feat: add soft clipping mode

Makefile

@@ -27,7 +27,7 @@ clean:
 	echo "Cleaning $$plugin..."; \
 	$(MAKE) clean -C plugins/$$plugin || true; \
 	done
-	rm -rf bin build core/*.o core/*.obj
+	rm -rf bin/* build/* core/*.o core/*.obj
 
 # --------------------------------------------------------------
 

core/Clipper.cpp

@@ -1,10 +1,12 @@
 #include "Clipper.hpp"
+#include <cmath>
 
-Clipper::Clipper(float init_clip) : clip_(init_clip) {}
+Clipper::Clipper(float init_clip, ClipperMode init_mode)
+    : clip_(init_clip), mode_(init_mode) {}
 
 void Clipper::process(const float *in, float *out, uint32_t frames) {
   for (uint32_t i = 0; i < frames; ++i) {
-    out[i] = in[i] > clip_ ? clip_ : in[i];
+    out[i] = clip(in[i]);
   }
 }
 void Clipper::processStereo(const float *inLeft, const float *inRight,
@@ -16,6 +18,9 @@ void Clipper::processStereo(const float *inLeft, const float *inRight,
 }
 
 float Clipper::clip(const float in) {
+  switch (mode_) {
+  default:
+  case kClipperModeHard: {
     float out = in;
     if (in > 0) {
       out = in > clip_ ? clip_ : in;
@@ -24,3 +29,9 @@ float Clipper::clip(const float in) {
     }
     return out;
   }
+  case kClipperModeSoft: {
+    float normalized = (in / clip_) * 0.75f;
+    return std::tanh(normalized) * clip_;
+  }
+  }
+}

core/Clipper.hpp

@@ -5,7 +5,9 @@
 
 class Clipper {
 public:
-  Clipper(float init_clip = 1.0f);
+  enum ClipperMode { kClipperModeSoft, kClipperModeHard, kClipperModeCount };
+
+  Clipper(float init_clip = 1.0f, ClipperMode mode = kClipperModeSoft);
 
   void process(const float *in, float *out, uint32_t frames);
   void processStereo(const float *inLeft, const float *inRight, float *outLeft,
@@ -14,10 +16,13 @@ public:
 private:
   float clip_;
   float clip(const float in);
+  ClipperMode mode_;
 
 public:
   void setGain(float c) { clip_ = c; }
   float getGain() const { return clip_; }
+  void setMode(ClipperMode m) { mode_ = m; }
+  ClipperMode getMode() const { return mode_; }
 };
 
 #endif // CLIPPER_HPP_INCLUDED

plugins/SquidgeDistortion/DistrhoPluginInfo.h

@@ -9,7 +9,7 @@
 #define DISTRHO_PLUGIN_NUM_INPUTS 2
 #define DISTRHO_PLUGIN_NUM_OUTPUTS 2
 
-#define DISTRHO_PLUGIN_NUM_PARAMETERS 1
+#define DISTRHO_PLUGIN_NUM_PARAMETERS 2
 
 #define DISTRHO_PLUGIN_WANT_PROGRAMS 0
 #define DISTRHO_PLUGIN_WANT_STATE 0

plugins/SquidgeDistortion/SquidgeDistortion.cpp

@@ -11,6 +11,7 @@ class SquidgeDistortion : public Plugin {
 public:
   enum Parameters {
     kParamGain,
+    kParamClipMode,
     kParameterCount // must be last
   };
   SquidgeDistortion() : Plugin(kParameterCount, 0, 0), gain_(2.0f) {}
@@ -26,7 +27,6 @@ protected:
   int64_t getUniqueId() const override { return d_cconst('S', 'Q', 'D', 'T'); }
 
   void initParameter(uint32_t index, Parameter &parameter) override {
-    parameter.unit = "!";
     switch (index) {
     case kParamGain:
       parameter.name = "Gain";
@@ -35,7 +35,18 @@ protected:
       parameter.ranges.def = 2.0f;
       parameter.ranges.max = 10.0f;
       parameter.hints = kParameterIsAutomatable;
-
+      break;
+    case kParamClipMode:
+      parameter.name = "Clip Mode";
+      parameter.symbol = "clipmode";
+      parameter.ranges.min = 0.0f;
+      parameter.ranges.def = 0.0f;
+      parameter.ranges.max = Clipper::kClipperModeCount - 1;
+      parameter.hints = kParameterIsAutomatable | kParameterIsInteger;
+      parameter.enumValues.count = Clipper::kClipperModeCount;
+      parameter.enumValues.restrictedMode = true;
+      parameter.enumValues.values =
+          new ParameterEnumerationValue[2]{{0.0f, "Soft"}, {1.0f, "Hard"}};
       break;
     }
   }
@@ -44,6 +55,8 @@ protected:
     switch (index) {
     case kParamGain:
       return gain_.getGain();
+    case kParamClipMode:
+      return (float)clipper_.getMode();
     }
     return 0.0f;
   }
@@ -53,6 +66,9 @@ protected:
     case kParamGain:
       gain_.setGain(value);
       break;
+    case kParamClipMode:
+      clipper_.setMode((Clipper::ClipperMode)value);
+      break;
     }
   }