0 votes

Hey. I am trying to implement a jump potion into my game which changes the jump height of player from -600 to -1000. I have declared the jump height variable in a script called "globals.gd" which is an enabled singleton.
For some reason the new jump height (of -1000) ist only applied when my KinematicBody2D (the Player) has died and the current scene is reloaded but not when he collects the jump potion (Area2D with signal "body_entered").

asked May 27 in Engine by Frenggie (27 points)

please show the scripts.

Sry, my bad. I cut it to the relevant parts.

The Player.gd

var JUMP_HEIGHT = Globals.JUMP_HEIGHT   # globals singleton
func _physics_process(delta):
#The jump part
    if is_on_floor():
        if Input.is_action_just_pressed("ui_up"):
            motion.y = JUMP_HEIGHT
        if friction == true:
        motion.x = lerp(motion.x, 0, 0.1)

The jump_potion.gd

func _on_Jump_Potion_body_entered(body):
    set_process(true)
    if body.name == "Player":
        Globals.JUMP_HEIGHT = -1000
        $Timer.start()
        print("AREA ENTERED")
        queue_free()
    else:
        pass


func _on_Timer_timeout():
    Globals.JUMP_HEIGHT = -600

The globals.gd (singleton)

var JUMP_HEIGHT = -600

1 Answer

0 votes

Code is VERY relevant ;)


Cause:
You create a variable JUMPHEIGHT and set it in the frist line to the value of Globals.JUMPHEIGHT. But after that, you never update JUMPHEIGHT.
JUMP
HEIGHT is just a variable, not a reference. So it does not change, when you change Globals.JUMP_HEIGHT.


Solution(s):

  • always use Globals.JUMPHEIGHT instead of JUMPHEIGHT
  • update JUMPHEIGHT on every _physicsprocess before calculations

PS.: You should not use UPPERCASE-Variable names. Thats for constants and enums ;)
Of course it works, but can cause confusion if you show your code to others.
(See here)

answered May 27 by whiteshampoo (976 points)

Thanks. By directly using the global variable, everything works fine. I thought that by changing the reference variable the referenced variable itself will change too.
I guess that's some pretty stupid beginner mistake xD.

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