gzdoom-gles/snes_spc/snes_spc/spc.h
Randy Heit 3bfcc5c09c - Removed lots of spc_* cvars that are no longer meaningful and changed
spc_amp from a x.4 fixed point number to a normal float.
- Switched SPC playback from the external SNESAPU.DLL to Blargg's LGPL
  snes_spc library. I've compiled it with the fast DSP rather than the
  highly accurate one, since I didn't notice a meaningful difference between
  the two in my limited testing. In short: SPC playback is now built in to
  ZDoom. You don't need to download anything extra to make it work, and it
  also works on Linux as well as Windows (though building with Linux is
  currently untested).
- Fixed: Stereo separation was calculated very wrongly when in 2D sound mode.


SVN r794 (trunk)
2008-03-11 22:17:57 +00:00

147 lines
4.6 KiB
C

/* SNES SPC-700 APU emulator C interface (also usable from C++) */
/* snes_spc 0.9.0 */
#ifndef SPC_H
#define SPC_H
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
/* Error string return. NULL if success, otherwise error message. */
typedef const char* spc_err_t;
typedef struct SNES_SPC SNES_SPC;
/* Creates new SPC emulator. NULL if out of memory. */
SNES_SPC* spc_new( void );
/* Frees SPC emulator */
void spc_delete( SNES_SPC* );
/* Sample pairs generated per second */
enum { spc_sample_rate = 32000 };
/**** Emulator use ****/
/* Sets IPL ROM data. Library does not include ROM data. Most SPC music files
don't need ROM, but a full emulator must provide this. */
enum { spc_rom_size = 0x40 };
void spc_init_rom( SNES_SPC*, unsigned char const rom [spc_rom_size] );
/* Sets destination for output samples */
typedef short spc_sample_t;
void spc_set_output( SNES_SPC*, spc_sample_t* out, int out_size );
/* Number of samples written to output since last set */
int spc_sample_count( SNES_SPC const* );
/* Resets SPC to power-on state. This resets your output buffer, so you must
call spc_set_output() after this. */
void spc_reset( SNES_SPC* );
/* Emulates pressing reset switch on SNES. This resets your output buffer, so
you must call spc_set_output() after this. */
void spc_soft_reset( SNES_SPC* );
/* 1024000 SPC clocks per second, sample pair every 32 clocks */
typedef int spc_time_t;
enum { spc_clock_rate = 1024000 };
enum { spc_clocks_per_sample = 32 };
/* Reads/writes port at specified time */
enum { spc_port_count = 4 };
int spc_read_port ( SNES_SPC*, spc_time_t, int port );
void spc_write_port( SNES_SPC*, spc_time_t, int port, int data );
/* Runs SPC to end_time and starts a new time frame at 0 */
void spc_end_frame( SNES_SPC*, spc_time_t end_time );
/**** Sound control ****/
/*Mutes voices corresponding to non-zero bits in mask. Reduces emulation accuracy. */
enum { spc_voice_count = 8 };
void spc_mute_voices( SNES_SPC*, int mask );
/* If true, prevents channels and global volumes from being phase-negated.
Only supported by fast DSP; has no effect on accurate DSP. */
void spc_disable_surround( SNES_SPC*, int disable );
/* Sets tempo, where spc_tempo_unit = normal, spc_tempo_unit / 2 = half speed, etc. */
enum { spc_tempo_unit = 0x100 };
void spc_set_tempo( SNES_SPC*, int );
/**** SPC music playback *****/
/* Loads SPC data into emulator. Returns NULL on success, otherwise error string. */
spc_err_t spc_load_spc( SNES_SPC*, void const* spc_in, long size );
/* Clears echo region. Useful after loading an SPC as many have garbage in echo. */
void spc_clear_echo( SNES_SPC* );
/* Plays for count samples and write samples to out. Discards samples if out
is NULL. Count must be a multiple of 2 since output is stereo. */
spc_err_t spc_play( SNES_SPC*, int count, short* out );
/* Skips count samples. Several times faster than spc_play(). */
spc_err_t spc_skip( SNES_SPC*, int count );
/**** State save/load (only available with accurate DSP) ****/
/* Saves/loads exact emulator state */
enum { spc_state_size = 67 * 1024L }; /* maximum space needed when saving */
typedef void (*spc_copy_func_t)( unsigned char** io, void* state, size_t );
void spc_copy_state( SNES_SPC*, unsigned char** io, spc_copy_func_t );
/* Writes minimal SPC file header to spc_out */
void spc_init_header( void* spc_out );
/* Saves emulator state as SPC file data. Writes spc_file_size bytes to spc_out.
Does not set up SPC header; use spc_init_header() for that. */
enum { spc_file_size = 0x10200 }; /* spc_out must have this many bytes allocated */
void spc_save_spc( SNES_SPC*, void* spc_out );
/* Returns non-zero if new key-on events occurred since last check. Useful for
trimming silence while saving an SPC. */
int spc_check_kon( SNES_SPC* );
/**** SPC_Filter ****/
typedef struct SPC_Filter SPC_Filter;
/* Creates new filter. NULL if out of memory. */
SPC_Filter* spc_filter_new( void );
/* Frees filter */
void spc_filter_delete( SPC_Filter* );
/* Filters count samples of stereo sound in place. Count must be a multiple of 2. */
void spc_filter_run( SPC_Filter*, spc_sample_t* io, int count );
/* Clears filter to silence */
void spc_filter_clear( SPC_Filter* );
/* Sets gain (volume), where spc_filter_gain_unit is normal. Gains greater than
spc_filter_gain_unit are fine, since output is clamped to 16-bit sample range. */
enum { spc_filter_gain_unit = 0x100 };
void spc_filter_set_gain( SPC_Filter*, int gain );
/* Sets amount of bass (logarithmic scale) */
enum { spc_filter_bass_none = 0 };
enum { spc_filter_bass_norm = 8 }; /* normal amount */
enum { spc_filter_bass_max = 31 };
void spc_filter_set_bass( SPC_Filter*, int bass );
#ifdef __cplusplus
}
#endif
#endif