initial import

[picodrive.git] / Pico / VideoPort.c

// This is part of Pico Library\r
\r
// (c) Copyright 2004 Dave, All rights reserved.\r
// (c) Copyright 2006 notaz, All rights reserved.\r
// Free for non-commercial use.\r
\r
// For commercial use, separate licencing terms must be obtained.\r
\r
\r
#include "PicoInt.h"\r
\r
extern const unsigned char  hcounts_32[];\r
extern const unsigned char  hcounts_40[];\r
extern const unsigned short vcounts[];\r
extern int rendstatus;\r
\r
typedef unsigned short u16;\r
\r
\r
static __inline void AutoIncrement()\r
{\r
  Pico.video.addr=(unsigned short)(Pico.video.addr+Pico.video.reg[0xf]);\r
}\r
\r
static void VideoWrite(u16 d)\r
{\r
  unsigned int a=Pico.video.addr;\r
\r
  switch (Pico.video.type)\r
  {\r
    case 1: if(a&1) d=(u16)((d<<8)|(d>>8)); // If address is odd, bytes are swapped (which game needs this?)\r
            Pico.vram [(a>>1)&0x7fff]=d;\r
            rendstatus|=0x10; break;\r
    case 3: Pico.m.dirtyPal = 1;\r
            //dprintf("w[%i] @ %04x, inc=%i [%i|%i]", Pico.video.type, a, Pico.video.reg[0xf], Pico.m.scanline, SekCyclesDone());\r
            Pico.cram [(a>>1)&0x003f]=d; break; // wraps (Desert Strike)\r
    case 5: Pico.vsram[(a>>1)&0x003f]=d; break;\r
  }\r
\r
  //dprintf("w[%i] @ %04x, inc=%i [%i|%i]", Pico.video.type, a, Pico.video.reg[0xf], Pico.m.scanline, SekCyclesDone());\r
  AutoIncrement();\r
}\r
\r
static unsigned int VideoRead()\r
{\r
  unsigned int a=0,d=0;\r
\r
  a=Pico.video.addr; a>>=1;\r
\r
  switch (Pico.video.type)\r
  {\r
    case 0: d=Pico.vram [a&0x7fff]; break;\r
    case 8: d=Pico.cram [a&0x003f]; break;\r
    case 4: d=Pico.vsram[a&0x003f]; break;\r
  }\r
  \r
  AutoIncrement();\r
  return d;\r
}\r
\r
// calculate the number of cycles 68k->VDP dma operation would take\r
static int DmaSlowBurn(int len)\r
{\r
  // test: Legend of Galahad, Time Killers\r
  int burn,maxlen,line=Pico.m.scanline;\r
\r
  if(line == -1) line=vcounts[SekCyclesDone()>>8];\r
  maxlen=(224-line)*18;\r
  if(len <= maxlen)\r
    burn = len*(((488<<8)/18))>>8;\r
  else {\r
    burn  = maxlen*(((488<<8)/18))>>8;\r
    burn += (len-maxlen)*(((488<<8)/180))>>8;\r
  }\r
\r
  return burn;\r
}\r
\r
static int GetDmaLength()\r
{\r
  struct PicoVideo *pvid=&Pico.video;\r
  int len=0;\r
  // 16-bit words to transfer:\r
  len =pvid->reg[0x13];\r
  len|=pvid->reg[0x14]<<8;\r
  // Charles MacDonald:\r
  if(!len) len = 0xffff;\r
  return len;\r
}\r
\r
static void DmaSlow(int len)\r
{\r
  u16 *pd=0, *pdend, *r;\r
  unsigned int a=Pico.video.addr, a2, d;\r
  unsigned char inc=Pico.video.reg[0xf];\r
  unsigned int source, burn;\r
\r
  source =Pico.video.reg[0x15]<<1;\r
  source|=Pico.video.reg[0x16]<<9;\r
  source|=Pico.video.reg[0x17]<<17;\r
\r
  //dprintf("DmaSlow[%i] %06x->%04x len %i inc=%i blank %i [%i|%i]", Pico.video.type, source, a, len, inc,\r
  //         (Pico.video.status&8)||!(Pico.video.reg[1]&0x40), Pico.m.scanline, SekCyclesDone());\r
\r
  if ((source&0xe00000)==0xe00000) { pd=(u16 *)(Pico.ram+(source&0xfffe)); pdend=(u16 *)(Pico.ram+0x10000); } // Ram\r
  else if(source<Pico.romsize)     { pd=(u16 *)(Pico.rom+(source&~1)); pdend=(u16 *)(Pico.rom+Pico.romsize); } // Rom\r
  else return; // Invalid source address\r
\r
  // CPU is stopped during DMA, so we burn some cycles to compensate that\r
  if((Pico.video.status&8)||!(Pico.video.reg[1]&0x40)) { // vblank?\r
      burn = (len*(((488<<8)/167))>>8); // very approximate\r
      if(!(Pico.video.status&8)) burn+=burn>>1; // a hack for Legend of Galahad\r
  } else burn = DmaSlowBurn(len);\r
  SekCyclesBurn(burn);\r
  if(!(Pico.video.status&8))\r
    SekEndRun(0);\r
  //dprintf("DmaSlow burn: %i @ %06x", burn, SekPc);\r
\r
  switch (Pico.video.type)\r
  {\r
    case 1: // vram\r
      r = Pico.vram;\r
      for(; len; len--)\r
      {\r
        d=*pd++;\r
        if(a&1) d=(d<<8)|(d>>8);\r
        r[a>>1] = (u16)d; // will drop the upper bits\r
        // AutoIncrement\r
        a=(u16)(a+inc);\r
        // didn't src overlap?\r
        if(pd >= pdend) pd-=0x8000; // should be good for RAM, bad for ROM\r
      }\r
      rendstatus|=0x10;\r
      break;\r
    \r
    case 3: // cram\r
      //dprintf("DmaSlow[%i] %06x->%04x len %i inc=%i blank %i [%i|%i]", Pico.video.type, source, a, len, inc,\r
      //         (Pico.video.status&8)||!(Pico.video.reg[1]&0x40), Pico.m.scanline, SekCyclesDone());\r
      Pico.m.dirtyPal = 1;\r
      r = Pico.cram;\r
      for(a2=a&0x7f; len; len--)\r
      {\r
        r[a2>>1] = (u16)*pd++;; // bit 0 is ignored\r
        // AutoIncrement\r
        a2+=inc;\r
        // didn't src overlap?\r
        if(pd >= pdend) pd-=0x8000;\r
        // good dest?\r
        if(a2 >= 0x80) break; // Todds Adventures in Slime World / Andre Agassi tennis\r
      }\r
      a=(a&0xff00)|a2;\r
      break;\r
\r
    case 5: // vsram[a&0x003f]=d;\r
      r = Pico.vsram;\r
      for(a2=a&0x7f; len; len--)\r
      {\r
        r[a2>>1] = (u16)*pd++;\r
        // AutoIncrement\r
        a2+=inc;\r
        // didn't src overlap?\r
        if(pd >= pdend) pd-=0x8000;\r
        // good dest?\r
        if(a2 >= 0x80) break;\r
      }\r
      a=(a&0xff00)|a2;\r
      break;\r
  }\r
  // remember addr\r
  Pico.video.addr=(u16)a;\r
}\r
\r
static void DmaCopy(int len)\r
{\r
  u16 a=Pico.video.addr;\r
  unsigned char *vr = (unsigned char *) Pico.vram;\r
  unsigned char *vrs;\r
  unsigned char inc=Pico.video.reg[0xf];\r
  int source;\r
  //dprintf("DmaCopy len %i [%i|%i]", len, Pico.m.scanline, SekCyclesDone());\r
\r
  source =Pico.video.reg[0x15];\r
  source|=Pico.video.reg[0x16]<<8;\r
  vrs=vr+source;\r
\r
  if(source+len > 0x10000) len=0x10000-source; // clip??\r
\r
  for(;len;len--)\r
  {\r
    vr[a] = *vrs++;\r
    // AutoIncrement\r
    a=(u16)(a+inc);\r
  }\r
  // remember addr\r
  Pico.video.addr=a;\r
  rendstatus|=0x10;\r
}\r
\r
// check: Contra, Megaman\r
// note: this is still inaccurate\r
static void DmaFill(int data)\r
{\r
  int len;\r
  unsigned short a=Pico.video.addr;\r
  unsigned char *vr=(unsigned char *) Pico.vram;\r
  unsigned char high = (unsigned char) (data >> 8);\r
  unsigned char inc=Pico.video.reg[0xf];\r
  \r
  len=GetDmaLength();\r
  //dprintf("DmaFill len %i inc %i [%i|%i]", len, inc, Pico.m.scanline, SekCyclesDone());\r
\r
  // from Charles MacDonald's genvdp.txt:\r
  // Write lower byte to address specified\r
  vr[a] = (unsigned char) data;\r
  a=(u16)(a+inc);\r
\r
  if(!inc) len=1;\r
\r
  for(;len;len--) {\r
    // Write upper byte to adjacent address\r
    // (here we are byteswapped, so address is already 'adjacent')\r
    vr[a] = high;\r
\r
    // Increment address register\r
    a=(u16)(a+inc);\r
  }\r
  // remember addr\r
  Pico.video.addr=a;\r
  // update length\r
  Pico.video.reg[0x13] = Pico.video.reg[0x14] = 0; // Dino Dini's Soccer (E) (by Haze)\r
\r
  rendstatus|=0x10;\r
}\r
\r
static void CommandDma()\r
{\r
  struct PicoVideo *pvid=&Pico.video;\r
  int len=0,method=0;\r
\r
  if ((pvid->reg[1]&0x10)==0) return; // DMA not enabled\r
\r
  len=GetDmaLength();\r
\r
  method=pvid->reg[0x17]>>6;\r
  if (method< 2) DmaSlow(len); // 68000 to VDP\r
  if (method==3) DmaCopy(len); // VRAM Copy\r
}\r
\r
static void CommandChange()\r
{\r
  struct PicoVideo *pvid=&Pico.video;\r
  unsigned int cmd=0,addr=0;\r
\r
  cmd=pvid->command;\r
\r
  // Get type of transfer 0xc0000030 (v/c/vsram read/write)\r
  pvid->type=(unsigned char)(((cmd>>2)&0xc)|(cmd>>30));\r
\r
  // Get address 0x3fff0003\r
  addr =(cmd>>16)&0x3fff;\r
  addr|=(cmd<<14)&0xc000;\r
  pvid->addr=(unsigned short)addr;\r
  //dprintf("addr set: %04x", addr);\r
\r
  // Check for dma:\r
  if (cmd&0x80) CommandDma();\r
}\r
\r
void PicoVideoWrite(unsigned int a,unsigned short d)\r
{\r
  struct PicoVideo *pvid=&Pico.video;\r
\r
  a&=0x1c;\r
\r
  if (a==0x00) // Data port 0 or 2\r
  {    \r
    if (pvid->pending) CommandChange();\r
    pvid->pending=0;\r
\r
    // If a DMA fill has been set up, do it\r
    if ((pvid->command&0x80) && (pvid->reg[1]&0x10) && (pvid->reg[0x17]>>6)==2)\r
    {\r
      DmaFill(d);\r
    }\r
    else\r
    {\r
      VideoWrite(d);\r
    }\r
    return;\r
  }\r
\r
  if (a==0x04) // Control (command) port 4 or 6\r
  {\r
    //dprintf("vdp cw(%04x), p=%i @ %06x [%i]", d, pvid->pending, SekPc, SekCyclesDone());\r
    if(pvid->pending)\r
    {\r
      // Low word of command:\r
      pvid->command&=0xffff0000;\r
      pvid->command|=d;\r
      pvid->pending=0;\r
      CommandChange();\r
    } else {\r
      if((d&0xc000)==0x8000)\r
      {\r
        // Register write:\r
        int num=(d>>8)&0x1f;\r
        //if(num==00) dprintf("hint_onoff: %i->%i [%i|%i] pend=%i @ %06x", (pvid->reg[0]&0x10)>>4, (d&0x10)>>4, Pico.m.scanline, SekCyclesDone(), (pvid->pending_ints&0x10)>>4, SekPc);\r
        //if(num==01) dprintf("vint_onoff: %i->%i [%i|%i] pend=%i @ %06x", (pvid->reg[1]&0x20)>>5, (d&0x20)>>5, Pico.m.scanline, SekCyclesDone(), (pvid->pending_ints&0x20)>>5, SekPc);\r
        //if(num==01) dprintf("set_blank: %i @ %06x [%i|%i]", !((d&0x40)>>6), SekPc, Pico.m.scanline, SekCyclesDone());\r
        //if(num==05) dprintf("spr_set: %i @ %06x [%i|%i]", (unsigned char)d, SekPc, Pico.m.scanline, SekCyclesDone());\r
        //if(num==10) dprintf("hint_set: %i @ %06x [%i|%i]", (unsigned char)d, SekPc, Pico.m.scanline, SekCyclesDone());\r
        pvid->reg[num]=(unsigned char)d;\r
#if !(defined(EMU_C68K) && defined(EMU_M68K)) // not debugging Cyclone\r
        // update IRQ level (Lemmings, Wiz 'n' Liz intro, ... )\r
        // may break if done improperly:\r
        // International Superstar Soccer Deluxe (crash), Street Racer (logos), Burning Force (gfx), Fatal Rewind (hang), Sesame Street Counting Cafe\r
        if(num < 2) {\r
#ifdef EMU_C68K\r
          // hack: make sure we do not touch the irq line if Cyclone is just about to take the IRQ\r
          if (PicoCpu.irq <= (PicoCpu.srh&7)) {\r
#endif\r
            int lines, pints;\r
            lines = (pvid->reg[1] & 0x20) | (pvid->reg[0] & 0x10);\r
            pints = (pvid->pending_ints&lines);\r
                 if(pints & 0x20) SekInterrupt(6);\r
            else if(pints & 0x10) SekInterrupt(4);\r
            else SekInterrupt(0);\r
#ifdef EMU_C68K\r
            // adjust cycles for Cyclone so it would take the int "in time"\r
            if(PicoCpu.irq) {\r
              SekEndRun(24);\r
            }\r
          }\r
#endif\r
        }\r
        else\r
#endif\r
        if(num == 5) rendstatus|=1;\r
        else if(num == 0xc) Pico.m.dirtyPal = 2; // renderers should update their palettes if sh/hi mode is changed\r
        pvid->type=0; // register writes clear command (else no Sega logo in Golden Axe II)\r
      } else {\r
        // High word of command:\r
        pvid->command&=0x0000ffff;\r
        pvid->command|=d<<16;\r
        pvid->pending=1;\r
      }\r
    }\r
  }\r
}\r
\r
unsigned int PicoVideoRead(unsigned int a)\r
{\r
  unsigned int d=0;\r
  \r
  a&=0x1c;\r
\r
  if (a==0x00) // data port\r
  {\r
    d=VideoRead();\r
    goto end;\r
  }\r
\r
  if (a==0x04) // control port\r
  {\r
    //dprintf("sr_read @ %06x [%i|%i]", SekPc, Pico.m.scanline, SekCyclesDone());\r
    d=Pico.video.status;\r
    if(PicoOpt&0x10) d|=0x0020; // sprite collision (Shadow of the Beast)\r
    if(Pico.m.rotate++&8) d|=0x0100; else d|=0x0200; // Toggle fifo full empty (who uses that stuff?)\r
    if(!(Pico.video.reg[1]&0x40)) d|=0x0008; // set V-Blank if display is disabled\r
    if(SekCyclesLeft < 84+4)      d|=0x0004; // H-Blank (Sonic3 vs)\r
\r
    Pico.video.pending=0; // ctrl port reads clear write-pending flag (Charles MacDonald)\r
\r
    goto end;\r
  }\r
\r
  // H-counter info (based on Generator):\r
  // frame:\r
  //                       |       <- hblank? ->      |\r
  // start    <416>       hint  <36> hdisplay <38>  end // CPU cycles\r
  // |---------...---------|------------|-------------|\r
  // 0                   B6 E4                       FF // 40 cells\r
  // 0                   93 E8                       FF // 32 cells\r
\r
  // Gens (?)              v-render\r
  // start  <hblank=84>   hint    hdisplay <404>      |\r
  // |---------------------|--------------------------|\r
  // E4  (hc[0x43]==0)    07                         B1 // 40\r
  // E8  (hc[0x45]==0)    05                         91 // 32\r
  \r
  // check: Sonic 3D Blast bonus, Cannon Fodder, Chase HQ II, 3 Ninjas kick back, Road Rash 3, Skitchin', Wheel of Fortune\r
  if ((a&0x1c)==0x08)\r
  {\r
    unsigned int hc;\r
\r
    if(Pico.m.scanline != -1) {\r
      int lineCycles=(488-SekCyclesLeft)&0x1ff;\r
      d=Pico.m.scanline; // V-Counter\r
\r
      if(Pico.video.reg[12]&1)\r
           hc=hcounts_40[lineCycles];\r
      else hc=hcounts_32[lineCycles];\r
\r
      if(lineCycles > 488-12) d++; // Wheel of Fortune\r
    } else {\r
      // get approximate V-Counter\r
      d=vcounts[SekCyclesDone()>>8];\r
      hc = Pico.m.rotate&0xff;\r
    }\r
\r
    if(Pico.m.pal) {\r
      if(d >= 0x103) d-=56; // based on Gens\r
    } else {\r
      if(d >= 0xEB)  d-=6;\r
    }\r
\r
    if((Pico.video.reg[12]&6) == 6) {\r
      // interlace mode 2 (Combat Cars (UE) [!])\r
      d <<= 1;\r
      if (d&0xf00) d|= 1;\r
    }\r
\r
    //dprintf("hv: %02x %02x (%i) @ %06x", hc, d, SekCyclesDone(), SekPc);\r
    d&=0xff; d<<=8;\r
    d|=hc;\r
    goto end;\r
  }\r
\r
end:\r
\r
  return d;\r
}\r