diff options
Diffstat (limited to 'plugins/gme/Game_Music_Emu-0.5.2/gme/Gbs_Emu.cpp')
-rw-r--r-- | plugins/gme/Game_Music_Emu-0.5.2/gme/Gbs_Emu.cpp | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/plugins/gme/Game_Music_Emu-0.5.2/gme/Gbs_Emu.cpp b/plugins/gme/Game_Music_Emu-0.5.2/gme/Gbs_Emu.cpp new file mode 100644 index 00000000..30a147e5 --- /dev/null +++ b/plugins/gme/Game_Music_Emu-0.5.2/gme/Gbs_Emu.cpp @@ -0,0 +1,288 @@ +// Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ + +#include "Gbs_Emu.h" + +#include "blargg_endian.h" +#include <string.h> + +/* Copyright (C) 2003-2006 Shay Green. This module is free software; you +can redistribute it and/or modify it under the terms of the GNU Lesser +General Public License as published by the Free Software Foundation; either +version 2.1 of the License, or (at your option) any later version. This +module 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 Lesser General Public License for more +details. You should have received a copy of the GNU Lesser General Public +License along with this module; if not, write to the Free Software Foundation, +Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ + +#include "blargg_source.h" + +Gbs_Emu::equalizer_t const Gbs_Emu::handheld_eq = { -47.0, 2000 }; +Gbs_Emu::equalizer_t const Gbs_Emu::headphones_eq = { 0.0, 300 }; + +Gbs_Emu::Gbs_Emu() +{ + set_type( gme_gbs_type ); + + static const char* const names [Gb_Apu::osc_count] = { + "Square 1", "Square 2", "Wave", "Noise" + }; + set_voice_names( names ); + + static int const types [Gb_Apu::osc_count] = { + wave_type | 1, wave_type | 2, wave_type | 0, mixed_type | 0 + }; + set_voice_types( types ); + + set_silence_lookahead( 6 ); + set_max_initial_silence( 21 ); + set_gain( 1.2 ); + + static equalizer_t const eq = { -1.0, 120 }; + set_equalizer( eq ); +} + +Gbs_Emu::~Gbs_Emu() { } + +void Gbs_Emu::unload() +{ + rom.clear(); + Music_Emu::unload(); +} + +// Track info + +static void copy_gbs_fields( Gbs_Emu::header_t const& h, track_info_t* out ) +{ + GME_COPY_FIELD( h, out, game ); + GME_COPY_FIELD( h, out, author ); + GME_COPY_FIELD( h, out, copyright ); +} + +blargg_err_t Gbs_Emu::track_info_( track_info_t* out, int ) const +{ + copy_gbs_fields( header_, out ); + return 0; +} + +static blargg_err_t check_gbs_header( void const* header ) +{ + if ( memcmp( header, "GBS", 3 ) ) + return gme_wrong_file_type; + return 0; +} + +struct Gbs_File : Gme_Info_ +{ + Gbs_Emu::header_t h; + + Gbs_File() { set_type( gme_gbs_type ); } + + blargg_err_t load_( Data_Reader& in ) + { + blargg_err_t err = in.read( &h, Gbs_Emu::header_size ); + if ( err ) + return (err == in.eof_error ? gme_wrong_file_type : err); + + set_track_count( h.track_count ); + return check_gbs_header( &h ); + } + + blargg_err_t track_info_( track_info_t* out, int ) const + { + copy_gbs_fields( h, out ); + return 0; + } +}; + +static Music_Emu* new_gbs_emu () { return BLARGG_NEW Gbs_Emu ; } +static Music_Emu* new_gbs_file() { return BLARGG_NEW Gbs_File; } + +gme_type_t_ const gme_gbs_type [1] = { "Game Boy", 0, &new_gbs_emu, &new_gbs_file, "GBS", 1 }; + +// Setup + +blargg_err_t Gbs_Emu::load_( Data_Reader& in ) +{ + assert( offsetof (header_t,copyright [32]) == header_size ); + RETURN_ERR( rom.load( in, header_size, &header_, 0 ) ); + + set_track_count( header_.track_count ); + RETURN_ERR( check_gbs_header( &header_ ) ); + + if ( header_.vers != 1 ) + set_warning( "Unknown file version" ); + + if ( header_.timer_mode & 0x78 ) + set_warning( "Invalid timer mode" ); + + unsigned load_addr = get_le16( header_.load_addr ); + if ( (header_.load_addr [1] | header_.init_addr [1] | header_.play_addr [1]) > 0x7F || + load_addr < 0x400 ) + set_warning( "Invalid load/init/play address" ); + + set_voice_count( Gb_Apu::osc_count ); + + apu.volume( gain() ); + + return setup_buffer( 4194304 ); +} + +void Gbs_Emu::update_eq( blip_eq_t const& eq ) +{ + apu.treble_eq( eq ); +} + +void Gbs_Emu::set_voice( int i, Blip_Buffer* c, Blip_Buffer* l, Blip_Buffer* r ) +{ + apu.osc_output( i, c, l, r ); +} + +// Emulation + +// see gb_cpu_io.h for read/write functions + +void Gbs_Emu::set_bank( int n ) +{ + blargg_long addr = rom.mask_addr( n * (blargg_long) bank_size ); + if ( addr == 0 && rom.size() > bank_size ) + { + // TODO: what is the correct behavior? Current Game & Watch Gallery + // rip requires that this have no effect or set to bank 1. + //dprintf( "Selected ROM bank 0\n" ); + return; + //n = 1; + } + cpu::map_code( bank_size, bank_size, rom.at_addr( addr ) ); +} + +void Gbs_Emu::update_timer() +{ + if ( header_.timer_mode & 0x04 ) + { + static byte const rates [4] = { 10, 4, 6, 8 }; + int shift = rates [ram [hi_page + 7] & 3] - (header_.timer_mode >> 7); + play_period = (256L - ram [hi_page + 6]) << shift; + } + else + { + play_period = 70224; // 59.73 Hz + } + if ( tempo() != 1.0 ) + play_period = blip_time_t (play_period / tempo()); +} + +static BOOST::uint8_t const sound_data [Gb_Apu::register_count] = { + 0x80, 0xBF, 0x00, 0x00, 0xBF, // square 1 + 0x00, 0x3F, 0x00, 0x00, 0xBF, // square 2 + 0x7F, 0xFF, 0x9F, 0x00, 0xBF, // wave + 0x00, 0xFF, 0x00, 0x00, 0xBF, // noise + 0x77, 0xF3, 0xF1, // vin/volume, status, power mode + 0, 0, 0, 0, 0, 0, 0, 0, 0, // unused + 0xAC, 0xDD, 0xDA, 0x48, 0x36, 0x02, 0xCF, 0x16, // waveform data + 0x2C, 0x04, 0xE5, 0x2C, 0xAC, 0xDD, 0xDA, 0x48 +}; + +void Gbs_Emu::cpu_jsr( gb_addr_t addr ) +{ + check( cpu::r.sp == get_le16( header_.stack_ptr ) ); + cpu::r.pc = addr; + cpu_write( --cpu::r.sp, idle_addr >> 8 ); + cpu_write( --cpu::r.sp, idle_addr&0xFF ); +} + +void Gbs_Emu::set_tempo_( double t ) +{ + apu.set_tempo( t ); + update_timer(); +} + +blargg_err_t Gbs_Emu::start_track_( int track ) +{ + RETURN_ERR( Classic_Emu::start_track_( track ) ); + + memset( ram, 0, 0x4000 ); + memset( ram + 0x4000, 0xFF, 0x1F80 ); + memset( ram + 0x5F80, 0, sizeof ram - 0x5F80 ); + ram [hi_page] = 0; // joypad reads back as 0 + + apu.reset(); + for ( int i = 0; i < (int) sizeof sound_data; i++ ) + apu.write_register( 0, i + apu.start_addr, sound_data [i] ); + + cpu::reset( rom.unmapped() ); + + unsigned load_addr = get_le16( header_.load_addr ); + cpu::rst_base = load_addr; + rom.set_addr( load_addr ); + + cpu::map_code( ram_addr, 0x10000 - ram_addr, ram ); + cpu::map_code( 0, bank_size, rom.at_addr( 0 ) ); + set_bank( rom.size() > bank_size ); + + ram [hi_page + 6] = header_.timer_modulo; + ram [hi_page + 7] = header_.timer_mode; + update_timer(); + next_play = play_period; + + cpu::r.a = track; + cpu::r.pc = idle_addr; + cpu::r.sp = get_le16( header_.stack_ptr ); + cpu_time = 0; + cpu_jsr( get_le16( header_.init_addr ) ); + + return 0; +} + +blargg_err_t Gbs_Emu::run_clocks( blip_time_t& duration, int ) +{ + cpu_time = 0; + while ( cpu_time < duration ) + { + long count = duration - cpu_time; + cpu_time = duration; + bool result = cpu::run( count ); + cpu_time -= cpu::remain(); + + if ( result ) + { + if ( cpu::r.pc == idle_addr ) + { + if ( next_play > duration ) + { + cpu_time = duration; + break; + } + + if ( cpu_time < next_play ) + cpu_time = next_play; + next_play += play_period; + cpu_jsr( get_le16( header_.play_addr ) ); + GME_FRAME_HOOK( this ); + // TODO: handle timer rates different than 60 Hz + } + else if ( cpu::r.pc > 0xFFFF ) + { + dprintf( "PC wrapped around\n" ); + cpu::r.pc &= 0xFFFF; + } + else + { + set_warning( "Emulation error (illegal/unsupported instruction)" ); + dprintf( "Bad opcode $%.2x at $%.4x\n", + (int) *cpu::get_code( cpu::r.pc ), (int) cpu::r.pc ); + cpu::r.pc = (cpu::r.pc + 1) & 0xFFFF; + cpu_time += 6; + } + } + } + + duration = cpu_time; + next_play -= cpu_time; + if ( next_play < 0 ) // could go negative if routine is taking too long to return + next_play = 0; + apu.end_frame( cpu_time ); + + return 0; +} |