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 "annhell.h"
  34
  35 /*******************
  36         Data
  37 ********************/
  38
  39 /*******************
  40         Code
  41 ********************/
  42
  43 /* grows a dynamic array */
  44 #define GROW(b,n,t) b=(t *)realloc(b,((n) + 1) * sizeof(t))
  45
  46 /**
  47  * ss_ins_init - Initializes an instrument.
  48  * @i: the instrument
  49  *
  50  * Initializes an instrument structure.
  51  */
  52 void ss_ins_init(struct ss_ins * i)
  53 {
  54         memset(i, '\0', sizeof(struct ss_ins));
  55
  56         /* default channels: stereo left and right, full volume */
  57         ss_ins_set_channel(i, 0, 1.0);
  58         ss_ins_set_channel(i, 1, 1.0);
  59
  60         /* sustain shouldn't be 0 to avoid end of note clicks */
  61         ss_ins_set_sustain(i, 50.0);
  62         ss_ins_set_vibrato(i, 0.0, 0.0);
  63 }
  64
  65
  66 /**
  67  * ss_ins_add_layer - Adds a layer to an instrument.
  68  * @i: the instrument
  69  * @w: wave describing the layer
  70  *
  71  * Adds a layer to an instrument.
  72  *
  73  * Returns 0 if the layer was added successfully.
  74  */
  75 void ss_ins_add_layer(struct ss_ins * i, struct ss_wave * w)
  76 {
  77         /* grow layers */
  78         GROW(i->layers, i->n_layers, struct ss_wave *);
  79
  80         i->layers[i->n_layers]=w;
  81
  82         i->n_layers++;
  83 }
  84
  85
  86 /**
  87  * ss_ins_copy_layers - Copies all layers from an instrument into another
  88  * @i: the destination instrument
  89  * @o: the source instrument
  90  *
  91  * Copies all layers inside the @o instrument into @i.
  92  */
  93 void ss_ins_copy_layers(struct ss_ins * i, struct ss_ins * o)
  94 {
  95         int n;
  96
  97         for(n=0;n < o->n_layers;n++)
  98                 ss_ins_add_layer(i, o->layers[n]);
  99 }
 100
 101
 102 /**
 103  * ss_ins_find_layer - Finds a layer inside an instrument
 104  * @i: the instrument
 105  * @freq: the desired frequency
 106  * @off: pointer to element offset to start searching
 107  *
 108  * Finds a layer inside the @i instrument with a matching @freq, starting
 109  * from the layer number pointed by @off. If a matching layer is found, its
 110  * struct ss_wave is returned and @off is left pointing to the next layer
 111  * (allowing it to be used as an enumerator). If no layer is found, NULL
 112  * is returned.
 113  */
 114 struct ss_wave * ss_ins_find_layer(struct ss_ins * i, double freq, int * off)
 115 {
 116         struct ss_wave * w=NULL;
 117
 118         /* find a matching layer, starting from *off */
 119         for(;*off < i->n_layers;(*off)++)
 120         {
 121                 w=i->layers[*off];
 122
 123                 if(freq >= w->min_freq && freq <= w->max_freq)
 124                         break;
 125         }
 126
 127         /* passed the end; none found */
 128         if(*off == i->n_layers)
 129                 w=NULL;
 130         else
 131                 (*off)++;
 132
 133         return(w);
 134 }
 135
 136
 137 /**
 138  * ss_ins_set_channel - Sets the volume for an instrument's channel.
 139  * @i: the instrument
 140  * @channel: channel number
 141  * @vol: volume
 142  *
 143  * Sets the volume for an instrument's channel. If the channel does
 144  * not exist, it's created and space allocated for it in the volume and
 145  * effect dynamic arrays.
 146  */
 147 void ss_ins_set_channel(struct ss_ins * i, int channel, float vol)
 148 {
 149         /* if channel is new, alloc space for it */
 150         if(channel <= i->n_channels)
 151         {
 152                 int n;
 153
 154                 GROW(i->vols, channel, float);
 155                 GROW(i->effs, channel, struct ss_eff *);
 156
 157                 /* fill newly allocated space */
 158                 for(n=i->n_channels;n <= channel;n++)
 159                 {
 160                         i->vols[n]=1.0;
 161                         i->effs[n]=NULL;
 162                 }
 163
 164                 i->n_channels=channel + 1;
 165         }
 166
 167         /* store volume */
 168         i->vols[channel]=vol;
 169 }
 170
 171
 172 /**
 173  * ss_ins_set_sustain - Sets the sustain for an instrument.
 174  * @i: the instrument
 175  * @sustain: the sustain time in milliseconds
 176  *
 177  * Sets the sustain for an instrument. @sustain is expressed in
 178  * milliseconds.
 179  */
 180 void ss_ins_set_sustain(struct ss_ins * i, double sustain)
 181 {
 182         i->sustain=sustain;
 183 }
 184
 185
 186 /**
 187  * ss_ins_set_vibrato - Sets the vibrato for an instrument.
 188  * @i: the instrument
 189  * @depth: vibrato depth in msecs
 190  * @freq: vibrato frequency in Hzs
 191  *
 192  * Sets the vibrato for an instrument. @depth is expressed in
 193  * milliseconds and @freq in Hzs.
 194  */
 195 void ss_ins_set_vibrato(struct ss_ins * i, double depth, double freq)
 196 {
 197         i->vib_depth=depth;
 198         i->vib_freq=freq;
 199 }
 200
 201
 202 /**
 203  * ss_ins_play - Plays a note given the desired wave.
 204  * @i: the instrument
 205  * @freq: frequency
 206  * @vol: volume
 207  * @note_id: note id
 208  * @w: the wave
 209  *
 210  * Orders the instrument to start playing a note, given a specific wave.
 211  * The wave is usually one of the instrument's layers, but it doesn't
 212  * have to.
 213  *
 214  * Returns zero if there were no free generators, or non-zero otherwise.
 215  */
 216 int ss_ins_play(struct ss_ins * i, double freq, float vol, int note_id,
 217         struct ss_wave * w)
 218 {
 219         struct ss_gen * g;
 220
 221         /* get a free generator, or fail */
 222         if((g=ss_gen_alloc(&i->gens)) == NULL)
 223                 return(0);
 224
 225         /* start the generator */
 226         ss_gen_play(g, freq, vol, note_id, w);
 227
 228         /* set sustain and vibrato */
 229         ss_gen_sustain(g, i->sustain);
 230         ss_gen_vibrato(g, i->vib_depth, i->vib_freq);
 231
 232         return(1);
 233 }
 234
 235
 236 /**
 237  * ss_ins_note_on - Plays a note.
 238  * @i: the instrument
 239  * @note: MIDI note to be played
 240  * @vol: note volume
 241  * @note_id: note id
 242  *
 243  * Locates a layer to play a note, and starts generators to
 244  * play it. The @note is expressed as a MIDI note and the
 245  * desired volume (from 0 to 1) stored in @vol. The note @id
 246  * should be a positive, unique identifier for this note; no two
 247  * simultaneously playing notes should share this id.
 248  *
 249  * Returns the number of generators that were activated.
 250  */
 251 int ss_ins_note_on(struct ss_ins * i, int note, float vol, int note_id)
 252 {
 253         int n, g;
 254         struct ss_wave * w;
 255         double freq;
 256
 257         freq=ss_note_frequency(note);
 258
 259         for(n=g=0;(w=ss_ins_find_layer(i, freq, &n)) != NULL;g++)
 260         {
 261                 if(!ss_ins_play(i, freq, vol, note_id, w))
 262                         break;
 263         }
 264
 265         return(g);
 266 }
 267
 268
 269 /**
 270  * ss_ins_note_off - Releases a note.
 271  * @i: the instrument
 272  * @note_id: the id of the note to be released
 273  *
 274  * Releases a note. The generators associated to it will enter release mode.
 275  */
 276 void ss_ins_note_off(struct ss_ins * i, int note_id)
 277 {
 278         struct ss_gen * g;
 279
 280         /* releases all generators with that note_id */
 281         for(g=i->gens;g != NULL;g=g->next)
 282         {
 283                 if(g->note_id == note_id)
 284                         ss_gen_release(g);
 285         }
 286 }
 287
 288
 289 /**
 290  * ss_ins_frame - Generates a frame of samples.
 291  * @i: the instrument
 292  * @frame: array where the output samples will be stored
 293  *
 294  * Generates a frame of samples mixing all the active generators
 295  * of a track.
 296  */
 297 void ss_ins_frame(struct ss_ins * i, float frame[])
 298 {
 299         struct ss_gen * g;
 300         struct ss_gen * t;
 301         int n;
 302         float l_frame[SS_MAX_CHANNELS];
 303
 304         /* resets this local frame */
 305         ss_output_init_frame(l_frame);
 306
 307         /* loops through the generators */
 308         for(g=i->gens;g != NULL;g=t)
 309         {
 310                 t=g->next;
 311
 312                 /* if the generator has stopped, free it */
 313                 if(ss_gen_frame(g, i->n_channels, l_frame))
 314                         ss_gen_free(&i->gens, g);
 315         }
 316
 317         /* loops through the effects and remixes */
 318         for(n=0;n < i->n_channels;n++)
 319                 frame[n] += ss_eff_process(i->effs[n],
 320                         l_frame[n] * i->vols[n]);
 321 }