quickerNES/core/mappers/mapper032.hpp

120 lines
2.8 KiB
C++

/* Copyright notice for this file:
* Copyright (C) 2018
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* This mapper was added by retrowertz for Libretro port of QuickNES.
*
* Mapper 32 - Irem's G-101
*
*/
#pragma once
#include "Nes_Mapper.h"
struct mapper32_state_t
{
uint8_t chr_bank [ 8 ];
uint8_t prg_bank [ 2 ];
uint8_t prg_mode;
uint8_t mirr;
};
BOOST_STATIC_ASSERT( sizeof ( mapper32_state_t ) == 12 );
// Irem_G101
class Mapper032 : public Nes_Mapper, mapper32_state_t {
public:
Mapper032()
{
mapper32_state_t * state = this;
register_state( state, sizeof * state );
}
virtual void reset_state()
{
prg_bank [ 0 ] = ~1;
prg_bank [ 1 ] = ~0;
enable_sram();
}
virtual void apply_mapping()
{
if ( prg_mode == 0 )
{
set_prg_bank ( 0x8000, bank_8k, prg_bank [ 0 ] );
set_prg_bank ( 0xA000, bank_8k, prg_bank [ 1 ] );
set_prg_bank ( 0xC000, bank_8k, ~1 );
set_prg_bank ( 0xE000, bank_8k, ~0 );
}
else
{
set_prg_bank ( 0xC000, bank_8k, prg_bank [ 0 ] );
set_prg_bank ( 0xA000, bank_8k, prg_bank [ 1 ] );
set_prg_bank ( 0x8000, bank_8k, ~1 );
set_prg_bank ( 0xE000, bank_8k, ~0 );
}
for ( unsigned long int i = 0; i < sizeof chr_bank; i++)
set_chr_bank( ( i << 10 ), bank_1k, chr_bank [ i ] );
switch ( mirr )
{
case 0: mirror_vert(); break;
case 1: mirror_horiz(); break;
}
}
virtual void write( nes_time_t, nes_addr_t addr, int data )
{
switch ( addr & 0xF000 )
{
case 0x8000:
prg_bank [ 0 ] = data;
switch ( prg_mode )
{
case 0: set_prg_bank ( 0x8000, bank_8k, data ); break;
case 1: set_prg_bank ( 0xC000, bank_8k, data ); break;
}
break;
case 0x9000:
mirr = data & 1;
prg_mode = ( data >> 1 ) & 1;
switch ( data & 1 )
{
case 0: mirror_vert(); break;
case 1: mirror_horiz(); break;
}
break;
case 0xA000:
prg_bank [ 1 ] = data;
set_prg_bank ( 0xA000, bank_8k, data );
break;
}
switch ( addr & 0xF007 )
{
case 0xB000: case 0xB001: case 0xB002: case 0xB003:
case 0xB004: case 0xB005: case 0xB006: case 0xB007:
chr_bank [ addr & 0x07 ] = data;
set_chr_bank( ( addr & 0x07 ) << 10, bank_1k, data );
break;
}
}
};