godot/demos/3d/platformer/enemy.gd

extends RigidBody

# member variables
const STATE_WALKING = 0
const STATE_DYING = 1

var prev_advance = false
var deaccel = 20.0
var accel = 5
var max_speed = 2
var rot_dir = 4
var rot_speed = 1

var dying = false


func _integrate_forces(state):
	var delta = state.get_step()
	var lv = state.get_linear_velocity()
	var g = state.get_total_gravity()

	lv += g*delta # apply gravity
	var up = -g.normalized()

	if (dying):
		state.set_linear_velocity(lv)
		return
	
	for i in range(state.get_contact_count()):
		var cc = state.get_contact_collider_object(i)
		var dp = state.get_contact_local_normal(i)
		
		if (cc):
			if (cc extends preload("res://bullet.gd") and not cc.disabled):
				set_mode(MODE_RIGID)
				dying = true
				#lv = s.get_contact_local_normal(i)*400
				state.set_angular_velocity(-dp.cross(up).normalized()*33.0)
				get_node("AnimationPlayer").play("impact")
				get_node("AnimationPlayer").queue("explode")
				set_friction(1)
				cc.disabled = true
				get_node("sound").play("hit")
				return
	
	var col_floor = get_node("Armature/ray_floor").is_colliding()
	var col_wall = get_node("Armature/ray_wall").is_colliding()
	
	var advance = not col_wall and col_floor
	
	var dir = get_node("Armature").get_transform().basis[2].normalized()
	var deaccel_dir = dir
	
	if (advance):
		if (dir.dot(lv) < max_speed):
			lv += dir*accel*delta
		deaccel_dir = dir.cross(g).normalized()
	else:
		if (prev_advance):
			rot_dir = 1 # randf()*2.0 - 1.0
		
		dir = Matrix3(up, rot_dir*rot_speed*delta).xform(dir)
		get_node("Armature").set_transform(Transform().looking_at(-dir, up))
	
	var dspeed = deaccel_dir.dot(lv)
	dspeed -= deaccel*delta
	if (dspeed < 0):
		dspeed = 0
	
	lv = lv - deaccel_dir*deaccel_dir.dot(lv) + deaccel_dir*dspeed
	
	state.set_linear_velocity(lv)
	prev_advance = advance


func _die():
	queue_free()