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Diffstat (limited to 'plugins/gme/game-music-emu-0.6pre/gme/Vgm_Core.h')
| -rw-r--r-- | plugins/gme/game-music-emu-0.6pre/gme/Vgm_Core.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Vgm_Core.h b/plugins/gme/game-music-emu-0.6pre/gme/Vgm_Core.h new file mode 100644 index 00000000..7f83610c --- /dev/null +++ b/plugins/gme/game-music-emu-0.6pre/gme/Vgm_Core.h @@ -0,0 +1,160 @@ +// Sega VGM music file emulator core + +// Game_Music_Emu 0.6-pre +#ifndef VGM_CORE_H +#define VGM_CORE_H + +#include "Gme_Loader.h" +#include "Ym2612_Emu.h" +#include "Ym2413_Emu.h" +#include "Sms_Apu.h" +#include "Multi_Buffer.h" + + template<class Emu> + class Ym_Emu : public Emu { + int last_time; + short* out; + enum { disabled_time = -1 }; + public: + Ym_Emu() { last_time = disabled_time; out = NULL; } + void enable( bool b = true ) { last_time = b ? 0 : disabled_time; } + bool enabled() const { return last_time != disabled_time; } + void begin_frame( short* buf ) { out = buf; last_time = 0; } + + int run_until( int time ) + { + int count = time - last_time; + if ( count > 0 ) + { + if ( last_time < 0 ) + return false; + last_time = time; + short* p = out; + out += count * Emu::out_chan_count; + Emu::run( count, p ); + } + return true; + } + }; + +class Vgm_Core : public Gme_Loader { +public: + + // VGM file header + struct header_t + { + enum { size = 0x40 }; + + char tag [4]; + byte data_size [4]; + byte version [4]; + byte psg_rate [4]; + byte ym2413_rate [4]; + byte gd3_offset [4]; + byte track_duration [4]; + byte loop_offset [4]; + byte loop_duration [4]; + byte frame_rate [4]; + byte noise_feedback [2]; + byte noise_width; + byte unused1; + byte ym2612_rate [4]; + byte ym2151_rate [4]; + byte data_offset [4]; + byte unused2 [8]; + + // True if header has valid file signature + bool valid_tag() const; + }; + + // Header for currently loaded file + header_t const& header() const { return *(header_t const*) file_begin(); } + + // Raw file data, for parsing GD3 tags + byte const* file_begin() const { return Gme_Loader::file_begin(); } + byte const* file_end () const { return Gme_Loader::file_end(); } + + // If file uses FM, initializes FM sound emulator using *sample_rate. If + // *sample_rate is zero, sets *sample_rate to the proper accurate rate and + // uses that. The output of the FM sound emulator is resampled to the + // final sampling rate. + blargg_err_t init_fm( double* sample_rate ); + + // True if any FM chips are used by file. Always false until init_fm() + // is called. + bool uses_fm() const { return ym2612.enabled() || ym2413.enabled(); } + + // Adjusts music tempo, where 1.0 is normal. Can be changed while playing. + // Loading a file resets tempo to 1.0. + void set_tempo( double ); + + // Starts track + void start_track(); + + // Runs PSG-only VGM for msec and returns number of clocks it ran for + blip_time_t run_psg( int msec ); + + // Plays FM for at most count samples into *out, and returns number of + // samples actually generated (always even). Also runs PSG for blip_time. + int play_frame( blip_time_t blip_time, int count, blip_sample_t out [] ); + + // True if all of file data has been played + bool track_ended() const { return pos >= file_end(); } + + // PCM sound is always generated here + Stereo_Buffer stereo_buf; + Blip_Buffer * blip_buf; + + // PSG sound chip, for assigning to Blip_Buffer, and setting volume and EQ + Sms_Apu psg; + + // PCM synth, for setting volume and EQ + Blip_Synth_Fast pcm; + + // FM sound chips + Ym_Emu<Ym2612_Emu> ym2612; + Ym_Emu<Ym2413_Emu> ym2413; + +// Implementation +public: + Vgm_Core(); + +protected: + virtual blargg_err_t load_mem_( byte const [], int ); + +private: + // blip_time_t // PSG clocks + typedef int vgm_time_t; // 44100 per second, REGARDLESS of sample rate + typedef int fm_time_t; // FM sample count + + int vgm_rate; // rate of log, 44100 normally, adjusted by tempo + double fm_rate; // FM samples per second + + // VGM to FM time + int fm_time_factor; + int fm_time_offset; + fm_time_t to_fm_time( vgm_time_t ) const; + + // VGM to PSG time + int blip_time_factor; + blip_time_t to_psg_time( vgm_time_t ) const; + + // Current time and position in log + vgm_time_t vgm_time; + byte const* pos; + byte const* loop_begin; + + // PCM + byte const* pcm_data; // location of PCM data in log + byte const* pcm_pos; // current position in PCM data + int dac_amp; + int dac_disabled; // -1 if disabled + void write_pcm( vgm_time_t, int amp ); + + blip_time_t run( vgm_time_t ); + int run_ym2413( int time ); + int run_ym2612( int time ); + void update_fm_rates( int* ym2413_rate, int* ym2612_rate ) const; +}; + +#endif |