move wayfinder files to Flumi folder

flumi/addons/SmoothScroll/scroll_damper/expo_scroll_damper.gd

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+extends ScrollDamper
+class_name ExpoScrollDamper
+
+
+## Friction, not physical. 
+## The higher the value, the more obvious the deceleration. 
+@export_range(0.001, 10000.0, 0.001, "or_greater", "hide_slider")
+var friction := 4.0:
+	set(val):
+		friction = max(val, 0.001)
+		_factor = pow(10.0, friction)
+
+## Factor to use in formula
+var _factor := 10000.0:
+	set(val): _factor = max(val, 1.000000000001)
+
+## Minumun velocity.
+@export_range(0.001, 100000.0, 0.001, "or_greater", "hide_slider")
+var minimum_velocity := 0.4:
+	set(val): minimum_velocity = max(val, 0.001)
+
+
+func _calculate_velocity_by_time(time: float) -> float:
+	var minimum_time = _calculate_time_by_velocity(minimum_velocity)
+	if time <= minimum_time: return 0.0
+	return pow(_factor, time)
+
+
+func _calculate_time_by_velocity(velocity: float) -> float:
+	return log(abs(velocity)) / log(_factor)
+
+
+func _calculate_offset_by_time(time: float) -> float:
+	return pow(_factor, time) / log(_factor)
+
+
+func _calculate_time_by_offset(offset: float) -> float:
+	return log(offset * log(_factor)) / log(_factor)
+
+
+func _calculate_velocity_to_dest(from: float, to: float) -> float:
+	var dist = to - from
+	var min_time = _calculate_time_by_velocity(minimum_velocity)
+	var min_offset = _calculate_offset_by_time(min_time)
+	var time = _calculate_time_by_offset(abs(dist) + min_offset)
+	var vel = _calculate_velocity_by_time(time) * sign(dist)
+	return vel