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// Nintendo Game Boy PAPU sound chip emulator
// Gb_Snd_Emu 0.1.5
#ifndef GB_APU_H
#define GB_APU_H
#include "Gb_Oscs.h"
class Gb_Apu {
public:
// Set overall volume of all oscillators, where 1.0 is full volume
void volume( double );
// Set treble equalization
void treble_eq( const blip_eq_t& );
// Outputs can be assigned to a single buffer for mono output, or to three
// buffers for stereo output (using Stereo_Buffer to do the mixing).
// Assign all oscillator outputs to specified buffer(s). If buffer
// is NULL, silences all oscillators.
void output( Blip_Buffer* mono );
void output( Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right );
// Assign single oscillator output to buffer(s). Valid indicies are 0 to 3,
// which refer to Square 1, Square 2, Wave, and Noise. If buffer is NULL,
// silences oscillator.
enum { osc_count = 4 };
void osc_output( int index, Blip_Buffer* mono );
void osc_output( int index, Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right );
// Reset oscillators and internal state
void reset();
// Reads and writes at addr must satisfy start_addr <= addr <= end_addr
enum { start_addr = 0xFF10 };
enum { end_addr = 0xFF3F };
enum { register_count = end_addr - start_addr + 1 };
// Write 'data' to address at specified time
void write_register( blip_time_t, unsigned addr, int data );
// Read from address at specified time
int read_register( blip_time_t, unsigned addr );
// Run all oscillators up to specified time, end current time frame, then
// start a new frame at time 0.
void end_frame( blip_time_t );
void set_tempo( double );
public:
Gb_Apu();
private:
// noncopyable
Gb_Apu( const Gb_Apu& );
Gb_Apu& operator = ( const Gb_Apu& );
Gb_Osc* oscs [osc_count];
blip_time_t next_frame_time;
blip_time_t last_time;
blip_time_t frame_period;
double volume_unit;
int frame_count;
Gb_Square square1;
Gb_Square square2;
Gb_Wave wave;
Gb_Noise noise;
BOOST::uint8_t regs [register_count];
Gb_Square::Synth square_synth; // used by squares
Gb_Wave::Synth other_synth; // used by wave and noise
void update_volume();
void run_until( blip_time_t );
void write_osc( int index, int reg, int data );
};
inline void Gb_Apu::output( Blip_Buffer* b ) { output( b, b, b ); }
inline void Gb_Apu::osc_output( int i, Blip_Buffer* b ) { osc_output( i, b, b, b ); }
inline void Gb_Apu::volume( double vol )
{
volume_unit = 0.60 / osc_count / 15 /*steps*/ / 2 /*?*/ / 8 /*master vol range*/ * vol;
update_volume();
}
#endif
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