tracker/pt: fix scale on the point filter

3 files changed, 15 insertions, 16 deletions

diff --git a/tracker-pt/FTNoIR_PT_Controls.ui b/tracker-pt/FTNoIR_PT_Controls.ui
index edb401da..08c3807b 100644
--- a/tracker-pt/FTNoIR_PT_Controls.ui
+++ b/tracker-pt/FTNoIR_PT_Controls.ui
@@ -736,7 +736,7 @@
              <number>0</number>
             </property>
             <property name="maximum">
-             <number>400</number>
+             <number>300</number>
             </property>
             <property name="singleStep">
              <number>1</number>
diff --git a/tracker-pt/point-filter.cpp b/tracker-pt/point-filter.cpp
index 4217ac1c..7a6f48c1 100644
--- a/tracker-pt/point-filter.cpp
+++ b/tracker-pt/point-filter.cpp
@@ -24,39 +24,38 @@ const PointOrder& point_filter::operator()(const PointOrder& input)
         return state_;
     }
 
-    const f K = progn(
-        constexpr int C = 1'000'000;
-        f x = (f)*s.point_filter_coefficient;
-        f log10_pos = -2+(int)x, rest = 1+fmod(x, (f)1)*9;
-        return C * pow((f)10, (f)-log10_pos) * rest;
+    constexpr f E = (f)1.75;
+    const f C = progn(
+        constexpr int A = 1'000'000;
+        double K = *s.point_filter_coefficient;
+        f log10_pos = -2 + (int)K, rest = (f)(.999-fmod(K, 1.)*.9);
+        return A * pow((f)10, (f)-log10_pos) * rest;
     );
-    f dt = (f)t->elapsed_seconds(); t->start();
     f dist[3], norm = 0;
 
     for (unsigned i = 0; i < 3; i++)
     {
         vec2 tmp = input[i] - state_[i];
-        dist[i] = sqrt(tmp.dot(tmp));
-        norm += dist[i];
+        f x = sqrt(tmp.dot(tmp));
+        dist[i] = x;
+        norm += x;
     }
 
     if (norm < (f)1e-6)
         return state_;
 
-    // gain
-    float delta = std::clamp(norm * norm * K * dt, (f)0, (f)1);
+    f dt = (f)t->elapsed_seconds(); t->start();
+    f delta = pow(norm, E) * C * dt; // gain
 
     for (unsigned i = 0; i < 3; i++)
     {
-        f x = delta * dist[i] / norm;
+        f x = std::clamp(delta * dist[i] / norm, (f)0, (f)1);
         state_[i] += x*(input[i] - state_[i]);
     }
 
     return state_;
 }
 
-point_filter::point_filter(const pt_settings& s) : s{s}
-{
-}
+point_filter::point_filter(const pt_settings& s) : s{s} {}
 
 } // ns pt_point_filter_impl
diff --git a/tracker-pt/pt-settings.hpp b/tracker-pt/pt-settings.hpp
index 8aa3c39b..a97fa73e 100644
--- a/tracker-pt/pt-settings.hpp
+++ b/tracker-pt/pt-settings.hpp
@@ -69,7 +69,7 @@ struct pt_settings final : options::opts
     value<slider_value> threshold_slider { b, "threshold-slider", { 128, 0, 255 } };
 
     value<bool> enable_point_filter{ b, "enable-point-filter", false };
-    value<slider_value> point_filter_coefficient { b, "point-filter-coefficient", { 1.5, 0, 4 } };
+    value<slider_value> point_filter_coefficient { b, "point-filter-coefficient", { 1.5, 0, 3 } };
 
     explicit pt_settings(const QString& name) : opts(name) {}
 };