void Bandpass::pull(AudioChunk &chunk, const Bandpass_Node &a, const Bandpass_Node &b) { //Pull source data source.pull(chunk); //Calculate RC multipliers float al = RCCONV / ((a.low<=0.0f)?40000.0f:a.low), ah = RCCONV / ((a.high<=0.0f)?10.0f:a.high), bl = RCCONV / ((b.low<=0.0f)?40000.0f:b.low), bh = RCCONV / ((b.high<=0.0f)?10.0f:b.high); float lpRC = al, hpRC = ah, lpM = pow(bl/al, 1.0f / float(chunk.length())), hpM = pow(bh/ah, 1.0f / float(chunk.length())), lpA, hpA, samp, dt = 1.0f / float(chunk.format().rate); //Apply effect! Uint32 chan = source.format().channels; for (Uint32 i = 0; i < chan; ++i) { Sint32 *pos = chunk.start(i), *end = chunk.end(i); float &lpPc = lpP[i], &hpDc = hpD[i]; while (pos < end) { //Interpolate settings lpA = dt / (lpRC + dt); lpRC *= lpM; hpA = hpRC / (hpRC + dt); hpRC *= hpM; //Get samples samp = float(*pos); //Lowpass samp = lpPc + lpA * (samp-lpPc); lpPc = samp; //Highpass (confusing but correct) samp = hpA * (samp+hpDc); hpDc = samp - lpPc; //Set samples *pos = Sint32(samp); ++pos; } } }
void Oscillator::pull(AudioChunk &chunk, const State &a, const State &b) { //Phase goes from -1 to 1. Wierd? Maybe. while (phase >= 1.0f) phase -= 2.0f; while (phase < -1.0f) phase += 2.0f; Sint32 samp; float v, x, sq; float step = (b.freq / output.rate) * 2.0f, amp = b.amp * 16777215.0f, ph = phase; Sint32 *i = chunk.start(0), *e = chunk.end(0); switch (type) { case SINE: while (i != e) { //Simple sine wave samp = amp*sin(PI * ph); ph += step; *i = samp; ++i; ph -= 2.0f*int(ph*.5f); //Restrict to [-1, 1] } break; case SQUARE: while (i != e) { samp = amp * ((ph>=0.0f) ? 1.0f : -1.0f); ph += step; *i = samp; ++i; ph -= 2.0f*int(ph*.5f); //Restrict to [-1, 1] } break; case TRIANGLE: while (i != e) { samp = amp * (2.0f*std::abs(ph) - 1.0f); ph += step; *i = samp; ++i; ph -= 2.0f*int(ph*.5f); //Restrict to [-1, 1] } break; case SAWTOOTH: while (i != e) { samp = amp * ph; ph += step; *i = samp; ++i; ph -= 2.0f*int(ph*.5f); //Restrict to [-1, 1] } break; case KLAXON: default: { const float PISQ = PI*PI; while (i != e) { //Sine wave approximation gone wrong sq = PISQ*ph*ph; x = PI*ph*amp; v = x * 1.02394347; //Makes the endpoints line up x *= sq; v -= x/6.0f; x *= sq; v += x/120.0f; x *= sq; v -= x/5040.0f; samp = x; ph += step; *i = samp; ++i; ph -= 2.0f*int(ph*.5f); //Restrict to [-1, 1] } } break; } phase = ph; //Copy signal into all other channels for (Uint32 c = chunk.channels()-1; c > 0; --c) { std::memcpy(chunk.start(c), chunk.start(0), 4*chunk.length()); } }