Example for making a drum machine with cppsketch

MyLiveAudio-drum-machine.h

#include "LiveAudio.h"
#include <math.h>
#include <stdlib.h>

class MyLiveAudio : public LiveAudio {
public:

	float frac(float f) {
		return f - (int)f;
	}


	float randf() {
		return (rand() %10000) / 5000.f - 1.f;
	}


	int pos = 0;
	float env = 0;

	int beat = 0;
	float freq = 1;

	float decay = 0.999;
	float freqDecay = 0.999;

	float noise = 0.f;

	float getSample() {
		pos++;
		if(pos>7000) {

			beat = (beat + 1) % 16;

			int seed = 4938 + beat * 151845845845848548584;

			if(frac(seed * 1.3498)<0.5) {
				env = 1.f;
				freq = 1 + 3 * (seed %10);
				decay = 1.f - pow(0.1, 3 + 2*frac(seed * 0.9));
				freqDecay = 1.f - pow(0.1, 4 + 3*frac(seed * 0.638437));
				if(frac(seed * 0.384338)>0.5) {
					freqDecay = 2.f - freqDecay;
				}
				noise = 0.5f * (seed & 1);
			}

			pos = 0;
		}

		env *= decay;
		freq *= freqDecay;

		float out = sin(pos*0.01*freq)*(1 - noise) + randf()*noise; 
		out = tanh(out * 10.f) * 0.4;
		return env*out;	
	}

	void audioOut(float *samples, int length, int numChans) override {
		for(int i = 0; i < length; i++) {
			samples[i*2] = samples[i*2+1] = getSample();
			
		}
	}	
};