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// Sega/Game Gear/Coleco SGC music file emulator
// Game_Music_Emu 0.6-pre
#ifndef SGC_EMU_H
#define SGC_EMU_H
#include "blargg_common.h"
#include "multi_buffer.h"
#include "rom_data.h"
#include "z80_cpu.h"
#include "sms_fm_apu.h"
#include "sms_apu.h"
#include "m3u_playlist.h"
#include "track_filter.h"
typedef struct Z80_Cpu Sgc_Cpu;
// SGC file header
enum { header_size = 0xA0 };
struct header_t
{
char tag [4]; // "SGC\x1A"
byte vers; // 0x01
byte rate; // 0=NTSC 1=PAL
byte reserved1 [2];
byte load_addr [2];
byte init_addr [2];
byte play_addr [2];
byte stack_ptr [2];
byte reserved2 [2];
byte rst_addrs [7*2];
byte mapping [4]; // Used by Sega only
byte first_song; // Song to start playing first
byte song_count;
byte first_effect;
byte last_effect;
byte system; // 0=Master System 1=Game Gear 2=Colecovision
byte reserved3 [23];
char game [32]; // strings can be 32 chars, NOT terminated
char author [32];
char copyright [32];
};
// True if header has valid file signature
static inline bool valid_tag( struct header_t* h )
{
return 0 == memcmp( h->tag, "SGC\x1A", 4 );
}
static inline int effect_count( struct header_t* h ) { return h->last_effect ? h->last_effect - h->first_effect + 1 : 0; }
struct Sgc_Emu {
bool fm_accessed;
cpu_time_t play_period;
cpu_time_t next_play;
void const* bank2; // ROM selected for bank 2, in case RAM is currently hiding it
addr_t vectors_addr; // RST vectors start here
addr_t idle_addr; // return address for init/play routines
void* coleco_bios;
// general
int voice_count;
int const* voice_types;
int mute_mask_;
int tempo;
int gain;
int sample_rate;
// track-specific
int current_track;
int track_count;
int clock_rate_;
unsigned buf_changed_count;
// M3u Playlist
struct M3u_Playlist m3u;
struct header_t header;
struct setup_t tfilter;
struct Track_Filter track_filter;
struct Multi_Buffer stereo_buf;
struct Sms_Apu apu;
struct Sms_Fm_Apu fm_apu;
Sgc_Cpu cpu;
// large items
struct Rom_Data rom;
byte vectors [page_size + page_padding];
byte unmapped_write [0x4000];
byte ram [0x2000 + page_padding];
byte ram2 [0x4000 + page_padding];
};
// Basic functionality (see Gme_File.h for file loading/track info functions)
void Sgc_init( struct Sgc_Emu* this );
blargg_err_t Sgc_load_mem( struct Sgc_Emu* this, const void* data, long size );
static inline int clock_rate( struct Sgc_Emu* this ) { return this->header.rate ? 3546893 : 3579545; }
// 0x2000 bytes
static inline void set_coleco_bios( struct Sgc_Emu* this, void* p ) { this->coleco_bios = p; }
// Set output sample rate. Must be called only once before loading file.
blargg_err_t Sgc_set_sample_rate( struct Sgc_Emu* this, int sample_rate );
// Start a track, where 0 is the first track. Also clears warning string.
blargg_err_t Sgc_start_track( struct Sgc_Emu* this, int track );
// Generate 'count' samples info 'buf'. Output is in stereo. Any emulation
// errors set warning string, and major errors also end track.
blargg_err_t Sgc_play( struct Sgc_Emu* this, int count, sample_t* buf );
// Track status/control
// Number of milliseconds (1000 msec = 1 second) played since beginning of track
int Track_tell( struct Sgc_Emu* this );
// Seek to new time in track. Seeking backwards or far forward can take a while.
blargg_err_t Track_seek( struct Sgc_Emu* this, int msec );
// Skip n samples
blargg_err_t Track_skip( struct Sgc_Emu* this, int n );
// Set start time and length of track fade out. Once fade ends track_ended() returns
// true. Fade time can be changed while track is playing.
void Track_set_fade( struct Sgc_Emu* this, int start_msec, int length_msec );
// True if a track has reached its end
static inline bool Track_ended( struct Sgc_Emu* this )
{
return track_ended( &this->track_filter );
}
// Disables automatic end-of-track detection and skipping of silence at beginning
static inline void Track_ignore_silence( struct Sgc_Emu* this, bool disable )
{
this->track_filter.silence_ignored_ = disable;
}
// Get track length in milliseconds
static inline int Track_get_length( struct Sgc_Emu* this, int n )
{
int length = 120 * 1000; /* 2 minutes */
if ( (this->m3u.size > 0) && (n < this->m3u.size) ) {
struct entry_t* entry = &this->m3u.entries [n];
length = entry->length;
}
return length;
}
// Sound customization
// Adjust song tempo, where 1.0 = normal, 0.5 = half speed, 2.0 = double speed.
// Track length as returned by track_info() assumes a tempo of 1.0.
void Sound_set_tempo( struct Sgc_Emu* this, int t );
// Mute/unmute voice i, where voice 0 is first voice
void Sound_mute_voice( struct Sgc_Emu* this, int index, bool mute );
// Set muting state of all voices at once using a bit mask, where -1 mutes them all,
// 0 unmutes them all, 0x01 mutes just the first voice, etc.
void Sound_mute_voices( struct Sgc_Emu* this, int mask );
// Change overall output amplitude, where 1.0 results in minimal clamping.
// Must be called before set_sample_rate().
static inline void Sound_set_gain( struct Sgc_Emu* this, int g )
{
assert( !this->sample_rate ); // you must set gain before setting sample rate
this->gain = g;
}
// True if Master System or Game Gear
static inline bool sega_mapping( struct Sgc_Emu* this )
{
return this->header.system <= 1;
}
// Emulation (You shouldn't touch these)
bool run_cpu( struct Sgc_Emu* this, cpu_time_t end_time );
void cpu_out( struct Sgc_Emu* this, cpu_time_t time, addr_t addr, int data );
void cpu_write( struct Sgc_Emu* this, addr_t addr, int data );
void jsr( struct Sgc_Emu* this, byte addr [2] );
#endif
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