1 // Sega Master System/Mark III, Sega Genesis/Mega Drive, BBC Micro VGM music file emulator 2 3 // Game_Music_Emu 0.5.5 4 #ifndef VGM_EMU_H 5 #define VGM_EMU_H 6 7 #include "Vgm_Emu_Impl.h" 8 9 // Emulates VGM music using SN76489/SN76496 PSG, YM2612, and YM2413 FM sound chips. 10 // Supports custom sound buffer and frequency equalization when VGM uses just the PSG. 11 // FM sound chips can be run at their proper rates, or slightly higher to reduce 12 // aliasing on high notes. Currently YM2413 support requires that you supply a 13 // YM2413 sound chip emulator. I can provide one I've modified to work with the library. 14 class Vgm_Emu : public Vgm_Emu_Impl { 15 public: 16 // True if custom buffer and custom equalization are supported 17 // TODO: move into Music_Emu and rename to something like supports_custom_buffer() is_classic_emu()18 bool is_classic_emu() const { return !uses_fm; } 19 20 // Disable running FM chips at higher than normal rate. Will result in slightly 21 // more aliasing of high notes. 22 void disable_oversampling( bool disable = true ) { disable_oversampling_ = disable; } 23 24 // VGM header format 25 enum { header_size = 0x40 }; 26 struct header_t 27 { 28 char tag [4]; 29 byte data_size [4]; 30 byte version [4]; 31 byte psg_rate [4]; 32 byte ym2413_rate [4]; 33 byte gd3_offset [4]; 34 byte track_duration [4]; 35 byte loop_offset [4]; 36 byte loop_duration [4]; 37 byte frame_rate [4]; 38 byte noise_feedback [2]; 39 byte noise_width; 40 byte unused1; 41 byte ym2612_rate [4]; 42 byte ym2151_rate [4]; 43 byte data_offset [4]; 44 byte unused2 [8]; 45 }; 46 47 // Header for currently loaded file header()48 header_t const& header() const { return *(header_t const*) data; } 49 static_type()50 static gme_type_t static_type() { return gme_vgm_type; } 51 52 public: 53 // deprecated 54 using Music_Emu::load; load(header_t const & h,Data_Reader & in)55 blargg_err_t load( header_t const& h, Data_Reader& in ) // use Remaining_Reader 56 { return load_remaining_( &h, sizeof h, in ); } 57 byte const* gd3_data( int* size_out = 0 ) const; // use track_info() 58 59 public: 60 Vgm_Emu(); 61 ~Vgm_Emu(); 62 protected: 63 blargg_err_t track_info_( track_info_t*, int track ) const; 64 blargg_err_t load_mem_( byte const*, long ); 65 blargg_err_t set_sample_rate_( long sample_rate ); 66 blargg_err_t start_track_( int ); 67 blargg_err_t play_( long count, sample_t* ); 68 blargg_err_t run_clocks( blip_time_t&, int ); 69 void set_tempo_( double ); 70 void mute_voices_( int mask ); 71 void set_voice( int, Blip_Buffer*, Blip_Buffer*, Blip_Buffer* ); 72 void update_eq( blip_eq_t const& ); 73 private: 74 // removed; use disable_oversampling() and set_tempo() instead 75 Vgm_Emu( bool oversample, double tempo = 1.0 ); 76 double fm_rate; 77 long psg_rate; 78 long vgm_rate; 79 bool disable_oversampling_; 80 bool uses_fm; 81 blargg_err_t setup_fm(); 82 }; 83 84 #endif 85