1 files changed, 36 insertions, 16 deletions

diff --git a/common/accel-natural.hpp b/common/accel-natural.hpp
index 03700c1..9f76d1a 100644
--- a/common/accel-natural.hpp
+++ b/common/accel-natural.hpp
@@ -1,35 +1,55 @@
 #pragma once
 
-#include <math.h>
+#include "rawaccel-base.hpp"
 
-#include "accel-base.hpp"
+#include <math.h>
 
 namespace rawaccel {
 
 	/// <summary> Struct to hold "natural" (vanishing difference) acceleration implementation. </summary>
-	struct natural_impl {
-		double rate;
-		double limit;
+	struct natural_base {
 		double offset;
+		double accel;
+		double limit;
 
-		natural_impl(const accel_args& args) :
-			rate(args.accel), limit(args.limit - 1), offset(args.offset)
+		natural_base(const accel_args& args) :
+			offset(args.offset),
+			limit(args.limit - 1)
 		{
-			rate /= limit;
+			accel = args.decay_rate / fabs(limit);
 		}
+	};
 
-		inline double operator()(double speed) const {
-			// f(x) = k(1-e^(-mx))
-			double base_speed = speed + offset;
-			return limit * (1 - ((exp(-rate * speed) * speed + offset) / base_speed));
-		}
+	struct natural_legacy : natural_base {
+
+		double operator()(double x) const 
+		{
+			if (x <= offset) return 1;
 
-		inline double legacy_offset(double speed) const {
-			return limit - (limit * exp(-rate * speed));
+			double offset_x = offset - x;
+			double decay = exp(accel * offset_x);
+			return limit * (1 - (offset - decay * offset_x) / x) + 1;
 		}
 
+		using natural_base::natural_base;
 	};
 
-	using accel_natural = additive_accel<natural_impl>;
+	struct natural : natural_base {
+		double constant;
+
+		double operator()(double x) const 
+		{
+			if (x <= offset) return 1;
+
+			double offset_x = offset - x;
+			double decay = exp(accel * offset_x);
+			double output = limit * (decay / accel - offset_x) + constant;
+			return output / x + 1;
+		}
+
+		natural(const accel_args& args) :
+			natural_base(args),
+			constant(-limit / accel) {}
+	};
 
 }