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const canvas = document.getElementById("tree-canvas")
const context = canvas.getContext("2d")
let angle = undefined
function tree(length, n) {
if (n === 0)
return
context.beginPath()
context.moveTo(0, 0)
context.lineTo(0, -length)
context.stroke()
context.save()
context.translate(0, -length)
context.save()
context.rotate(angle)
tree(length / 2, n - 1)
context.restore()
context.save()
context.rotate(-angle)
tree(length / 2, n - 1)
context.restore()
context.restore()
}
const depth_input = document.getElementById("depth")
const angle_input = document.getElementById("angle")
function draw() {
context.clearRect(0, 0, canvas.width, canvas.height)
context.save()
context.translate(canvas.width / 2, canvas.height)
angle = 2 * Math.PI * (parseInt(angle_input.value) / 360)
tree(canvas.height / 2, parseInt(depth_input.value))
context.restore()
}
depth_input.addEventListener("input", draw)
angle_input.addEventListener("input", draw)
function updateCanvas() {
const canvas_size = Math.min(window.innerWidth, window.innerHeight - 200)
canvas.width = canvas_size
canvas.height = canvas_size
context.strokeStyle = "#DDDDDD"
context.lineWidth = 0.7
draw()
}
window.addEventListener("resize", updateCanvas)
updateCanvas()
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