diff options
Diffstat (limited to 'gme/Kss_Scc_Apu.h')
-rw-r--r-- | gme/Kss_Scc_Apu.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/gme/Kss_Scc_Apu.h b/gme/Kss_Scc_Apu.h new file mode 100644 index 00000000..03a6a108 --- /dev/null +++ b/gme/Kss_Scc_Apu.h @@ -0,0 +1,106 @@ +// Konami SCC sound chip emulator + +// Game_Music_Emu 0.5.2 +#ifndef KSS_SCC_APU_H +#define KSS_SCC_APU_H + +#include "blargg_common.h" +#include "Blip_Buffer.h" +#include <string.h> + +class Scc_Apu { +public: + // Set buffer to generate all sound into, or disable sound if NULL + void output( Blip_Buffer* ); + + // Reset sound chip + void reset(); + + // Write to register at specified time + enum { reg_count = 0x90 }; + void write( blip_time_t time, int reg, int data ); + + // Run sound to specified time, end current time frame, then start a new + // time frame at time 0. Time frames have no effect on emulation and each + // can be whatever length is convenient. + void end_frame( blip_time_t length ); + +// Additional features + + // Set sound output of specific oscillator to buffer, where index is + // 0 to 4. If buffer is NULL, the specified oscillator is muted. + enum { osc_count = 5 }; + void osc_output( int index, Blip_Buffer* ); + + // Set overall volume (default is 1.0) + void volume( double ); + + // Set treble equalization (see documentation) + void treble_eq( blip_eq_t const& ); + +public: + Scc_Apu(); +private: + enum { amp_range = 0x8000 }; + struct osc_t + { + int delay; + int phase; + int last_amp; + Blip_Buffer* output; + }; + osc_t oscs [osc_count]; + blip_time_t last_time; + unsigned char regs [reg_count]; + Blip_Synth<blip_med_quality,1> synth; + + void run_until( blip_time_t ); +}; + +inline void Scc_Apu::volume( double v ) { synth.volume( 0.43 / osc_count / amp_range * v ); } + +inline void Scc_Apu::treble_eq( blip_eq_t const& eq ) { synth.treble_eq( eq ); } + +inline void Scc_Apu::osc_output( int index, Blip_Buffer* b ) +{ + assert( (unsigned) index < osc_count ); + oscs [index].output = b; +} + +inline void Scc_Apu::write( blip_time_t time, int addr, int data ) +{ + assert( (unsigned) addr < reg_count ); + run_until( time ); + regs [addr] = data; +} + +inline void Scc_Apu::end_frame( blip_time_t end_time ) +{ + if ( end_time > last_time ) + run_until( end_time ); + last_time -= end_time; + assert( last_time >= 0 ); +} + +inline void Scc_Apu::output( Blip_Buffer* buf ) +{ + for ( int i = 0; i < osc_count; i++ ) + oscs [i].output = buf; +} + +inline Scc_Apu::Scc_Apu() +{ + output( 0 ); +} + +inline void Scc_Apu::reset() +{ + last_time = 0; + + for ( int i = 0; i < osc_count; i++ ) + memset( &oscs [i], 0, offsetof (osc_t,output) ); + + memset( regs, 0, sizeof regs ); +} + +#endif |