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crudely fix mmc5 split screen for SDF

This commit is contained in:
zeromus 2017-03-18 17:43:25 +00:00
parent 984d9b0035
commit 1c39740f3d
1 changed files with 47 additions and 1 deletions
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48
trunk/src/boards/mmc5.cpp
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@ -137,11 +137,35 @@ static void mmc5_PPUWrite(uint32 A, uint8 V) {
}
extern uint32 NTRefreshAddr;
uint8 FASTCALL mmc5_PPURead(uint32 A) {
uint8 FASTCALL mmc5_PPURead(uint32 A)
{
bool split = false;
if(newppu)
{
if((MMC5HackSPMode&0x80) && !(MMC5HackCHRMode&2))
{
int target = MMC5HackSPMode&0x1f;
int side = MMC5HackSPMode&0x40;
int ht = NTRefreshAddr&31;
if(side==0)
{
if(ht<target) split = true;
}
else
{
if(ht>=target) split = true;
}
}
}
if (A < 0x2000)
{
if (ppuphase == PPUPHASE_BG )
{
if(split)
return MMC5HackVROMPTR[MMC5HackSPPage*0x1000 + (A&0xFFF)];
//uhhh call through to this more sophisticated function, only if it's really needed?
//we should probably reuse it completely, if we can
if (MMC5HackCHRMode == 1) {
@ -153,10 +177,32 @@ uint8 FASTCALL mmc5_PPURead(uint32 A) {
if(PPU[1] & 0x10)
return *MMC5BGVRAMADR(A);
}
return MMC5SPRVPage[(A) >> 10][(A)];
}
else
{
if(split)
{
static const int kHack = -1; //dunno if theres science to this or if it just fixes SDF (cant be bothered to think about it)
int linetile = (newppu_get_scanline()+kHack)/8 + MMC5HackSPScroll;
//REF NT: return 0x2000 | (v << 0xB) | (h << 0xA) | (vt << 5) | ht;
//REF AT: return 0x2000 | (v << 0xB) | (h << 0xA) | 0x3C0 | ((vt & 0x1C) << 1) | ((ht & 0x1C) >> 2);
if((A&0x3FF)>=0x3C0)
{
A &= ~(0x1C<<1); //mask off VT
A |= (linetile&0x1C)<<1; //mask on adjusted VT
return ExRAM[A & 0x3FF];
}
else
{
A &= ~((0x1F<<5) | (1<<0xB)); //mask off VT and V
A |= (linetile&31)<<5; //mask on adjusted VT (V doesnt make any sense, I think)
return ExRAM[A & 0x3FF];
}
}
return vnapage[(A >> 10) & 0x3][A & 0x3FF];
}
}