From 283a7a39c74dfb02aad3f2d5624e6a610f9d019e Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Sun, 27 Sep 2020 15:34:12 +0200
Subject: [PATCH] Make filN_random real-valued, and bipolar

---
 src/sfizz/Defaults.h          | 4 ++--
 src/sfizz/FilterDescription.h | 2 +-
 src/sfizz/FilterPool.cpp      | 4 ++--
 src/sfizz/FilterPool.h        | 2 --
 4 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/sfizz/Defaults.h b/src/sfizz/Defaults.h
index 1550e749..e0ba851b 100644
--- a/src/sfizz/Defaults.h
+++ b/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 };
diff --git a/src/sfizz/FilterDescription.h b/src/sfizz/FilterDescription.h
index f78b80d3..2f3193a0 100644
--- a/src/sfizz/FilterDescription.h
+++ b/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 };
 };
 }
diff --git a/src/sfizz/FilterPool.cpp b/src/sfizz/FilterPool.cpp
index c5eadcef..2463e721 100644
--- a/src/sfizz/FilterPool.cpp
+++ b/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);
diff --git a/src/sfizz/FilterPool.h b/src/sfizz/FilterPool.h
index f11ede24..76074a0c 100644
--- a/src/sfizz/FilterPool.h
+++ b/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 };
 };
 
 }