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vdp, some small improvements

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This commit is contained in:
kub 2020-03-03 20:32:38 +01:00
parent 2d84b9254c
commit b6bdccb747
1 changed files with 27 additions and 8 deletions
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35
pico/videoport.c
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@ -53,6 +53,8 @@ int (*PicoDmaHook)(unsigned int source, int len, unsigned short **base, unsigned
* FIFORead executes a 68k read. 68k is blocked until the next transfer slot.
*/
// FIFO transfer slots per line: [active][h40]
static const short vdpslots[2][2] = {{ 166, 204 },{ 16, 18 }};
// mapping between slot# and 68k cycles in a blanked scanline [H32, H40]
static const int vdpcyc2sl_bl[] = { (166<<16)/488, (204<<16)/488 };
static const int vdpsl2cyc_bl[] = { (488<<16)/166, (488<<16)/204 };
@ -115,6 +117,14 @@ static __inline int GetFIFOSlot(struct PicoVideo *pv, int cycles)
else return (cycles * vdpcyc2sl_bl[h40] + cycles) >> 16;
}
static __inline int GetMaxFIFOSlot(struct PicoVideo *pv)
{
int active = !(pv->status & SR_VB) && (pv->reg[1] & 0x40);
int h40 = pv->reg[12] & 1;
return vdpslots[active][h40];
}
// map FIFO slot to cycles
static __inline int GetFIFOCycles(struct PicoVideo *pv, int slot)
{
@ -150,7 +160,7 @@ static __inline int AdvanceFIFOEntry(struct PicoVideo *pv, int slots)
}
// start processing for next entry if there is one
if (fifo_ql)
pv->fifo_cnt= (fifo_queue[fifo_qx] >> 3) << (fifo_queue[fifo_qx] & FQ_BYTE);
pv->fifo_cnt = (fifo_queue[fifo_qx] >> 3) << (fifo_queue[fifo_qx] & FQ_BYTE);
else
fifo_total = 0;
}
@ -190,14 +200,15 @@ void PicoVideoFIFOSync(int cycles)
done -= l;
}
SetFIFOState(pv);
if (done != slots)
SetFIFOState(pv);
}
// drain FIFO, blocking 68k on the way. FIFO must be synced prior to drain.
int PicoVideoFIFODrain(int level, int cycles, int bgdma)
{
struct PicoVideo *pv = &Pico.video;
int maxsl = GetFIFOSlot(pv, 488); // max xfer slots in this scanline
int maxsl = GetMaxFIFOSlot(pv); // max xfer slots in this scanline
int burn = 0;
// process FIFO entries until low level is reached
@ -279,10 +290,17 @@ int PicoVideoFIFOWrite(int count, int flags, unsigned sr_mask,unsigned sr_flags)
fifo_queue[(x+1) & 7] = (pv->fifo_cnt >> (f & FQ_BYTE) << 3) | f;
pv->fifo_cnt = count << (flags & FQ_BYTE);
}
} else
x = (x-1) & 7;
}
if (fifo_ql && (fifo_queue[x] & 7) == flags) {
// amalgamate entries if of same type
fifo_queue[x] += (count << 3);
if (fifo_ql == 1) pv->fifo_cnt += count << (flags & FQ_BYTE);
} else {
fifo_ql ++;
x = (x+1) & 7;
fifo_queue[x] = (count << 3) | flags;
fifo_ql ++;
fifo_queue[x] = (count << 3) | flags;
}
if (!(flags & FQ_BGDMA))
fifo_total += count;
}
@ -340,9 +358,10 @@ static __inline void AutoIncrement(void)
static __inline void UpdateSAT(u32 a, u32 d)
{
unsigned num = (a-sat) >> 3;
Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;
if (!(a & 4)) {
int num = (a-sat) >> 3;
if (!(a & 4) && num < 128) {
((u16 *)&VdpSATCache[num])[(a&3) >> 1] = d;
}
}