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         int n=0;
 117         struct ss_wave * w=NULL;
 118
 119         /* if off is NULL, point to the first layer */
 120         if(off == NULL) off=&n;
 121
 122         /* find a matching layer, starting from *off */
 123         for(;*off < i->n_layers;(*off)++)
 124         {
 125                 w=i->layers[*off];
 126
 127                 if(freq >= w->min_freq && freq <= w->max_freq)
 128                         break;
 129         }
 130
 131         /* passed the end; none found */
 132         if(*off == i->n_layers)
 133                 w=NULL;
 134         else
 135                 (*off)++;
 136
 137         return(w);
 138 }
 139
 140
 141 /**
 142  * ss_ins_set_channel - Sets the volume for an instrument's channel.
 143  * @i: the instrument
 144  * @channel: channel number
 145  * @vol: volume
 146  *
 147  * Sets the volume for an instrument's channel. If the channel does
 148  * not exist, it's created and space allocated for it in the volume and
 149  * effect dynamic arrays.
 150  */
 151 void ss_ins_set_channel(struct ss_ins * i, int channel, sample_t vol)
 152 {
 153         /* if channel is new, alloc space for it */
 154         if(channel <= i->n_channels)
 155         {
 156                 int n;
 157
 158                 GROW(i->vols, channel, sample_t);
 159                 GROW(i->effs, channel, struct ss_eff *);
 160
 161                 /* fill newly allocated space */
 162                 for(n=i->n_channels;n <= channel;n++)
 163                 {
 164                         i->vols[n]=1.0;
 165                         i->effs[n]=NULL;
 166                 }
 167
 168                 i->n_channels=channel + 1;
 169         }
 170
 171         /* store volume */
 172         i->vols[channel]=vol;
 173 }
 174
 175
 176 /**
 177  * ss_ins_set_sustain - Sets the sustain for an instrument.
 178  * @i: the instrument
 179  * @sustain: the sustain time in milliseconds
 180  *
 181  * Sets the sustain for an instrument. @sustain is expressed in
 182  * milliseconds.
 183  */
 184 void ss_ins_set_sustain(struct ss_ins * i, double sustain)
 185 {
 186         i->sustain=sustain;
 187 }
 188
 189
 190 /**
 191  * ss_ins_set_vibrato - Sets the vibrato for an instrument.
 192  * @i: the instrument
 193  * @depth: vibrato depth in msecs
 194  * @freq: vibrato frequency in Hzs
 195  *
 196  * Sets the vibrato for an instrument. @depth is expressed in
 197  * milliseconds and @freq in Hzs.
 198  */
 199 void ss_ins_set_vibrato(struct ss_ins * i, double depth, double freq)
 200 {
 201         i->vib_depth=depth;
 202         i->vib_freq=freq;
 203 }
 204
 205
 206 /**
 207  * ss_ins_play - Plays a note given the desired wave.
 208  * @i: the instrument
 209  * @freq: frequency
 210  * @vol: volume
 211  * @note_id: note id
 212  * @w: the wave
 213  *
 214  * Orders the instrument to start playing a note, given a specific wave.
 215  * The wave is usually one of the instrument's layers, but it doesn't
 216  * have to.
 217  *
 218  * Returns zero if there were no free generators, or non-zero otherwise.
 219  */
 220 int ss_ins_play(struct ss_ins * i, double freq, sample_t vol, int note_id,
 221         struct ss_wave * w)
 222 {
 223         struct ss_gen * g;
 224
 225         /* get a free generator, or fail */
 226         if((g=ss_gen_alloc(&i->gens)) == NULL)
 227                 return(0);
 228
 229         /* start the generator */
 230         ss_gen_play(g, freq, vol, note_id, w);
 231
 232         /* set sustain and vibrato */
 233         ss_gen_sustain(g, i->sustain);
 234         ss_gen_vibrato(g, i->vib_depth, i->vib_freq);
 235
 236         return(1);
 237 }
 238
 239
 240 /**
 241  * ss_ins_note_on - Plays a note.
 242  * @i: the instrument
 243  * @note: MIDI note to be played
 244  * @vol: note volume
 245  * @note_id: note id
 246  *
 247  * Locates a layer to play a note, and starts generators to
 248  * play it. The @note is expressed as a MIDI note and the
 249  * desired volume (from 0 to 1) stored in @vol. The note @id
 250  * should be a positive, unique identifier for this note; no two
 251  * simultaneously playing notes should share this id.
 252  *
 253  * Returns the number of generators that were activated.
 254  */
 255 int ss_ins_note_on(struct ss_ins * i, int note, sample_t vol, int note_id)
 256 {
 257         int n, g;
 258         struct ss_wave * w;
 259         double freq;
 260
 261         freq=ss_note_frequency(note);
 262
 263         for(n=g=0;(w=ss_ins_find_layer(i, freq, &n)) != NULL;g++)
 264         {
 265                 if(!ss_ins_play(i, freq, vol, note_id, w))
 266                         break;
 267         }
 268
 269         return(g);
 270 }
 271
 272
 273 /**
 274  * ss_ins_note_off - Releases a note.
 275  * @i: the instrument
 276  * @note_id: the id of the note to be released
 277  *
 278  * Releases a note. The generators associated to it will enter release mode.
 279  */
 280 void ss_ins_note_off(struct ss_ins * i, int note_id)
 281 {
 282         struct ss_gen * g;
 283
 284         /* releases all generators with that note_id */
 285         for(g=i->gens;g != NULL;g=g->next)
 286         {
 287                 if(g->note_id == note_id)
 288                         ss_gen_release(g);
 289         }
 290 }
 291
 292
 293 /**
 294  * ss_ins_frame - Generates a frame of samples.
 295  * @i: the instrument
 296  * @frame: array where the output samples will be stored
 297  *
 298  * Generates a frame of samples mixing all the active generators
 299  * of a track.
 300  */
 301 void ss_ins_frame(struct ss_ins * i, sample_t frame[])
 302 {
 303         struct ss_gen * g;
 304         struct ss_gen * t;
 305         int n;
 306         sample_t l_frame[SS_MAX_CHANNELS];
 307
 308         /* resets this local frame */
 309         ss_output_init_frame(l_frame);
 310
 311         /* loops through the generators */
 312         for(g=i->gens;g != NULL;g=t)
 313         {
 314                 t=g->next;
 315
 316                 /* if the generator has stopped, free it */
 317                 if(ss_gen_frame(g, i->n_channels, l_frame))
 318                         ss_gen_free(&i->gens, g);
 319         }
 320
 321         /* loops through the effects and remixes */
 322         for(n=0;n < i->n_channels;n++)
 323                 frame[n] += ss_eff_process(i->effs[n],
 324                         l_frame[n] * i->vols[n]);
 325 }