/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General 
** Public License as published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful, 
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
** Library General Public License for more details.  To obtain a 
** copy of the GNU Library General Public License, write to the Free 
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** map9.c
**
** mapper 9 interface
** $Id: map009.c,v 1.2 2001/04/27 14:37:11 neil Exp $
*/

#include <string.h>
#include <noftypes.h>
#include <nes_mmc.h>
#include <nes_ppu.h>
#include <libsnss.h>

static uint8 latch[2];
static uint8 regs[4];

/* Used when tile $FD/$FE is accessed */
static void mmc9_latchfunc(uint32 address, uint8 value)
{
   if (0xFD == value || 0xFE == value)
   {
      int reg;

      if (address)
      {
         latch[1] = value;
         reg = 2 + (value - 0xFD);
      }
      else
      {
         latch[0] = value;
         reg = value - 0xFD;
      }

      mmc_bankvrom(4, address, regs[reg]);
   }
}

/* mapper 9: MMC2 */
/* MMC2: Punch-Out! */
static void map9_write(uint32 address, uint8 value)
{
   switch ((address & 0xF000) >> 12)
   {
   case 0xA:
      mmc_bankrom(8, 0x8000, value);
      break;

   case 0xB:
      regs[0] = value;
      if (0xFD == latch[0])
         mmc_bankvrom(4, 0x0000, value);
      break;

   case 0xC:
      regs[1] = value;
      if (0xFE == latch[0])
         mmc_bankvrom(4, 0x0000, value);
      break;

   case 0xD:
      regs[2] = value;
      if (0xFD == latch[1])
         mmc_bankvrom(4, 0x1000, value);
      break;

   case 0xE:
      regs[3] = value;
      if (0xFE == latch[1])
         mmc_bankvrom(4, 0x1000, value);
      break;

   case 0xF:
      if (value & 1)
         ppu_mirror(0, 0, 1, 1); /* horizontal */
      else
         ppu_mirror(0, 1, 0, 1); /* vertical */
      break;

   default:
      break;
   }
}

static void map9_init(void)
{
   memset(regs, 0, sizeof(regs));

   mmc_bankrom(8, 0x8000, 0);
   mmc_bankrom(8, 0xA000, (mmc_getinfo()->rom_banks * 2) - 3);
   mmc_bankrom(8, 0xC000, (mmc_getinfo()->rom_banks * 2) - 2);
   mmc_bankrom(8, 0xE000, (mmc_getinfo()->rom_banks * 2) - 1);

   latch[0] = 0xFE;
   latch[1] = 0xFE;

   ppu_setlatchfunc(mmc9_latchfunc);
}

static void map9_getstate(SnssMapperBlock *state)
{
   state->extraData.mapper9.latch[0] = latch[0];
   state->extraData.mapper9.latch[1] = latch[1];
   state->extraData.mapper9.lastB000Write = regs[0];
   state->extraData.mapper9.lastC000Write = regs[1];
   state->extraData.mapper9.lastD000Write = regs[2];
   state->extraData.mapper9.lastE000Write = regs[3];
}

static void map9_setstate(SnssMapperBlock *state)
{
   latch[0] = state->extraData.mapper9.latch[0];
   latch[1] = state->extraData.mapper9.latch[1];
   regs[0] = state->extraData.mapper9.lastB000Write;
   regs[1] = state->extraData.mapper9.lastC000Write;
   regs[2] = state->extraData.mapper9.lastD000Write;
   regs[3] = state->extraData.mapper9.lastE000Write;
}

static map_memwrite map9_memwrite[] =
{
   { 0x8000, 0xFFFF, map9_write },
   {     -1,     -1, NULL }
};

mapintf_t map9_intf =
{
   9, /* mapper number */
   "MMC2", /* mapper name */
   map9_init, /* init routine */
   NULL, /* vblank callback */
   NULL, /* hblank callback */
   map9_getstate, /* get state (snss) */
   map9_setstate, /* set state (snss) */
   NULL, /* memory read structure */
   map9_memwrite, /* memory write structure */
   NULL /* external sound device */
};

/*
** $Log: map009.c,v $
** Revision 1.2  2001/04/27 14:37:11  neil
** wheeee
**
** Revision 1.1  2001/04/27 12:54:40  neil
** blah
**
** Revision 1.1.1.1  2001/04/27 07:03:54  neil
** initial
**
** Revision 1.1  2000/10/24 12:19:33  matt
** changed directory structure
**
** Revision 1.9  2000/10/22 19:17:46  matt
** mapper cleanups galore
**
** Revision 1.8  2000/10/22 15:03:14  matt
** simplified mirroring
**
** Revision 1.7  2000/10/21 19:33:38  matt
** many more cleanups
**
** Revision 1.6  2000/07/17 05:11:35  matt
** minor update from making PPU code less filthy
**
** Revision 1.5  2000/07/15 23:52:19  matt
** rounded out a bunch more mapper interfaces
**
** Revision 1.4  2000/07/10 05:29:03  matt
** cleaned up some mirroring issues
**
** Revision 1.3  2000/07/06 02:48:43  matt
** clearly labelled structure members
**
** Revision 1.2  2000/07/05 22:50:33  matt
** fixed punchout -- works 100% now
**
** Revision 1.1  2000/07/05 05:05:18  matt
** initial revision
**
*/