filter/accela: simplify signum, retval

2 files changed, 19 insertions, 4 deletions

diff --git a/filter-accela/ftnoir_filter_accela.cpp b/filter-accela/ftnoir_filter_accela.cpp
index 439638eb..24287e48 100644
--- a/filter-accela/ftnoir_filter_accela.cpp
+++ b/filter-accela/ftnoir_filter_accela.cpp
@@ -99,10 +99,7 @@ void FTNoIR_Filter::filter(const double* input, double *output)
                                ? (std::pow(out_/s.max_rot_nl, rot_nl) * s.max_rot_nl)
                                : out_;
         const double val = m.getValue(float(out));
-        const double signum = int(vec < 0) * -2 + 1;
-        const double result = last_output[i] + signum * dt * val;
-
-        last_output[i] = output[i] = result;
+        last_output[i] = output[i] = last_output[i] + signum(vec) * dt * val;
     }
 }
 
diff --git a/filter-accela/ftnoir_filter_accela.h b/filter-accela/ftnoir_filter_accela.h
index b347c30b..da011228 100644
--- a/filter-accela/ftnoir_filter_accela.h
+++ b/filter-accela/ftnoir_filter_accela.h
@@ -50,6 +50,24 @@ private:
     double last_output[6];
     double smoothed_input[6];
     Timer t;
+
+    template <typename T>
+    static inline int signum(T x, std::false_type)
+    {
+        return T(0) < x;
+    }
+
+    template <typename T>
+    static inline int signum(T x, std::true_type)
+    {
+        return (T(0) < x) - (x < T(0));
+    }
+
+    template <typename T>
+    static inline int signum(T x)
+    {
+        return signum(x, std::is_signed<T>());
+    }
 };
 
 class FilterControls: public IFilterDialog