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// Nintendo Game Boy sound hardware emulator with save state support
// Gb_Snd_Emu 0.1.4
#ifndef GB_APU_H
#define GB_APU_H
#include "Gb_Oscs.h"
struct gb_apu_state_t;
class Gb_Apu {
public:
// Basics
// Sets buffer(s) to generate sound into, or NULL to mute. If only center is not NULL,
// output is mono.
void set_output( Blip_Buffer* center, Blip_Buffer* left = NULL, Blip_Buffer* right = NULL );
// Emulates to time t, then writes data to addr
void write_register( blip_time_t t, int addr, int data );
// Emulates to time t, then subtracts t from the current time.
// OK if previous write call had time slightly after t.
void end_frame( blip_time_t t );
// More features
// Clock rate sound hardware runs at
enum { clock_rate = 4194304 * GB_APU_OVERCLOCK };
// Registers are at io_addr to io_addr+io_size-1
enum { io_addr = 0xFF10 };
enum { io_size = 0x30 };
// Emulates to time t, then reads from addr
int read_register( blip_time_t t, int addr );
// Resets hardware to state after power, BEFORE boot ROM runs. Mode selects
// sound hardware. If agb_wave is true, enables AGB's extra wave features.
enum mode_t {
mode_dmg, // Game Boy monochrome
mode_cgb, // Game Boy Color
mode_agb // Game Boy Advance
};
void reset( mode_t mode = mode_cgb, bool agb_wave = false );
// Same as set_output(), but for a particular channel
// 0: Square 1, 1: Square 2, 2: Wave, 3: Noise
enum { osc_count = 4 }; // 0 <= chan < osc_count
void set_output( int chan, Blip_Buffer* center,
Blip_Buffer* left = NULL, Blip_Buffer* right = NULL );
// Sets overall volume, where 1.0 is normal
void volume( double );
// Sets treble equalization
void treble_eq( blip_eq_t const& );
// Treble and bass values for various hardware.
enum {
speaker_treble = -47, // speaker on system
speaker_bass = 2000,
dmg_treble = 0, // headphones on each system
dmg_bass = 30,
cgb_treble = 0,
cgb_bass = 300, // CGB has much less bass
agb_treble = 0,
agb_bass = 30
};
// If true, reduces clicking by disabling DAC biasing. Note that this reduces
// emulation accuracy, since the clicks are authentic.
void reduce_clicks( bool reduce = true );
// Sets frame sequencer rate, where 1.0 is normal. Meant for adjusting the
// tempo in a music player.
void set_tempo( double );
// Saves full emulation state to state_out. Data format is portable and
// includes some extra space to avoid expansion in case more state needs
// to be stored in the future.
void save_state( gb_apu_state_t* state_out );
// Loads state. You should call reset() BEFORE this.
blargg_err_t load_state( gb_apu_state_t const& in );
private:
// noncopyable
Gb_Apu( const Gb_Apu& );
Gb_Apu& operator = ( const Gb_Apu& );
// Implementation
public:
Gb_Apu();
// Use set_output() in place of these
BLARGG_DEPRECATED( void output ( Blip_Buffer* c ); )
BLARGG_DEPRECATED( void output ( Blip_Buffer* c, Blip_Buffer* l, Blip_Buffer* r ); )
BLARGG_DEPRECATED( void osc_output( int i, Blip_Buffer* c ) { set_output( i, c, c, c ); } )
BLARGG_DEPRECATED( void osc_output( int i, Blip_Buffer* c, Blip_Buffer* l, Blip_Buffer* r ) { set_output( i, c, l, r ); } )
BLARGG_DEPRECATED_TEXT( enum { start_addr = 0xFF10 }; )
BLARGG_DEPRECATED_TEXT( enum { end_addr = 0xFF3F }; )
BLARGG_DEPRECATED_TEXT( enum { register_count = end_addr - start_addr + 1 }; )
private:
Gb_Osc* oscs [osc_count];
blip_time_t last_time; // time sound emulator has been run to
blip_time_t frame_period; // clocks between each frame sequencer step
double volume_;
bool reduce_clicks_;
Gb_Sweep_Square square1;
Gb_Square square2;
Gb_Wave wave;
Gb_Noise noise;
blip_time_t frame_time; // time of next frame sequencer action
int frame_phase; // phase of next frame sequencer step
enum { regs_size = io_size + 0x10 };
BOOST::uint8_t regs [regs_size];// last values written to registers
// large objects after everything else
Blip_Synth_Norm norm_synth;
Blip_Synth_Fast fast_synth;
void reset_lengths();
void reset_regs();
int calc_output( int osc ) const;
void apply_stereo();
void apply_volume();
void synth_volume( int );
void run_until_( blip_time_t );
void run_until( blip_time_t );
void silence_osc( Gb_Osc& );
void write_osc( int reg, int old_data, int data );
const char* save_load( gb_apu_state_t*, bool save );
void save_load2( gb_apu_state_t*, bool save );
friend class Gb_Apu2;
};
// Format of save state. Should be stable across versions of the library,
// with earlier versions properly opening later save states. Includes some
// room for expansion so the state size shouldn't increase.
struct gb_apu_state_t
{
#if GB_APU_CUSTOM_STATE
// Values stored as plain int so your code can read/write them easily.
// Structure can NOT be written to disk, since format is not portable.
typedef int val_t;
#else
// Values written in portable little-endian format, allowing structure
// to be written directly to disk.
typedef unsigned char val_t [4];
#endif
enum { format0 = 0x50414247 }; // 'GBAP'
val_t format; // format of all following data
val_t version; // later versions just add fields to end
unsigned char regs [0x40];
val_t frame_time;
val_t frame_phase;
val_t sweep_freq;
val_t sweep_delay;
val_t sweep_enabled;
val_t sweep_neg;
val_t noise_divider;
val_t wave_buf;
val_t delay [4];
val_t length_ctr [4];
val_t phase [4];
val_t enabled [4];
val_t env_delay [3];
val_t env_volume [3];
val_t env_enabled [3];
val_t unused [13]; // for future expansion
};
inline void Gb_Apu::set_output( Blip_Buffer* c, Blip_Buffer* l, Blip_Buffer* r )
{
for ( int i = osc_count; --i >= 0; )
set_output( i, c, l, r );
}
BLARGG_DEPRECATED_TEXT( inline void Gb_Apu::output( Blip_Buffer* c ) { set_output( c, c, c ); } )
BLARGG_DEPRECATED_TEXT( inline void Gb_Apu::output( Blip_Buffer* c, Blip_Buffer* l, Blip_Buffer* r ) { set_output( c, l, r ); } )
#endif
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