turtle: option for direction turtle can spike

objects/enemy/turtle.gd

@@ -1,10 +1,14 @@
 tool
 extends "res://objects/enemy/enemy_move_sidesideupdown.gd"
 
+enum SpikeDirection {BOTH, LEFT, RIGHT}
+
 ## positions along the path where spikes will trigger
 export (Array, float) var spike_positions: Array = []
 ## time spikes stay active
 export var spike_time: float = 0.25
+## which direction the turtle should be able to spike
+export (SpikeDirection) var spike_direction: int = SpikeDirection.BOTH
 
 # animates the spikes
 var can_spike: bool = true
@@ -57,7 +61,8 @@ func _physics_process(delta: float) -> void:
 				if pos >= pos_start + spike_positions[current_spike_position]:
 					# move on to next position
 					current_spike_position += 1
-					spike()
+					if spike_direction != SpikeDirection.LEFT:
+						spike()
 		-1.0:
 			# make sure there are still positions left in this direction
 			if current_spike_position - 1 >= 0:
@@ -65,7 +70,8 @@ func _physics_process(delta: float) -> void:
 				if pos <= pos_start + spike_positions[current_spike_position - 1]:
 					# move on to next (previous because backwards) position
 					current_spike_position -= 1
-					spike()
+					if spike_direction != SpikeDirection.RIGHT:
+						spike()
 
 ## performs the spike animation
 func spike() -> void: