instrument.h

   1 /*
   2
   3     Ann Hell Ex Machina - Music Software
   4     Copyright (C) 2003 Angel Ortega <angel@triptico.com>
   5
   6     This program is free software; you can redistribute it and/or
   7     modify it under the terms of the GNU General Public License
   8     as published by the Free Software Foundation; either version 2
   9     of the License, or (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  19
  20     http://www.triptico.com
  21
  22 */
  23
  24 #define NUM_NOTES               128
  25 #define VALID_NOTE(n)           ((n) >= 0 && (n) < NUM_NOTES)
  26
  27 #define LAY_PER_INSTR   32
  28 #define GEN_PER_INSTR   32
  29
  30 struct layer
  31 {
  32         int base_note;          /* base note */
  33         int min_note;           /* minimum note */
  34         int max_note;           /* maximum note */
  35
  36         int n_channels;         /* # of channels */
  37         float * wave[CHANNELS]; /* the PCM waves */
  38
  39         double size;            /* size in samples */
  40         double loop_start;      /* start of loop (-1, no loop) */
  41         double loop_end;        /* end of loop */
  42 };
  43
  44
  45 struct instrument
  46 {
  47         struct layer layers[LAY_PER_INSTR];     /* layers */
  48         int n_layers;                           /* # of layers */
  49         struct generator generators[GEN_PER_INSTR];     /* generators */
  50
  51         float vol[CHANNELS];                    /* channel map */
  52         int sustain;                            /* sustain */
  53
  54         int note_gen[NUM_NOTES];                /* generator / note index */
  55 };
  56
  57
  58 void build_note_frequencies(void);
  59
  60 void init_instrument(struct instrument * i);
  61
  62 int add_instrument_layer(struct instrument * i,
  63         int base_note, int min_note, int max_note,
  64         int n_channels, float * wave[],
  65         double size, double loop_start, double loop_end);
  66
  67 void instrument_set_channel_map(struct instrument * i,
  68         int n_channels, float vol[]);
  69 void instrument_set_sustain(struct instrument * i, int sustain);
  70
  71 int instrument_play_note(struct instrument * i, int note, float vol);
  72 int instrument_release_note(struct instrument * i, int note);
  73
  74 void generate_instrument(struct instrument * i, float sample[]);