90 lines
2.5 KiB
C
90 lines
2.5 KiB
C
|
// Turbo Grafx 16 (PC Engine) ADPCM sound chip emulator
|
||
|
|
|
||
|
|
// Game_Music_Emu 0.6-pre
|
||
|
|
#ifndef HES_APU_ADPCM_H
|
||
|
|
#define HES_APU_ADPCM_H
|
||
|
|
|
||
|
|
#include "blargg_source.h"
|
||
|
|
#include "blargg_common.h"
|
||
|
|
#include "blip_buffer.h"
|
||
|
|
|
||
|
|
enum { adpcm_amp_range = 2048 };
|
||
|
|
enum { adpcm_osc_count = 1 }; // 0 <= chan < osc_count
|
||
|
|
|
||
|
|
// Registers are at io_addr to io_addr+io_size-1
|
||
|
|
enum { io_addr = 0x1800 };
|
||
|
|
enum { io_size = 0x400 };
|
||
|
|
|
||
|
|
struct State
|
||
|
|
{
|
||
|
|
byte pcmbuf [0x10000];
|
||
|
|
byte port [0x10];
|
||
|
|
int ad_sample;
|
||
|
|
int ad_ref_index;
|
||
|
|
bool ad_low_nibble;
|
||
|
|
int freq;
|
||
|
|
unsigned short addr;
|
||
|
|
unsigned short writeptr;
|
||
|
|
unsigned short readptr;
|
||
|
|
unsigned short playptr;
|
||
|
|
byte playflag;
|
||
|
|
byte repeatflag;
|
||
|
|
int length;
|
||
|
|
int playlength;
|
||
|
|
int playedsamplecount;
|
||
|
|
int volume;
|
||
|
|
int fadetimer;
|
||
|
|
int fadecount;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct Hes_Apu_Adpcm {
|
||
|
|
struct State state;
|
||
|
|
struct Blip_Synth synth;
|
||
|
|
|
||
|
|
struct Blip_Buffer* output;
|
||
|
|
blip_time_t last_time;
|
||
|
|
double next_timer;
|
||
|
|
int last_amp;
|
||
|
|
};
|
||
|
|
|
||
|
|
// Init HES adpcm sound chip
|
||
|
|
void Adpcm_init( struct Hes_Apu_Adpcm* this );
|
||
|
|
|
||
|
|
// Rest HES adpcm sound chip
|
||
|
|
void Adpcm_reset( struct Hes_Apu_Adpcm* this );
|
||
|
|
|
||
|
|
// Sets buffer(s) to generate sound into, or 0 to mute. If only center is not 0,
|
||
|
|
// output is mono.
|
||
|
|
static inline void Adpcm_set_output( struct Hes_Apu_Adpcm* this, int chan, struct Blip_Buffer* center, struct Blip_Buffer* left, struct Blip_Buffer* right )
|
||
|
|
{
|
||
|
|
// Must be silent (all NULL), mono (left and right NULL), or stereo (none NULL)
|
||
|
|
require( !center || (center && !left && !right) || (center && left && right) );
|
||
|
|
require( (unsigned) chan < adpcm_osc_count ); // fails if you pass invalid osc index
|
||
|
|
|
||
|
|
#if defined(ROCKBOX)
|
||
|
|
(void) chan;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
if ( !center || !left || !right )
|
||
|
|
{
|
||
|
|
left = center;
|
||
|
|
right = center;
|
||
|
|
}
|
||
|
|
|
||
|
|
this->output = center;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Emulates to time t, then writes data to addr
|
||
|
|
void Adpcm_write_data( struct Hes_Apu_Adpcm* this, blip_time_t t, int addr, int data ) ICODE_ATTR;
|
||
|
|
|
||
|
|
// Emulates to time t, then reads from addr
|
||
|
|
int Adpcm_read_data( struct Hes_Apu_Adpcm* this, blip_time_t t, int addr ) ICODE_ATTR;
|
||
|
|
|
||
|
|
// Emulates to time t, then subtracts t from the current time.
|
||
|
|
// OK if previous write call had time slightly after t.
|
||
|
|
void Adpcm_end_frame( struct Hes_Apu_Adpcm* this,blip_time_t t ) ICODE_ATTR;
|
||
|
|
|
||
|
|
// Sets overall volume, where 1.0 is normal
|
||
|
|
static inline void Adpcm_volume( struct Hes_Apu_Adpcm* this, double v ) { Synth_volume( &this->synth, 0.6 / adpcm_osc_count / adpcm_amp_range * v ); }
|
||
|
|
#endif
|