Change classic, natural, naturalgain to use gain offset

3 files changed, 15 insertions, 6 deletions

diff --git a/common/accel-classic.hpp b/common/accel-classic.hpp
index 4cc52ca..3f409c3 100644
--- a/common/accel-classic.hpp
+++ b/common/accel-classic.hpp
@@ -10,14 +10,20 @@ namespace rawaccel {
 	struct classic_impl {
 		double accel;
 		double power;
+		double power_inc;
+		double offset;
+		double multiplicative_const;
 
 		classic_impl(const accel_args& args) :
-			accel(args.accel), power(args.exponent - 1)
-		{}
+			accel(args.accel), power(args.exponent - 1), offset(args.offset) {
+			multiplicative_const = pow(accel, power);
+			power_inc = power + 1;
+		}
 
 		inline double operator()(double speed) const {
 			//f(x) = (mx)^(k-1)
-			return pow(accel * speed, power);
+			double base_speed = speed + offset;
+			return multiplicative_const * pow(speed, power_inc) / base_speed;
 		}
 	};
 
diff --git a/common/accel-natural.hpp b/common/accel-natural.hpp
index c7d0dcd..32bc365 100644
--- a/common/accel-natural.hpp
+++ b/common/accel-natural.hpp
@@ -10,16 +10,18 @@ namespace rawaccel {
 	struct natural_impl {
 		double rate;
 		double limit;
+		double offset;
 
 		natural_impl(const accel_args& args) :
-			rate(args.accel), limit(args.limit - 1)
+			rate(args.accel), limit(args.limit - 1), offset(args.offset)
 		{
 			rate /= limit;
 		}
 
 		inline double operator()(double speed) const {
 			// f(x) = k(1-e^(-mx))
-			return limit - (limit * exp(-rate * speed));
+			double base_speed = speed + offset;
+			return limit * (1 - ((exp(-rate * speed) * speed + offset) / base_speed));
 		}
 
 	};
diff --git a/common/accel-naturalgain.hpp b/common/accel-naturalgain.hpp
index 03d749f..5979d92 100644
--- a/common/accel-naturalgain.hpp
+++ b/common/accel-naturalgain.hpp
@@ -18,8 +18,9 @@ namespace rawaccel {
 				return 0;
 			}
 
+			double base_speed = speed + offset;
 			double scaled_speed = rate * speed;
-			return limit * (((exp(-scaled_speed) - 1) / scaled_speed) + 1);
+			return limit * (((exp(-scaled_speed) - 1) / (base_speed * rate) ) + 1 - offset / base_speed);
 		}
 		
 	};