Range -> Interval

Author: dhemery

CMakeLists.txt

@@ -22,4 +22,4 @@ add_library(plugin SHARED
         src/plugin/dhe-modules.h
         src/stage/stage.cpp
         src/stage/stage.h
-        src/stage/stage-widget.cpp src/stage/stage-widget.h src/util/range.h src/upstage/upstage.h)
+        src/stage/stage-widget.cpp src/stage/stage-widget.h src/util/interval.h src/upstage/upstage.h)

src/stage/stage.cpp

@@ -48,7 +48,7 @@ void Stage::start_envelope() {
 }
 
 float Stage::duration() const {
-  static const Range range{1e-3, 10.0f};
+  static const Interval range{1e-3, 10.0f};
   static constexpr float curvature{0.8f}; // Gives ~1s at center position
 
   return range.scale(sigmoid(duration_knob_rotation(), curvature));
@@ -63,6 +63,6 @@ float Stage::shape() const {
 float Stage::envelope_voltage() const {
   auto shaped{sigmoid(envelope_ramp.phase(), shape())};
 
-  return Range::scale(shaped, stage_input_follower.value(), level_knob_voltage());
+  return Interval::scale(shaped, stage_input_follower.value(), level_knob_voltage());
 }
 } // namespace DHE

src/stage/stage.h

@@ -45,12 +45,12 @@ struct Stage : rack::Module {
   void start_envelope();
   float envelope_voltage() const;
 
-  float active_out_voltage() const { return UNIPOLAR_VOLTAGE.scale(is_active()); }
+  float active_out_voltage() const { return UNIPOLAR_CV.scale(is_active()); }
   float duration_knob_rotation() const { return params[DURATION_KNOB].value; }
-  float eoc_out_voltage() const { return UNIPOLAR_VOLTAGE.scale(end_of_cycle_pulse.is_active()); }
+  float eoc_out_voltage() const { return UNIPOLAR_CV.scale(end_of_cycle_pulse.is_active()); }
   bool is_active() const { return defer_gate.is_high() || envelope_ramp.is_active(); }
   float level_knob_rotation() const { return params[LEVEL_KNOB].value; }
-  float level_knob_voltage() const { return UNIPOLAR_VOLTAGE.scale(level_knob_rotation()); }
+  float level_knob_voltage() const { return UNIPOLAR_CV.scale(level_knob_rotation()); }
   float out_voltage() const { return defer_gate.is_high() ? stage_input_follower.value() : envelope_voltage(); }
   float shape_knob_rotation() const { return params[SHAPE_KNOB].value; }
   float shape_position() const { return BIPOLAR_NORMAL.scale(shape_knob_rotation()); }

src/upstage/upstage.h

@@ -8,7 +8,7 @@
 #include <algorithm>
 #include <engine.hpp>
 
-#include "util/range.h"
+#include "util/interval.h"
 
 namespace DHE {
 
@@ -40,10 +40,10 @@ struct Upstage : rack::Module {
   bool is_sending_triggers() const { return wait_port_in() < 1.0f and not wait_button_is_pressed(); }
   float level_cv_in() const { return inputs[LEVEL_CV_INPUT].value; }
   float level_knob_rotation() const { return params[LEVEL_KNOB].value; }
-  float level_knob_voltage() const { return UNIPOLAR_VOLTAGE.scale(level_knob_rotation()); }
-  float level_voltage() const { return UNIPOLAR_VOLTAGE.clamp(level_knob_voltage() + level_cv_in()); }
+  float level_knob_voltage() const { return UNIPOLAR_CV.scale(level_knob_rotation()); }
+  float level_voltage() const { return UNIPOLAR_CV.clamp(level_knob_voltage() + level_cv_in()); }
   bool trigger_button_is_pressed() const { return params[TRIG_BUTTON].value > 0.0f; }
-  float trigger_button_voltage() const { return UNIPOLAR_VOLTAGE.scale(trigger_button_is_pressed()); }
+  float trigger_button_voltage() const { return UNIPOLAR_CV.scale(trigger_button_is_pressed()); }
   float trigger_port_in() const { return inputs[TRIG_INPUT].value; }
   float trigger_out_voltage() const { return is_sending_triggers() ? trigger_voltage() : 0.0f; }
   float trigger_voltage() const { return std::max(trigger_port_in(), trigger_button_voltage()); }

src/util/interval.h

@@ -0,0 +1,42 @@
+#ifndef DHE_UTIL_RANGE_H
+#define DHE_UTIL_RANGE_H
+
+namespace DHE {
+
+struct Interval {
+  const float lower_bound;
+  const float upper_bound;
+
+  constexpr Interval(float lower_bound, float upper_bound) noexcept : lower_bound(lower_bound), upper_bound(upper_bound) {}
+
+  static float scale(float proportion, float lower_bound, float upper_bound) {
+    return proportion*(upper_bound - lower_bound) + lower_bound;
+  }
+
+  float scale(float proportion) const {
+    return scale(proportion, lower_bound, upper_bound);
+  }
+
+  float scale(bool state) const {
+    return state ? upper_bound : lower_bound;
+  }
+
+  float normalize(float member) const {
+    return (member - lower_bound)/(upper_bound - lower_bound);
+  }
+
+  float clamp(float f) const {
+    if (f < lower_bound)
+      return lower_bound;
+    if (f > upper_bound)
+      return upper_bound;
+    return f;
+  }
+};
+
+constexpr auto NORMAL = Interval{0.0f, 1.0f};
+constexpr auto BIPOLAR_NORMAL = Interval{-1.0f, 1.0f};
+constexpr auto UNIPOLAR_CV = Interval{0.0f, 10.0f};
+constexpr auto BIPOLAR_CV = Interval{-5.0f, 5.0f};
+}
+#endif

src/util/range.h

@@ -4,14 +4,14 @@
 #include <cmath>
 #include <functional>
 
-#include "range.h"
+#include "interval.h"
 
 namespace DHE {
 
 inline float sigmoid(float x, float curvature) {
   static constexpr auto precision{1e-4f};
   static constexpr auto max_curvature{1.0f - precision};
-  static const auto curvature_range = Range{-max_curvature, max_curvature};
+  static const auto curvature_range = Interval{-max_curvature, max_curvature};
 
   curvature = curvature_range.clamp(curvature);
   x = BIPOLAR_NORMAL.clamp(x);