src/lib/gme/gme.pas

   1 unit GME;
   2
   3 {$IFDEF FPC}
   4 {$PACKRECORDS C}
   5 {$MODE OBJFPC}
   6 {$ENDIF}
   7
   8 interface
   9
  10 uses ctypes;
  11
  12 {$IF DEFINED(WINDOWS)}
  13   {$IFDEF LIBGME_WINDOZE_STATIC}
  14     {$ERROR libgme won't static-link on Windows until we switch to FPC 3.2.0}
  15     // {$LINKLIB libgme.a}
  16   {$ELSE}
  17     {$DEFINE GME_DYNAMIC}
  18     const gmelib = 'libgme.dll';
  19   {$ENDIF}
  20 {$ELSEIF DEFINED(UNIX)}
  21   {$DEFINE GME_DYNAMIC}
  22   const gmelib = 'libgme.so';
  23 {$ELSE}
  24   {$ERROR libgme not supported on this platform. Fix it!}
  25 {$ENDIF}
  26
  27 type
  28   // first parameter of most gme_ functions is a pointer to the Music_Emu
  29   pgme_music_emu = pointer;
  30   ppgme_music_emu = ^pgme_music_emu;
  31
  32   // track information
  33   gme_info_t = record
  34     // times in milliseconds, -1 if unknown
  35     length:       longint; // total length, if file specifies it
  36     intro_length: longint; // length of song up to looping section
  37     loop_length:  longint; // length of looping section
  38     play_length:  longint; // length if available, otherwise intro_length+loop_length*2 if available,
  39                            // otherwise a default of 150000 (2.5 minutes).
  40     i4,i5,i6,i7,i8,i9,i10,i11,i12,i13,i14,i15: longint; // reserved (jesus christ)
  41     // various metadata (empty string if not available)
  42     system:    pchar;
  43     game:      pchar;
  44     song:      pchar;
  45     author:    pchar;
  46     copyright: pchar;
  47     comment:   pchar;
  48     dump:      pchar;
  49     // reserved (holy fuck)
  50     s7,s8,s9,s10,s11,s12,s13,s14,s15: pchar;
  51   end;
  52   pgme_info_t = ^gme_info_t;
  53   ppgme_info_t = ^pgme_info_t;
  54
  55   // frequency equalizer parameters
  56   gme_equalizer_t = record
  57     treble: double;
  58     bass: double;
  59     d2,d3,d4,d5,d6,d7,d8,d9: double; // reserved (please stop)
  60   end;
  61   pgme_equalizer_t = ^gme_equalizer_t;
  62
  63   // music file type identifier; can also hold NULL
  64   gme_type_t = pointer;
  65   pgme_type_t = ^gme_type_t;
  66
  67   // all errors are just const char* msg, NULL === success
  68   gme_err_t = pchar;
  69
  70 const
  71   gme_info_only = -1;
  72
  73 var
  74   // emulator type constants for each supported file type
  75   gme_ay_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  76   gme_gbs_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  77   gme_gym_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  78   gme_hes_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  79   gme_kss_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  80   gme_nsf_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  81   gme_nsfe_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  82   gme_sap_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  83   gme_spc_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  84   gme_vgm_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  85   gme_vgz_type: gme_type_t; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  86
  87   // error returned if GME encounters an invalid file type
  88   gme_wrong_file_type: pchar; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  89
  90 { basic API }
  91
  92 // create emulator and load game music file/data into it. Sets *out to new emulator.
  93 function gme_open_file(const path: pchar; eout: ppgme_music_emu; sample_rate: longint): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  94
  95 // same as gme_open_file(), but uses file data already in memory; makes copy of data;
  96 // the resulting Music_Emu object will be set to single channel mode
  97 function gme_open_data(const data: pointer; size: clong; eout: ppgme_music_emu; sample_rate: longint): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
  98
  99 // number of tracks available
 100 function gme_track_count(const emu: pgme_music_emu): longint; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 101
 102 // start a track, where 0 is the first track
 103 function gme_start_track(emu: pgme_music_emu; track: longint): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 104
 105 // generate 'count' 16-bit signed samples into 'out'; output is in stereo
 106 function gme_play(emu: pgme_music_emu; count: longint; buf: pword): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 107
 108 // finish using emulator and free memory
 109 procedure gme_delete(emu: pgme_music_emu); cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 110
 111 { track positioning }
 112
 113 // Set time to start fading track out. Once fade ends track_ended() returns true.
 114 // Fade time can be changed while track is playing.
 115 procedure gme_set_fade(emu: pgme_music_emu; start_msec: longint); cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 116
 117 // true if a track has reached its end
 118 function gme_track_ended(const emu: pgme_music_emu): longint; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 119
 120 // number of milliseconds (1000 = one second) played since beginning of track
 121 function gme_tell(const emu: pgme_music_emu): longint; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 122
 123 // number of samples generated since beginning of track
 124 function gme_tell_samples(const emu: pgme_music_emu): longint; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 125
 126 // seek to new time in track; seeking backwards or far forward can take a while
 127 function gme_seek(emu: pgme_music_emu; msec: longint): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 128
 129 // equivalent to restarting track then skipping n samples
 130 function gme_seek_samples(emu: pgme_music_emu; n: longint): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 131
 132 // If do_autoload_limit is nonzero, then automatically load track length
 133 // metadata (if present) and terminate playback once the track length has been
 134 // reached. Otherwise playback will continue for an arbitrary period of time
 135 // until a prolonged period of silence is detected.
 136 // By default, playback limits are loaded and applied.
 137 procedure gme_set_autoload_playback_limit(emu: pgme_music_emu; do_autoload_limit: longint); cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 138
 139 { informational }
 140
 141 // most recent warning string, or NULL if none; clears current warning after returning
 142 function gme_warning(emu: pgme_music_emu): pchar; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 143
 144 // gets information for a particular track (length, name, author, etc.); must be freed after use
 145 function gme_track_info(const emu: pgme_music_emu; iout: ppgme_info_t; track: longint): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 146
 147 // frees track information
 148 procedure gme_free_info(info: pgme_info_t); cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 149
 150 { advanced playback }
 151
 152 // Adjust stereo echo depth, where 0.0 = off and 1.0 = maximum.
 153 // Has no effect for GYM, SPC, and Sega Genesis VGM music
 154 procedure gme_set_stereo_depth(emu: pgme_music_emu; depth: double); cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 155
 156 // enables/disables most accurate sound emulation options
 157 procedure gme_enable_accuracy(emu: pgme_music_emu; enable: longint); cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 158
 159 { music type ident }
 160
 161 // Type of this emulator
 162 function gme_type(const emu: pgme_music_emu): gme_type_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 163
 164 // Pointer to array of all music types, with NULL entry at end. Allows a player linked
 165 // to this library to support new music types without having to be updated.
 166 function gme_type_list(): pgme_type_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 167
 168 // Determine likely game music type based on first four bytes of file. Returns
 169 // string containing proper file suffix (i.e. "NSF", "SPC", etc.) or "" if
 170 // file header is not recognized.
 171 function gme_identify_header(const header: pointer): pchar; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 172
 173 // Get corresponding music type for file path or extension passed in.
 174 function gme_identify_extension(const path_or_extension: pchar): gme_type_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 175
 176 // Create new emulator and set sample rate. Returns NULL if out of memory.
 177 // If you only need track information, pass gme_info_only for sample_rate.
 178 function gme_new_emu(stype: gme_type_t; sample_rate: longint): pgme_music_emu; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 179
 180 // Load music file into emulator
 181 function gme_load_file(emu: pgme_music_emu; const path: pchar): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 182
 183 // Load music file from memory into emulator. Makes a copy of data passed.
 184 function gme_load_data(emu: pgme_music_emu; const data: pointer; len: clong): gme_err_t; cdecl; external {$IFDEF GME_DYNAMIC}gmelib{$ENDIF};
 185
 186
 187 implementation
 188
 189
 190 end.