Added DaisySP

daisysp/Synthesis/oscillator.cpp

@@ -0,0 +1,83 @@
+#include "dsp.h"
+#include "oscillator.h"
+
+using namespace daisysp;
+static inline float Polyblep(float phase_inc, float t);
+
+float Oscillator::Process()
+{
+    float out, t;
+    switch(waveform_)
+    {
+        case WAVE_SIN: out = sinf(phase_ * TWOPI_F); break;
+        case WAVE_TRI:
+            t   = -1.0f + (2.0f * phase_);
+            out = 2.0f * (fabsf(t) - 0.5f);
+            break;
+        case WAVE_SAW: out = -1.0f * (((phase_ * 2.0f)) - 1.0f); break;
+        case WAVE_RAMP: out = ((phase_ * 2.0f)) - 1.0f; break;
+        case WAVE_SQUARE: out = phase_ < pw_ ? (1.0f) : -1.0f; break;
+        case WAVE_POLYBLEP_TRI:
+            t   = phase_;
+            out = phase_ < 0.5f ? 1.0f : -1.0f;
+            out += Polyblep(phase_inc_, t);
+            out -= Polyblep(phase_inc_, fastmod1f(t + 0.5f));
+            // Leaky Integrator:
+            // y[n] = A + x[n] + (1 - A) * y[n-1]
+            out       = phase_inc_ * out + (1.0f - phase_inc_) * last_out_;
+            last_out_ = out;
+            out *= 4.f; // normalize amplitude after leaky integration
+            break;
+        case WAVE_POLYBLEP_SAW:
+            t   = phase_;
+            out = (2.0f * t) - 1.0f;
+            out -= Polyblep(phase_inc_, t);
+            out *= -1.0f;
+            break;
+        case WAVE_POLYBLEP_SQUARE:
+            t   = phase_;
+            out = phase_ < pw_ ? 1.0f : -1.0f;
+            out += Polyblep(phase_inc_, t);
+            out -= Polyblep(phase_inc_, fastmod1f(t + (1.0f - pw_)));
+            out *= 0.707f; // ?
+            break;
+        default: out = 0.0f; break;
+    }
+    phase_ += phase_inc_;
+    if(phase_ > 1.0f)
+    {
+        phase_ -= 1.0f;
+        eoc_ = true;
+    }
+    else
+    {
+        eoc_ = false;
+    }
+    eor_ = (phase_ - phase_inc_ < 0.5f && phase_ >= 0.5f);
+
+    return out * amp_;
+}
+
+float Oscillator::CalcPhaseInc(float f)
+{
+    return f * sr_recip_;
+}
+
+static float Polyblep(float phase_inc, float t)
+{
+    float dt = phase_inc;
+    if(t < dt)
+    {
+        t /= dt;
+        return t + t - t * t - 1.0f;
+    }
+    else if(t > 1.0f - dt)
+    {
+        t = (t - 1.0f) / dt;
+        return t * t + t + t + 1.0f;
+    }
+    else
+    {
+        return 0.0f;
+    }
+}