1 /* Copyright 2016 Jack Humbert
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation, either version 2 of the License, or
6 * (at your option) any later version.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 // these are imported from audio.c
21 extern uint16_t envelope_index;
22 extern float note_timbre;
23 extern float polyphony_rate;
24 extern bool glissando;
26 voice_type voice = default_voice;
28 void set_voice(voice_type v) {
32 void voice_iterate() {
33 voice = (voice + 1) % number_of_voices;
36 void voice_deiterate() {
37 voice = (voice - 1 + number_of_voices) % number_of_voices;
40 float voice_envelope(float frequency) {
41 // envelope_index ranges from 0 to 0xFFFF, which is preserved at 880.0 Hz
42 __attribute__ ((unused))
43 uint16_t compensated_index = (uint16_t)((float)envelope_index * (880.0 / frequency));
48 note_timbre = TIMBRE_50;
57 switch (compensated_index) {
59 note_timbre = TIMBRE_12;
63 note_timbre = TIMBRE_25;
67 note_timbre = .125 + .125;
79 // switch (compensated_index) {
84 // note_timbre = 0.5 * (21 - compensated_index) / 10;
90 // frequency = (rand() % (int)(frequency * 1.2 - frequency)) + (frequency * 0.8);
92 if (frequency < 80.0) {
94 } else if (frequency < 160.0) {
96 // Bass drum: 60 - 100 Hz
97 frequency = (rand() % (int)(40)) + 60;
98 switch (envelope_index) {
103 note_timbre = 0.5 * (21 - envelope_index) / 10;
110 } else if (frequency < 320.0) {
113 // Snare drum: 1 - 2 KHz
114 frequency = (rand() % (int)(1000)) + 1000;
115 switch (envelope_index) {
120 note_timbre = 0.5 * (21 - envelope_index) / 15;
127 } else if (frequency < 640.0) {
129 // Closed Hi-hat: 3 - 5 KHz
130 frequency = (rand() % (int)(2000)) + 3000;
131 switch (envelope_index) {
136 note_timbre = 0.5 * (21 - envelope_index) / 5;
143 } else if (frequency < 1280.0) {
145 // Open Hi-hat: 3 - 5 KHz
146 frequency = (rand() % (int)(2000)) + 3000;
147 switch (envelope_index) {
152 note_timbre = 0.5 * (51 - envelope_index) / 15;
164 switch (compensated_index) {
166 frequency = frequency / 4;
167 note_timbre = TIMBRE_12;
171 frequency = frequency / 2;
172 note_timbre = TIMBRE_12;
176 note_timbre = .125 - pow(((float)compensated_index - 20) / (200 - 20), 2)*.125;
185 // case octave_crunch:
186 // polyphony_rate = 0;
187 // switch (compensated_index) {
191 // frequency = frequency / 2;
192 // note_timbre = TIMBRE_12;
198 // frequency = frequency * 2;
199 // note_timbre = TIMBRE_12;
203 // note_timbre = TIMBRE_12;
209 // This slows the loop down a substantial amount, so higher notes may freeze
212 switch (compensated_index) {
217 // note_timbre = (sin((float)compensated_index/10000*OCS_SPEED) * OCS_AMP / 2) + .5;
218 // triangle wave is a bit faster
219 note_timbre = (float)abs((compensated_index*OCS_SPEED % 3000) - 1500) * ( OCS_AMP / 1500 ) + (1 - OCS_AMP) / 2;
224 case duty_octave_down:
227 note_timbre = (envelope_index % 2) * .125 + .375 * 2;
228 if ((envelope_index % 4) == 0)
230 if ((envelope_index % 8) == 0)
233 case delayed_vibrato:
236 note_timbre = TIMBRE_50;
237 #define VOICE_VIBRATO_DELAY 150
238 #define VOICE_VIBRATO_SPEED 50
239 switch (compensated_index) {
240 case 0 ... VOICE_VIBRATO_DELAY:
243 frequency = frequency * vibrato_lut[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
247 // case delayed_vibrato_octave:
248 // polyphony_rate = 0;
249 // if ((envelope_index % 2) == 1) {
250 // note_timbre = 0.55;
252 // note_timbre = 0.45;
254 // #define VOICE_VIBRATO_DELAY 150
255 // #define VOICE_VIBRATO_SPEED 50
256 // switch (compensated_index) {
257 // case 0 ... VOICE_VIBRATO_DELAY:
260 // frequency = frequency * VIBRATO_LUT[(int)fmod((((float)compensated_index - (VOICE_VIBRATO_DELAY + 1))/1000*VOICE_VIBRATO_SPEED), VIBRATO_LUT_LENGTH)];
264 // case duty_fifth_down:
265 // note_timbre = 0.5;
266 // if ((envelope_index % 3) == 0)
267 // note_timbre = 0.75;
269 // case duty_fourth_down:
270 // note_timbre = 0.0;
271 // if ((envelope_index % 12) == 0)
272 // note_timbre = 0.75;
273 // if (((envelope_index % 12) % 4) != 1)
274 // note_timbre = 0.75;
276 // case duty_third_down:
277 // note_timbre = 0.5;
278 // if ((envelope_index % 5) == 0)
279 // note_timbre = 0.75;
281 // case duty_fifth_third_down:
282 // note_timbre = 0.5;
283 // if ((envelope_index % 5) == 0)
284 // note_timbre = 0.75;
285 // if ((envelope_index % 3) == 0)
286 // note_timbre = 0.25;