diff options
Diffstat (limited to 'plugins/gme/Game_Music_Emu-0.5.2/gme/Spc_Dsp.h')
| -rw-r--r-- | plugins/gme/Game_Music_Emu-0.5.2/gme/Spc_Dsp.h | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/plugins/gme/Game_Music_Emu-0.5.2/gme/Spc_Dsp.h b/plugins/gme/Game_Music_Emu-0.5.2/gme/Spc_Dsp.h new file mode 100644 index 00000000..36492275 --- /dev/null +++ b/plugins/gme/Game_Music_Emu-0.5.2/gme/Spc_Dsp.h @@ -0,0 +1,152 @@ +// Super Nintendo (SNES) SPC DSP emulator + +// Game_Music_Emu 0.5.2 +#ifndef SPC_DSP_H +#define SPC_DSP_H + +#include "blargg_common.h" + +class Spc_Dsp { + typedef BOOST::int8_t int8_t; + typedef BOOST::uint8_t uint8_t; +public: + + // Keeps pointer to 64K ram + Spc_Dsp( uint8_t* ram ); + + // Mute voice n if bit n (1 << n) of mask is clear. + enum { voice_count = 8 }; + void mute_voices( int mask ); + + // Clear state and silence everything. + void reset(); + + // Set gain, where 1.0 is normal. When greater than 1.0, output is clamped to + // the 16-bit sample range. + void set_gain( double ); + + // If true, prevent channels and global volumes from being phase-negated + void disable_surround( bool disable ); + + // Read/write register 'n', where n ranges from 0 to register_count - 1. + enum { register_count = 128 }; + int read ( int n ); + void write( int n, int ); + + // Run DSP for 'count' samples. Write resulting samples to 'buf' if not NULL. + void run( long count, short* buf = NULL ); + + +// End of public interface +private: + + struct raw_voice_t { + int8_t left_vol; + int8_t right_vol; + uint8_t rate [2]; + uint8_t waveform; + uint8_t adsr [2]; // envelope rates for attack, decay, and sustain + uint8_t gain; // envelope gain (if not using ADSR) + int8_t envx; // current envelope level + int8_t outx; // current sample + int8_t unused [6]; + }; + + struct globals_t { + int8_t unused1 [12]; + int8_t left_volume; // 0C Main Volume Left (-.7) + int8_t echo_feedback; // 0D Echo Feedback (-.7) + int8_t unused2 [14]; + int8_t right_volume; // 1C Main Volume Right (-.7) + int8_t unused3 [15]; + int8_t left_echo_volume; // 2C Echo Volume Left (-.7) + uint8_t pitch_mods; // 2D Pitch Modulation on/off for each voice + int8_t unused4 [14]; + int8_t right_echo_volume; // 3C Echo Volume Right (-.7) + uint8_t noise_enables; // 3D Noise output on/off for each voice + int8_t unused5 [14]; + uint8_t key_ons; // 4C Key On for each voice + uint8_t echo_ons; // 4D Echo on/off for each voice + int8_t unused6 [14]; + uint8_t key_offs; // 5C key off for each voice (instantiates release mode) + uint8_t wave_page; // 5D source directory (wave table offsets) + int8_t unused7 [14]; + uint8_t flags; // 6C flags and noise freq + uint8_t echo_page; // 6D + int8_t unused8 [14]; + uint8_t wave_ended; // 7C + uint8_t echo_delay; // 7D ms >> 4 + char unused9 [2]; + }; + + union { + raw_voice_t voice [voice_count]; + uint8_t reg [register_count]; + globals_t g; + }; + + uint8_t* const ram; + + // Cache of echo FIR values for faster access + short fir_coeff [voice_count]; + + // fir_buf [i + 8] == fir_buf [i], to avoid wrap checking in FIR code + short fir_buf [16] [2]; + int fir_offset; // (0 to 7) + + enum { emu_gain_bits = 8 }; + int emu_gain; + + int keyed_on; // 8-bits for 8 voices + int keys; + + int echo_ptr; + int noise_amp; + int noise; + int noise_count; + + int surround_threshold; + + static BOOST::int16_t const gauss []; + + enum state_t { + state_attack, + state_decay, + state_sustain, + state_release + }; + + struct voice_t { + short volume [2]; + short fraction;// 12-bit fractional position + short interp3; // most recent four decoded samples + short interp2; + short interp1; + short interp0; + short block_remain; // number of nybbles remaining in current block + unsigned short addr; + short block_header; // header byte from current block + short envcnt; + short envx; + short on_cnt; + short enabled; // 7 if enabled, 31 if disabled + short envstate; + short unused; // pad to power of 2 + }; + + voice_t voice_state [voice_count]; + + int clock_envelope( int ); +}; + +inline void Spc_Dsp::disable_surround( bool disable ) { surround_threshold = disable ? 0 : -0x7FFF; } + +inline void Spc_Dsp::set_gain( double v ) { emu_gain = (int) (v * (1 << emu_gain_bits)); } + +inline int Spc_Dsp::read( int i ) +{ + assert( (unsigned) i < register_count ); + return reg [i]; +} + +#endif |