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Monorepo for Aesthetic.Computer aesthetic.computer
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118#include "comp_1176.h"#include "util.h"#include <math.h>#include <string.h>
float comp_1176_knob_to_attack_us(float knob) { // knob 1 → 800 μs, knob 7 → 20 μs (exponential). float t = (knob - 1.0f) / 6.0f; if (t < 0.0f) t = 0.0f; else if (t > 1.0f) t = 1.0f; return 800.0f * powf(20.0f / 800.0f, t);}
float comp_1176_knob_to_release_ms(float knob) { // knob 1 → 1100 ms, knob 7 → 50 ms (exponential). float t = (knob - 1.0f) / 6.0f; if (t < 0.0f) t = 0.0f; else if (t > 1.0f) t = 1.0f; return 1100.0f * powf(50.0f / 1100.0f, t);}
void comp_1176_init(comp_1176_t *c, float sr) { memset(c, 0, sizeof(*c)); c->sr = sr; c->input_db = 0.0f; c->output_db = 0.0f; c->ratio = 4.0f; c->attack_us = comp_1176_knob_to_attack_us(4.0f); // ~127 μs c->release_ms = comp_1176_knob_to_release_ms(4.0f); // ~234 ms c->iron = 0.5f; c->threshold_db = -10.0f; c->knee_db = 6.0f; c->gr_db = 0.0f; c->gr_peak_db = 0.0f; comp_1176_update(c);}
void comp_1176_update(comp_1176_t *c) { // Single-pole smoothing: y[n] = target + coef*(y[n-1] - target) // Time constant τ → coef = exp(-1 / (τ * sr)). Smaller τ ⇒ smaller coef ⇒ faster. float a_tau = c->attack_us * 1e-6f; float r_tau = c->release_ms * 1e-3f; c->a_coef = expf(-1.0f / (a_tau * c->sr)); c->r_coef = expf(-1.0f / (r_tau * c->sr));}
// Soft-knee static curve (RBJ-style quadratic).// Returns the *gain reduction* in dB (≤ 0) the curve would apply to a// signal currently at `in_db`.static inline float static_curve_db(float in_db, float th, float ratio, float knee) { float over = in_db - th; float slope = 1.0f - 1.0f / ratio; float half = knee * 0.5f; if (over <= -half) return 0.0f; if (over >= half) return -over * slope; float t = (over + half) / knee; // 0..1 across the knee float full = -half * slope; // GR at top of knee return full * t * t;}
// FET asymmetric saturation. Drive bias toward positive → 2nd-harmonic// dominance, the audible FET fingerprint. `drive` modulates depth.static inline float fet_sat(float x, float drive) { if (drive <= 0.0f) return x; float bias = 0.05f * drive; float k = 1.0f + 4.0f * drive; float y = tanhf((x + bias) * k) - tanhf(bias * k); return y / k;}
// A12 line-amp gentle symmetric tanh (the post-FET stage adds warmth).static inline float a12_sat(float x, float drive) { if (drive <= 0.0f) return x; float k = 1.0f + 0.5f * drive; return tanhf(x * k) / k;}
void comp_1176_process(comp_1176_t *c, float *buf, int n_frames, int channels) { float in_lin = acdsp_db2lin(c->input_db); float out_lin = acdsp_db2lin(c->output_db); float fet_d_base = 0.6f * c->iron; float a12_d = 0.3f * c->iron;
for (int i = 0; i < n_frames; i++) { float L = buf[i * channels] * in_lin; float R = (channels > 1) ? buf[i * channels + 1] * in_lin : L;
// Stereo-linked peak detector (max abs across both channels). float det = fabsf(L); if (channels > 1) { float ar = fabsf(R); if (ar > det) det = ar; } float det_db = acdsp_lin2db(det); float target = static_curve_db(det_db, c->threshold_db, c->ratio, c->knee_db);
// Attack when target wants MORE reduction (more negative); release otherwise. float coef = (target < c->gr_db) ? c->a_coef : c->r_coef; c->gr_db = target + coef * (c->gr_db - target); if (c->gr_db < c->gr_peak_db) c->gr_peak_db = c->gr_db;
float g = acdsp_db2lin(c->gr_db); L *= g; if (channels > 1) R *= g;
// FET drive scales with current GR amount (the physical FET conducts // harder ⇒ more nonlinearity). 0 GR ⇒ 30% of base; 18 dB GR ⇒ 100%. float gr_amt = fminf(-c->gr_db, 18.0f) / 18.0f; float fd = fet_d_base * (0.3f + 0.7f * gr_amt); L = fet_sat(L, fd); if (channels > 1) R = fet_sat(R, fd);
L = a12_sat(L, a12_d); if (channels > 1) R = a12_sat(R, a12_d);
L *= out_lin; if (channels > 1) R *= out_lin;
buf[i * channels] = L; if (channels > 1) buf[i * channels + 1] = R; }}