cog/Frameworks/GME/gme/Gbs_Core.h

110 lines
2.5 KiB
C++

// Nintendo Game Boy GBS music file emulator core
// Game_Music_Emu $vers
#ifndef GBS_CORE_H
#define GBS_CORE_H
#include "Gme_Loader.h"
#include "Rom_Data.h"
#include "Gb_Cpu.h"
#include "Gb_Apu.h"
class Gbs_Core : public Gme_Loader {
public:
// GBS file header
struct header_t
{
enum { size = 112 };
char tag [ 3];
byte vers;
byte track_count;
byte first_track;
byte load_addr [ 2];
byte init_addr [ 2];
byte play_addr [ 2];
byte stack_ptr [ 2];
byte timer_modulo;
byte timer_mode;
char game [32]; // strings can be 32 chars, NOT terminated
char author [32];
char copyright [32];
// True if header has valid file signature
bool valid_tag() const;
};
// Header for currently loaded file
header_t const& header() const { return header_; }
// Sound chip
Gb_Apu& apu() { return apu_; }
// ROM data
Rom_Data const& rom_() const { return rom; }
// Adjusts music tempo, where 1.0 is normal. Can be changed while playing.
void set_tempo( double );
// Starts track, where 0 is the first. Uses specified APU mode.
blargg_err_t start_track( int, Gb_Apu::mode_t = Gb_Apu::mode_cgb );
// Ends time frame at time t
typedef int time_t; // clock count
blargg_err_t end_frame( time_t t );
// Clocks between calls to play routine
time_t play_period() const { return play_period_; }
protected:
typedef int addr_t;
// Current time
time_t time() const { return cpu.time() + end_time; }
// Runs emulator to time t
blargg_err_t run_until( time_t t );
// Runs CPU until time becomes >= 0
void run_cpu();
// Reads/writes memory and I/O
int read_mem( addr_t );
void write_mem( addr_t, int );
// Implementation
public:
Gbs_Core();
~Gbs_Core();
virtual void unload();
protected:
virtual blargg_err_t load_( Data_Reader& );
private:
enum { ram_addr = 0xA000 };
enum { io_base = 0xFF00 };
enum { hi_page = io_base - ram_addr };
Rom_Data rom;
int tempo;
time_t end_time;
time_t play_period_;
time_t next_play;
header_t header_;
Gb_Cpu cpu;
Gb_Apu apu_;
byte ram [0x4000 + 0x2000 + Gb_Cpu::cpu_padding];
void update_timer();
void jsr_then_stop( byte const [] );
void set_bank( int n );
void write_io_inline( int offset, int data, int base );
void write_io_( int offset, int data );
int read_io( int offset );
void write_io( int offset, int data );
};
#endif