1 files changed, 33 insertions, 0 deletions
diff --git a/common/accel-logarithm.hpp b/common/accel-logarithm.hpp
new file mode 100644
index 0000000..0dbf433
--- /dev/null
+++ b/common/accel-logarithm.hpp
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <math.h>
+
+#include "accel-base.hpp"
+
+namespace rawaccel {
+
+	/// <summary> Struct to hold sigmoid (s-shaped) gain implementation. </summary>
+	struct logarithm_impl {
+		double rate;
+		double offset;
+		double additive_const;
+
+		logarithm_impl (const accel_args& args) :
+			rate(args.rate), offset (args.offset) {
+			additive_const = offset * rate;
+		}
+
+		inline double operator()(double speed) const {
+			//f(x) = k/(1+e^(-m(c-x)))
+			double scaled_speed = rate * speed + 1;
+			double base_speed = speed + offset;
+
+			return (scaled_speed * log(scaled_speed) + additive_const ) / ( rate * base_speed) - 1;
+		}
+
+		inline double legacy_offset(double speed) const { return operator()(speed); }
+	};
+
+	using accel_logarithm = additive_accel<logarithm_impl>;
+
+}