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zero out capture buffer in case advanced spu logic is disabled (prevents noise in savestates taken with a different advanced spu logic setting)

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zeromus 2016-03-29 07:12:26 +00:00
parent 660248816e
commit f22f05959d
1 changed files with 46 additions and 3 deletions
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49
desmume/src/SPU.cpp
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@ -1,7 +1,7 @@
/*
Copyright (C) 2006 yopyop
Copyright (C) 2006 Theo Berkau
Copyright (C) 2008-2015 DeSmuME team
Copyright (C) 2008-2016 DeSmuME team
Ideas borrowed from Stephane Dallongeville's SCSP core
@ -1555,9 +1555,10 @@ static void SPU_MixAudio(bool actuallyMix, SPU_struct *SPU, int length)
//we used to use master enable here, and do nothing if audio is disabled.
//now, master enable is emulated better..
//but for a speed optimization we will still do it
//is this still a good idea? zeroing the capture buffers is important...
if(!SPU->regs.masteren) return;
bool advanced = CommonSettings.spu_advanced ;
bool advanced = CommonSettings.spu_advanced;
//branch here so that slow computers don't have to take the advanced (slower) codepath.
//it remainds to be seen exactly how much slower it is
@ -1582,7 +1583,44 @@ static void SPU_MixAudio(bool actuallyMix, SPU_struct *SPU, int length)
// Mix audio
_SPU_ChanUpdate(!CommonSettings.spu_muteChannels[i] && actuallyMix, SPU, chan);
}
}
//zero out capture buffers - effectively transform no-advanced-spu-emulation to capturing-zeroes
//this is needed so when the option is changed (or a state with a different setting is loaded)
//this code is bulkier and slower than it might otherwise be to reduce the chance of bugs
//IDEALLY the non-advanced codepath would be removed (while the advanced codepath was optimized and improved)
//and this code would disappear, to be replaced with code more capable of emitting zeroes at the opportune time.
for(int capchan=0;capchan<2;capchan++)
{
SPU_struct::REGS::CAP& cap = SPU->regs.cap[capchan];
if(cap.runtime.running)
{
for(int samp=0;samp<length;samp++)
{
u32 last = sputrunc(cap.runtime.sampcnt);
cap.runtime.sampcnt += SPU->channels[1+2*capchan].sampinc;
u32 curr = sputrunc(cap.runtime.sampcnt);
for(u32 j=last;j<curr;j++)
{
if(cap.bits8)
{
_MMU_write08<1,MMU_AT_DMA>(cap.runtime.curdad,0);
cap.runtime.curdad++;
}
else
{
_MMU_write16<1,MMU_AT_DMA>(cap.runtime.curdad,0);
cap.runtime.curdad+=2;
}
if(cap.runtime.curdad>=cap.runtime.maxdad) {
cap.runtime.curdad = cap.dad;
cap.runtime.sampcnt -= cap.len*(cap.bits8?4:2);
}
}
}
}
}
} //non-advanced branch
//we used to bail out if speakers were disabled.
//this is technically wrong. sound may still be captured, or something.
@ -1968,6 +2006,11 @@ void spu_savestate(EMUFILE* os)
bool spu_loadstate(EMUFILE* is, int size)
{
//note! if we load a state created with advanced spu logic on a system without it,
//there's a high likelihood of captured data existing.
//this would get played back forever without being replaced by captured data.
//it's been solved by capturing zeroes though even when advanced spu logic is disabled.
u64 temp64;
//read version