furnace/src/engine/platform/sound/c64_d/dsid.c
2023-07-11 17:21:51 -05:00

371 lines
14 KiB
C

#include "dsid.h"
#include <stdio.h>
#include <math.h> // INFINITY
#include <stdlib.h>
#include <string.h> // memset, memcpy
#define SID_OUT_SCALE (0x10000 * 3 * 16)
// CONTROL
#define GAT 0x01
#define SYN 0x02
#define RNG 0x04
#define TST 0x08
#define TRI 0x10
#define SAW 0x20
#define PUL 0x40
#define NOI 0x80
#define _HZ 0x10
#define DECSUS 0x40
#define ATK 0x80
// filter mode (high)
#define LP 0x10
#define BP 0x20
#define HP 0x40
#define OFF3 0x80
#define waveforms_add_sample(_id,_s) \
sid->lastOut[_id]=(_s);
const int Aexp[256] = {
1, 30, 30, 30, 30, 30, 30, 16, 16, 16, 16, 16, 16, 16, 16, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
double cmbWF(int chn, int *wfa, int index, int differ6581, struct SID_globals *g) {
if (differ6581 && g->model == 6581)
index &= 0x7FF;
return wfa[index];
}
void cCmbWF(int *wfa, double bitmul, double bstr, double trh) {
for (int i = 0; i < 4096; i++) {
wfa[i] = 0;
for (int j = 0; j < 12; j++) {
double blvl = 0;
for (int k = 0; k < 12; k++) {
blvl += (bitmul / pow(bstr, abs(k - j))) * (((i >> k) & 1) - 0.5);
}
wfa[i] += (blvl >= trh) ? pow(2, j) : 0;
}
wfa[i] *= 12;
}
}
void dSID_init(struct SID_chip* sid, double clockRate, double samplingRate, int model, unsigned char init_wf) {
if (model == 6581) {
sid->g.model = 6581;
} else {
sid->g.model = 8580;
}
memset(sid->M,0,MemLen);
memset(sid->SIDct, 0, sizeof(sid->SIDct));
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
sid->SIDct[i].ch[j].Ast = _HZ;
sid->SIDct[i].ch[j].nLFSR = 0x7FFFF8;
sid->SIDct[i].ch[j].prevwfout = 0;
}
sid->SIDct[i].ch[0].FSW = 1;
sid->SIDct[i].ch[1].FSW = 2;
sid->SIDct[i].ch[2].FSW = 4;
}
sid->g.ctfr = -2.0 * 3.14 * (12500.0 / 256.0) / samplingRate,
sid->g.ctf_ratio_6581 = -2.0 * 3.14 * (samplingRate / 44100.0) * (20000.0 / 256.0) / samplingRate;
sid->g.ckr = clockRate / samplingRate;
const double bAprd[16] = {9, 32 * 1, 63 * 1, 95 * 1, 149 * 1, 220 * 1,
267 * 1, 313 * 1, 392 * 1, 977 * 1, 1954 * 1, 3126 * 1,
3907 * 1, 11720 * 1, 19532 * 1, 31251 * 1};
const int bAstp[16] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
memcpy(&sid->g.Aprd, &bAprd, sizeof(bAprd));
memcpy(&sid->g.Astp, &bAstp, sizeof(bAstp));
if (init_wf) {
cCmbWF(sid->g.trsaw, 0.8, 2.4, 0.64);
cCmbWF(sid->g.pusaw, 1.4, 1.9, 0.68);
cCmbWF(sid->g.Pulsetrsaw, 0.8, 2.5, 0.64);
for (int i = 0; i < 2048; i++) {
double ctf = (double) i / 8.0 + 0.2;
if (model == 8580) {
ctf = 1 - exp(ctf * sid->g.ctfr);
} else {
if (ctf < 24) {
ctf = 2.0 * sin(771.78 / samplingRate);
} else {
ctf = (44100.0 / samplingRate) - 1.263 * (44100.0 / samplingRate) * exp(ctf * sid->g.ctf_ratio_6581);
}
}
sid->g.ctf_table[i] = ctf;
}
}
double prd0 = sid->g.ckr > 9 ? sid->g.ckr : 9;
sid->g.Aprd[0] = prd0;
sid->g.Astp[0] = ceil(prd0 / 9);
for (int i=0; i<3; i++) {
sid->fakeplp[i]=0;
sid->fakepbp[i]=0;
}
}
double dSID_render(struct SID_chip* sid) {
double flin = 0, output = 0;
double wfout = 0;
double step = 0;
for (int chn = 0; chn < 3; chn++) {
struct SIDVOICE *voic = &((struct SIDMEM *) (sid->M))->v[chn];
double pgt = (sid->SIDct->ch[chn].Ast & GAT);
uint8_t ctrl = voic->control;
uint8_t wf = ctrl & 0xF0;
uint8_t test = ctrl & TST;
uint8_t SR = voic->susres;
double tmp = 0;
if (pgt != (ctrl & GAT)) {
if (pgt) {
sid->SIDct->ch[chn].Ast &= 0xFF - (GAT | ATK | DECSUS);
} else {
sid->SIDct->ch[chn].Ast = (GAT | ATK | DECSUS);
if ((SR & 0xF) > (sid->SIDct->ch[chn].pSR & 0xF))
tmp = 1;
}
}
sid->SIDct->ch[chn].pSR = SR;
sid->SIDct->ch[chn].rcnt += sid->g.ckr;
if (sid->SIDct->ch[chn].rcnt >= 0x8000)
sid->SIDct->ch[chn].rcnt -= 0x8000;
double prd;
if (sid->SIDct->ch[chn].Ast & ATK) {
step = voic->attack;
prd = sid->g.Aprd[(int) step];
} else if (sid->SIDct->ch[chn].Ast & DECSUS) {
step = voic->decay;
prd = sid->g.Aprd[(int) step];
} else {
step = SR & 0xF;
prd = sid->g.Aprd[(int) step];
}
step = sid->g.Astp[(int) step];
if (sid->SIDct->ch[chn].rcnt >= prd && sid->SIDct->ch[chn].rcnt < prd + sid->g.ckr &&
tmp == 0) {
sid->SIDct->ch[chn].rcnt -= prd;
if ((sid->SIDct->ch[chn].Ast & ATK) ||
++sid->SIDct->ch[chn].expcnt == Aexp[(int) sid->SIDct->ch[chn].envcnt]) {
if (!(sid->SIDct->ch[chn].Ast & _HZ)) {
if (sid->SIDct->ch[chn].Ast & ATK) {
sid->SIDct->ch[chn].envcnt += step;
if (sid->SIDct->ch[chn].envcnt >= 0xFF) {
sid->SIDct->ch[chn].envcnt = 0xFF;
sid->SIDct->ch[chn].Ast &= 0xFF - ATK;
}
} else if (!(sid->SIDct->ch[chn].Ast & DECSUS) ||
sid->SIDct->ch[chn].envcnt > (SR >> 4) + (SR & 0xF0)) {
sid->SIDct->ch[chn].envcnt -= step;
if (sid->SIDct->ch[chn].envcnt <= 0 &&
sid->SIDct->ch[chn].envcnt + step != 0) {
sid->SIDct->ch[chn].envcnt = 0;
sid->SIDct->ch[chn].Ast |= _HZ;
}
}
}
sid->SIDct->ch[chn].expcnt = 0;
} else {
}
}
sid->SIDct->ch[chn].envcnt = (int) sid->SIDct->ch[chn].envcnt & 0xFF;
double aAdd = (voic->freq_low + voic->freq_high * 256) * sid->g.ckr;
if (test || ((ctrl & SYN) && sid->SIDct->sMSBrise)) {
sid->SIDct->ch[chn].pacc = 0;
} else {
sid->SIDct->ch[chn].pacc += aAdd;
if (sid->SIDct->ch[chn].pacc > 0xFFFFFF)
sid->SIDct->ch[chn].pacc -= 0x1000000;
}
double MSB = (int) sid->SIDct->ch[chn].pacc & 0x800000;
sid->SIDct->sMSBrise = (MSB > ((int) sid->SIDct->ch[chn].pracc & 0x800000)) ? 1 : 0;
if (wf & NOI) {
tmp = sid->SIDct->ch[chn].nLFSR;
if ((((int) sid->SIDct->ch[chn].pacc & 0x100000) !=
((int) sid->SIDct->ch[chn].pracc & 0x100000)) ||
aAdd >= 0x100000) {
step = ((int) tmp & 0x400000) ^ (((int) tmp & 0x20000) << 5);
tmp = (((int) tmp << 1) + (step > 0 || test)) & 0x7FFFFF;
sid->SIDct->ch[chn].nLFSR = tmp;
}
wfout = (wf & 0x70) ? 0
: (((int) tmp & 0x100000) >> 5) + (((int) tmp & 0x40000) >> 4) +
(((int) tmp & 0x4000) >> 1) + (((int) tmp & 0x800) << 1) +
(((int) tmp & 0x200) << 2) + (((int) tmp & 0x20) << 5) +
(((int) tmp & 0x04) << 7) + (((int) tmp & 0x01) << 8);
} else if (wf & PUL) {
double pw = (voic->pw_low + (voic->pw_high) * 256) * 16;
tmp = (int) aAdd >> 9;
if (0 < pw && pw < tmp)
pw = tmp;
tmp = (int) tmp ^ 0xFFFF;
if (pw > tmp)
pw = tmp;
tmp = (int) sid->SIDct->ch[chn].pacc >> 8;
if (wf == PUL) {
int lel = ((int) aAdd >> 16);
if (lel > 0) {
step = 256.0 / (double) lel;
} else {
step = INFINITY;
}
if (test)
wfout = 0xFFFF;
else if (tmp < pw) {
double lim = (0xFFFF - pw) * step;
if (lim > 0xFFFF)
lim = 0xFFFF;
wfout = lim - (pw - tmp) * step;
if (wfout < 0)
wfout = 0;
} else {
double lim = pw * step;
if (lim > 0xFFFF)
lim = 0xFFFF;
wfout = (0xFFFF - tmp) * step - lim;
if (wfout >= 0)
wfout = 0xFFFF;
wfout = (int) wfout & 0xFFFF;
}
} else {
wfout = (tmp >= pw || test) ? 0xFFFF : 0;
if (wf & TRI) {
if (wf & SAW) {
wfout =
(wfout) ? cmbWF(chn, sid->g.Pulsetrsaw, (int) tmp >> 4, 1, &sid->g) : 0;
} else {
tmp = (int) sid->SIDct->ch[chn].pacc ^ (ctrl & RNG ? sid->SIDct->sMSB : 0);
wfout =
(wfout)
? cmbWF(chn, sid->g.pusaw,
((int) tmp ^ ((int) tmp & 0x800000 ? 0xFFFFFF : 0)) >> 11,
0, &sid->g)
: 0;
}
} else if (wf & SAW)
wfout = (wfout) ? cmbWF(chn, sid->g.pusaw, (int) tmp >> 4, 1, &sid->g) : 0;
}
} else if (wf & SAW) {
wfout = (int) sid->SIDct->ch[chn].pacc >> 8;
if (wf & TRI)
wfout = cmbWF(chn, sid->g.trsaw, (int) wfout >> 4, 1, &sid->g);
else {
step = aAdd / 0x1200000;
wfout += wfout * step;
if (wfout > 0xFFFF)
wfout = 0xFFFF - (wfout - 0x10000) / step;
}
} else if (wf & TRI) {
tmp = (int) sid->SIDct->ch[chn].pacc ^ (ctrl & RNG ? sid->SIDct->sMSB : 0);
wfout = ((int) tmp ^ ((int) tmp & 0x800000 ? 0xFFFFFF : 0)) >> 7;
}
if (wf)
sid->SIDct->ch[chn].prevwfout = wfout;
else {
wfout = sid->SIDct->ch[chn].prevwfout;
}
sid->SIDct->ch[chn].pracc = sid->SIDct->ch[chn].pacc;
sid->SIDct->sMSB = MSB;
// double preflin = flin;
if ((sid->mute_mask & (1 << chn))) {
if (sid->M[0x17] & sid->SIDct->ch[chn].FSW) {
double chnout = (wfout - 0x8000) * (sid->SIDct->ch[chn].envcnt / 256);
flin += chnout;
// fake filter for solo waveform ahead
// mostly copypasted from below
double fakeflin = chnout;
double fakeflout = 0;
double ctf = sid->g.ctf_table[((sid->M[0x15]&7)|(sid->M[0x16]<<3))&0x7ff];
double reso;
if (sid->g.model == 8580) {
reso = pow(2, ((double) (4 - (double) (sid->M[0x17] >> 4)) / 8));
} else {
reso = (sid->M[0x17] > 0x5F) ? 8.0 / (double) (sid->M[0x17] >> 4) : 1.41;
}
double tmp = fakeflin + sid->fakepbp[chn] * reso + sid->fakeplp[chn];
if (sid->M[0x18] & HP)
fakeflout -= tmp;
tmp = sid->fakepbp[chn] - tmp * ctf;
sid->fakepbp[chn] = tmp;
if (sid->M[0x18] & BP)
fakeflout -= tmp;
tmp = sid->fakeplp[chn] + tmp * ctf;
sid->fakeplp[chn] = tmp;
if (sid->M[0x18] & LP)
fakeflout += tmp;
double wf_out = (fakeflout / SID_OUT_SCALE) * (sid->M[0x18] & 0xF) * 65535;
waveforms_add_sample(chn, wf_out);
} else if ((chn % 3) != 2 || !(sid->M[0x18] & OFF3)) {
double chnout = (wfout - 0x8000) * (sid->SIDct->ch[chn].envcnt / 256);
output += chnout;
double wf_out = (chnout / SID_OUT_SCALE) * (sid->M[0x18] & 0xF) * 65535;
waveforms_add_sample(chn, wf_out);
}
} else {
waveforms_add_sample(chn, 0);
}
}
int M1 = 0;
if (M1 & 3)
sid->M[0x1B] = (int) wfout >> 8;
sid->M[0x1C] = sid->SIDct->ch[2].envcnt;
double ctf = sid->g.ctf_table[((sid->M[0x15]&7)|(sid->M[0x16]<<3))&0x7ff];
double reso;
if (sid->g.model == 8580) {
reso = pow(2, ((double) (4 - (double) (sid->M[0x17] >> 4)) / 8));
} else {
reso = (sid->M[0x17] > 0x5F) ? 8.0 / (double) (sid->M[0x17] >> 4) : 1.41;
}
double tmp = flin + sid->SIDct->pbp * reso + sid->SIDct->plp;
if (sid->M[0x18] & HP)
output -= tmp;
tmp = sid->SIDct->pbp - tmp * ctf;
sid->SIDct->pbp = tmp;
if (sid->M[0x18] & BP)
output -= tmp;
tmp = sid->SIDct->plp + tmp * ctf;
sid->SIDct->plp = tmp;
if (sid->M[0x18] & LP)
output += tmp;
return (output / SID_OUT_SCALE) * (sid->M[0x18] & 0xF);
}
void dSID_setMuteMask(struct SID_chip* sid, int mute_mask) {
sid->mute_mask = mute_mask;
}
float dSID_getVolume(struct SID_chip* sid, int channel) {
if ((sid->M[0x18] & 0xF) == 0)
return 0;
return sid->SIDct[0].ch[channel].envcnt / 256.0f;
}
void dSID_write(struct SID_chip* sid, unsigned char addr, unsigned char val) {
sid->M[addr&0x1f]=val;
}