otomatalabs/furnace
8
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Some fleshing out YMF278B

Browse source 
Add OpenMSX YMF278B core option, Expand RAM size option
This commit is contained in:
cam900 2024-07-12 12:16:24 +09:00
parent a8ec76699b
commit 221fa5aa42
11 changed files with 275 additions and 104 deletions
Download patch file Download diff file Expand all files Collapse all files

40
src/engine/platform/sound/ymf278b/ymf278.cpp
View file

@ -29,6 +29,10 @@
// interaction with the FM registers (e.g. the NEW2 bit) is currently handled
// in the MSXMoonSound class.
// MODIFIED:
// Add YMW258 support by Grauw
// Add DO1 output support by cam900
#include "ymf278.h"
#include <algorithm>
#include <cassert>
@ -476,10 +480,12 @@ static constexpr int vol_factor(int x, unsigned envVol)
return (x * ((0x8000 * vol_mul) >> vol_shift)) >> 15;
}
void YMF278Base::generate(short& left, short& right, short* channelBufs)
void YMF278Base::generate(short& fleft, short& fright, short& rleft, short& rright, short* channelBufs)
{
int sampleLeft = 0;
int sampleRight = 0;
int sampleFLeft = 0;
int sampleFRight = 0;
int sampleRLeft = 0;
int sampleRRight = 0;
for (size_t i = 0, count = slots.size(); i < count; i++) {
Slot& sl = slots[i];
if (sl.state == EG_OFF) {
@ -512,8 +518,16 @@ void YMF278Base::generate(short& left, short& right, short* channelBufs)
volLeft = (0x20 - (volLeft & 0x0f)) >> (volLeft >> 4);
volRight = (0x20 - (volRight & 0x0f)) >> (volRight >> 4);
sampleLeft += (smplOut * volLeft ) >> 5;
sampleRight += (smplOut * volRight) >> 5;
if (sl.ch)
{
sampleRLeft += (smplOut * volLeft ) >> 5;
sampleRRight += (smplOut * volRight) >> 5;
}
else
{
sampleFLeft += (smplOut * volLeft ) >> 5;
sampleFRight += (smplOut * volRight) >> 5;
}
unsigned step = (sl.lfo_active && sl.vib)
? calcStep(sl.OCT, sl.FN, sl.compute_vib())
@ -531,8 +545,10 @@ void YMF278Base::generate(short& left, short& right, short* channelBufs)
}
advance();
left = sampleLeft >> 4;
right = sampleRight >> 4;
fleft = sampleFLeft >> 4;
fright = sampleFRight >> 4;
rleft = sampleRLeft >> 4;
rright = sampleRRight >> 4;
}
void YMF278Base::keyOnHelper(Slot& slot)
@ -683,14 +699,8 @@ void YMF278::writeReg(byte reg, byte data)
break;
}
case 4:
if (data & 0x10) {
// output to DO1 pin:
// this pin is not used in moonsound
// we emulate this by muting the sound
slot.pan = 8; // both left/right -inf dB
} else {
slot.pan = data & 0x0F;
}
slot.ch = data & 0x10;
slot.pan = data & 0x0F;
if (data & 0x20) {
// LFO reset