Make filN_random real-valued, and bipolar

src/sfizz/Defaults.h

@@ -160,7 +160,7 @@ namespace Default
     constexpr float filterGain { 0 };
     constexpr int filterKeytrack { 0 };
     constexpr uint8_t filterKeycenter { 60 };
-    constexpr int filterRandom { 0 };
+    constexpr float filterRandom { 0 };
     constexpr int filterVeltrack { 0 };
     constexpr float filterCutoffCC { 0 };
     constexpr float filterResonanceCC { 0 };
@@ -170,7 +170,7 @@ namespace Default
     constexpr Range<float> filterGainRange { -96.0f, 96.0f };
     constexpr Range<float> filterGainModRange { -96.0f, 96.0f };
     constexpr Range<int> filterKeytrackRange { 0, 1200 };
-    constexpr Range<int> filterRandomRange { 0, 9600 };
+    constexpr Range<float> filterRandomRange { 0, 9600 };
     constexpr Range<int> filterVeltrackRange { -9600, 9600 };
     constexpr Range<float> filterResonanceRange { 0.0f, 96.0f };
     constexpr Range<float> filterResonanceModRange { 0.0f, 96.0f };

src/sfizz/FilterDescription.h

@@ -20,7 +20,7 @@ struct FilterDescription
     int keytrack { Default::filterKeytrack };
     uint8_t keycenter { Default::filterKeycenter };
     int veltrack { Default::filterVeltrack };
-    int random { Default::filterRandom };
+    float random { Default::filterRandom };
     FilterType type { FilterType::kFilterLpf2p };
 };
 }

src/sfizz/FilterPool.cpp

@@ -30,8 +30,8 @@ void sfz::FilterHolder::setup(const Region& region, unsigned filterId, int noteN
     // Setup the base values
     baseCutoff = description->cutoff;
     if (description->random != 0) {
-       dist.param(filterRandomDist::param_type(0, description->random));
-       baseCutoff *= centsFactor(dist(Random::randomGenerator));
+        fast_real_distribution<float> dist { -description->random, description->random };
+        baseCutoff *= centsFactor(dist(Random::randomGenerator));
     }
     const auto keytrack = description->keytrack * (noteNumber - description->keycenter);
     baseCutoff *= centsFactor(keytrack);

src/sfizz/FilterPool.h

@@ -54,8 +54,6 @@ private:
     ModMatrix::TargetId cutoffTarget;
     ModMatrix::TargetId resonanceTarget;
     bool prepared { false };
-    using filterRandomDist = std::uniform_int_distribution<int>;
-    filterRandomDist dist { 0, sfz::Default::filterRandom };
 };
 
 }