Added missing file for compiling Stages latest firmware

stages/variable_shape_oscillator.h

@@ -0,0 +1,160 @@
+// Copyright 2022 Emilie Gillet.
+//
+// Author: Emilie Gillet ([email protected])
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+// 
+// See http://creativecommons.org/licenses/MIT/ for more information.
+//
+// -----------------------------------------------------------------------------
+//
+// Continuously variable waveform: triangle > saw > square. Both square and
+// triangle have variable slope / pulse-width.
+//
+// Taken from Plaits and simplified to remove all unused sync stuff + remove
+// interpolation of PW and shape modulation
+
+#ifndef STAGES_VARIABLE_SHAPE_OSCILLATOR_H_
+#define STAGES_VARIABLE_SHAPE_OSCILLATOR_H_
+
+#include "stmlib/dsp/dsp.h"
+#include "stmlib/dsp/parameter_interpolator.h"
+#include "stmlib/dsp/polyblep.h"
+
+#include "plaits/dsp/oscillator/oscillator.h"
+
+#include <algorithm>
+
+namespace stages {
+
+class VariableShapeOscillator {
+ public:
+  VariableShapeOscillator() { }
+  ~VariableShapeOscillator() { }
+
+  void Init() {
+    phase_ = 0.0f;
+    next_sample_ = 0.0f;
+    high_ = false;
+  }
+
+  void Render(
+      float frequency,
+      float macro,
+      float* out,
+      size_t size) {
+    float shape = macro * 1.5f;
+    CONSTRAIN(shape, 0.0f, 1.0f);
+
+    float pw = 0.5f + (macro - 0.66f) * 1.46f;
+    CONSTRAIN(pw, 0.5f, 0.995f);
+
+    Render(frequency, pw, shape, out, size);
+  }
+
+  void Render(
+      float frequency,
+      float pw,
+      float waveshape,
+      float* out,
+      size_t size) {
+    if (frequency >= plaits::kMaxFrequency) {
+      frequency = plaits::kMaxFrequency;
+    }
+
+    if (frequency >= 0.25f) {
+      pw = 0.5f;
+    } else {
+      CONSTRAIN(pw, frequency * 2.0f, 1.0f - 2.0f * frequency);
+    }
+
+    float next_sample = next_sample_;
+
+    const float square_amount = std::max(waveshape - 0.5f, 0.0f) * 2.0f;
+    const float triangle_amount = std::max(1.0f - waveshape * 2.0f, 0.0f);
+    const float slope_up = 1.0f / (pw);
+    const float slope_down = 1.0f / (1.0f - pw);
+
+    while (size--) {
+      float this_sample = next_sample;
+      next_sample = 0.0f;
+      phase_ += frequency;
+      if (!high_ && phase_ >= pw) {
+        float t = (phase_ - pw) / frequency;
+        float triangle_step = (slope_up + slope_down) * frequency;
+        triangle_step *= triangle_amount;
+        this_sample += square_amount * stmlib::ThisBlepSample(t);
+        next_sample += square_amount * stmlib::NextBlepSample(t);
+        this_sample -= triangle_step * stmlib::ThisIntegratedBlepSample(t);
+        next_sample -= triangle_step * stmlib::NextIntegratedBlepSample(t);
+        high_ = true;
+      } else if (phase_ >= 1.0f) {
+        phase_ -= 1.0f;
+        float t = phase_ / frequency;
+        float triangle_step = (slope_up + slope_down) * frequency;
+        triangle_step *= triangle_amount;
+
+        this_sample -= (1.0f - triangle_amount) * stmlib::ThisBlepSample(t);
+        next_sample -= (1.0f - triangle_amount) * stmlib::NextBlepSample(t);
+        this_sample += triangle_step * stmlib::ThisIntegratedBlepSample(t);
+        next_sample += triangle_step * stmlib::NextIntegratedBlepSample(t);
+        high_ = false;
+      }
+
+      next_sample += ComputeNaiveSample(
+          phase_,
+          pw,
+          slope_up,
+          slope_down,
+          triangle_amount,
+          square_amount);
+      *out++ = (2.0f * this_sample - 1.0f);
+    }
+    next_sample_ = next_sample;
+  }
+
+ private:
+  inline float ComputeNaiveSample(
+      float phase,
+      float pw,
+      float slope_up,
+      float slope_down,
+      float triangle_amount,
+      float square_amount) const {
+    float saw = phase;
+    float square = phase < pw ? 0.0f : 1.0f;
+    float triangle = phase < pw
+        ? phase * slope_up
+        : 1.0f - (phase - pw) * slope_down;
+    saw += (square - saw) * square_amount;
+    saw += (triangle - saw) * triangle_amount;
+    return saw;
+  }
+
+  // Oscillator state.
+  float phase_;
+  float next_sample_;
+  bool high_;
+
+  DISALLOW_COPY_AND_ASSIGN(VariableShapeOscillator);
+};
+
+}  // namespace stages
+
+#endif  // STAGES_VARIABLE_SHAPE_OSCILLATOR_H_