GPN20 display hack

display.js

let tx = document.getElementById("text-input")
let h = 2
let state = Array(24).fill([h, '_'])
let c = ['/', '_', '\\']
let interval

function step () {
    let direction = Math.floor(Math.random() * 2.9999) - 1
    let d = Math.min(3, Math.max(0, h+direction))
    state.shift()
    let uuu = c[d-h +1]
    state.push([h, uuu])
    h = d
    tx.value = render(state)
    updateDisplay()
}

function render(state) {
    let asdf = Array(4).fill(null)
    let buuu = asdf.map(_ => Array(24).fill(' '))
    for (let index in state) {
        let arr = state[index]
        let realh = arr[0]+(arr[1] == '\\')
        buuu[realh][index] = arr[1]
        realh +=1
        for (;realh<4;realh++) {
            buuu[realh][index] = '8'
        }
    }
    return buuu.map(a => a.join('')).join('\n')
}

int = setInterval(step, 250)