ref: a3f2d6d23ed1be69fee607bdedadc0438fd01305
dir: /sys/src/games/midi/dmid.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include "midifile.h"
typedef struct Opl Opl;
enum{
Rwse = 0x01,
Mwse = 1<<5, /* wave selection enable */
Rctl = 0x20,
Rsca = 0x40,
Mlvl = 63<<0, /* total level */
Mscl = 3<<6, /* scaling level */
Ratk = 0x60,
Rsus = 0x80,
Rnum = 0xa0, /* f number lsb */
Roct = 0xb0,
Mmsb = 3<<0, /* f number msb */
Moct = 7<<2,
Mkon = 1<<5,
Rfed = 0xc0,
Rwav = 0xe0,
Rop3 = 0x105,
};
struct Inst{
int fixed;
int dbl;
int fine;
uchar n;
uchar i[13];
uchar i2[13];
s16int base[2];
};
struct Opl{
Chan *c;
int n;
int midn;
int blk;
int v;
vlong t;
uchar *i;
};
Opl opl[18], *ople = opl + nelem(opl);
int port[] = {
0x0, 0x1, 0x2, 0x8, 0x9, 0xa, 0x10, 0x11, 0x12,
0x100, 0x101, 0x102, 0x108, 0x109, 0x10a, 0x110, 0x111, 0x112
};
int sport[] = {
0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8,
0x100, 0x101, 0x102, 0x103, 0x104, 0x105, 0x106, 0x107, 0x108
};
uchar ovol[] = {
0, 32, 48, 58, 64, 70, 74, 77, 80, 83, 86, 88, 90, 92, 93, 95, 96,
98, 99, 100, 102, 103, 104, 105, 106, 107, 108, 108, 109, 110, 111,
112, 112, 113, 114, 114, 115, 116, 116, 117, 118, 118, 119, 119,
120, 120, 121, 121, 122, 122, 123, 123, 124, 124, 124, 125, 125,
126, 126, 126, 127, 127, 127, 128, 128
};
double freq[128];
int opl2;
void
putcmd(u16int r, u8int v, u16int dt)
{
uchar *p, u[5];
p = u;
*p++ = r;
if(!opl2)
*p++ = r >> 8;
*p++ = v;
*p++ = dt;
*p++ = dt >> 8;
write(1, u, p-u);
}
void
setinst(Opl *o, uchar *i)
{
int p;
p = sport[o - opl];
putcmd(Roct+p, o->blk, 0);
putcmd(Rfed+p, i[6] & ~0x30 | o->c->pan, 0);
p = port[o - opl];
putcmd(Rctl+p, i[0], 0);
putcmd(Ratk+p, i[1], 0);
putcmd(Rsus+p, i[2], 0);
putcmd(Rwav+p, i[3] & 3, 0);
putcmd(Rctl+3+p, i[7], 0);
putcmd(Ratk+3+p, i[8], 0);
putcmd(Rsus+3+p, i[9], 0);
putcmd(Rwav+3+p, i[10] & 3, 0);
o->i = i;
}
void
noteoff(Chan *c, int n, int)
{
Opl *o;
for(o=opl; o<ople; o++)
if(o->c == c && o->midn == n){
putcmd(Roct+sport[o-opl], o->blk, 0);
o->n = -1;
}
}
Opl *
getch(void)
{
Opl *o, *p;
p = opl;
for(o=opl; o<ople; o++){
if(o->n < 0)
return o;
if(o->t < p->t)
p = o;
}
return p;
}
void
setoct(Opl *o)
{
int n, b, f, d;
double e;
d = o->c->bend;
d += o->i == o->c->i->i2 ? o->c->i->fine : 0;
n = o->n + d / 0x1000 & 0x7f;
e = freq[n] + (d % 0x1000) * (freq[n+1] - freq[n]) / 0x1000;
if(o->c->i->fixed)
e = (double)(int)e;
f = (e * (1 << 20)) / samprate;
for(b=1; b<8; b++, f>>=1)
if(f < 1024)
break;
o->blk = b << 2 & Moct | f >> 8 & Mmsb;
putcmd(Rnum+sport[o-opl], f & 0xff, 0);
putcmd(Roct+sport[o-opl], Mkon | o->blk, 0);
}
void
setvol(Opl *o)
{
int p, w, x;
p = port[o - opl];
w = o->v * o->c->vol / 127;
w = ovol[w * 64 / 127] * 63 / 128;
x = 63 + (o->i[5] & Mlvl) * w / 63 - w;
putcmd(Rsca+p, o->i[4] & Mscl | x, 0);
x = 63 + (o->i[12] & Mlvl) * w / 63 - w;
putcmd(Rsca+p+3, o->i[11] & Mscl | x, 0);
}
void
putnote(Chan *c, int midn, int n, int v, vlong t, uchar *i)
{
Opl *o;
o = getch();
o->c = c;
o->n = n;
o->midn = midn;
o->v = v;
o->t = t;
if(o->i != i)
setinst(o, i);
setvol(o);
setoct(o);
}
void
noteon(Chan *c, int n, int v, vlong t)
{
int x, m;
m = n;
if(c - chan == 9){
/* asspull workaround for percussions above gm set */
if(m == 85)
m = 37;
if(m == 82)
m = 44;
if(m < 35 || m > 81)
return;
c->i = inst + 128 + m - 35;
}
if(c->i->fixed)
m = c->i->n;
if(v == 0){
noteoff(c, n, 0);
return;
}
x = m + (c->i->fixed ? 0 : c->i->base[0]);
while(x < 0)
x += 12;
while(x > 8*12-1)
x -= 12;
putnote(c, n, x & 0xff, v, t, c->i->i);
if(c->i->dbl){
x = m + (c->i->fixed ? 0 : c->i->base[1]);
while(x < 0)
x += 12;
while(x > 95)
x -= 12;
putnote(c, n, x & 0xff, v, t, c->i->i2);
}
}
void
resetchan(Chan *c)
{
Opl *o;
for(o=opl; o<ople; o++)
if(o->c == c && o->n >= 0){
putcmd(Rfed+sport[o-opl], o->i[6] & ~0x30 | c->pan, 0);
setvol(o);
setoct(o);
}
}
void
samp(double n)
{
vlong t;
double Δ;
static double ε;
Δ = delay(n) + ε;
t = Δ;
ε = Δ - t;
while(t > 0){
putcmd(0, 0, t > 0xffff ? 0xffff : t);
t -= 0xffff;
}
}
void
event(Track *t)
{
int e;
Msg msg;
Chan *c;
e = nextev(t);
translate(t, e, &msg);
c = msg.chan;
switch(msg.type){
case Cnoteoff: noteoff(msg.chan, msg.arg1, msg.arg2); break;
case Cnoteon: noteon(msg.chan, msg.arg1, msg.arg2, t->t); break;
case Cbankmsb: if(msg.arg2 < Ninst) c->i = inst + msg.arg2; break;
case Cprogram: if(msg.arg2 < Ninst) c->i = inst + msg.arg1; break;
case Cchanvol: /* wet floor */
case Cpan: /* wet floor */
case Cpitchbend: resetchan(c); break;
}
}
void
readinst(char *file)
{
int n;
uchar u[8];
Inst *i;
Chan *c;
inbf = eopen(file, OREAD);
Bread(inbf, u, sizeof u);
if(memcmp(u, "#OPL_II#", sizeof u) != 0)
sysfatal("invalid patch file");
inst = emalloc(Ninst * sizeof *inst);
for(i=inst; i<inst+Ninst; i++){
n = get8(nil);
i->fixed = n & 1<<0;
i->dbl = opl2 ? 0 : n & 1<<2;
get8(nil);
i->fine = (get8(nil) - 128) * 64;
i->n = get8(nil);
Bread(inbf, i->i, sizeof i->i);
get8(nil);
n = get8(nil);
n |= get8(nil) << 8;
i->base[0] = (s16int)n;
Bread(inbf, i->i2, sizeof i->i2);
get8(nil);
n = get8(nil);
n |= get8(nil) << 8;
i->base[1] = (s16int)n;
}
Bterm(inbf);
inbf = nil;
for(c=chan; c<chan+nelem(chan); c++)
c->i = inst;
}
void
usage(void)
{
fprint(2, "usage: %s [-2Ds] [-i inst] [mid]\n", argv0);
exits("usage");
}
void
main(int argc, char **argv)
{
int n;
char *i;
double f;
Opl *o;
samprate = 49716, /* opl3 sampling rate */
i = "/mnt/wad/genmidi";
ARGBEGIN{
case '2': opl2 = 1; ople = opl + 9; break;
case 'D': trace = 1; break;
case 'i': i = EARGF(usage()); break;
case 's': stream = 1; break;
default: usage();
}ARGEND
initmid();
readinst(i);
if(readmid(*argv) < 0)
sysfatal("readmid: %r");
f = pow(2, 1./12);
for(n=0; n<nelem(freq); n++)
freq[n] = 440 * pow(f, n - 69);
for(o=opl; o<ople; o++)
o->n = -1;
putcmd(Rwse, Mwse, 0);
putcmd(Rop3, 1, 0);
evloop();
exits(nil);
}