138 lines
4.1 KiB
Markdown
138 lines
4.1 KiB
Markdown
The template for the character controller in Godot is very basic.
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```
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extends CharacterBody2D
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const SPEED = 300.0
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const JUMP_VELOCITY = -300.0
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# Get the gravity from the project settings to be synced with RigidBody nodes.
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var gravity = ProjectSettings.get_setting("physics/2d/default_gravity")
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func _physics_process(delta):
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# Add the gravity.
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if not is_on_floor():
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velocity.y += gravity * delta
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# Handle jump.
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if Input.is_action_just_pressed("ui_accept") and is_on_floor():
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velocity.y = JUMP_VELOCITY
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# Get the input direction and handle the movement/deceleration.
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# As good practice, you should replace UI actions with custom gameplay actions.
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var direction = Input.get_axis("ui_left", "ui_right")
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if direction:
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velocity.x = direction * SPEED
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else:
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velocity.x = move_toward(velocity.x, 0, SPEED)
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move_and_slide()
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```
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The basic template uses two helper functions `is_on_floor` and `move_and_slide` along with the `velocity` variable to achieve jumping, falling, and movement.
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Let us use some of our newfound knowledge of physics to improve our player character!
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### Exported Variables
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Exported variables allow us to make changes to them in the Godot editor. This is nice for play testing as it gives us a visual way to tweak our code. Let's take the imortant variables and export them.
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```
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@export var SPEED = 10400
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@export var JUMP_VELOCITY = -300
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```
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### Collisions with RigidBodies
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Each time a PlayerCharacter body moves via `move_and_slide` any colliders it made contact with are stored in an array that can be retrieved via the `get_slide_collision` method.
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We can use that to apply an impulse to any RigidBody the player collided with.
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```
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# This represents the player's inertia
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# after calling move_and_slide()
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for i in get_slide_collision_count():
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var c = get_slide_collision(i)
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if c.get_collider() is RigidBody2D:
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c.get_collider().apply_central_impulse(-c.get_normal() * PUSH_FORCE)
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```
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## Creating a Melee Force Push Attack
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We can use our new knowledge of impulses to do some pretty cool attacks agains RigidBodies!
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To pull off the attack we need to know:
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* Is there a target in range?
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* What direction is the player facing?
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* Is there a target in front of them in range?
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* Are they attacking?
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* How much force should be applied?
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To tell if there is a target in range, we can use a handy feature called a Raycast.
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### Raycasts
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Raycasts can be used to detect collisions within a very narrow line. They are very helpful for detecting objects within a certain proximity.
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We will use them to detect if there are any items we can attack with a force-push within range of the player character.
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First we make a reference to our two raycasts:
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```
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@onready var rightRay = $RightRaycast
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@onready var leftRay = $LeftRaycast
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var pushRightEnabled = false
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var pushLeftEnabled = false
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#note no type assigned
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var pushTarget
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#can not force-push right if facing left
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var faceLeft = false
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```
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When we detect the action of a raycast we need to respond. First of all, we need to track which direction the player is facing, assuming that they can only force-push in the direction they are facing.
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```
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if direction:
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velocity.x = direction * SPEED
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faceLeft = true if direction<0 else false
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```
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```
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if rightRay.is_colliding():
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var collider = rightRay.get_collider()
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if collider is Node:
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if collider.is_in_group("boxes"):
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pushRightEnabled = true
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pushTarget = collider
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else:
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pushRightEnabled = false
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```
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And we can do the same for the left ray:
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```
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if leftRay.is_colliding():
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var collider = leftRay.get_collider()
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if collider is Node:
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if collider.is_in_group("boxes"):
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pushLeftEnabled = true
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pushTarget = collider
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else:
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pushLeftEnabled = false
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```
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Now we just have to detect if the player is holding the force push button.
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```
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if Input.is_action_just_pressed("push") && pushRightEnabled && faceLeft == false:
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label.text="shove"
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pushTarget.apply_central_impulse(Vector2(1,0) * PUSH_FORCE * 20)
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pushRightEnabled = false
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if Input.is_action_just_pressed("push") && pushLeftEnabled :
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label.text="shove"
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pushTarget.apply_central_impulse(Vector2(-1,0) * PUSH_FORCE * 20)
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pushLeftEnabled = false
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``` |