Hes_Apu.h

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// Turbo Grafx 16 (PC Engine) PSG sound chip emulator
 
// Game_Music_Emu https://bitbucket.org/mpyne/game-music-emu/
#ifndef HES_APU_H
#define HES_APU_H
 
#include "blargg_common.h"
#include "Blip_Buffer.h"
 
struct Hes_Osc
{
        unsigned char wave [32];
        short volume [2];
        int last_amp [2];
        int delay;
        int period;
        unsigned char noise;
        unsigned char phase;
        unsigned char balance;
        unsigned char dac;
        blip_time_t last_time;
        
        Blip_Buffer* outputs [2];
        Blip_Buffer* chans [3];
        unsigned noise_lfsr;
        unsigned char control;
        
        enum { amp_range = 0x8000 };
        typedef Blip_Synth<blip_med_quality,1> synth_t;
        
        void run_until( synth_t& synth, blip_time_t );
};
 
class Hes_Apu {
public:
        void treble_eq( blip_eq_t const& );
        void volume( double );
        
        enum { osc_count = 6 };
        void osc_output( int index, Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right );
        
        void reset();
        
        enum { start_addr = 0x0800 };
        enum { end_addr   = 0x0809 };
        void write_data( blip_time_t, int addr, int data );
        
        void end_frame( blip_time_t );
        
public:
        Hes_Apu();
private:
        Hes_Osc oscs [osc_count];
        int latch;
        int balance;
        Hes_Osc::synth_t synth;
        
        void balance_changed( Hes_Osc& );
        void recalc_chans();
};
 
inline void Hes_Apu::volume( double v ) { synth.volume( 1.8 / osc_count / Hes_Osc::amp_range * v ); }
 
inline void Hes_Apu::treble_eq( blip_eq_t const& eq ) { synth.treble_eq( eq ); }
 
#endif