generator.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 /*
  25
  26 generator modes:
  27
  28 GEN_MODE_PLAYING - Generator is generating sound after a call
  29         to generator_play(). If sound is not looped, jumps
  30         to GEN_MODE_ZOMBIE when the cursor reaches loop_end.
  31
  32 GEN_MODE_RELEASED - Generator is generating the sustain of a sound
  33         after a call to generator_release(). When the sustain
  34         ends, jumps to GEN_MODE_FREE.
  35
  36 GEN_MODE_ZOMBIE - Generator was playing a non-looped sound and the
  37         cursor got beyond loop_end. No sound is being generated.
  38         Waiting for a call to generator_release() to enter
  39         GEN_MODE_FREE immediately.
  40
  41 GEN_MODE_FREE - Generator is free to be used.
  42
  43 */
  44
  45 #define GEN_MODE_PLAYING        3
  46 #define GEN_MODE_RELEASED       2
  47 #define GEN_MODE_ZOMBIE         1
  48 #define GEN_MODE_FREE           0
  49
  50 struct generator
  51 {
  52         int mode;               /* GEN_MODE_* */
  53
  54         float * wave[CHANNELS]; /* the PCM waves */
  55         float vol[CHANNELS];    /* the volumes */
  56
  57         double size;            /* size in samples */
  58         double loop_start;      /* start of loop (-1, no loop) */
  59         double loop_end;        /* end of loop */
  60
  61         double inc;             /* increment (frequency) */
  62         double cursor;          /* offset to next sample */
  63
  64         int sustain;            /* number of samples to play after release */
  65         float dvol[CHANNELS];   /* volume decrement for each sample in sustain */
  66
  67         int portamento;         /* number of samples of portamento */
  68         double dest_inc;        /* final portamento inc */
  69         double dinc;            /* delta of inc */
  70 };
  71
  72
  73 int generator_play(struct generator * g,
  74         float * wave[], float vol[], double size, double inc,
  75         double loop_start, double loop_end, int sustain);
  76
  77 int generator_release(struct generator * g);
  78
  79 int generator(struct generator * g, float sample[]);
  80
  81 int generator_portamento(struct generator * g, int portamento,
  82         double dest_inc);