64 lines
1.7 KiB
C
64 lines
1.7 KiB
C
|
// Sega Master System SN76489 PSG sound chip emulator
|
||
|
|
|
||
|
|
// Sms_Snd_Emu 0.1.2
|
||
|
|
#ifndef SMS_APU_H
|
||
|
|
#define SMS_APU_H
|
||
|
|
|
||
|
|
#include "blargg_common.h"
|
||
|
|
#include "blip_buffer.h"
|
||
|
|
|
||
|
|
// 0: Square 1, 1: Square 2, 2: Square 3, 3: Noise
|
||
|
|
enum { sms_osc_count = 4 }; // 0 <= chan < osc_count
|
||
|
|
|
||
|
|
struct Osc
|
||
|
|
{
|
||
|
|
struct Blip_Buffer* outputs [4]; // NULL, right, left, center
|
||
|
|
struct Blip_Buffer* output;
|
||
|
|
int last_amp;
|
||
|
|
|
||
|
|
int volume;
|
||
|
|
int period;
|
||
|
|
int delay;
|
||
|
|
unsigned phase;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct Sms_Apu {
|
||
|
|
struct Osc oscs [sms_osc_count];
|
||
|
|
int ggstereo;
|
||
|
|
int latch;
|
||
|
|
|
||
|
|
blip_time_t last_time;
|
||
|
|
int min_tone_period;
|
||
|
|
unsigned noise_feedback;
|
||
|
|
unsigned looped_feedback;
|
||
|
|
struct Blip_Synth synth;
|
||
|
|
};
|
||
|
|
|
||
|
|
// Basics
|
||
|
|
|
||
|
|
void Sms_apu_init( struct Sms_Apu* this );
|
||
|
|
|
||
|
|
// Sets buffer(s) to generate sound into, or 0 to mute. If only center is not 0,
|
||
|
|
// output is mono.
|
||
|
|
void Sms_apu_set_output( struct Sms_Apu* this, int i, struct Blip_Buffer* center, struct Blip_Buffer* left, struct Blip_Buffer* right);
|
||
|
|
|
||
|
|
// Emulates to time t, then writes data to Game Gear left/right assignment byte
|
||
|
|
void Sms_apu_write_ggstereo( struct Sms_Apu* this, blip_time_t t, int data ) ICODE_ATTR;
|
||
|
|
|
||
|
|
// Emulates to time t, then writes data
|
||
|
|
void Sms_apu_write_data( struct Sms_Apu* this, blip_time_t t, int data ) ICODE_ATTR;
|
||
|
|
|
||
|
|
// Emulates to time t, then subtracts t from the current time.
|
||
|
|
// OK if previous write call had time slightly after t.
|
||
|
|
void Sms_apu_end_frame( struct Sms_Apu* this, blip_time_t t ) ICODE_ATTR;
|
||
|
|
|
||
|
|
// More features
|
||
|
|
|
||
|
|
// Resets sound chip and sets noise feedback bits and width
|
||
|
|
void Sms_apu_reset( struct Sms_Apu* this, unsigned noise_feedback, int noise_width );
|
||
|
|
|
||
|
|
// Sets overall volume, where 1.0 is normal
|
||
|
|
void Sms_apu_volume( struct Sms_Apu* this, double vol );
|
||
|
|
|
||
|
|
#endif
|