is_on_floor is not working in the game I am making.

Question

var motion = Vector2(0,0)

const SPEED = 500
const GRAVITY = 5
const UP = Vector2(0,-1)
const JUMP = -3000

func physicsprocess(delta):
if Input.isactionpressed("uiup"):
print("should jump but isnt")
applygravity()
jump()
move()
animate()
moveandslide(motion)

func applygravity():
if not ison_floor():
motion.y += GRAVITY
else:
motion.y = GRAVITY

func move():
if Input.isactionpressed("uileft") and not Input.isactionpressed("uiright"):
motion.x = -SPEED
elif Input.isactionpressed("uiright") and not Input.isactionpressed("uileft"):
motion.x = SPEED
else:
motion.x = 0

func jump():
if Input.isactionjustpressed("uiup") and isonfloor():
motion.y = JUMP

Answer 1

Your move_and_slide doesn't have an up direction so it defaults to Vector2.ZERO. It mentions in the docs 'used to determine what is a wall and what is a floor or a ceiling'

move_and_slide(motion, Vector2.UP)