Problem transitioning between states

NJL64

Sometimes, when my player collides with a "Bumper", they are obstructed by the collision, but they don't transition to the BOUNCE state. I'm looking for help with what I'm missing.

States.MOVE: 
			if Input.is_action_just_released("move"):
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif collision:
				if collision.get_collider().name == "Bumper":
					state = States.BOUNCE
			else: # run move code
				speed = speed_move # set speed to move speed
				velocity = direction_input * speed # move
				move_and_slide() # define movement and slide across walls

xyz

NJL64 but they don't transition to the BOUNCE state

How did you determine that? Put a print statement before every state change so you can follow what exactly is happening.

NJL64

xyz I put a print statement to confirm it. What happens is when I test it, the player sometimes collides with the bumper, but doesn't bounce away from it or print the statement. They are simply obstructed by it.

xyz

NJL64 Let's see the complete code with all print statements and the actual output of those prints in both cases (working as expected and not working)

NJL64

xyz
I'm kind of desperate at this point. Here is the code and the project.

isometric-2025-11-30-19-25-04.zip

43kB

Code:

extends CharacterBody2D

# states 
enum States {IDLE, MOVE, CHARGE, BLAST, SPIN, BOUNCE}
var state = States.IDLE # default state

# main variables
var pwr_lvl = 0 # What bar is it on for how far it can shoot
var speed = 0 # speed when moving 
var deceleration = 0
var button_held_for = 0 # amount of time button is being held for

# boolean variables
var can_charge_player = true 
var can_call_timer = true

# exportable variables (can be altered in editor)
@export var acceleration = 2.5 # higher starts quicker
@export var deceleration_bounce = 9.5
@export var deceleration_blast = 9.5 # higher stops quicker
@export var deceleration_spin = 3.5 # higher stops quicker
@export var direction_last = Vector2(1, 1) # default direction facing (SE)
@export var speed_move = 50 # speed when moving with input
@export var speed_spin = 100 # speed when spinning
@export var speed_max = 999 # maximum speed
@export var bounce_strength = 500
@export var pwr_lvl_min = 200
@export var pwr_lvl_max = 1000
@export var pwr_lvl_increment = 200

# node variables
@onready var anim_power_meter = $PowerMeter/AnimationPowerMeter
@onready var anim_turtle = $AnimationTurtle
@onready var sound_ricochet = $SoundRicochet
@onready var timer_blast_cooldown = $TimerBlastCooldown
@onready var timer_power_meter = $PowerMeter/TimerPowerMeter

# functions
func _physics_process(delta: float): # delta variable has value of the frame time that engine passes to function.
	# local variables 
	var collision = move_and_collide(velocity * delta) # define collision
	var direction_input = Input.get_vector("left", "right", "up", "down")
	var direction_facing = direction_last # last direction is direction you are facing
	direction_last = get_direction() # returns value from respective function
	
	match state:
		
		States.IDLE:
			if Input.is_action_pressed("move"):
				state = States.MOVE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif Input.is_action_just_pressed("spin"):
				state = States.SPIN # change state
			else: # run idle code
				velocity = Vector2.ZERO # idle
				speed = 0 # reset speed
				anim_turtle.play("idle") # resume idle animation
			
		States.MOVE:
			if collision and collision.get_collider().name == "Bumper":
				print("BOUNCE")
				state = States.BOUNCE
			elif Input.is_action_just_released("move"):
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			else: # run move code
				speed = speed_move # set speed to move speed
				velocity = direction_input * speed # move
				move_and_slide() # define movement and slide across walls
				anim_turtle.play("animate") # play animation
				if collision:
					print("C")
			
		States.BOUNCE:
			if velocity.is_zero_approx():
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif collision:
				if collision.get_collider().name == "Bumper": # bounce code
					velocity = velocity.bounce(collision.get_normal()).normalized() * bounce_strength # bounce (get collision vector's normal)
					deceleration = deceleration_bounce # this goes here so the rate doesn't reset after being established in a prev state
				else:
					velocity = velocity.bounce(collision.get_normal()) # bounce (get collision vector's normal)
				anim_turtle.play("shell")
				sound_ricochet.play()
			apply_deceleration() # always decelerate
				
		States.CHARGE:
			if Input.is_action_just_released("space_bar"):
				state = States.BLAST # change state
			else: # charge code
				if Input.is_action_pressed("move"):
					direction_last = direction_input # able to change direction while spinning
				if ! velocity.is_zero_approx(): # if velocity not 0
					speed = 0 # start from zero everytime pressed
				velocity = Vector2.ZERO # be still while charging
				can_call_timer = true # reenable ability to call timer
				anim_turtle.play("shell") # play animation
				button_held_for += delta # number increases every frame that button is held down to keep track of how long
				speed = pwr_lvl # power level determines speed for blast attack (pl can't fit in for spd by itself)
				
		States.BLAST:
			if ! speed: # if speed reaches 0 (no speed)
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif collision:
				state = States.BOUNCE
			else: # run blast code
				velocity = direction_facing * speed # blast in direction facing
				velocity = velocity.normalized() * speed # prevent going faster when going diagonal
				deceleration = deceleration_blast # set deceleration value
				apply_deceleration() # decelerate
				anim_turtle.play("shell") # play animation
				button_held_for = 0 # reset
				pwr_lvl = 0 # reset
				if can_call_timer: # makes sure the timer doesn't start every frame while in the BLAST state
					can_call_timer = false # because it has already been started once
					timer_blast_cooldown.start() # start cooldown
				
		States.SPIN:
			if Input.is_action_just_pressed("spin"):
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif Input.is_action_just_released("space_bar"):
				state = States.BLAST # change state
			elif Input.is_action_just_released("move"):
				deceleration = deceleration_spin
				apply_deceleration()
			elif collision:
				velocity = velocity.bounce(collision.get_normal()) # bounce
				sound_ricochet.play() # play sfx
			else: # spin code (accelerate/move)
				apply_acceleration(direction_input)
				position += velocity * delta # move without move_and_slide() dictating collision effect
				anim_turtle.play("shell") # play animation
			speed = velocity.length() # speed value reflects velocity
			
	if collision:
		print("colliding")
	get_direction()
	power_meter()
	_on_timer_blast_cooldown_timeout()
	#print("Direction Facing: ", direction_facing)
	#print("Speed: ", speed)
	#print("Velocity: ", velocity)
	#print("Power Level: ", power_level)
	#print("Button Held For: ", button_held_for)
	#print("Timer: ", timer_blast_cooldown.time_left)
	#print("Can Charge Player: ", can_charge_player)
	#print("Can Call Timer: ", can_call_timer)

func power_meter() -> void: # under construction
	if Input.is_action_just_pressed("space_bar"): # if button just pressed (otherwise timer would reset and never timeout)
		pwr_lvl = pwr_lvl_min # power level starts at minimum
		timer_power_meter.start() # start timer
		print("held down!")
	elif Input.is_action_just_released("space_bar"):
		timer_power_meter.stop()
		anim_power_meter.frame = 0
		print("released!")
		
func _on_timer_power_bar_timeout() -> void:
	if pwr_lvl < pwr_lvl_max: # only if lower than max
		pwr_lvl += pwr_lvl_increment # increase power meter
		anim_power_meter.frame = (anim_power_meter.frame + 1)
	elif pwr_lvl >= pwr_lvl_max: # if reached max
		pwr_lvl = pwr_lvl_max # stay at max
	print(pwr_lvl)
	print("increased!")
	
func apply_acceleration(direction_input) -> void: # currently, acceleration is only being used for SPIN
	speed = speed_spin
	velocity = velocity.move_toward(direction_input * speed, acceleration) # to, by
	
func apply_deceleration() -> void:
	velocity = velocity.move_toward(Vector2.ZERO, deceleration) # decelerate velocity
	speed = move_toward(speed, 0, deceleration) # decelerate speed
	
func _on_timer_blast_cooldown_timeout() -> void: # on timer node timeout
	if timer_blast_cooldown.time_left > 0: # timer starts 
		can_charge_player = false # disable ability to charge
	else: # og code: elif ! Input.is_action_pressed("space_bar"):
		can_charge_player = true # enable ability to charge
	# with this small timer you can stop to charge very quickly, without being able to button mash
		
func _on_cool_down_blast_timeout() -> void:
	if ! States.BLAST: # if not in the BLAST state
		can_call_timer = true # reenable ability to call timer
		
func get_direction(): # used for obtaining directions (getting what the last direction was)
	var direction = velocity # value of direction
	var angle = fposmod(rad_to_deg(direction.angle()), 360) # (f for float; a positive modulus is 0 or greater), normalizes the angle and ensures it remains within the range of 0 to 360 (circle)
	var sector = wrapi(snapped(angle, 45) / 45, 0, 8) # snap a 45 degree angle and wrap between 0-8; determine sector based on the snapped angle (360 / 45 = 8; there are 8 directions)
	if velocity.is_zero_approx(): # when you let go
		return direction_last # return and maintain last value of dir_last (it maintains it when you stop because its zero. That's why it works)
	direction_last = [Vector2(1, 0), # E
	Vector2(1, 1), # SE
	Vector2(0, 1), # S
	Vector2(-1, 1), # SW
	Vector2(-1, 0), # W
	Vector2(-1, -1), # NW
	Vector2(0, -1), # N
	Vector2(1, -1)] [sector] # NE (select direction based on sector index)
	return direction_last # return corresponding vector coordinates
	# Next up: 
	# Study Vector Math
	# study other parts of code you want to understand better
	# practice typing the lines of code over and over
	# tidy up code to make it more readable

Many thanks to anyone who can help

kuligs2

And what state does it go in when it collides?

Maybe your conditionals are not working?

NJL64

kuligs2 I printed it. Sometimes it switches to the BOUNCE state, but other times it stays in the MOVE state.

kuligs2

NJL64 then its conditional problem..

Try using if statements and not elif

YolloY

NJL64 `enum States { IDLE, MOVE, CHARGE, BOUNCE }

state = States.IDLE

func process_state(delta):
match state:
States.IDLE:
if Input.is_action_pressed("move"):
state = States.MOVE
States.MOVE:
if Input.is_action_just_released("move"):
state = States.IDLE
elif Input.is_action_just_pressed("space_bar") and can_charge_player:
state = States.CHARGE
elif collision and collision.get_collider().name == "Bumper":
state = States.BOUNCE
else:
speed = speed_move
velocity = direction_input * speed
move_and_slide()
States.CHARGE:
pass # Logic for charging goes here
States.BOUNCE:
pass # Bounce logic goes here`

NJL64

kuligs2

YolloY

These seem to yield the same result unfortunately.

NJL64

I think there may be an issue where it is detecting the initial collision, but not the continued touching of the collisions. Maybe it's skipping a frame or only detects the first frame for some reason?

I stated

if collision: print("colliding")

in the physics process function, and got the same problem

I'm willing to share the whole project if anyone wants to volunteer to help. I'll keep working on it in the meantime.

trizZzle

You basically moved 2 steps per frame when you were in move state and probably missed some collisions I guess.
You called move_and_collide() and move_and_slide()

In the move_and_collide() function I would pass in "true" as second argument, so it only checks for collisions and does not affect movement.

func _physics_process(delta: float): # delta variable has value of the frame time that engine passes to function.
	# local variables 
	var collision = move_and_collide(velocity * delta, true) # define collision

And put the move_and_slide() function outside of your move state. For example at the end of your _physics_process() when all changes to the velocity are done. This way your character moves by its velocity only once per update.
You will notice the turtle will move only half the speed now. Real turtle speed 😆

I have 2 suggestions:
Once you add more than 1 bumper to the scene, checking by name won't work (Bumper2, Bumper3..).
One way is to add the Bumper scene to a group and check for it:
if collision and collision.get_collider().is_in_group("bumper"):

Maybe concider using a circle collision shape for your turtle. It makes movement around objects smoother.
It also improved collision detection before I noticed the issue with move_and_collide().

I really love the look of the game. 🙂

NJL64

trizZzle Thank you so much for the good advice and compliments on the project! I really appreciate it!

Adding true to move_and_collide seems to make it detect collision consistently! I'll just have to figure out how to move around some side effects:

adding true to move_and_collide causes the BLAST ability to stop working and bounce doesn't work (though it DOES detect the collision consistently)
placing move_and_slide in the physics process makes the collision detection inaccurate again

I like your suggestion for dealing with when I use more bumpers. I'll create a scene group like you said.

I'll keep editing it though and moving stuff around while keeping what you said in mind. I think your good suggestions offer great improvement. It's nice to get that interaction. Thank you so much again! I'm really glad you like the look of the project. 🥰

trizZzle

NJL64 I forgot to mention, that you have to add the bumper scene to the group you are checking for.

https://docs.godotengine.org/en/stable/tutorials/scripting/groups.html

I don't understand what you are refering to with the sideeffects. 🤔
Isn't this what it should look like?

NJL64

trizZzle Huh. Maybe I didn't place your suggestions correctly. Here's how it acts for me right now.
<iframe width="560" height="315" src="" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

I added true to move_and_collide() in my physics process,

and I tried removing move_and_slide() from the MOVE state and placing it at the bottom of physics process.

Is this how you did it?

Thank you for getting back to me by the way. I'm VERY grateful for your help!

I'll share the code as it exists now just in case:

extends CharacterBody2D

# states 
enum States {IDLE, MOVE, CHARGE, BLAST, SPIN, BOUNCE}
var state = States.IDLE # default state

# main variables
var pwr_lvl = 0 # What bar is it on for how far it can shoot
var speed = 0 # speed when moving 
var deceleration = 0
var button_held_for = 0 # amount of time button is being held for

# boolean variables
var can_charge_player = true 
var can_call_timer = true

# exportable variables (can be altered in editor)
@export var acceleration = 2.5 # higher starts quicker
@export var deceleration_bounce = 9.5
@export var deceleration_blast = 9.5 # higher stops quicker
@export var deceleration_spin = 3.5 # higher stops quicker
@export var direction_last = Vector2(1, 1) # default direction facing (SE)
@export var speed_move = 50 # speed when moving with input
@export var speed_spin = 100 # speed when spinning
@export var speed_max = 999 # maximum speed
@export var bounce_strength = 500
@export var pwr_lvl_min = 200
@export var pwr_lvl_max = 1000
@export var pwr_lvl_increment = 200

# node variables
@onready var anim_power_meter = $PowerMeter/AnimationPowerMeter
@onready var anim_turtle = $AnimationTurtle
@onready var sound_ricochet = $SoundRicochet
@onready var timer_blast_cooldown = $TimerBlastCooldown
@onready var timer_power_meter = $PowerMeter/TimerPowerMeter

# functions
func _physics_process(delta: float): # delta variable has value of the frame time that engine passes to function.
	# local variables 
	var collision = move_and_collide(velocity * delta, true) # define collision (true added)
	var direction_input = Input.get_vector("left", "right", "up", "down")
	var direction_facing = direction_last # last direction is direction you are facing
	direction_last = get_direction() # returns value from respective function
	
	match state:
		
		States.IDLE:
			if Input.is_action_pressed("move"):
				state = States.MOVE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif Input.is_action_just_pressed("spin"):
				state = States.SPIN # change state
			else: # run idle code
				velocity = Vector2.ZERO # idle
				speed = 0 # reset speed
				anim_turtle.play("idle") # resume idle animation
			
		States.MOVE:
			if collision and collision.get_collider().name == "Bumper":
				state = States.BOUNCE
			elif Input.is_action_just_released("move"):
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			else: # run move code
				speed = speed_move # set speed to move speed
				velocity = direction_input * speed # move
				anim_turtle.play("animate") # play animation
			
		States.BOUNCE:
			if velocity.is_zero_approx():
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif collision:
				if collision.get_collider().name == "Bumper": # bounce code
					velocity = velocity.bounce(collision.get_normal()).normalized() * bounce_strength # bounce (get collision vector's normal)
					deceleration = deceleration_bounce # this goes here so the rate doesn't reset after being established in a prev state
				else:
					velocity = velocity.bounce(collision.get_normal()) # bounce (get collision vector's normal)
				anim_turtle.play("shell")
				sound_ricochet.play()
			apply_deceleration() # always decelerate
				
		States.CHARGE:
			if Input.is_action_just_released("space_bar"):
				state = States.BLAST # change state
			else: # charge code
				if Input.is_action_pressed("move"):
					direction_last = direction_input # able to change direction while spinning
				if ! velocity.is_zero_approx(): # if velocity not 0
					speed = 0 # start from zero everytime pressed
				velocity = Vector2.ZERO # be still while charging
				can_call_timer = true # reenable ability to call timer
				anim_turtle.play("shell") # play animation
				button_held_for += delta # number increases every frame that button is held down to keep track of how long
				speed = pwr_lvl # power level determines speed for blast attack (pl can't fit in for spd by itself)
				
		States.BLAST:
			if ! speed: # if speed reaches 0 (no speed)
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif collision:
				state = States.BOUNCE
			else: # run blast code
				velocity = direction_facing * speed # blast in direction facing
				velocity = velocity.normalized() * speed # prevent going faster when going diagonal
				deceleration = deceleration_blast # set deceleration value
				apply_deceleration() # decelerate
				anim_turtle.play("shell") # play animation
				button_held_for = 0 # reset
				pwr_lvl = 0 # reset
				if can_call_timer: # makes sure the timer doesn't start every frame while in the BLAST state
					can_call_timer = false # because it has already been started once
					timer_blast_cooldown.start() # start cooldown
				
		States.SPIN:
			if Input.is_action_just_pressed("spin"):
				state = States.IDLE # change state
			elif Input.is_action_pressed("space_bar") and can_charge_player:
				state = States.CHARGE # change state
			elif Input.is_action_just_released("space_bar"):
				state = States.BLAST # change state
			elif Input.is_action_just_released("move"):
				deceleration = deceleration_spin
				apply_deceleration()
			elif collision:
				velocity = velocity.bounce(collision.get_normal()) # bounce
				sound_ricochet.play() # play sfx
			else: # spin code (accelerate/move)
				apply_acceleration(direction_input)
				position += velocity * delta # move without move_and_slide() dictating collision effect
				anim_turtle.play("shell") # play animation
			speed = velocity.length() # speed value reflects velocity
			
	get_direction()
	power_meter()
	_on_timer_blast_cooldown_timeout()
	move_and_slide() # taken from MOVE state
	#print("Direction Facing: ", direction_facing)
	#print("Speed: ", speed)
	#print("Velocity: ", velocity)
	#print("Power Level: ", power_level)
	#print("Button Held For: ", button_held_for)
	#print("Timer: ", timer_blast_cooldown.time_left)
	#print("Can Charge Player: ", can_charge_player)
	#print("Can Call Timer: ", can_call_timer)

func power_meter() -> void: # under construction
	if Input.is_action_just_pressed("space_bar"): # if button just pressed (otherwise timer would reset and never timeout)
		pwr_lvl = pwr_lvl_min # power level starts at minimum
		timer_power_meter.start() # start timer
		print("held down!")
	elif Input.is_action_just_released("space_bar"):
		timer_power_meter.stop()
		anim_power_meter.frame = 0
		print("released!")
		
func _on_timer_power_bar_timeout() -> void:
	if pwr_lvl < pwr_lvl_max: # only if lower than max
		pwr_lvl += pwr_lvl_increment # increase power meter
		anim_power_meter.frame = (anim_power_meter.frame + 1)
	elif pwr_lvl >= pwr_lvl_max: # if reached max
		pwr_lvl = pwr_lvl_max # stay at max
	print(pwr_lvl)
	print("increased!")
	
func apply_acceleration(direction_input) -> void: # currently, acceleration is only being used for SPIN
	speed = speed_spin
	velocity = velocity.move_toward(direction_input * speed, acceleration) # to, by
	
func apply_deceleration() -> void:
	velocity = velocity.move_toward(Vector2.ZERO, deceleration) # decelerate velocity
	speed = move_toward(speed, 0, deceleration) # decelerate speed
	
func _on_timer_blast_cooldown_timeout() -> void: # on timer node timeout
	if timer_blast_cooldown.time_left > 0: # timer starts 
		can_charge_player = false # disable ability to charge
	else: # og code: elif ! Input.is_action_pressed("space_bar"):
		can_charge_player = true # enable ability to charge
	# with this small timer you can stop to charge very quickly, without being able to button mash
		
func _on_cool_down_blast_timeout() -> void:
	if ! States.BLAST: # if not in the BLAST state
		can_call_timer = true # reenable ability to call timer
		
func get_direction(): # used for obtaining directions (getting what the last direction was)
	var direction = velocity # value of direction
	var angle = fposmod(rad_to_deg(direction.angle()), 360) # (f for float; a positive modulus is 0 or greater), normalizes the angle and ensures it remains within the range of 0 to 360 (circle)
	var sector = wrapi(snapped(angle, 45) / 45, 0, 8) # snap a 45 degree angle and wrap between 0-8; determine sector based on the snapped angle (360 / 45 = 8; there are 8 directions)
	if velocity.is_zero_approx(): # when you let go
		return direction_last # return and maintain last value of dir_last (it maintains it when you stop because its zero. That's why it works)
	direction_last = [Vector2(1, 0), # E
	Vector2(1, 1), # SE
	Vector2(0, 1), # S
	Vector2(-1, 1), # SW
	Vector2(-1, 0), # W
	Vector2(-1, -1), # NW
	Vector2(0, -1), # N
	Vector2(1, -1)] [sector] # NE (select direction based on sector index)
	return direction_last # return corresponding vector coordinates
	# Next up: 
	# Study Vector Math
	# study other parts of code you want to understand better
	# practice typing the lines of code over and over
	# tidy up code to make it more readable

If yours is different, would you consider sharing the project back to me for comparison?

trizZzle

NJL64 Yes, your code looks like mine. I just remembered something else I changed 😅 Sorry. When I tested your game I looked at a lot of different things.

I changed the characters motion mode to floating, which is recommended for top down games (for isometric as well I guess).
In floating mode the character handles slopes differently. Hover over the the "Motion Mode" text to read the info about it.

The only other thing I changed is setting the speed_move variable from 50 to 100 to get the same speed as before when both move functions applied the velocity. I believe that was all I changed. 🤔

NJL64

AAAAH! IT WORKS!!! You don't know how thrilled I am!

I had no idea what motion mode did (or that it was even there lol)! Thank you so much! I'm so relieved. I would have been stuck forever and my morale crushed. I'm so happy I can proceed. I learned a lot!

I'm forever grateful that you helped keep this project alive and even polished it up. THX! 😃

trizZzle

NJL64 You're welcome! 🙂 I'm curious what else you have planned for the game, it looks really interesting and the turtle is cute. 😊 Good luck and have fun!