wip: synth api && adder

src/Adder.cpp

@@ -0,0 +1,22 @@
+#include "Adder.h"
+
+std::vector<float> & Adder::SumOscillators(const std::vector<Oscillator*> & oscillators, float duration)
+{
+    size_t sample_count = (size_t)(duration * SAMPLE_RATE);
+
+    std::vector<float> output;// = new std::vector<float>();
+    output.reserve(sample_count);
+
+    for (size_t i = 0; i < sample_count; i++) 
+    {
+        float sample = 0.0f;
+        for (Oscillator* osc : oscillators)
+        {
+            sample += osc->GenerateSample(duration);
+        }
+
+        output.push_back(sample);
+    }
+
+    return output;
+}