float p, dp, y, A, B, slope;
float a0, a1, a2, b0, b1, b2;
float Adp, Bdp;

p = 0;     // goes between -1 and +1
slope = 1; // anything positive

int32_t idp;
MTOFEXTENDED(param_pitch + inlet_pitch, idp);
if (inlet_symm < 0) {
  A = 2 + (((float)(-inlet_symm)) / (1 << 22));
  if (A * dp > 1)
    A = 1 / dp; // max slope is one sample period
  B = A / (1 - A);
} else {
  B = -2 - (((float)inlet_symm) / (1 << 22));
  if (B * dp < -1)
    B = -1 / dp; // max slope is one sample period
  A = B / (1 + B);
}
dp = idp * (0.25f / (1 << 30));
Adp = A * dp;
Bdp = B * dp;
// Indicate to k-rate loop that poly coefficients may need recalculating
// TODO: Only do this if pitch or symm has changed
if (slope > 0)
  slope = 2 * Adp;
else
  slope = 2 * Bdp;
// Triangle EPTR polynomial coefficients
// While technically, we could calculate the a and b coefficients on demand,
// it's not really worth it as worst case we need to do this every k-rate period
// anyway (when the oscillator frequency is >= 3 kHz).
a2 = (-0.25f / (Adp - dp));
a1 = ((Adp - 2 * dp + 1) / (2 * (Adp - dp)));
a0 = (-(Adp - 1) * (Adp - 1) / (4 * (Adp - dp)));
b2 = (-0.25f / (Bdp + dp));
b1 = ((Bdp + 2 * dp - 1) / (2 * (Bdp + dp)));
b0 = (-(Bdp + 1) * (Bdp + 1) / (4 * (Bdp + dp)));

p += slope;
if (slope > 0) {
  if (p > 1 - Adp) {
    y = p * (a2 * p + a1) + a0; // corr_max
    p = 1 + (p - 1) * B / A;
    slope = 2 * Bdp;
  } else {
    y = p; // linear region
  }
} else {
  if (p < -1 - Bdp) {
    y = p * (b2 * p + b1) + b0; // corr_min
    p = -1 + (p + 1) * A / B;
    slope = 2 * Adp;
  } else {
    y = p; // linear region
  }
}
// p += dp; if (p > 1) p = -1;
// y = p;
outlet_wave = (int32_t)(y * (1 << 27));