ss_ins.c

   1 /*
   2
   3     Ann Hell Ex Machina - Music Software
   4     Copyright (C) 2003/2005 Angel Ortega <angel@triptico.com>
   5
   6     ss_ins.c - Software synthesizer's instruments
   7
   8     This program is free software; you can redistribute it and/or
   9     modify it under the terms of the GNU General Public License
  10     as published by the Free Software Foundation; either version 2
  11     of the License, or (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21
  22     http://www.triptico.com
  23
  24 */
  25
  26 #include "config.h"
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <math.h>
  32
  33 #include "ss_core.h"
  34 #include "ss_gen.h"
  35 #include "ss_eff.h"
  36 #include "ss_ins.h"
  37 #include "ss_output.h"
  38
  39 /*******************
  40         Data
  41 ********************/
  42
  43 /*******************
  44         Code
  45 ********************/
  46
  47 /* grows a dynamic array */
  48 #define GROW(b,n,t) b=(t *)realloc(b,((n) + 1) * sizeof(t))
  49
  50 /**
  51  * ss_ins_init - Initializes an instrument.
  52  * @i: the instrument
  53  *
  54  * Initializes an instrument structure.
  55  */
  56 void ss_ins_init(struct ss_ins * i)
  57 {
  58         memset(i, '\0', sizeof(struct ss_ins));
  59
  60         /* default channels: stereo left and right, full volume */
  61         ss_ins_set_channel(i, 0, 1.0);
  62         ss_ins_set_channel(i, 1, 1.0);
  63
  64         /* sustain shouldn't be 0 to avoid end of note clicks */
  65         ss_ins_set_sustain(i, 50.0);
  66 }
  67
  68
  69 /**
  70  * ss_ins_add_layer - Adds a layer to an instrument.
  71  * @i: the instrument
  72  * @w: wave describing the layer
  73  *
  74  * Adds a layer to an instrument.
  75  *
  76  * Returns 0 if the layer was added successfully.
  77  */
  78 void ss_ins_add_layer(struct ss_ins * i, struct ss_wave * w)
  79 {
  80         /* grow layers */
  81         GROW(i->layers, i->n_layers, struct ss_wave *);
  82
  83         i->layers[i->n_layers]=w;
  84
  85         i->n_layers++;
  86 }
  87
  88
  89 /**
  90  * ss_ins_set_channel - Sets the volume for an instrument's channel.
  91  * @i: the instrument
  92  * @channel: channel number
  93  * @vol: volume
  94  *
  95  * Sets the volume for an instrument's channel. If the channel does
  96  * not exist, it's created and space allocated for it in the volume and
  97  * effect dynamic arrays.
  98  */
  99 void ss_ins_set_channel(struct ss_ins * i, int channel, float vol)
 100 {
 101         /* if channel is new, alloc space for it */
 102         if(channel <= i->n_channels)
 103         {
 104                 int n;
 105
 106                 GROW(i->vols, channel, float);
 107                 GROW(i->effs, channel, struct ss_eff *);
 108
 109                 /* fill newly allocated space */
 110                 for(n=i->n_channels;n <= channel;n++)
 111                 {
 112                         i->vols[n]=1.0;
 113                         i->effs[n]=NULL;
 114                 }
 115
 116                 i->n_channels=channel + 1;
 117         }
 118
 119         /* store volume */
 120         i->vols[channel]=vol;
 121 }
 122
 123
 124 /**
 125  * ss_ins_set_sustain - Sets the sustain for an instrument.
 126  * @i: the instrument
 127  * @sustain: the sustain time in milliseconds
 128  *
 129  * Sets the sustain for an instrument. @sustain is expressed in
 130  * milliseconds.
 131  */
 132 void ss_ins_set_sustain(struct ss_ins * i, double sustain)
 133 {
 134         i->sustain=sustain;
 135 }
 136
 137
 138 /**
 139  * ss_ins_note_on - Plays a note.
 140  * @i: the instrument
 141  * @note: MIDI note to be played
 142  * @vol: note volume
 143  * @note_id: note id
 144  *
 145  * Locates a layer to play a note, and starts generators to
 146  * play it. The @note is expressed as a MIDI note and the
 147  * desired volume (from 0 to 1) stored in @vol. The note @id
 148  * should be a positive, unique identifier for this note; no two
 149  * simultaneously playing notes should share this id.
 150  *
 151  * Returns the number of generators that were activated.
 152  */
 153 int ss_ins_note_on(struct ss_ins * i, int note, float vol, int note_id)
 154 {
 155         int n;
 156         struct ss_wave * w;
 157         double note_freq;
 158         int notes=0;
 159         struct ss_gen * g;
 160
 161         note_freq=ss_note_frequency(note);
 162
 163         /* loop layers */
 164         for(n=0;n < i->n_layers;n++)
 165         {
 166                 w=i->layers[n];
 167
 168                 if(note_freq < w->min_freq || note_freq > w->max_freq)
 169                         continue;
 170
 171                 /* get a free generator, or fail */
 172                 if((g=ss_gen_alloc(&i->gens)) == NULL)
 173                         break;
 174
 175                 /* start the generator */
 176                 ss_gen_play(g, note_freq, vol, note_id, w);
 177
 178                 /* set sustain */
 179                 ss_gen_sustain(g, i->sustain);
 180 #if 0
 181                 /* TEST: portamento */
 182                 if(i->trk_id == 2)
 183                         g->portamento=-0.000001;
 184 #endif
 185                 notes++;
 186         }
 187
 188         return(notes);
 189 }
 190
 191
 192 /**
 193  * ss_ins_note_off - Releases a note.
 194  * @i: the instrument
 195  * @note_id: the id of the note to be released
 196  *
 197  * Releases a note. The generators associated to it will enter release mode.
 198  */
 199 void ss_ins_note_off(struct ss_ins * i, int note_id)
 200 {
 201         struct ss_gen * g;
 202
 203         /* releases all generators with that note_id */
 204         for(g=i->gens;g != NULL;g=g->next)
 205         {
 206                 if(g->note_id == note_id)
 207                         ss_gen_release(g);
 208         }
 209 }
 210
 211
 212 /**
 213  * ss_ins_frame - Generates a frame of samples.
 214  * @i: the instrument
 215  * @frame: array where the output samples will be stored
 216  *
 217  * Generates a frame of samples mixing all the active generators
 218  * of a track.
 219  */
 220 void ss_ins_frame(struct ss_ins * i, float frame[])
 221 {
 222         struct ss_gen * g;
 223         struct ss_gen * t;
 224         int n;
 225         float l_frame[SS_MAX_CHANNELS];
 226
 227         /* resets this local frame */
 228         ss_output_init_frame(l_frame);
 229
 230         /* loops through the generators */
 231         for(g=i->gens;g != NULL;g=t)
 232         {
 233                 t=g->next;
 234
 235                 /* if the generator has stopped, free it */
 236                 if(ss_gen_frame(g, i->n_channels, l_frame))
 237                         ss_gen_free(&i->gens, g);
 238         }
 239
 240         /* loops through the effects and remixes */
 241         for(n=0;n < i->n_channels;n++)
 242                 frame[n] += ss_eff_process(i->effs[n],
 243                         l_frame[n] * i->vols[n]);
 244 }