gzdoom/libraries/game-music-emu/gme/Sms_Apu.h

75 lines
2 KiB
C++

// Sega Master System SN76489 PSG sound chip emulator
// Sms_Snd_Emu 0.1.4
#ifndef SMS_APU_H
#define SMS_APU_H
#include "Sms_Oscs.h"
class Sms_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, Square 3, 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( unsigned noise_feedback = 0, int noise_width = 0 );
// Write GameGear left/right assignment byte
void write_ggstereo( blip_time_t, int );
// Write to data port
void write_data( blip_time_t, int );
// Run all oscillators up to specified time, end current frame, then
// start a new frame at time 0.
void end_frame( blip_time_t );
public:
Sms_Apu();
~Sms_Apu();
private:
// noncopyable
Sms_Apu( const Sms_Apu& );
Sms_Apu& operator = ( const Sms_Apu& );
Sms_Osc* oscs [osc_count];
Sms_Square squares [3];
Sms_Square::Synth square_synth; // used by squares
blip_time_t last_time;
int latch;
Sms_Noise noise;
unsigned noise_feedback;
unsigned looped_feedback;
void run_until( blip_time_t );
};
struct sms_apu_state_t
{
unsigned char regs [8] [2];
unsigned char latch;
};
inline void Sms_Apu::output( Blip_Buffer* b ) { output( b, b, b ); }
inline void Sms_Apu::osc_output( int i, Blip_Buffer* b ) { osc_output( i, b, b, b ); }
#endif