effect.md

How effect work

What is an effect

An effect is a godot script who is call to apply different modification (example : change stat, move bullet or shoot in different angle).

How the effect system work

0. The effect is set in the entity or listed in the list of givable item.
1. The effect is given to an entity in the entity code or in the effect menu.
2. Some effects apply itself the bullet (ex: effect to move the bullet).
3. Some effect also applies itself to the enemy (ex : burning effect).

Make effect

There is the minimal code of an effect.

class_name effectName extends AbstractEffect

const name = "effect name"

From here you can add various function.

Example :

func onShoot(entity:Node2D):
	var bullet = entity.generateBullet()
	bullet.rotation_degrees = 90
	bullet.global_position = entity.global_position
	entity.find_parent("gameInfo").add_child(bullet)

This code make the entity shoot on the side, see the function list for more information.

Add your effect to the game

If the effect is for the player, to add the class in listOfGivableItem.gd.

If it used in another way, use the addEffets() of the AbstractEffectEntity.

Helper methods

These function can't help you while making effect :

entity.generateBullet()

return : Bullet object

Generate a bullet with effect, use this to shot it.

Effect methods

applyInit()

Call when the effect is initialized.

applyBallEffect():

argument : bullet : bullet object

Call to add effect to bullet before shoot.

# MorePierce.gd
func applyBallEffect(bullet:Bullet):
	bullet.pierce += level * 2

onShoot() :

Call when shooting.

moveBullet():

argument : speed : float | bullet : bullet object

Call to handle bullet movement.

# MoveNormal.gd
func moveBullet(speed:float,bullet:Bullet):
	bullet.position += Vector2.UP.rotated(bullet.rotation) * speed

onBulletCollide()

argument : bullet:Bullet | colider:Node2D

call when bullet touch something

onBulletDied()

argument : bullet:Bullet

Call when bullet is destroyed. You can use bullet.doNotFree = true to cancel the destruction (freeing in godot) of the bullet.

# MissileBullet.gd
func onBulletDied(bullet):
	var explosion = load("res://object/effect/explosion.tscn").instantiate()
	explosion.position = bullet.position
	explosion.scale = Vector2.ONE * 3
	explosion.origin = bullet.origin
	bullet.find_parent("gameInfo").add_child(explosion)