Add function for speed unit conversion to unit values

src/strings.cpp

@@ -798,6 +798,20 @@ uint ConvertSpeedToDisplaySpeed(uint speed)
 	return _units_velocity[_settings_game.locale.units_velocity].c.ToDisplay(speed, false);
 }
 
+/**
+ * Convert the given (internal) speed to the display speed, in units (not decimal values).
+ * @param speed the speed to convert
+ * @return the converted speed.
+ */
+uint ConvertSpeedToUnitDisplaySpeed(uint speed)
+{
+	uint result = ConvertSpeedToDisplaySpeed(speed);
+	for (uint i = 0; i < _units_velocity[_settings_game.locale.units_velocity].decimal_places; i++) {
+		result /= 10;
+	}
+	return result;
+}
+
 /**
  * Convert the given display speed to the (internal) speed.
  * @param speed the speed to convert

src/unit_conversion.h

@@ -8,6 +8,7 @@
 /** @file unit_conversion.h Functions related to unit conversion. */
 
 uint ConvertSpeedToDisplaySpeed(uint speed);
+uint ConvertSpeedToUnitDisplaySpeed(uint speed);
 uint ConvertDisplaySpeedToSpeed(uint speed);
 uint ConvertWeightToDisplayWeight(uint weight);
 uint ConvertDisplayWeightToWeight(uint weight);