osc: blep, and an analog polysynth with drift and unison spread

docs/NODES.md

@@ -944,6 +944,20 @@ Band-pass oscillator
 | `out` | out | The wave |  | -1 to 1 | full scale |  |
 | `last` | state |  |  |  |  |  |
 
+### osc::blep
+
+Band-limited oscillator (PolyBLEP saw, pulse, triangle)
+
+| Arg | Dir | Description | Default | Range | Units | Values |
+|---|---|---|---|---|---|---|
+| `freq` | in | Frequency |  |  | Hz |  |
+| `waveform` | in | Which wave |  |  |  | 0 = Sawtooth, 1 = Pulse, 2 = Triangle |
+| `pw` | in | Pulse width: how much of the cycle is high | 0.5 | 0 to 1 |  |  |
+| `phase` | in | Where the cycle starts, read on the voice's first sample |  | 0 to 1 |  |  |
+| `out` | out | The wave |  | -1 to 1 | full scale |  |
+| `sync` | out | 1 on the sample the cycle wraps, 0 otherwise |  | 0 to 1 |  |  |
+| `state` | state |  |  |  |  |  |
+
 ### osc::buzzer
 
 Buzzer oscillator

dsp/analog.dsp

@@ -0,0 +1,281 @@
+# Analog -- a polysynth voice that is never quite in tune.
+#
+# What makes a vintage polysynth sound like one is mostly what its
+# designers were fighting: oscillators that wander a few cents, a
+# filter that sits slightly differently on every voice, two copies of a
+# saw that are never in phase. Take that away and the same circuit
+# sounds like a plug-in. This graph puts it back on purpose.
+#
+# THE OSCILLATORS DO NOT ALIAS. Three osc::blep saws (or pulses, or
+# triangles) at the center and `Unison' cents either side, a second
+# oscillator `Interval' semitones away, and a square an octave down for
+# the sub. PolyBLEP is what keeps a high note from growing tones that
+# are not in it.
+#
+# EVERY OSCILLATOR DRIFTS ON ITS OWN. A misc::drift per oscillator moves
+# its pitch up to `Drift' cents at about a third of a hertz, seeded from
+# the note and the oscillator so no two wander alike -- and a piece
+# replays the same, because the seed is the note and not a clock. The
+# cutoff drifts too, by a few percent.
+#
+# THE UNISON IS SPREAD. The flat copy leans left and the sharp one right
+# by `Spread', and the center one is in both: the beating between them
+# becomes width rather than a wobble in the middle.
+#
+# THE FILTER IS 24 dB AN OCTAVE: two filt::svf low-passes in series,
+# the resonance on the second, the cutoff opened by its own envelope and
+# by velocity, and tracking the keyboard by `Key Track'.
+
+name "Analog";
+author "Misha Nasledov";
+description "A drifting, band-limited polysynth: three unison oscillators spread in stereo, a second oscillator, a sub, and a 24 dB filter.";
+category "Leads and stabs";
+
+    @wave1 = 0;
+    @wave1.widget = 1;
+    @wave1.min = 0;
+    @wave1.max = 2;
+    @wave1.step = 1;
+    @wave1.values = "Sawtooth,Pulse,Triangle";
+    @wave1.label = "Wave";
+    @wave1.group = "Oscillators";
+
+    @wave2 = 1;
+    @wave2.widget = 1;
+    @wave2.min = 0;
+    @wave2.max = 2;
+    @wave2.step = 1;
+    @wave2.values = "Sawtooth,Pulse,Triangle";
+    @wave2.label = "Wave 2";
+    @wave2.group = "Oscillators";
+
+    @semi2 = -12;
+    @semi2.widget = 1;
+    @semi2.min = -24;
+    @semi2.max = 24;
+    @semi2.step = 1;
+    @semi2.label = "Interval (semitones)";
+    @semi2.group = "Oscillators";
+
+    @mix2 = 0.3;
+    @mix2.widget = 1;
+    @mix2.min = 0;
+    @mix2.max = 1;
+    @mix2.label = "Osc 2 Level";
+    @mix2.group = "Oscillators";
+
+    @pw = 0.4;
+    @pw.widget = 1;
+    @pw.min = 0.05;
+    @pw.max = 0.95;
+    @pw.label = "Pulse Width";
+    @pw.group = "Oscillators";
+
+    @sub = 0.2;
+    @sub.widget = 1;
+    @sub.min = 0;
+    @sub.max = 1;
+    @sub.label = "Sub";
+    @sub.group = "Oscillators";
+
+    @unison = 7;
+    @unison.widget = 1;
+    @unison.min = 0;
+    @unison.max = 40;
+    @unison.label = "Unison (cents)";
+    @unison.group = "Warmth";
+
+    @spread = 0.7;
+    @spread.widget = 1;
+    @spread.min = 0;
+    @spread.max = 1;
+    @spread.label = "Spread";
+    @spread.group = "Warmth";
+
+    @drift = 4;
+    @drift.widget = 1;
+    @drift.min = 0;
+    @drift.max = 25;
+    @drift.label = "Drift (cents)";
+    @drift.group = "Warmth";
+
+    @cutoff = 1200;
+    @cutoff.widget = 1;
+    @cutoff.min = 40;
+    @cutoff.max = 12000;
+    @cutoff.label = "Cutoff (Hz)";
+    @cutoff.group = "Filter";
+
+    @res = 0.3;
+    @res.widget = 1;
+    @res.min = 0;
+    @res.max = 0.95;
+    @res.label = "Resonance";
+    @res.group = "Filter";
+
+    @envamt = 2500;
+    @envamt.widget = 1;
+    @envamt.min = 0;
+    @envamt.max = 10000;
+    @envamt.label = "Env Amount (Hz)";
+    @envamt.group = "Filter";
+
+    @keytrack = 0.5;
+    @keytrack.widget = 1;
+    @keytrack.min = 0;
+    @keytrack.max = 1;
+    @keytrack.label = "Key Track";
+    @keytrack.group = "Filter";
+
+    @fa = 5 ms;
+    @fa.widget = 1;
+    @fa.min = 0 ms;
+    @fa.max = 3000 ms;
+    @fa.label = "Attack";
+    @fa.group = "Filter Envelope";
+
+    @fd = 500 ms;
+    @fd.widget = 1;
+    @fd.min = 0 ms;
+    @fd.max = 5000 ms;
+    @fd.label = "Decay";
+    @fd.group = "Filter Envelope";
+
+    @fs = 0.3;
+    @fs.widget = 1;
+    @fs.min = 0.01;
+    @fs.max = 1;
+    @fs.label = "Sustain";
+    @fs.group = "Filter Envelope";
+
+    @fr = 400 ms;
+    @fr.widget = 1;
+    @fr.min = 0 ms;
+    @fr.max = 5000 ms;
+    @fr.label = "Release";
+    @fr.group = "Filter Envelope";
+
+    @a = 5 ms;
+    @a.widget = 1;
+    @a.min = 0 ms;
+    @a.max = 3000 ms;
+    @a.label = "Attack";
+    @a.group = "Envelope";
+
+    @d = 400 ms;
+    @d.widget = 1;
+    @d.min = 0 ms;
+    @d.max = 5000 ms;
+    @d.label = "Decay";
+    @d.group = "Envelope";
+
+    @s = 0.7;
+    @s.widget = 1;
+    @s.min = 0.01;
+    @s.max = 1;
+    @s.label = "Sustain";
+    @s.group = "Envelope";
+
+    @r = 300 ms;
+    @r.widget = 1;
+    @r.min = 70 ms;
+    @r.max = 5000 ms;
+    @r.label = "Release";
+    @r.group = "Envelope";
+
+node ionode {
+    channels = 2;
+    out0 = vcal->out;
+    out1 = vcar->out;
+    play = env->play;
+};
+
+node freq misc::midi2freq {
+    note = ionode->note;
+};
+
+# One wanderer per oscillator, in cents, and one for the cutoff.
+node driftc misc::drift { rate = 0.3;  depth = @drift; seed = ionode->note; };
+node driftl misc::drift { rate = 0.37; depth = @drift; seed = ionode->note + 1000; };
+node driftr misc::drift { rate = 0.29; depth = @drift; seed = ionode->note + 2000; };
+node drift2 misc::drift { rate = 0.33; depth = @drift; seed = ionode->note + 3000; };
+node driftf misc::drift { rate = 0.2;  depth = 0.05;   seed = ionode->note + 4000; };
+node drifts misc::drift { rate = 0.31; depth = @drift; seed = ionode->note + 5000; };
+
+node oscc osc::blep {
+    freq = freq->out * exp2(driftc->out / 1200);
+    waveform = @wave1;
+    pw = @pw;
+    phase = 0;
+};
+node oscl osc::blep {
+    freq = freq->out * exp2((driftl->out - @unison) / 1200);
+    waveform = @wave1;
+    pw = @pw;
+    phase = 0.33;
+};
+node oscr osc::blep {
+    freq = freq->out * exp2((driftr->out + @unison) / 1200);
+    waveform = @wave1;
+    pw = @pw;
+    phase = 0.67;
+};
+node osc2 osc::blep {
+    freq = freq->out * exp2((@semi2 * 100 + drift2->out) / 1200);
+    waveform = @wave2;
+    pw = @pw;
+    phase = 0.5;
+};
+node subosc osc::blep {
+    freq = freq->out * 0.5 * exp2(drifts->out / 1200);
+    waveform = 1;
+    pw = 0.5;
+    phase = 0.25;
+};
+
+# What both sides share, and the unison leaning each way.
+node common math::add {
+    in0 = oscc->out + osc2->out * @mix2;
+    in1 = subosc->out * @sub;
+};
+node mixl math::add {
+    in0 = common->out + oscl->out * (1 + @spread) * 0.5;
+    in1 = oscr->out * (1 - @spread) * 0.5;
+};
+node mixr math::add {
+    in0 = common->out + oscr->out * (1 + @spread) * 0.5;
+    in1 = oscl->out * (1 - @spread) * 0.5;
+};
+
+node fenv env::adsr {
+    a = @fa;
+    d = @fd;
+    s = @fs;
+    r = @fr;
+    trigger = ionode->trigger;
+};
+
+node cut math::min {
+    in0 = (@cutoff + fenv->out * @envamt * ionode->velocity) *
+          exp2(@keytrack * (ionode->note - 60) / 12) * (1 + driftf->out);
+    in1 = 18000;
+};
+
+node lp1l filt::svf { in = mixl->out * 0.2; cutoff = cut->out; res = 0; };
+node lp2l filt::svf { in = lp1l->out_low; cutoff = cut->out; res = @res; };
+node lp1r filt::svf { in = mixr->out * 0.2; cutoff = cut->out; res = 0; };
+node lp2r filt::svf { in = lp1r->out_low; cutoff = cut->out; res = @res; };
+
+node env env::adsr {
+    a = @a;
+    d = @d;
+    s = @s * ionode->velocity;
+    r = @r;
+    p = ionode->velocity;
+    trigger = ionode->trigger;
+};
+
+node vcal mixer::mul { in0 = lp2l->out_low; in1 = env->out; };
+node vcar mixer::mul { in0 = lp2r->out_low; in1 = env->out; };
+
+io ionode;

plugins/CMakeLists.txt

@@ -56,7 +56,7 @@ think_add_plugin_category(misc     latch noisegate midi2freq midi2range
 think_add_plugin_category(mixer    add fade mul pan)
 
 think_add_plugin_category(osc      static simple sinsaw buzzer softsqr softsqr2
-                                   fmop sample grain pad
+                                   fmop blep sample grain pad
                                    bandosc shapeo multiwave multisined window
                                    noise)