Fix interpolation

The macro approach doesn't work here as long as values are passed by reference

src/Utilities/Interpolation.h

@@ -5,9 +5,6 @@
 
 namespace detail
 {
-	#define FROM_DOUBLE(type, first, second, percentage, mode) \
-		 (type)(interpolate((double&)first, (double&)second, percentage, mode));
-
 	template <typename T>
 	inline T interpolate(T& first, T& second, double percentage, InterpolationMode mode)
 	{
@@ -34,24 +31,34 @@ namespace detail
 	template <>
 	inline int interpolate<int>(int& first, int& second, double percentage, InterpolationMode mode)
 	{
-		return FROM_DOUBLE(int, first, second, percentage, mode);
+		double firstValue = first;
+		double secondValue = second;
+		return (int)interpolate(firstValue, secondValue, percentage, mode);
+	}
+
+	template <>
+	inline BYTE interpolate<BYTE>(BYTE& first, BYTE& second, double percentage, InterpolationMode mode)
+	{
+		double firstValue = first;
+		double secondValue = second;
+		return (BYTE)interpolate(firstValue, secondValue, percentage, mode);
 	}
 
 	template <>
 	inline ColorStruct interpolate<ColorStruct>(ColorStruct& first, ColorStruct& second, double percentage, InterpolationMode mode)
 	{
-		BYTE r = FROM_DOUBLE(BYTE, first.R, second.R, percentage, mode);
-		BYTE g = FROM_DOUBLE(BYTE, first.G, second.G, percentage, mode);
-		BYTE b = FROM_DOUBLE(BYTE, first.B, second.B, percentage, mode);
+		BYTE r = interpolate(first.R, second.R, percentage, mode);
+		BYTE g = interpolate(first.G, second.G, percentage, mode);
+		BYTE b = interpolate(first.B, second.B, percentage, mode);
 		return ColorStruct { r, g, b };
 	}
 
 	template <>
 	inline TranslucencyLevel interpolate<TranslucencyLevel>(TranslucencyLevel& first, TranslucencyLevel& second, double percentage, InterpolationMode mode)
 	{
-		int firstValue = first.GetIntValue();
-		int secondValue = second.GetIntValue();
-		int value = FROM_DOUBLE(int, firstValue, secondValue, percentage, mode);
+		double firstValue = first.GetIntValue();
+		double secondValue = second.GetIntValue();
+		int value = (int)interpolate(firstValue, secondValue, percentage, mode);
 		return TranslucencyLevel(value, true);
 	}
 }