Added DaisySP

daisysp/Synthesis/oscillator.h

@@ -0,0 +1,125 @@
+/*
+Copyright (c) 2020 Electrosmith, Corp
+
+Use of this source code is governed by an MIT-style
+license that can be found in the LICENSE file or at
+https://opensource.org/licenses/MIT.
+*/
+
+#pragma once
+#ifndef DSY_OSCILLATOR_H
+#define DSY_OSCILLATOR_H
+#include <stdint.h>
+#include "Utility/dsp.h"
+#ifdef __cplusplus
+
+namespace daisysp
+{
+/** Synthesis of several waveforms, including polyBLEP bandlimited waveforms.
+*/
+class Oscillator
+{
+  public:
+    Oscillator() {}
+    ~Oscillator() {}
+    /** Choices for output waveforms, POLYBLEP are appropriately labeled. Others are naive forms.
+    */
+    enum
+    {
+        WAVE_SIN,
+        WAVE_TRI,
+        WAVE_SAW,
+        WAVE_RAMP,
+        WAVE_SQUARE,
+        WAVE_POLYBLEP_TRI,
+        WAVE_POLYBLEP_SAW,
+        WAVE_POLYBLEP_SQUARE,
+        WAVE_LAST,
+    };
+
+
+    /** Initializes the Oscillator
+
+        \param sample_rate - sample rate of the audio engine being run, and the frequency that the Process function will be called.
+
+        Defaults:
+        - freq_ = 100 Hz
+        - amp_ = 0.5
+        - waveform_ = sine wave.
+    */
+    void Init(float sample_rate)
+    {
+        sr_        = sample_rate;
+        sr_recip_  = 1.0f / sample_rate;
+        freq_      = 100.0f;
+        amp_       = 0.5f;
+        pw_        = 0.5f;
+        phase_     = 0.0f;
+        phase_inc_ = CalcPhaseInc(freq_);
+        waveform_  = WAVE_SIN;
+        eoc_       = true;
+        eor_       = true;
+    }
+
+
+    /** Changes the frequency of the Oscillator, and recalculates phase increment.
+    */
+    inline void SetFreq(const float f)
+    {
+        freq_      = f;
+        phase_inc_ = CalcPhaseInc(f);
+    }
+
+
+    /** Sets the amplitude of the waveform.
+    */
+    inline void SetAmp(const float a) { amp_ = a; }
+    /** Sets the waveform to be synthesized by the Process() function.
+    */
+    inline void SetWaveform(const uint8_t wf)
+    {
+        waveform_ = wf < WAVE_LAST ? wf : WAVE_SIN;
+    }
+    /** Sets the pulse width for WAVE_SQUARE and WAVE_POLYBLEP_SQUARE (range 0 - 1)
+     */
+    inline void SetPw(const float pw) { pw_ = fclamp(pw, 0.0f, 1.0f); }
+
+    /** Returns true if cycle is at end of rise. Set during call to Process.
+    */
+    inline bool IsEOR() { return eor_; }
+
+    /** Returns true if cycle is at end of cycle. Set during call to Process.
+    */
+    inline bool IsEOC() { return eoc_; }
+
+    /** Returns true if cycle rising.
+    */
+    inline bool IsRising() { return phase_ < 0.5f; }
+
+    /** Returns true if cycle falling.
+    */
+    inline bool IsFalling() { return phase_ >= 0.5f; }
+
+    /** Processes the waveform to be generated, returning one sample. This should be called once per sample period.
+    */
+    float Process();
+
+
+    /** Adds a value 0.0-1.0 (equivalent to 0.0-TWO_PI) to the current phase. Useful for PM and "FM" synthesis.
+    */
+    void PhaseAdd(float _phase) { phase_ += _phase; }
+    /** Resets the phase to the input argument. If no argumeNt is present, it will reset phase to 0.0;
+    */
+    void Reset(float _phase = 0.0f) { phase_ = _phase; }
+
+  private:
+    float   CalcPhaseInc(float f);
+    uint8_t waveform_;
+    float   amp_, freq_, pw_;
+    float   sr_, sr_recip_, phase_, phase_inc_;
+    float   last_out_, last_freq_;
+    bool    eor_, eoc_;
+};
+} // namespace daisysp
+#endif
+#endif