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C64: fix dSID filters

This commit is contained in:
tildearrow 2023-07-06 02:12:34 -05:00
parent 59e93892dd
commit 2dde6159a1
2 changed files with 23 additions and 16 deletions
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37
src/engine/platform/sound/c64_d/dsid.c
View File

@ -1,4 +1,5 @@
#include "dsid.h"
#include <stdio.h>
#include <math.h> // INFINITY
#include <stdlib.h>
#include <string.h> // memset, memcpy
@ -82,7 +83,7 @@ void dSID_init(struct SID_chip* sid, double clockRate, double samplingRate, int
}
sid->g.ctfr = -2.0 * 3.14 * (12500.0 / 256.0) / samplingRate,
sid->g.ctf_ratio_6581 = -2.0 * 3.14 * (20000.0 / 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,
@ -92,9 +93,23 @@ void dSID_init(struct SID_chip* sid, double clockRate, double samplingRate, int
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);
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;
@ -278,16 +293,11 @@ double dSID_render(struct SID_chip* sid) {
double fakeflout = 0;
static double fakeplp[3] = {0};
static double fakepbp[3] = {0};
double ctf = ((double) (sid->M[0x15] & 7)) / 8 + sid->M[0x16] + 0.2;
double ctf = sid->g.ctf_table[((sid->M[0x15]&7)|(sid->M[0x16]<<3))&0x7ff];
double reso;
if (sid->g.model == 8580) {
ctf = 1 - exp(ctf * sid->g.ctfr);
reso = pow(2, ((double) (4 - (double) (sid->M[0x17] >> 4)) / 8));
} else {
if (ctf < 24)
ctf = 0.035;
else
ctf = 1 - 1.263 * exp(ctf * sid->g.ctf_ratio_6581);
reso = (sid->M[0x17] > 0x5F) ? 8.0 / (double) (sid->M[0x17] >> 4) : 1.41;
}
double tmp = fakeflin + fakepbp[chn] * reso + fakeplp[chn];
@ -320,16 +330,11 @@ double dSID_render(struct SID_chip* sid) {
sid->M[0x1B] = (int) wfout >> 8;
sid->M[0x1C] = sid->SIDct->ch[2].envcnt;
double ctf = ((double) (sid->M[0x15] & 7)) / 8 + sid->M[0x16] + 0.2;
double ctf = sid->g.ctf_table[((sid->M[0x15]&7)|(sid->M[0x16]<<3))&0x7ff];
double reso;
if (sid->g.model == 8580) {
ctf = 1 - exp(ctf * sid->g.ctfr);
reso = pow(2, ((double) (4 - (double) (sid->M[0x17] >> 4)) / 8));
} else {
if (ctf < 24)
ctf = 0.035;
else
ctf = 1 - 1.263 * exp(ctf * sid->g.ctf_ratio_6581);
reso = (sid->M[0x17] > 0x5F) ? 8.0 / (double) (sid->M[0x17] >> 4) : 1.41;
}

2
src/engine/platform/sound/c64_d/dsid.h
View File

@ -62,6 +62,8 @@ struct SID_globals {
double ctfr;
double ctf_ratio_6581;
double ctf_table[2048];
int trsaw[4096];
int pusaw[4096];
int Pulsetrsaw[4096];