/* Mednafen - Multi-system Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2002 Xodnizel
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "mapinc.h"

static uint8 lastA;
static uint8 DRegs[8];
static uint8 cmd;
static uint8 MirCache[8];

static void dragonbust_ppu(uint32 A)
{ 
 static int last=-1;
 static uint8 z;

 if(A>=0x2000) return;

 A>>=10;

 lastA=A;  

 z=MirCache[A];
 if(z!=last)
 {
  setmirror(z?MI_1:MI_0);
  last=z;
 }
}

static void toot(void)
{
 int x;

 MirCache[0]=MirCache[1]=(DRegs[0]>>4)&1;
 MirCache[2]=MirCache[3]=(DRegs[1]>>4)&1;

 for(x=0;x<4;x++)
  MirCache[4+x]=(DRegs[2+x]>>5)&1;
 setmirror(MirCache[lastA]?MI_1:MI_0);
}

static DECLFW(Mapper95_write)
{
        switch(A&0xF001)
	{

         case 0x8000:
         cmd = V;
         break;

         case 0x8001:
                switch(cmd&0x07)
		{
                 case 0: DRegs[0]=(V&0x3F)>>1;toot();V>>=1;setchr2(0x0000,V&0x1F);break;
                 case 1: DRegs[1]=(V&0x3F)>>1;toot();V>>=1;setchr2(0x0800,V&0x1F);break;
                 case 2: DRegs[2]=V&0x3F;toot();setchr1(0x1000,V&0x1F); break;
                 case 3: DRegs[3]=V&0x3F;toot();setchr1(0x1400,V&0x1F); break;
                 case 4: DRegs[4]=V&0x3F;toot();setchr1(0x1800,V&0x1F); break;
                 case 5: DRegs[5]=V&0x3F;toot();setchr1(0x1C00,V&0x1F); break;
                 case 6: DRegs[6]=V&0x3F;
                         setprg8(0x8000,V);
                         break;
                 case 7: DRegs[7]=V&0x3F;
                         setprg8(0xA000,V);
                         break;
                }
                break;
	}
}

static void DBSync()
{
 int x;

 setchr2(0x0000,DRegs[0]);
 setchr2(0x0800,DRegs[1]);

 for(x=0;x<4;x++) 
  setchr1(0x1000+x*0x400,DRegs[2+x]);

 setprg8(0x8000,DRegs[6]);
 setprg8(0xa000,DRegs[7]);
 toot();
}

static void DBPower(CartInfo *info)
{
 memset(DRegs,0x3F,8);
 DRegs[0]=DRegs[1]=0x1F;

 DBSync();

 setprg8(0xc000,0x3E);
 setprg8(0xe000,0x3F);

 SetReadHandler(0x8000,0xffff,CartBR);
 SetWriteHandler(0x8000,0xffff,Mapper95_write);
}

static int StateAction(StateMem *sm, int load, int data_only)
{
 SFORMAT StateRegs[]={
        SFARRAYN(DRegs, 8, "DREG"),
	SFVARN(cmd, "CMD"),
	SFVARN(lastA, "LAST"),
	SFEND
 };


 int ret = MDFNSS_StateAction(sm, load, data_only, StateRegs, "MAPR");

 if(load)
  DBSync();

 return(ret);
}

int Mapper95_Init(CartInfo *info)
{
  info->Power=DBPower;
  info->StateAction = StateAction;
  PPU_hook=dragonbust_ppu;
  return(1);
}

