mirror of
https://github.com/tildearrow/furnace.git
synced 2024-11-19 11:05:11 +00:00
218 lines
7 KiB
C++
218 lines
7 KiB
C++
/**
|
|
* Furnace Tracker - multi-system chiptune tracker
|
|
* Copyright (C) 2021-2022 tildearrow and contributors
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include "zsm.h"
|
|
#include "../ta-log.h"
|
|
#include "../utfutils.h"
|
|
#include "song.h"
|
|
|
|
DivZSM::DivZSM() {
|
|
w = NULL;
|
|
init();
|
|
}
|
|
|
|
DivZSM::~DivZSM() {
|
|
}
|
|
|
|
void DivZSM::init(unsigned int rate) {
|
|
if (w != NULL) delete w;
|
|
w = new SafeWriter;
|
|
w->init();
|
|
// write default ZSM data header
|
|
w->write("zm",2); // magic header
|
|
w->writeC(ZSM_VERSION);
|
|
// no loop offset
|
|
w->writeS(0);
|
|
w->writeC(0);
|
|
// no PCM
|
|
w->writeS(0x00);
|
|
w->writeC(0x00);
|
|
// FM channel mask
|
|
w->writeC(0x00);
|
|
// PSG channel mask
|
|
w->writeS(0x00);
|
|
w->writeS((unsigned short)rate);
|
|
// 2 reserved bytes (set to zero)
|
|
w->writeS(0x00);
|
|
tickRate = rate;
|
|
loopOffset=-1;
|
|
numWrites=0;
|
|
memset(&ymState,-1,sizeof(ymState));
|
|
memset(&psgState,-1,sizeof(psgState));
|
|
ticks=0;
|
|
}
|
|
|
|
int DivZSM::getoffset() {
|
|
return w->tell();
|
|
}
|
|
|
|
void DivZSM::writeYM(unsigned char a, unsigned char v) {
|
|
int lastMask = ymMask;
|
|
if (a==0x19 && v>=0x80) a=0x1a; // AMD/PSD use same reg addr. store PMD as 0x1a
|
|
if (a==0x08 && (v&0xf8)) ymMask |= (1 << (v & 0x07)); // mark chan as in-use if keyDN
|
|
if (a!=0x08) ymState[ym_NEW][a] = v; // cache the newly-written value
|
|
bool writeit=false; // used to suppress spurious writes to unused channels
|
|
if (a < 0x20) {
|
|
if (a == 0x08) {
|
|
// write keyUPDN messages if channel is active.
|
|
writeit = (ymMask & (1 << (v & 0x07))) > 0;
|
|
}
|
|
else {
|
|
// do not suppress global registers
|
|
writeit = true;
|
|
}
|
|
} else {
|
|
writeit = (ymMask & (1 << (a & 0x07))) > 0; // a&0x07 = chan ID for regs >=0x20
|
|
}
|
|
if (lastMask != ymMask) {
|
|
// if the ymMask just changed, then the channel has become active.
|
|
// This can only happen on a KeyDN event, so voice = v & 0x07
|
|
// insert a keyUP just to be safe.
|
|
ymwrites.push_back(DivRegWrite(0x08,v&0x07));
|
|
numWrites++;
|
|
// flush the ym_NEW cached states for this channel into the ZSM....
|
|
for ( int i=0x20 + (v&0x07); i <= 0xff ; i+=8) {
|
|
if (ymState[ym_NEW][i] != ymState[ym_PREV][i]) {
|
|
ymwrites.push_back(DivRegWrite(i,ymState[ym_NEW][i]));
|
|
numWrites++;
|
|
// ...and update the shadow
|
|
ymState[ym_PREV][i] = ymState[ym_NEW][i];
|
|
}
|
|
}
|
|
}
|
|
// Handle the current write if channel is active
|
|
if (writeit && ((ymState[ym_NEW][a] != ymState[ym_PREV][a])||a==0x08) ) {
|
|
// update YM shadow if not the KeyUPDN register.
|
|
if (a!=0x008) ymState[ym_PREV][a] = ymState[ym_NEW][a];
|
|
// if reg = PMD, then change back to real register 0x19
|
|
if (a==0x1a) a=0x19;
|
|
ymwrites.push_back(DivRegWrite(a,v));
|
|
numWrites++;
|
|
}
|
|
}
|
|
|
|
void DivZSM::writePSG(unsigned char a, unsigned char v) {
|
|
// TODO: suppress writes to PSG voice that is not audible (volume=0)
|
|
if (a >= 64) {
|
|
logD ("ZSM: ignoring VERA PSG write a=%02x v=%02x",a,v);
|
|
return;
|
|
}
|
|
if(psgState[psg_PREV][a] == v) {
|
|
if (psgState[psg_NEW][a] != v)
|
|
// NEW value is being reset to the same as PREV value
|
|
// so it is no longer a new write.
|
|
numWrites--;
|
|
} else {
|
|
if (psgState[psg_PREV][a] == psgState[psg_NEW][a])
|
|
// if this write changes the NEW cached value to something other
|
|
// than the PREV value, then this is a new write.
|
|
numWrites++;
|
|
}
|
|
psgState[psg_NEW][a] = v;
|
|
// mark channel as used in the psgMask if volume is set > 0.
|
|
if ((a % 4 == 2) && (v & 0x3f)) psgMask |= (1 << (a>>2));
|
|
}
|
|
|
|
void DivZSM::writePCM(unsigned char a, unsigned char v) {
|
|
// ZSM standard for PCM playback has not been established yet.
|
|
}
|
|
|
|
void DivZSM::tick(int numticks) {
|
|
flushWrites();
|
|
ticks += numticks;
|
|
}
|
|
|
|
void DivZSM::setLoopPoint() {
|
|
tick(0); // flush any ticks+writes
|
|
flushTicks(); // flush ticks incase no writes were pending
|
|
logI("ZSM: loop at file offset %d bytes",w->tell());
|
|
loopOffset=w->tell();
|
|
// update the ZSM header's loop offset value
|
|
w->seek(0x03,SEEK_SET);
|
|
w->writeS((short)(loopOffset&0xffff));
|
|
w->writeC((unsigned char)((loopOffset>>16)&0xff));
|
|
w->seek(loopOffset,SEEK_SET);
|
|
// reset the PSG shadow and write cache
|
|
memset(&psgState,-1,sizeof(psgState));
|
|
// reset the YM shadow....
|
|
memset(&ymState[ym_PREV],-1,sizeof(ymState[ym_PREV]));
|
|
// ... and cache (except for unused channels)
|
|
memset(&ymState[ym_NEW],-1,0x20);
|
|
for (int chan=0; chan<8 ; chan++) {
|
|
// do not clear state for as-yet-unused channels
|
|
if (!(ymMask & (1<<chan))) continue;
|
|
// clear the state for channels in use so they match the unknown state
|
|
// of the YM shadow.
|
|
for (int i=0x20+chan; i<=0xff; i+= 8) ymState[ym_NEW][i] = -1;
|
|
}
|
|
}
|
|
|
|
SafeWriter* DivZSM::finish() {
|
|
tick(0); // flush any pending writes / ticks
|
|
flushTicks(); // flush ticks in case there were no writes pending
|
|
w->writeC(ZSM_EOF);
|
|
// update channel use masks.
|
|
w->seek(0x09,SEEK_SET);
|
|
w->writeC((unsigned char)(ymMask & 0xff));
|
|
w->writeS((short)(psgMask & 0xffff));
|
|
// todo: put PCM offset/data writes here once defined in ZSM standard.
|
|
return w;
|
|
}
|
|
|
|
void DivZSM::flushWrites() {
|
|
logD("ZSM: flushWrites.... numwrites=%d ticks=%d ymwrites=%d",numWrites,ticks,ymwrites.size());
|
|
if (numWrites==0) return;
|
|
flushTicks(); // only flush ticks if there are writes pending.
|
|
for (unsigned char i=0;i<64;i++) {
|
|
if (psgState[psg_NEW][i] == psgState[psg_PREV][i]) continue;
|
|
psgState[psg_PREV][i]=psgState[psg_NEW][i];
|
|
w->writeC(i);
|
|
w->writeC(psgState[psg_NEW][i]);
|
|
}
|
|
int n=0; // n = completed YM writes. used to determine when to write the CMD byte...
|
|
for (DivRegWrite& write: ymwrites) {
|
|
if (n%ZSM_YM_MAX_WRITES == 0) {
|
|
if(ymwrites.size()-n > ZSM_YM_MAX_WRITES) {
|
|
w->writeC((unsigned char)(ZSM_YM_CMD+ZSM_YM_MAX_WRITES));
|
|
logD("ZSM: YM-write: %d (%02x) [max]",ZSM_YM_MAX_WRITES,ZSM_YM_MAX_WRITES+ZSM_YM_CMD);
|
|
} else {
|
|
w->writeC((unsigned char)(ZSM_YM_CMD+ymwrites.size()-n));
|
|
logD("ZSM: YM-write: %d (%02x)",ymwrites.size()-n,ZSM_YM_CMD+ymwrites.size()-n);
|
|
}
|
|
}
|
|
n++;
|
|
w->writeC(write.addr);
|
|
w->writeC(write.val);
|
|
}
|
|
ymwrites.clear();
|
|
numWrites=0;
|
|
}
|
|
|
|
void DivZSM::flushTicks() {
|
|
while (ticks > ZSM_DELAY_MAX) {
|
|
logD("ZSM: write delay %d (max)",ZSM_DELAY_MAX);
|
|
w->writeC((unsigned char)(ZSM_DELAY_CMD+ZSM_DELAY_MAX));
|
|
ticks -= ZSM_DELAY_MAX;
|
|
}
|
|
if (ticks>0) {
|
|
logD("ZSM: write delay %d",ticks);
|
|
w->writeC(ZSM_DELAY_CMD+ticks);
|
|
}
|
|
ticks=0;
|
|
}
|