3 Ann Hell Ex Machina - Music Software
4 Copyright (C) 2003/2006 Angel Ortega <angel@triptico.com>
6 ss_ins.c - Software synthesizer's instruments
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.
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.
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.
22 http://www.triptico.com
44 * ss_ins_init - Initializes an instrument.
47 * Initializes an instrument structure.
49 void ss_ins_init(struct ss_ins
* i
)
51 memset(i
, '\0', sizeof(struct ss_ins
));
53 /* default channels: stereo left and right, full volume */
54 ss_ins_set_channel(i
, 0, 1.0);
55 ss_ins_set_channel(i
, 1, 1.0);
57 /* sustain shouldn't be 0 to avoid end of note clicks */
58 ss_ins_set_sustain(i
, 50.0);
59 ss_ins_set_vibrato(i
, 0.0, 0.0);
64 * ss_ins_add_layer - Adds a layer to an instrument.
66 * @w: wave describing the layer
68 * Adds a layer to an instrument.
70 * Returns 0 if the layer was added successfully.
72 void ss_ins_add_layer(struct ss_ins
* i
, struct ss_wave
* w
)
75 GROW(i
->layers
, i
->n_layers
, struct ss_wave
*);
77 i
->layers
[i
->n_layers
] = w
;
84 * ss_ins_find_layer - Finds a layer inside an instrument
86 * @freq: the desired frequency
87 * @off: pointer to element offset to start searching
89 * Finds a layer inside the @i instrument with a matching @freq, starting
90 * from the layer number pointed by @off. If a matching layer is found, its
91 * struct ss_wave is returned and @off is left pointing to the next layer
92 * (allowing it to be used as an enumerator). If no layer is found, NULL
95 struct ss_wave
* ss_ins_find_layer(struct ss_ins
* i
, double freq
, int * off
)
98 struct ss_wave
* w
= NULL
;
100 /* if off is NULL, point to the first layer */
101 if(off
== NULL
) off
= &n
;
103 /* find a matching layer, starting from *off */
104 for(;*off
< i
->n_layers
;(*off
)++)
108 if(freq
>= w
->min_freq
&& freq
<= w
->max_freq
)
112 /* passed the end; none found */
113 if(*off
== i
->n_layers
)
123 * ss_ins_set_channel - Sets the volume for an instrument's channel.
125 * @channel: channel number
128 * Sets the volume for an instrument's channel. If the channel does
129 * not exist, it's created and space allocated for it in the volume and
130 * effect dynamic arrays.
132 void ss_ins_set_channel(struct ss_ins
* i
, int channel
, sample_t vol
)
134 /* if channel is new, alloc space for it */
135 if(channel
<= i
->n_channels
)
139 GROW(i
->vols
, channel
, sample_t
);
140 GROW(i
->effs
, channel
, struct ss_eff
*);
142 /* fill newly allocated space */
143 for(n
= i
->n_channels
;n
<= channel
;n
++)
149 i
->n_channels
= channel
+ 1;
153 i
->vols
[channel
] = vol
;
158 * ss_ins_set_sustain - Sets the sustain for an instrument.
160 * @sustain: the sustain time in milliseconds
162 * Sets the sustain for an instrument. @sustain is expressed in
165 void ss_ins_set_sustain(struct ss_ins
* i
, double sustain
)
167 i
->sustain
= sustain
;
172 * ss_ins_set_vibrato - Sets the vibrato for an instrument.
174 * @depth: vibrato depth in msecs
175 * @freq: vibrato frequency in Hzs
177 * Sets the vibrato for an instrument. @depth is expressed in
178 * milliseconds and @freq in Hzs.
180 void ss_ins_set_vibrato(struct ss_ins
* i
, double depth
, double freq
)
182 i
->vib_depth
= depth
;
188 * ss_ins_play - Plays a note given the desired wave.
195 * Orders the instrument to start playing a note, given a specific wave.
196 * The wave is usually one of the instrument's layers, but it doesn't
199 * Returns zero if there were no free generators, or non-zero otherwise.
201 int ss_ins_play(struct ss_ins
* i
, double freq
, sample_t vol
, int note_id
,
206 /* get a free generator, or fail */
207 if((g
= ss_gen_alloc(&i
->gens
)) == NULL
)
210 /* start the generator */
211 ss_gen_play(g
, freq
, vol
, note_id
, w
);
213 /* set sustain and vibrato */
214 ss_gen_sustain(g
, i
->sustain
);
215 ss_gen_vibrato(g
, i
->vib_depth
, i
->vib_freq
);
222 * ss_ins_note_on - Plays a note.
224 * @note: MIDI note to be played
228 * Locates a layer to play a note, and starts generators to
229 * play it. The @note is expressed as a MIDI note and the
230 * desired volume (from 0 to 1) stored in @vol. The note @id
231 * should be a positive, unique identifier for this note; no two
232 * simultaneously playing notes should share this id.
234 * Returns the number of generators that were activated.
236 int ss_ins_note_on(struct ss_ins
* i
, int note
, sample_t vol
, int note_id
)
242 freq
= ss_note_frequency(note
);
244 for(n
= g
= 0;(w
=ss_ins_find_layer(i
, freq
, &n
)) != NULL
;g
++)
246 if(!ss_ins_play(i
, freq
, vol
, note_id
, w
))
255 * ss_ins_note_off - Releases a note.
257 * @note_id: the id of the note to be released
259 * Releases a note. The generators associated to it will enter release mode.
261 void ss_ins_note_off(struct ss_ins
* i
, int note_id
)
265 /* releases all generators with that note_id */
266 for(g
= i
->gens
;g
!= NULL
;g
= g
->next
)
268 if(g
->note_id
== note_id
)
275 * ss_ins_frame - Generates a frame of samples.
277 * @frame: array where the output samples will be stored
279 * Generates a frame of samples mixing all the active generators
282 void ss_ins_frame(struct ss_ins
* i
, sample_t frame
[])
287 sample_t l_frame
[SS_MAX_CHANNELS
];
289 /* resets this local frame */
290 ss_output_init_frame(l_frame
);
292 /* loops through the generators */
293 for(g
= i
->gens
;g
!= NULL
;g
= t
)
297 /* if the generator has stopped, free it */
298 if(ss_gen_frame(g
, i
->n_channels
, l_frame
))
299 ss_gen_free(&i
->gens
, g
);
302 /* loops through the effects and remixes */
303 for(n
= 0;n
< i
->n_channels
;n
++)
304 frame
[n
] += ss_eff_process(i
->effs
[n
],
305 l_frame
[n
] * i
->vols
[n
]);