furnace/src/engine/platform/sms.cpp

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#include "sms.h"
#include "../engine.h"
#include <math.h>
void DivPlatformSMS::acquire(int& l, int& r) {
short v;
sn->sound_stream_update(&v,1);
l=v;
r=v;
}
void DivPlatformSMS::tick() {
for (int i=0; i<4; i++) {
chan[i].std.next();
if (chan[i].std.hadVol) sn->write(0x90|(i<<5)|(15-((chan[i].vol*chan[i].std.vol)>>4)));
if (chan[i].std.hadArp) {
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if (chan[i].std.arpMode) {
chan[i].baseFreq=round(1712.0f/pow(2.0f,((float)(chan[i].std.arp-12)/12.0f)));
} else {
chan[i].baseFreq=round(1712.0f/pow(2.0f,((float)(chan[i].note+chan[i].std.arp-12)/12.0f)));
}
chan[i].freqChanged=true;
}
}
for (int i=0; i<3; i++) {
if (chan[i].freqChanged) {
chan[i].freq=(chan[i].baseFreq*(ONE_SEMITONE-chan[i].pitch))/ONE_SEMITONE;
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if (chan[i].note>0x5d) chan[i].freq=0x01;
sn->write(0x80|i<<5|(chan[i].freq&15));
sn->write(chan[i].freq>>4);
chan[i].freqChanged=false;
}
}
if (chan[3].freqChanged || updateSNMode) {
updateSNMode=false;
chan[3].freq=(chan[3].baseFreq*(ONE_SEMITONE-chan[3].pitch))/ONE_SEMITONE;
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if (chan[3].note>0x5d) chan[3].freq=0x01;
chan[3].freqChanged=false;
if (snNoiseMode&2) { // take period from channel 3
if (snNoiseMode&1) {
sn->write(0xe7);
} else {
sn->write(0xe3);
}
sn->write(0xdf);
sn->write(0xc0|(chan[3].freq&15));
sn->write(chan[3].freq>>4);
} else { // 3 fixed values
unsigned char value=chan[3].note%12;
if (value>2) value=2;
value=2-value;
sn->write(0xe0|value|((snNoiseMode&1)<<2));
}
}
}
int DivPlatformSMS::dispatch(DivCommand c) {
switch (c.cmd) {
case DIV_CMD_NOTE_ON:
chan[c.chan].baseFreq=round(1712.0f/pow(2.0f,((float)c.value/12.0f)));
chan[c.chan].freqChanged=true;
chan[c.chan].note=c.value;
chan[c.chan].active=true;
sn->write(0x90|c.chan<<5|(15-chan[c.chan].vol));
chan[c.chan].std.init(parent->song.ins[chan[c.chan].ins]);
break;
case DIV_CMD_NOTE_OFF:
chan[c.chan].active=false;
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sn->write(0x9f|c.chan<<5);
chan[c.chan].std.init(NULL);
break;
case DIV_CMD_INSTRUMENT:
chan[c.chan].ins=c.value;
//chan[c.chan].std.init(parent->song.ins[chan[c.chan].ins]);
break;
case DIV_CMD_VOLUME:
chan[c.chan].vol=c.value;
sn->write(0x90|c.chan<<5|(15-chan[c.chan].vol));
break;
case DIV_CMD_PITCH:
chan[c.chan].pitch=c.value;
chan[c.chan].freqChanged=true;
break;
case DIV_CMD_NOTE_PORTA: {
int destFreq=round(1712.0f/pow(2.0f,((float)c.value2/12.0f)));
bool return2=false;
if (destFreq>chan[c.chan].baseFreq) {
chan[c.chan].baseFreq+=c.value;
if (chan[c.chan].baseFreq>=destFreq) {
chan[c.chan].baseFreq=destFreq;
return2=true;
}
} else {
chan[c.chan].baseFreq-=c.value;
if (chan[c.chan].baseFreq<=destFreq) {
chan[c.chan].baseFreq=destFreq;
return2=true;
}
}
chan[c.chan].freqChanged=true;
if (return2) return 2;
break;
}
case DIV_CMD_STD_NOISE_MODE:
snNoiseMode=(c.value&1)|((c.value&16)>>3);
updateSNMode=true;
break;
case DIV_CMD_LEGATO:
chan[c.chan].baseFreq=round(1712.0f/pow(2.0f,((float)c.value/12.0f)));
chan[c.chan].freqChanged=true;
chan[c.chan].note=c.value;
break;
default:
break;
}
return 1;
}
int DivPlatformSMS::init(DivEngine* p, int channels, int sugRate) {
parent=p;
rate=223722;
sn=new sn76496_device("sn",223722);
sn->device_start();
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snNoiseMode=3;
updateSNMode=false;
return 4;
}