Merge pull request #19 from JacobPalecki/gainOffset

Add gain offset & make gain options default

9 files changed, 49 insertions, 9 deletions

diff --git a/common/accel-base.hpp b/common/accel-base.hpp
index 560c0b5..714162f 100644
--- a/common/accel-base.hpp
+++ b/common/accel-base.hpp
@@ -5,6 +5,7 @@ namespace rawaccel {
     /// <summary> Struct to hold arguments for an acceleration function. </summary>
     struct accel_args {
         double offset = 0;
+        double legacy_offset = 0;
         double accel = 0;
         double limit = 2;
         double exponent = 2;
@@ -19,6 +20,7 @@ namespace rawaccel {
 
     template <typename Func>
     struct accel_val_base {
+        bool legacy_offset = false;
         double offset = 0;
         double weight = 1;
         Func fn;
@@ -31,14 +33,15 @@ namespace rawaccel {
     struct additive_accel : accel_val_base<Func> {
 
         additive_accel(const accel_args& args) : accel_val_base(args) {
-            offset = args.offset;
+            legacy_offset = args.offset <= 0 && args.legacy_offset > 0;
+            offset = legacy_offset ? args.legacy_offset : args.offset;
             weight = args.weight;
         }
 
         inline double operator()(double speed) const {
-            return 1 + fn(maxsd(speed - offset, 0)) * weight;
+            double offset_speed = speed - offset;
+            return offset_speed > 0 ? ( legacy_offset ? 1 + fn.legacy_offset(offset_speed) * weight : 1 + fn(offset_speed) ) : 1;
         }
-
     };
 
     template <typename Func>
diff --git a/common/accel-classic.hpp b/common/accel-classic.hpp
index 4cc52ca..1df888a 100644
--- a/common/accel-classic.hpp
+++ b/common/accel-classic.hpp
@@ -10,13 +10,23 @@ 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)
+			double base_speed = speed + offset;
+			return multiplicative_const * pow(speed, power_inc) / base_speed;
+		}
+
+		inline double legacy_offset(double speed) const {
 			return pow(accel * speed, power);
 		}
 	};
diff --git a/common/accel-linear.hpp b/common/accel-linear.hpp
index a943594..2bd57b8 100644
--- a/common/accel-linear.hpp
+++ b/common/accel-linear.hpp
@@ -7,13 +7,23 @@ namespace rawaccel {
 	/// <summary> Struct to hold linear acceleration implementation. </summary>
 	struct linear_impl { 
 		double accel;
+		double offset;
+		double subtractive_const;
+		double divisive_const;
 		
-		linear_impl(const accel_args& args) : accel(args.accel) {}
+		linear_impl(const accel_args& args) : accel(args.accel), offset(args.offset) {
+			subtractive_const = 2 * accel * offset;
+			divisive_const = accel * offset * offset;
+		}
 
 		inline double operator()(double speed) const {
-			return accel * speed;
+			double base_speed = speed + offset;
+			return accel * base_speed - subtractive_const + divisive_const / base_speed;
 		}
 
+		inline double legacy_offset(double speed) const {
+			return accel * speed;
+		}
 	};
 
 	using accel_linear = additive_accel<linear_impl>;
diff --git a/common/accel-logarithmic.hpp b/common/accel-logarithmic.hpp
index c7991c7..1ab0e53 100644
--- a/common/accel-logarithmic.hpp
+++ b/common/accel-logarithmic.hpp
@@ -16,6 +16,9 @@ namespace rawaccel {
 			//f(x) = log(m*x+1)
 			return log(accel * speed + 1);
 		}
+		
+		// incorrect but this style is slated for removal
+		inline double legacy_offset(double speed) const { return operator()(speed); }
 	};
 
 	using accel_logarithmic = additive_accel<logarithmic_impl>;
diff --git a/common/accel-natural.hpp b/common/accel-natural.hpp
index c7d0dcd..03700c1 100644
--- a/common/accel-natural.hpp
+++ b/common/accel-natural.hpp
@@ -10,15 +10,21 @@ 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))
+			double base_speed = speed + offset;
+			return limit * (1 - ((exp(-rate * speed) * speed + offset) / base_speed));
+		}
+
+		inline double legacy_offset(double speed) const {
 			return limit - (limit * exp(-rate * speed));
 		}
 
diff --git a/common/accel-naturalgain.hpp b/common/accel-naturalgain.hpp
index 646b2bb..cdfd1fa 100644
--- a/common/accel-naturalgain.hpp
+++ b/common/accel-naturalgain.hpp
@@ -13,10 +13,15 @@ namespace rawaccel {
 
 		inline double operator()(double speed) const {
 			// f(x) = k((e^(-mx)-1)/mx + 1)
+			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);
 		}
 		
+		inline double legacy_offset(double speed) const {
+			double scaled_speed = rate * speed;
+			return limit * (((exp(-scaled_speed) - 1) / scaled_speed) + 1);
+		}
 	};
 
 	using accel_naturalgain = additive_accel<naturalgain_impl>;
diff --git a/common/accel-noaccel.hpp b/common/accel-noaccel.hpp
index ae6f5f8..c803c2f 100644
--- a/common/accel-noaccel.hpp
+++ b/common/accel-noaccel.hpp
@@ -12,6 +12,7 @@ namespace rawaccel {
 
 		inline double operator()(double) const { return 1; }
 		
+		inline double legacy_offset(double speed) const { return operator()(speed); }
 	};
 
 }
diff --git a/common/accel-sigmoid.hpp b/common/accel-sigmoid.hpp
index c8112ee..239bd9d 100644
--- a/common/accel-sigmoid.hpp
+++ b/common/accel-sigmoid.hpp
@@ -21,6 +21,7 @@ namespace rawaccel {
 			return limit / (exp(-rate * (speed - midpoint)) + 1);
 		}
 
+		inline double legacy_offset(double speed) const { return operator()(speed); }
 	};
 
 	using accel_sigmoid = additive_accel<sigmoid_impl>;
diff --git a/common/accel-sigmoidgain.hpp b/common/accel-sigmoidgain.hpp
index 99bb146..bed2f16 100644
--- a/common/accel-sigmoidgain.hpp
+++ b/common/accel-sigmoidgain.hpp
@@ -26,6 +26,7 @@ namespace rawaccel {
 			return limit * ((log(additive_constant+exp(scaled_speed)) - integration_constant)/scaled_speed);
 		}
 
+		inline double legacy_offset(double speed) const { return operator()(speed); }
 	};
 
 	using accel_sigmoidgain = additive_accel<sigmoidgain_impl>;