new acc mode timing, VDP FIFO code

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@244 be3aeb3a-fb24-0410-a615-afba39da0efa
2025-09-05 15:27:46 -04:00 · 2007-09-11 20:52:21 +00:00 · 2007-09-11 20:52:21 +00:00 · 69996cb7c6
commit 69996cb7c6
parent 83c093a48a
14 changed files with 373 additions and 132 deletions
--- a/Pico/PicoFrameHints.c
+++ b/Pico/PicoFrameHints.c
@ -0,0 +1,180 @@
+#define CYCLES_M68K_LINE     488 // suitable for both PAL/NTSC
+#define CYCLES_M68K_VINT_LAG  68
+#define CYCLES_M68K_ASD      148
+#define CYCLES_Z80_LINE      228
+#define CYCLES_Z80_ASD        69
+
+// pad delay (for 6 button pads)
+#define PAD_DELAY \
+  if (PicoOpt&0x20) { \
+    if(Pico.m.padDelay[0]++ > 25) Pico.m.padTHPhase[0]=0; \
+    if(Pico.m.padDelay[1]++ > 25) Pico.m.padTHPhase[1]=0; \
+  }
+
+#define Z80_RUN(z80_cycles) \
+{ \
+  if ((PicoOpt&4) && Pico.m.z80Run) \
+  { \
+    if (Pico.m.z80Run & 2) z80CycleAim += z80_cycles; \
+    else { \
+      int cnt = SekCyclesDone() - z80startCycle; \
+      cnt = (cnt>>1)-(cnt>>5); \
+      if (cnt > (z80_cycles)) cnt = z80_cycles; \
+      Pico.m.z80Run |= 2; \
+      z80CycleAim+=cnt; \
+    } \
+    total_z80+=z80_run(z80CycleAim-total_z80); \
+  } \
+}
+
+// Accurate but slower frame which does hints
+static int PicoFrameHints(void)
+{
+  struct PicoVideo *pv=&Pico.video;
+  int total_z80=0,lines,y,lines_vis = 224,z80CycleAim = 0,line_sample;
+  int skip=PicoSkipFrame || (PicoOpt&0x10);
+  int hint; // Hint counter
+
+  if (Pico.m.pal) {
+    //cycles_68k = (int) ((double) OSC_PAL  /  7 / 50 / 312 + 0.4); // should compile to a constant (488)
+    //cycles_z80 = (int) ((double) OSC_PAL  / 15 / 50 / 312 + 0.4); // 228
+    line_sample = 68;
+    if(pv->reg[1]&8) lines_vis = 240;
+  } else {
+    //cycles_68k = (int) ((double) OSC_NTSC /  7 / 60 / 262 + 0.4); // 488
+    //cycles_z80 = (int) ((double) OSC_NTSC / 15 / 60 / 262 + 0.4); // 228
+    line_sample = 93;
+  }
+
+  SekCyclesReset();
+
+  pv->status&=~0x88; // clear V-Int, come out of vblank
+
+  hint=pv->reg[10]; // Load H-Int counter
+  //dprintf("-hint: %i", hint);
+
+  // This is to make active scan longer (needed for Double Dragon 2, mainly)
+  SekRun(CYCLES_M68K_ASD);
+  Z80_RUN(CYCLES_Z80_ASD);
+
+  for (y=0;y<lines_vis;y++)
+  {
+    Pico.m.scanline=(short)y;
+
+    // VDP FIFO
+    pv->lwrite_cnt -= 12;
+    if (pv->lwrite_cnt <= 0) {
+      pv->lwrite_cnt=0;
+      Pico.video.status|=0x200;
+    }
+
+    PAD_DELAY
+
+    // H-Interrupts:
+    if (--hint < 0) // y <= lines_vis: Comix Zone, Golden Axe
+    {
+      hint=pv->reg[10]; // Reload H-Int counter
+      pv->pending_ints|=0x10;
+      if (pv->reg[0]&0x10) {
+        elprintf(EL_INTS, "hint: @ %06x [%i]", SekPc, SekCycleCnt);
+        SekInterrupt(4);
+      }
+    }
+
+    // decide if we draw this line
+#if CAN_HANDLE_240_LINES
+    if(!skip && ((!(pv->reg[1]&8) && y<224) || (pv->reg[1]&8)) )
+#else
+    if(!skip && y<224)
+#endif
+      PicoLine(y);
+
+    if(PicoOpt&1)
+      sound_timers_and_dac(y);
+
+    // get samples from sound chips
+    if(y == 32 && PsndOut)
+      emustatus &= ~1;
+    else if((y == 224 || y == line_sample) && PsndOut)
+      getSamples(y);
+
+    // Run scanline:
+    if (Pico.m.dma_xfers) SekCyclesBurn(CheckDMA());
+    SekRun(CYCLES_M68K_LINE);
+    Z80_RUN(CYCLES_Z80_LINE);
+  }
+
+  // V-int line (224 or 240)
+  Pico.m.scanline=(short)y;
+
+  // VDP FIFO
+  pv->lwrite_cnt=0;
+  Pico.video.status|=0x200;
+
+  PAD_DELAY
+
+  // Last H-Int:
+  if (--hint < 0)
+  {
+    hint=pv->reg[10]; // Reload H-Int counter
+    pv->pending_ints|=0x10;
+    //printf("rhint: %i @ %06x [%i|%i]\n", hint, SekPc, y, SekCycleCnt);
+    if (pv->reg[0]&0x10) SekInterrupt(4);
+  }
+
+  // V-Interrupt:
+  pv->status|=0x08; // go into vblank
+  pv->pending_ints|=0x20;
+
+  // the following SekRun is there for several reasons:
+  // there must be a delay after vblank bit is set and irq is asserted (Mazin Saga)
+  // also delay between F bit (bit 7) is set in SR and IRQ happens (Ex-Mutants)
+  // also delay between last H-int and V-int (Golden Axe 3)
+  SekRun(CYCLES_M68K_VINT_LAG);
+  if (pv->reg[1]&0x20) {
+    elprintf(EL_INTS, "vint: @ %06x [%i]", SekPc, SekCycleCnt);
+    SekInterrupt(6);
+  }
+  if (Pico.m.z80Run && (PicoOpt&4))
+    z80_int();
+
+  if (PicoOpt&1)
+    sound_timers_and_dac(y);
+
+  // get samples from sound chips
+  if ((y == 224) && PsndOut)
+    getSamples(y);
+
+  // Run scanline:
+  if (Pico.m.dma_xfers) SekCyclesBurn(CheckDMA());
+  SekRun(CYCLES_M68K_LINE - CYCLES_M68K_VINT_LAG - CYCLES_M68K_ASD);
+  Z80_RUN(CYCLES_Z80_LINE - CYCLES_Z80_ASD);
+
+  // PAL line count might actually be 313 according to Steve Snake, but that would complicate things.
+  lines = Pico.m.pal ? 312 : 262;
+
+  for (y++;y<lines;y++)
+  {
+    Pico.m.scanline=(short)y;
+
+    PAD_DELAY
+
+    if(PicoOpt&1)
+      sound_timers_and_dac(y);
+
+    // Run scanline:
+    if (Pico.m.dma_xfers) SekCyclesBurn(CheckDMA());
+    SekRun(CYCLES_M68K_LINE);
+    Z80_RUN(CYCLES_Z80_LINE);
+  }
+
+  // draw a frame just after vblank in alternative render mode
+  if (!PicoSkipFrame && (PicoOpt&0x10))
+    PicoFrameFull();
+
+  return 0;
+}
+
+#undef PAD_DELAY
+#undef Z80_RUN
+