Sample *process_data(Samples samples) { constexpr unsigned int size = samples.size(); constexpr unsigned int D = 2000; float alpha = readalt() / 4095.; static Sample output[size]; static Sample prev[D]; // prev[0] = output[0 - D] // Do calculations with previous output for (unsigned int i = 0; i < D; i++) output[i] = samples[i] + alpha * (prev[i] - 2048); // Do calculations with current samples for (unsigned int i = D; i < size; i++) output[i] = samples[i] + alpha * (output[i - D] - 2048); // Save outputs for next computation for (unsigned int i = 0; i < D; i++) prev[i] = output[size - (D - i)]; return output; }