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mcd, implement pre/post reading in play/read state

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kub 2024-04-21 16:20:28 +02:00
parent 691abdfa0f
commit d9bb2921ee
1 changed files with 40 additions and 4 deletions
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44
pico/cd/cdd.c
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@ -829,6 +829,12 @@ void cdd_update(void)
Pico_mcd->s68k_regs[0x36+0] = 0x01;
}
}
if (Pico_mcd->s68k_regs[0x4b] & 0x1) {
/* pending delayed command */
cdd_process();
Pico_mcd->s68k_regs[0x4b] &= ~0x1;
}
}
#define set_reg16(r, v) { \
@ -844,7 +850,7 @@ void cdd_process(void)
{
case 0x00: /* Drive Status */
{
if (cdd.latency <= 3) {
if (cdd.latency == 0) {
/* RS1-RS8 normally unchanged */
Pico_mcd->s68k_regs[0x38+0] = cdd.status;
@ -999,6 +1005,12 @@ void cdd_process(void)
(Pico_mcd->s68k_regs[0x46+0] * 10 + Pico_mcd->s68k_regs[0x46+1])) * 75 +
(Pico_mcd->s68k_regs[0x48+0] * 10 + Pico_mcd->s68k_regs[0x48+1]) - 150;
/* if drive is currently reading, another block or 2 are decoded before the seek starts */
if (cdd.status == CD_PLAY && !(Pico_mcd->s68k_regs[0x4b] & 0x1)) {
Pico_mcd->s68k_regs[0x4b] |= 0x1;
return;
}
/* CD drive latency */
if (!cdd.latency)
{
@ -1024,9 +1036,14 @@ void cdd_process(void)
cdd.latency += (((cdd.lba - lba) * 120) / 270000);
}
/* block transfer always starts 3 blocks earlier */
cdd.latency -= 3;
lba -= 3;
/* get track index */
while ((cdd.toc.tracks[index].end <= lba) && (index < cdd.toc.last)) index++;
/* seek to block */
cdd_seek(index, lba);
/* no audio track playing (yet) */
@ -1041,7 +1058,7 @@ void cdd_process(void)
set_reg16(0x3c, 0x0000);
set_reg16(0x3e, 0x0000);
set_reg16(0x40, ~(CD_SEEK + 0xf) & 0x0f);
break;
return;
}
case 0x04: /* Seek */
@ -1054,6 +1071,12 @@ void cdd_process(void)
(Pico_mcd->s68k_regs[0x46+0] * 10 + Pico_mcd->s68k_regs[0x46+1])) * 75 +
(Pico_mcd->s68k_regs[0x48+0] * 10 + Pico_mcd->s68k_regs[0x48+1]) - 150;
/* if drive is currently reading, another block or 2 are decoded before the seek starts */
if (cdd.status == CD_PLAY && !(Pico_mcd->s68k_regs[0x4b] & 0x1)) {
Pico_mcd->s68k_regs[0x4b] |= 0x1;
return;
}
/* CD drive seek time */
/* We are using similar linear model as above, although still not exactly accurate, */
/* it works fine for Switch/Panic! intro (Switch needs at least 30 interrupts while */
@ -1067,10 +1090,10 @@ void cdd_process(void)
cdd.latency = ((cdd.lba - lba) * 120) / 270000;
}
/* get current track index */
/* get track index */
while ((cdd.toc.tracks[index].end <= lba) && (index < cdd.toc.last)) index++;
/* seek to current block */
/* seek to block */
cdd_seek(index, lba);
/* no audio track playing */
@ -1090,6 +1113,8 @@ void cdd_process(void)
case 0x06: /* Pause */
{
/* TODO another block is decoded before pausing? */
/* no audio track playing */
Pico_mcd->s68k_regs[0x36+0] = 0x01;
@ -1100,6 +1125,17 @@ void cdd_process(void)
case 0x07: /* Resume */
{
int lba = (cdd.lba < 0 ? 0 : cdd.lba);
/* CD drive latency */
if (!cdd.latency)
{
cdd.latency = 11;
}
/* always restart 4 blocks earlier */
cdd_seek(cdd.index, lba - 4);
/* update status (RS1-RS8 unchanged) */
cdd.status = Pico_mcd->s68k_regs[0x38+0] = CD_PLAY;
break;