gd: added input addon

addons/guide/inputs/guide_input_touch_distance.gd

@@ -0,0 +1,76 @@
+## Input representing the distance changes between two fingers. 
+@tool
+class_name GUIDEInputTouchDistance
+extends GUIDEInput
+
+var _initial_distance:float = INF
+
+# We use the reset call to calculate the distance for this frame
+# so it can serve as reference for the next frame
+func _needs_reset() -> bool:
+	return true
+
+func _reset():
+	var distance = _calculate_distance()
+	# update initial distance when input is actuated or stops being actuated
+	if is_finite(_initial_distance) != is_finite(distance):
+		_initial_distance = distance
+		
+
+func _begin_usage() -> void:
+	# subscribe to relevant input events
+	_state.touch_state_changed.connect(_refresh)
+	_refresh()
+	
+func _end_usage() -> void:
+	# unsubscribe from input events
+	_state.touch_state_changed.disconnect(_refresh)
+	
+
+func _refresh() -> void:
+	var distance := _calculate_distance()
+	# if either current distance or initial distance is not set,
+	# we are zero
+	if not is_finite(distance) or not is_finite(_initial_distance):
+		_value = Vector3.ZERO
+		return
+		
+	# we assume that _initial_distance is never 0 because
+	# you cannot have two fingers physically at the same place
+	# on a touch screen
+	_value = Vector3(distance / _initial_distance, 0, 0)
+		
+	
+func _calculate_distance() -> float:
+	var pos1:Vector2 = _state.get_finger_position(0, 2)
+	# if we have no position for first finger, we can immediately abort
+	if not pos1.is_finite():
+		return INF
+		
+	var pos2:Vector2 = _state.get_finger_position(1, 2)
+	# if there is no second finger, we can abort as well
+	if not pos2.is_finite():
+		return INF
+		
+	# calculate distance for the fingers
+	return pos1.distance_to(pos2)
+	
+ 		
+func is_same_as(other:GUIDEInput):
+	return other is GUIDEInputTouchDistance
+
+
+func _to_string():
+	return "(GUIDEInputTouchDistance)"
+
+
+func _editor_name() -> String:
+	return "Touch Distance"
+
+	
+func _editor_description() -> String:
+	return "Distance of two touching fingers."
+
+
+func _native_value_type() -> GUIDEAction.GUIDEActionValueType:
+	return GUIDEAction.GUIDEActionValueType.AXIS_1D