// Highly accurate SNES SPC-700 DSP emulator // snes_spc 0.9.0 #ifndef SPC_DSP_H #define SPC_DSP_H #include "blargg_common.h" extern "C" { typedef void (*dsp_copy_func_t)( unsigned char** io, void* state, size_t ); } struct SPC_DSP { public: typedef BOOST::uint8_t uint8_t; // Setup // Initializes DSP and has it use the 64K RAM provided void init( void* ram_64k ); // Sets destination for output samples. If out is NULL or out_size is 0, // doesn't generate any. typedef short sample_t; void set_output( sample_t* out, int out_size ); // Number of samples written to output since it was last set, always // a multiple of 2. Undefined if more samples were generated than // output buffer could hold. int sample_count() const; // Emulation // Resets DSP to power-on state void reset(); // Emulates pressing reset switch on SNES void soft_reset(); // Reads/writes DSP registers. For accuracy, you must first call run() // to catch the DSP up to present. int read ( int addr ) const; void write( int addr, int data ); // Runs DSP for specified number of clocks (~1024000 per second). Every 32 clocks // a pair of samples is be generated. void run( int clock_count ); // Sound control // Mutes voices corresponding to non-zero bits in mask (issues repeated KOFF events). // Reduces emulation accuracy. enum { voice_count = 8 }; void mute_voices( int mask ); // State // Resets DSP and uses supplied values to initialize registers enum { register_count = 128 }; void load( uint8_t const regs [register_count] ); // Saves/loads exact emulator state enum { state_size = 640 }; // maximum space needed when saving typedef dsp_copy_func_t copy_func_t; void copy_state( unsigned char** io, copy_func_t ); // Returns non-zero if new key-on events occurred since last call bool check_kon(); // DSP register addresses // Global registers enum { r_mvoll = 0x0C, r_mvolr = 0x1C, r_evoll = 0x2C, r_evolr = 0x3C, r_kon = 0x4C, r_koff = 0x5C, r_flg = 0x6C, r_endx = 0x7C, r_efb = 0x0D, r_pmon = 0x2D, r_non = 0x3D, r_eon = 0x4D, r_dir = 0x5D, r_esa = 0x6D, r_edl = 0x7D, r_fir = 0x0F // 8 coefficients at 0x0F, 0x1F ... 0x7F }; // Voice registers enum { v_voll = 0x00, v_volr = 0x01, v_pitchl = 0x02, v_pitchh = 0x03, v_srcn = 0x04, v_adsr0 = 0x05, v_adsr1 = 0x06, v_gain = 0x07, v_envx = 0x08, v_outx = 0x09 }; public: enum { extra_size = 16 }; sample_t* extra() { return m.extra; } sample_t const* out_pos() const { return m.out; } void disable_surround( bool ) { } // not supported public: BLARGG_DISABLE_NOTHROW typedef BOOST::int8_t int8_t; typedef BOOST::int16_t int16_t; enum { echo_hist_size = 8 }; enum env_mode_t { env_release, env_attack, env_decay, env_sustain }; enum { brr_buf_size = 12 }; struct voice_t { int buf [brr_buf_size*2];// decoded samples (twice the size to simplify wrap handling) int buf_pos; // place in buffer where next samples will be decoded int interp_pos; // relative fractional position in sample (0x1000 = 1.0) int brr_addr; // address of current BRR block int brr_offset; // current decoding offset in BRR block uint8_t* regs; // pointer to voice's DSP registers int vbit; // bitmask for voice: 0x01 for voice 0, 0x02 for voice 1, etc. int kon_delay; // KON delay/current setup phase env_mode_t env_mode; int env; // current envelope level int hidden_env; // used by GAIN mode 7, very obscure quirk uint8_t t_envx_out; }; private: enum { brr_block_size = 9 }; struct state_t { uint8_t regs [register_count]; // Echo history keeps most recent 8 samples (twice the size to simplify wrap handling) int echo_hist [echo_hist_size * 2] [2]; int (*echo_hist_pos) [2]; // &echo_hist [0 to 7] int every_other_sample; // toggles every sample int kon; // KON value when last checked int noise; int counter; int echo_offset; // offset from ESA in echo buffer int echo_length; // number of bytes that echo_offset will stop at int phase; // next clock cycle to run (0-31) bool kon_check; // set when a new KON occurs // Hidden registers also written to when main register is written to int new_kon; uint8_t endx_buf; uint8_t envx_buf; uint8_t outx_buf; // Temporary state between clocks // read once per sample int t_pmon; int t_non; int t_eon; int t_dir; int t_koff; // read a few clocks ahead then used int t_brr_next_addr; int t_adsr0; int t_brr_header; int t_brr_byte; int t_srcn; int t_esa; int t_echo_enabled; // internal state that is recalculated every sample int t_dir_addr; int t_pitch; int t_output; int t_looped; int t_echo_ptr; // left/right sums int t_main_out [2]; int t_echo_out [2]; int t_echo_in [2]; voice_t voices [voice_count]; // non-emulation state uint8_t* ram; // 64K shared RAM between DSP and SMP int mute_mask; sample_t* out; sample_t* out_end; sample_t* out_begin; sample_t extra [extra_size]; }; state_t m; void init_counter(); void run_counters(); unsigned read_counter( int rate ); int interpolate( voice_t const* v ); void run_envelope( voice_t* const v ); void decode_brr( voice_t* v ); void misc_27(); void misc_28(); void misc_29(); void misc_30(); void voice_output( voice_t const* v, int ch ); void voice_V1( voice_t* const ); void voice_V2( voice_t* const ); void voice_V3( voice_t* const ); void voice_V3a( voice_t* const ); void voice_V3b( voice_t* const ); void voice_V3c( voice_t* const ); void voice_V4( voice_t* const ); void voice_V5( voice_t* const ); void voice_V6( voice_t* const ); void voice_V7( voice_t* const ); void voice_V8( voice_t* const ); void voice_V9( voice_t* const ); void voice_V7_V4_V1( voice_t* const ); void voice_V8_V5_V2( voice_t* const ); void voice_V9_V6_V3( voice_t* const ); void echo_read( int ch ); int echo_output( int ch ); void echo_write( int ch ); void echo_22(); void echo_23(); void echo_24(); void echo_25(); void echo_26(); void echo_27(); void echo_28(); void echo_29(); void echo_30(); void soft_reset_common(); }; #include <assert.h> inline int SPC_DSP::sample_count() const { return int(m.out - m.out_begin); } inline int SPC_DSP::read( int addr ) const { assert( (unsigned) addr < register_count ); return m.regs [addr]; } inline void SPC_DSP::write( int addr, int data ) { assert( (unsigned) addr < register_count ); m.regs [addr] = (uint8_t) data; switch ( addr & 0x0F ) { case v_envx: m.envx_buf = (uint8_t) data; break; case v_outx: m.outx_buf = (uint8_t) data; break; case 0x0C: if ( addr == r_kon ) m.new_kon = (uint8_t) data; if ( addr == r_endx ) // always cleared, regardless of data written { m.endx_buf = 0; m.regs [r_endx] = 0; } break; } } inline void SPC_DSP::mute_voices( int mask ) { m.mute_mask = mask; } inline bool SPC_DSP::check_kon() { bool old = m.kon_check; m.kon_check = 0; return old; } #if !SPC_NO_COPY_STATE_FUNCS class SPC_State_Copier { SPC_DSP::copy_func_t func; unsigned char** buf; public: SPC_State_Copier( unsigned char** p, SPC_DSP::copy_func_t f ) { func = f; buf = p; } void copy( void* state, size_t size ); int copy_int( int state, int size ); void skip( int count ); void extra(); }; #define SPC_COPY( type, state )\ {\ state = (BOOST::type) copier.copy_int( state, sizeof (BOOST::type) );\ assert( (BOOST::type) state == state );\ } #endif #endif