Added DaisySP

daisysp/Drums/hihat.cpp

@@ -0,0 +1,96 @@
+#include "dsp.h"
+#include "hihat.h"
+#include <math.h>
+
+using namespace daisysp;
+
+void SquareNoise::Init(float sample_rate)
+{
+    for(int i = 0; i < 6; i++)
+    {
+        phase_[i] = 0;
+    }
+}
+
+float SquareNoise::Process(float f0)
+{
+    const float ratios[6] = {// Nominal f0: 414 Hz
+                             1.0f,
+                             1.304f,
+                             1.466f,
+                             1.787f,
+                             1.932f,
+                             2.536f};
+
+    uint32_t increment[6];
+    uint32_t phase[6];
+    for(int i = 0; i < 6; ++i)
+    {
+        float f = f0 * ratios[i];
+        if(f >= 0.499f)
+            f = 0.499f;
+        increment[i] = static_cast<uint32_t>(f * 4294967296.0f);
+        phase[i]     = phase_[i];
+    }
+
+    phase[0] += increment[0];
+    phase[1] += increment[1];
+    phase[2] += increment[2];
+    phase[3] += increment[3];
+    phase[4] += increment[4];
+    phase[5] += increment[5];
+    uint32_t noise = 0;
+    noise += (phase[0] >> 31);
+    noise += (phase[1] >> 31);
+    noise += (phase[2] >> 31);
+    noise += (phase[3] >> 31);
+    noise += (phase[4] >> 31);
+    noise += (phase[5] >> 31);
+
+    for(int i = 0; i < 6; ++i)
+    {
+        phase_[i] = phase[i];
+    }
+
+    return 0.33f * static_cast<float>(noise) - 1.0f;
+}
+
+void RingModNoise::Init(float sample_rate)
+{
+    sample_rate_ = sample_rate;
+
+    for(int i = 0; i < 6; ++i)
+    {
+        oscillator_[i].Init(sample_rate_);
+    }
+}
+
+float RingModNoise::Process(float f0)
+{
+    const float ratio = f0 / (0.01f + f0);
+    const float f1a   = 200.0f / sample_rate_ * ratio;
+    const float f1b   = 7530.0f / sample_rate_ * ratio;
+    const float f2a   = 510.0f / sample_rate_ * ratio;
+    const float f2b   = 8075.0f / sample_rate_ * ratio;
+    const float f3a   = 730.0f / sample_rate_ * ratio;
+    const float f3b   = 10500.0f / sample_rate_ * ratio;
+
+    float out = ProcessPair(&oscillator_[0], f1a, f1b);
+    out += ProcessPair(&oscillator_[2], f2a, f2b);
+    out += ProcessPair(&oscillator_[4], f3a, f3b);
+
+    return out;
+}
+
+float RingModNoise::ProcessPair(Oscillator* osc, float f1, float f2)
+{
+    osc[0].SetWaveform(Oscillator::WAVE_SQUARE);
+    osc[0].SetFreq(f1 * sample_rate_);
+    float temp_1 = osc[0].Process();
+
+    osc[1].SetWaveform(Oscillator::WAVE_SAW);
+    osc[1].SetFreq(f2 * sample_rate_);
+    float temp_2 = osc[1].Process();
+
+    return temp_1 * temp_2;
+}