: 1, y: -2}) // 4.123

finiteStateMachine

// Create states
const walkState = state({
	name: "walk"
	enter: () => console.log("enter"),
})
const runState = state({
	name: "run"
	exit: () => console.log("leave run"),
	update: () => console.log("update run"),
})

// Create state machine
const fsm = finiteStateMachine([walkState, runState])

// Update on every tick
raf.add(fsm.update)

// Change current state
fsm.setState("run")

fract Loop a value between 0 and 1

fract(10.2) // 0.2

inertia

// Create inertia value
const value = inertia(0)

rad.add(() => {
  value.update()

  // Get value
  consol.log(value.get())
})

window.addEventListner("mousemove", (e) => {
  // Add delta
  value.add(e.clientX - value.get())
})

intersectionObserver

TODO: document

lerp Linear interpolation between two known points.

const value = 10;
lerp(value, 50, 0.4) // 26

map Re-maps a number from one range to another.

const value = 5;
map(value, 0, 10, 3, 20) // 11.5

objectPool Declare items once and then reuse them

const objects = objectPool([...Array(10)].map(new AnimatedLine))
objects.getNext() // will get the next object in the pool, once at the end, will get the first again

prefetch Prefectch a page, waits until the main thread is idle

prefetch(["/about.html", "/contact.html"])

prng Generate a pseudo random number between 0 and 1 based on a seed

const generator = prng("Your seed")
console.log(generator()) // 0.093 - will be same for every time the seed is called 

raf Central request animation frame loop, that starts and cancels itself.

// Add function to raf
const remove = raf(() => console.log("hello"))

// Remove function again
setTimeout(remove, 1000)

random Returns a random number in a given range.

const value = random(0, 100)

randomBool Randomly returns true or false

randomBool()

randomInt Returns a random integer in between two values

randomInt(0, 10) // 3

randomGaussian Random number that more likely returns the medium of the standard deviation to more closely mimic a natural randomness

randomGaussian(1) // Returns a value between 1 and -1

round Round to given decimal

const value = 10.4567890
round(value, 1000) // 10.456

smoothstep

TODO: document

smootherstep

TODO: document

spring

// Create spring
const spring = createSpring(0, { stiffness: 0.2, damping: 0.4, mass: 1.2 } )

rad.add(() => {
  // Update spring every tick
  spring.update()

  // Get value
  console.log(spring.get())
})

window.addEventListner("mousemove", (e) => {
  // Set target value
  spring.set(e.clientX)
})

weightedList

const list = weightedList([
  { item: "Option 1", weight: 9 },
  { item: "Option 2", weight: 1 }
])

list.get() // 9 out of 10 times will return "Option 1"