sclass RenderFrequencySample_SquareWave extends Meta is RenderFrequencySample {

  public double get(Complex c, double frac) {

    double abs = c.abs();

    if (abs == 0) ret 0;

    frac = frac_nonNeg(frac + c.fracAngle());

    ret abs * (frac < .5 ? 1 : -1);

  }

  //@Override

  public void __subtractPeriodFrom(IAddPlateau audio, DoubleRange period, Complex intensity) {

    double goHigh = fracNonNeg(-intensity.fracAngle());

    double abs = intensity.abs();

    double goLow = fracNonNeg(goHigh+.5);

    double t1 = period.start, t2 = period.end, n = l(period);

    bool highFirst = goHigh < goLow;

    double min = min(goHigh, goLow), minPos = t1+min*n;

    double max = max(goHigh, goLow), maxPos = t1+max*n;

    double val = highFirst ? -abs : abs;

    if (metaGet("scaffolding") != null)

      printVars(+t1, +t2, +goHigh, +goLow, +abs, +minPos, +maxPos, +n);

    audio.subtractPlateau(t1, minPos,        val);

    audio.subtractPlateau(    minPos, maxPos, -val);

    audio.subtractPlateau(    maxPos, t2,    val);

  }

}