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Diffstat (limited to 'gme/Gb_Apu.h')
-rw-r--r-- | gme/Gb_Apu.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/gme/Gb_Apu.h b/gme/Gb_Apu.h new file mode 100644 index 00000000..e74ebc55 --- /dev/null +++ b/gme/Gb_Apu.h @@ -0,0 +1,90 @@ +// Nintendo Game Boy PAPU sound chip emulator + +// Gb_Snd_Emu 0.1.5 +#ifndef GB_APU_H +#define GB_APU_H + +#include "Gb_Oscs.h" + +class Gb_Apu { +public: + + // Set overall volume of all oscillators, where 1.0 is full volume + void volume( double ); + + // Set treble equalization + void treble_eq( const blip_eq_t& ); + + // Outputs can be assigned to a single buffer for mono output, or to three + // buffers for stereo output (using Stereo_Buffer to do the mixing). + + // Assign all oscillator outputs to specified buffer(s). If buffer + // is NULL, silences all oscillators. + void output( Blip_Buffer* mono ); + void output( Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right ); + + // Assign single oscillator output to buffer(s). Valid indicies are 0 to 3, + // which refer to Square 1, Square 2, Wave, and Noise. If buffer is NULL, + // silences oscillator. + enum { osc_count = 4 }; + void osc_output( int index, Blip_Buffer* mono ); + void osc_output( int index, Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right ); + + // Reset oscillators and internal state + void reset(); + + // Reads and writes at addr must satisfy start_addr <= addr <= end_addr + enum { start_addr = 0xFF10 }; + enum { end_addr = 0xFF3F }; + enum { register_count = end_addr - start_addr + 1 }; + + // Write 'data' to address at specified time + void write_register( blip_time_t, unsigned addr, int data ); + + // Read from address at specified time + int read_register( blip_time_t, unsigned addr ); + + // Run all oscillators up to specified time, end current time frame, then + // start a new frame at time 0. + void end_frame( blip_time_t ); + + void set_tempo( double ); + +public: + Gb_Apu(); +private: + // noncopyable + Gb_Apu( const Gb_Apu& ); + Gb_Apu& operator = ( const Gb_Apu& ); + + Gb_Osc* oscs [osc_count]; + blip_time_t next_frame_time; + blip_time_t last_time; + blip_time_t frame_period; + double volume_unit; + int frame_count; + + Gb_Square square1; + Gb_Square square2; + Gb_Wave wave; + Gb_Noise noise; + BOOST::uint8_t regs [register_count]; + Gb_Square::Synth square_synth; // used by squares + Gb_Wave::Synth other_synth; // used by wave and noise + + void update_volume(); + void run_until( blip_time_t ); + void write_osc( int index, int reg, int data ); +}; + +inline void Gb_Apu::output( Blip_Buffer* b ) { output( b, b, b ); } + +inline void Gb_Apu::osc_output( int i, Blip_Buffer* b ) { osc_output( i, b, b, b ); } + +inline void Gb_Apu::volume( double vol ) +{ + volume_unit = 0.60 / osc_count / 15 /*steps*/ / 2 /*?*/ / 8 /*master vol range*/ * vol; + update_volume(); +} + +#endif |