// -----------------------------------------------------------------
// To enable searching for optimal delay loop length, insert 
// this code at the beginning of the ChucK script.
// -----------------------------------------------------------------
spork ~ keepIncrementingDelayAndPrintingRMS();
0.001::ms    => dur searchStepSize;     // If you enable search, step size. 

// .
// .
// .
//  main sound cancellation code goes here 
// .
// .
// .

// ========================= SEARCH CODE START ====================
// (if you don't need to automatically search for the best delay,
//  you can ignore this code.)
// Call using: spork ~ keepIncrementingDelayAndPrintingRMS();
// (This line is below, right above the main program loop.)

// -----------------------------------------------------------------
// Here we set up the analyzer so we can measure how much sound
// is not being cancelled out.  If it's high, we should search
// for a better delay.
// -----------------------------------------------------------------
dac => FFT fft =^ RMS rms => blackhole;
1024 => fft.size;
Windowing.hann(1024) => fft.window;
// -----------------------------------------------------------------
// This function is started up by the "spork" command below, and
// increments the delay while measuring RMS (total sound energy).
// We want the lowest RMS possible.
// -----------------------------------------------------------------
fun void keepIncrementingDelayAndPrintingRMS()
{
        while (true)
        {
                delayLength + searchStepSize => delayLength;
                delayLength => delay.max => delay.delay;
                <<< "  " >>>;
                <<< delayLength / 1::ms >>>;
                2::second => now;

                0 => float sum;
                for (0 => int x; x < 4; x++)
                {
                        rms.upchuck() @=> UAnaBlob blob;
                        sum + blob.fval(0) => sum;
                        // <<< blob.fval(0) >>>;
                        fft.size()::samp => now;
                        500::ms => now;
                }
                <<< "average" >>>;
                <<< sum / 4.0 >>>;
        }
}


// ========================= SEARCH CODE END ====================