desc:GFX Model 44
//tags: channel strip preamp tape saturation rack companding punch
//author: JGWizrad / Garden FX (GFX)
//
// Requires gfx-output, gfx-input, gfx-ui, gfx-panel and gfx-dyn (.jsfx-inc) in the same folder.
//
// A single-channel strip in the spirit of the early-90s rack-mountable cassette portable-studio ecosystem:
// a cleaner, higher-headroom solid-state preamp, a tighter semi-parametric EQ, a dense magnetic
// saturation ceiling with a Normal / Double speed switch, and a companding noise reduction tuned for
// less pumping than the earlier 80s machines (personal use; the sound is designed from scratch).
//
// GAIN    - a clean, high-headroom preamp: it stays pristine well past unity before the tape stage's
//           ceiling takes over.
// MID     - a sweepable mid-band (FREQ / GAIN, fixed Q): surgical sculpting without falling apart.
// TREBLE / BASS - clean fixed shelves (12 kHz / 80 Hz).
// TAPE    DRIVE - the magnetic saturation ceiling's depth.
//         SPEED - Normal (1 7/8 ips) or Double (3 3/4 ips): double speed pushes the ceiling higher,
//                 extends the top end, tightens the sub-bass and keeps transients punchier.
//         NR    - 2:1 / 1:2 compander noise reduction, in / out: gentler and less pumpy than an 80s unit.
// MIX     - blend of the coloured signal against the dry input.
// IN/OUT  - input TRIM and GUARD, OUTPUT level, and the output band-saturation / clipper / limiter stage.
// PRESETS.

import gfx-output.jsfx-inc
import gfx-input.jsfx-inc
import gfx-ui.jsfx-inc
import gfx-panel.jsfx-inc
import gfx-dyn.jsfx-inc

slider1:6<-6,24,0.1>-Gain (dB)
slider2:1000<200,5000,1>-Mid freq (Hz)
slider3:0<-12,12,0.1>-Mid gain (dB)
slider4:0<-10,10,0.1>-Treble (12 kHz) (dB)
slider5:0<-10,10,0.1>-Bass (80 Hz) (dB)
slider6:35<0,100,1>-Tape drive (%)
slider7:0<0,1,1{Normal (1 7/8 ips),Double (3 3/4 ips)}>-Speed
slider8:1<0,1,1{Off,On}>-Noise reduction
slider9:100<0,100,1>-Mix (%)
slider10:0<-24,12,0.1>-Output (dB)
slider11:0<0,100,1>-Band sat (%)
slider12:30<0,100,1>-Bias (%)
slider13:120<40,400,1>-Sat low band (Hz)
slider14:6000<2000,16000,10>-Sat high band (Hz)
slider15:-0.3<-24,0,0.1>-Ceiling / limit threshold (dB)
slider16:1<0,2,1{Off,Clip,Limit}>-Output stage
slider17:0<-24,12,0.1>-Input trim (dB)
slider18:1<0,1,1{Off,On}>-Input guard

in_pin:left input
in_pin:right input
out_pin:left output
out_pin:right output

@init
#ui_man = "gfx-model-44";

DEN = 0.00000000000000000001;

// ---------- clean, high-headroom preamp: no coloration here, the ceiling lives in the tape stage ----------
function vx_gain(x) ( x * g_lin );

// ---------- semi-parametric EQ: sweepable mid, clean fixed shelves ----------
function vx_eq_set() instance(mid, ts, bsf) ( mid.bq_set(2, mid_hz, 0.9, mid_db); ts.bq_set(3, 12000, 0.7, tr_db); bsf.bq_set(4, 80, 0.7, bs_db); );
function vx_eq(x) instance(mid, ts, bsf) ( bsf.bq_run(ts.bq_run(mid.bq_run(x))) );

// ---------- the dense, punchy magnetic saturation ceiling ----------
function vx_ceil(x) local(a, y) (
  a = abs(x);
  a <= vx_knee ? y = a : y = vx_knee + (1 - vx_knee) * ost_tanh((a - vx_knee) * vx_drv / max(1 - vx_knee, 0.0001));
  sign(x) * y;
);

// ---------- the tape: ceiling saturation, speed-dependent HF / sub-bass, 2:1 / 1:2 compander NR ----------
function vx_tape_set() instance(hp) ( hp.bq_set(1, sub_hz, 0.7, 0); );
function vx_tape(x, nron) instance(pe, de, hp, lp, ee, ed) local(y, lv) (
  // record-side NR encode: compress 2:1 around -20 dBFS, with a treble lift into the tape
  nron ? (
    y = pe.bq_run(x);
    ee += (y * y - ee) * nr_c + DEN; lv = 10 * log10(ee);
    y *= 10 ^ (min(-0.5 * (lv + 20), 24) / 20);
  ) : y = x;
  // the ceiling, and the speed switch's sub-bass tightening
  y = y + tape_wet * (vx_ceil(y) - y);
  y = hp.bq_run(y);
  // the speed switch's top-end behaviour (fixed per speed, not dynamic: this unit stays clean)
  lp += (y - lp) * hf_c;
  y = lp;
  // playback-side NR decode: 1:2 expand against what came off the tape
  nron ? (
    ed += (y * y - ed) * nr_c + DEN; lv = 10 * log10(ed);
    y *= 10 ^ (max(lv + 20, -60) / 20);
    y = de.bq_run(y);
  );
  y;
);

function update() (
  g_db = slider1; g_lin = 10 ^ (g_db / 20);

  mid_hz = slider2; mid_db = slider3; tr_db = slider4; bs_db = slider5;

  tape_amt = slider6 / 100;
  speed = slider7;
  vx_knee = speed ? 0.75 : 0.55;
  vx_drv = 2 + 7 * tape_amt;
  tape_wet = min(tape_amt * 2, 1);
  sub_hz = speed ? 45 : 25;
  hf_hz = speed ? 16000 : 10000;
  hf_c = 1 - exp(-2 * $pi * min(hf_hz, srate * 0.45) / srate);

  nr_c = 1 - exp(-1 / (0.035 * srate));           // slower than an 80s unit: a gentler, less pumpy compander
  nr_on = slider8;
  mix_t = slider9 / 100;
  out_t = 10 ^ (slider10 / 20);

  eqL.vx_eq_set(); eqR.vx_eq_set();
  tpL.pe.bq_set(3, 2000, 0.6, 10); tpL.de.bq_set(3, 2000, 0.6, -10);
  tpR.pe.bq_set(3, 2000, 0.6, 10); tpR.de.bq_set(3, 2000, 0.6, -10);
  tpL.vx_tape_set(); tpR.vx_tape_set();
  in_setup(slider17, slider18);
  ost_setup(slider11 / 100, slider12 / 100, slider13, slider14, slider15, slider16);
);

// ---------- presets (gain, mid freq, mid gain, treble, bass, drive, speed, nr, mix - output is left alone) ----------
function setp(g, mf, mg, tr, bs, dr, sp, n, mx) (
  slider1 = g; slider2 = mf; slider3 = mg; slider4 = tr; slider5 = bs; slider6 = dr; slider7 = sp; slider8 = n; slider9 = mx;
);
function pname(p) (
  p == 1 ? "Clean Double Speed" :
  p == 2 ? "Normal Speed Warm" :
  p == 3 ? "Rack Punch" :
  p == 4 ? "Scooped Mids" :
  p == 5 ? "No NR" :
  "Reset all to defaults";
);
function load_preset(p) (
  p == 1 ? setp(6, 1000, 0, 2, 0, 20, 1, 1, 100) :        // Clean Double Speed
  p == 2 ? setp(9, 800, 1, 0, 1, 35, 0, 1, 100) :         // Normal Speed Warm
  p == 3 ? setp(14, 2500, 2, 3, 0, 55, 1, 1, 100) :       // Rack Punch
  p == 4 ? setp(6, 600, -4, 1, 1, 25, 1, 1, 100) :        // Scooped Mids
  p == 5 ? setp(6, 1000, 0, 0, 0, 30, 0, 0, 100);         // No NR
  p >= 1 && p <= 5 ? slider_automate(1023);
  p == 6 ? (                                                // Reset all to defaults
    setp(6, 1000, 0, 0, 0, 35, 0, 1, 100); slider10 = 0;
    slider11 = 0; slider12 = 30; slider13 = 120; slider14 = 6000; slider15 = -0.3; slider16 = 1;
    slider17 = 0; slider18 = 1;
    slider_automate(262143);
  );
);

ost_init(40000); ostL.ost_ch_init(); ostR.ost_ch_init();
in_init();
sm = 1 - exp(-1 / (0.02 * srate));
vuc = 1 - exp(-1 / (0.3 * srate));
cur_preset = 1;
!ui_dflt ? ui_thm = 5; !ui_dflt ? ui_hw = 1;
update();
mix_s = mix_t; out_s = out_t;
ui_dflt = 1;

@slider
update();

@block
update();

@serialize
file_var(0, ui_sz);

@sample
in_process(spl0, spl1);
inL = in_l; inR = in_r;

gL = vx_gain(inL); gR = vx_gain(inR);
eL = eqL.vx_eq(gL); eR = eqR.vx_eq(gR);
tL = tpL.vx_tape(eL, nr_on); tR = tpR.vx_tape(eR, nr_on);

mix_s += (mix_t - mix_s) * sm;
out_s += (out_t - out_s) * sm;

oL = inL * (1 - mix_s) + tL * mix_s;
oR = inR * (1 - mix_s) + tR * mix_s;

oL = ostL.ost_band(oL) * out_s;
oR = ostR.ost_band(oR) * out_s;
ost_out(oL, oR);
spl0 = ost_l; spl1 = ost_r;
vmL += (spl0 * spl0 - vmL) * vuc; vmR += (spl1 * spl1 - vmR) * vuc;
pkL = max(pkL, abs(spl0)); pkR = max(pkR, abs(spl1));

@gfx 760 404
ui_begin(760, 404);
PNL = 0xB4B8BE; INK = 0x1C1F24; ACC = 0x2F6FD0; WIN = 0x1A1C20;
dy_ink = INK; dy_bg = PNL; dy_kst = 20; dy_nov = 1;

ui_col(0x0A0A0B); gfx_rect(0, 0, gfx_w, gfx_h);
pk_chassis(8 * sc, 4 * sc, 744 * sc, 396 * sc, PNL);
ui_col(INK); gfx_circle(40 * sc, 34 * sc, 14 * sc, 1, 1);
gfx_setfont(4); ui_col(PNL); ui_text(40 * sc, 29 * sc, "GFX");
gfx_setfont(6, "Trebuchet MS", 24 * sc, 'b'); ui_col(INK); gfx_x = 62 * sc; gfx_y = 20 * sc; gfx_drawstr("MODEL 44");
gfx_setfont(4); ui_col(ACC); gfx_x = 208 * sc; gfx_y = 30 * sc; gfx_drawstr("RACK CHANNEL");
ui_button(388 * sc, 20 * sc, 26 * sc, 28 * sc, "<", 0, 1) ? (
  cur_preset = cur_preset <= 1 ? 6 : cur_preset - 1;
  load_preset(cur_preset);
);
ui_button(416 * sc, 20 * sc, 26 * sc, 28 * sc, ">", 0, 1) ? (
  cur_preset = cur_preset >= 6 ? 1 : cur_preset + 1;
  load_preset(cur_preset);
);
ui_button(450 * sc, 20 * sc, 90 * sc, 28 * sc, "PRESETS", 0, 1) ? (
  gfx_x = 450 * sc; gfx_y = 48 * sc;
  cur_preset = gfx_showmenu("Clean Double Speed|Normal Speed Warm|Rack Punch|Scooped Mids|No NR|Reset all to defaults");
  cur_preset > 0 ? load_preset(cur_preset);
);
ui_size_picker(560 * sc, 22 * sc);
pk_lcd(624 * sc, 16 * sc, 120 * sc, 32 * sc, 1);
pk_lcdfont(9, 9 * sc); ui_col(pk_lcdc);
gfx_x = 630 * sc; gfx_y = 22 * sc; gfx_drawstr("PATCH");
pk_lcdfont(9, 11 * sc); ui_col(pk_lcdc);
gfx_x = 630 * sc; gfx_y = 33 * sc; gfx_drawstr(pname(cur_preset));
ui_col(ACC); gfx_rect(14 * sc, 60 * sc, 732 * sc, 3 * sc);

// ---------- CHANNEL: gain, mid, shelves, trim / guard, mix ----------
ui_cola(INK, 0.06); gfx_rect(22 * sc, 72 * sc, 368 * sc, 316 * sc);
gfx_setfont(6, "Trebuchet MS", 13 * sc, 'b'); ui_col(ACC); gfx_x = 34 * sc; gfx_y = 82 * sc; gfx_drawstr("CHANNEL");
ui_col(ACC); gfx_rect(34 * sc, 98 * sc, 344 * sc, 1 * sc);
LPK = max(max(pkL, pkR), LPK * 0.9); pkL = 0; pkR = 0;
pk_led(206 * sc, 112 * sc, 3.5 * sc, LPK > 0.001, dy_grn);
sprintf(#v, "%+.1f dB", slider1); dy_knob(90, 160, 20, 1, -6, 24, 6, 0, ACC, "GAIN", #v);
sprintf(#v, "%.0f Hz", slider2); dy_knob(170, 160, 16, 2, 200, 5000, 1000, 1, 0xB8BCC2, "MID FREQ", #v);
sprintf(#v, "%+.1f dB", slider3); dy_knob(250, 160, 16, 3, -12, 12, 0, 0, 0xB8BCC2, "MID GAIN", #v);
sprintf(#v, "%+.1f dB", slider4); dy_knob(330, 160, 16, 4, -10, 10, 0, 0, 0xB8BCC2, "TREBLE", #v);
sprintf(#v, "%+.1f dB", slider5); dy_knob(90, 260, 16, 5, -10, 10, 0, 0, 0xB8BCC2, "BASS", #v);
sprintf(#v, "%+.1f dB", slider17); dy_knob(170, 260, 16, 17, -24, 12, 0, 0, 0xB8BCC2, "TRIM", #v);
dy_btn(238, 244, slider18, dy_grn, "GUARD") ? ( slider18 = 1 - slider18; ui_auto(18); );
sprintf(#v, "%.0f%%", slider9); dy_knob(330, 260, 16, 9, 0, 100, 100, 0, 0xF2F2EE, "MIX", #v);

// ---------- meters ----------
vuL.ui_vu(400 * sc, 72 * sc, 170 * sc, 104 * sc, 10 * log10(vmL + 0.0000000001) + 18, "L");
vuR.ui_vu(576 * sc, 72 * sc, 170 * sc, 104 * sc, 10 * log10(vmR + 0.0000000001) + 18, "R");

// ---------- tape + output ----------
ui_cola(INK, 0.06); gfx_rect(400 * sc, 188 * sc, 346 * sc, 200 * sc);
gfx_setfont(6, "Trebuchet MS", 13 * sc, 'b'); ui_col(ACC); gfx_x = 410 * sc; gfx_y = 194 * sc; gfx_drawstr("TAPE");
ui_col(ACC); gfx_rect(410 * sc, 210 * sc, 326 * sc, 1 * sc);
dy_nov = 0;
sprintf(#v, "%.0f%%", slider6); dy_knob(452, 250, 20, 6, 0, 100, 35, 0, ACC, "DRIVE", #v);
sprintf(#v, "%+.1f dB", slider10); dy_knob(710, 250, 20, 10, -24, 12, 0, 0, 0xF2F2EE, "OUTPUT", #v);
dy_btn(540, 236, speed == 0, ACC, "NORMAL") ? ( slider7 = 0; ui_auto(7); );
dy_btn(540, 270, speed == 1, ACC, "DOUBLE") ? ( slider7 = 1; ui_auto(7); );
dy_lbl(562, 224, "SPEED", 0.6);
dy_btn(650, 330, slider8, dy_grn, "NR") ? ( slider8 = 1 - slider8; ui_auto(8); );
dy_lbl(574, 338, speed ? "3 3/4 IPS" : "1 7/8 IPS", 0.7);
dy_lbl(574, 352, "COMPANDER NR", 0.7);

pk_end();
ui_end();