Add 3-argument smoothstep and smootherstep

libs/math/include/psemek/math/interval.hpp

@@ -287,7 +287,9 @@ namespace psemek::math
 	template <typename T>
 	T clamp(T x, interval<T> const & i)
 	{
-		return std::max(i.min, std::min(i.max, x));
+		using std::min;
+		using std::max;
+		return max(i.min, min(i.max, x));
 	}
 
 	template <typename T>

libs/math/include/psemek/math/math.hpp

@@ -183,6 +183,14 @@ namespace psemek::math
 		return (x >= 0) ? std::fmod(x, m) : (m - std::fmod(-x, m));
 	}
 
+	template <typename T>
+	auto clamp(T const & x, T const & low, T const & high)
+	{
+		using std::min;
+		using std::max;
+		return min(high, max(low, x));
+	}
+
 	template <typename T>
 	bool make_min(T & target, T const & source)
 	{
@@ -222,6 +230,12 @@ namespace psemek::math
 		return x * x * (T{3} - T{2} * x);
 	}
 
+	template <typename T>
+	T smoothstep(T edge0, T edge1, T x)
+	{
+		return smoothstep(clamp((x - edge0) / (edge1 - edge0), T{0}, T{1}));
+	}
+
 	template <typename T>
 	T smootherstep(T x)
 	{
@@ -229,6 +243,12 @@ namespace psemek::math
 		return x * x2 * (T{10} - x * T{15} + x2 * T{6});
 	}
 
+	template <typename T>
+	T smootherstep(T edge0, T edge1, T x)
+	{
+		return smootherstep(clamp((x - edge0) / (edge1 - edge0), T{0}, T{1}));
+	}
+
 	template <typename T>
 	T inverse_smoothstep(T x)
 	{