Clemens Valens / SoundEngine

This is a part of the Kinetiszer project.

Dependencies:   inc

Dependents:   kinetisizer

lfo.c@1:8ae4ab73ca6a, 2014-10-28 (annotated)

Committer:
Clemo
Date:
Tue Oct 28 20:09:12 2014 +0000
Revision:
1:8ae4ab73ca6a
Parent:
0:cb80470434eb 
First publication (untested)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Clemo 0:cb80470434eb 1 /*
Clemo 0:cb80470434eb 2 Copyright 2013 Paul Soulsby www.soulsbysynths.com
Clemo 0:cb80470434eb 3 This file is part of Atmegatron.
Clemo 0:cb80470434eb 4
Clemo 0:cb80470434eb 5 Atmegatron is free software: you can redistribute it and/or modify
Clemo 0:cb80470434eb 6 it under the terms of the GNU General Public License as published by
Clemo 0:cb80470434eb 7 the Free Software Foundation, either version 3 of the License, or
Clemo 0:cb80470434eb 8 (at your option) any later version.
Clemo 0:cb80470434eb 9
Clemo 0:cb80470434eb 10 Atmegatron is distributed in the hope that it will be useful,
Clemo 0:cb80470434eb 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
Clemo 0:cb80470434eb 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
Clemo 0:cb80470434eb 13 GNU General Public License for more details.
Clemo 0:cb80470434eb 14
Clemo 0:cb80470434eb 15 You should have received a copy of the GNU General Public License
Clemo 0:cb80470434eb 16 along with Atmegatron. If not, see <http://www.gnu.org/licenses/>.
Clemo 0:cb80470434eb 17 */
Clemo 0:cb80470434eb 18
Clemo 0:cb80470434eb 19 //**********Bipolar LFO. 16 waveforms, each 64 samples long.***************
Clemo 0:cb80470434eb 20
Clemo 0:cb80470434eb 21 #include "atmegatron.h"
Clemo 0:cb80470434eb 22
Clemo 0:cb80470434eb 23 //lfo waveforms store in PROGMEM
Clemo 0:cb80470434eb 24 const signed char lfo_store[16][LFO_LEN] =
Clemo 0:cb80470434eb 25 {
Clemo 0:cb80470434eb 26 {0,12,25,37,49,60,71,81,90,98,106,112,117,122,125,126,127,126,125,122,117,112,106,98,90,81,71,60,49,37,25,12,0,-12,-25,-37,-49,-60,-71,-81,-90,-98,-106,-112,-117,-122,-125,-126,-127,-126,-125,-122,-117,-112,-106,-98,-90,-81,-71,-60,-49,-37,-25,-12}, //sine
Clemo 0:cb80470434eb 27 {0,8,16,24,32,40,48,56,64,71,79,87,95,103,111,119,127,119,111,103,95,87,79,71,64,56,48,40,32,24,16,8,0,-8,-16,-24,-32,-40,-48,-56,-64,-71,-79,-87,-95,-103,-111,-119,-127,-119,-111,-103,-95,-87,-79,-71,-64,-56,-48,-40,-32,-24,-16,-8}, //triangle
Clemo 0:cb80470434eb 28 {127,123,119,115,111,107,103,99,95,91,87,83,79,75,71,67,64,60,56,52,48,44,40,36,32,28,24,20,16,12,8,4,0,-4,-8,-12,-16,-20,-24,-28,-32,-36,-40,-44,-48,-52,-56,-60,-64,-67,-71,-75,-79,-83,-87,-91,-95,-99,-103,-107,-111,-115,-119,-123}, //saw down
Clemo 0:cb80470434eb 29 {-127,-127,-127,-127,-127,-126,-126,-126,-126,-126,-126,-125,-125,-125,-125,-124,-124,-124,-123,-123,-122,-122,-121,-121,-120,-119,-118,-118,-117,-116,-115,-113,-112,-111,-109,-107,-105,-103,-101,-99,-96,-93,-90,-87,-83,-79,-74,-69,-64,-58,-52,-45,-37,-29,-20,-11,0,12,24,38,53,69,87,107}, //Exponential ramp up
Clemo 0:cb80470434eb 30 {0,25,48,70,88,102,112,118,120,118,114,108,101,95,89,86,85,86,89,95,101,108,114,118,120,118,112,102,88,70,48,25,0,-25,-48,-70,-88,-102,-112,-118,-120,-118,-114,-108,-101,-95,-89,-86,-85,-86,-89,-95,-101,-108,-114,-118,-120,-118,-112,-102,-88,-70,-48,-25}, //3rd sine harmonics
Clemo 0:cb80470434eb 31 {127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127}, //5%
Clemo 0:cb80470434eb 32 {127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127}, //25%
Clemo 0:cb80470434eb 33 {127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127}, //50%
Clemo 0:cb80470434eb 34 {127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127}, //75%
Clemo 0:cb80470434eb 35 {127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,-127,-127,-127,-127}, //95%
Clemo 0:cb80470434eb 36 {0,4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,67,71,75,79,83,87,91,95,99,103,107,111,115,119,123,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127}, //Ramp up and hold
Clemo 0:cb80470434eb 37 {127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,123,119,115,111,107,103,99,95,91,87,83,79,75,71,67,64,60,56,52,48,44,40,36,32,28,24,20,16,12,8,4}, //Hold and ramp down
Clemo 0:cb80470434eb 38 {127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,-127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127}, //duh dugga
Clemo 0:cb80470434eb 39 {127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,-127,-127,-127,-127,-127,-127,-127,-127}, //dugga duh
Clemo 0:cb80470434eb 40 {-104,-72,-14,91,-35,38,-20,-21,83,47,22,-73,-111,-104,-28,27,79,25,34,-112,-45,20,36,-30,-124,-74,-95,56,63,-91,94,78,-121,-27,49,-110,-25,24,-9,11,-80,65,-10,-56,-101,116,105,58,-67,-108,-127,95,-71,88,54,-2,83,109,-37,59,40,-77,84,-28}, //noise
Clemo 0:cb80470434eb 41 {127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127} //DC offset //95%
Clemo 0:cb80470434eb 42 };
Clemo 0:cb80470434eb 43 unsigned long lfo_ticklen = 500; //ticks per LFO cycle. only used when MIDI clock not present. default = 500 ticks, therefore 1 cycle per beat
Clemo 0:cb80470434eb 44 unsigned long lfo_clockticklen = 24; //clock ticks per LFO cylcle. only used when MIDI clock present. 24 ticks per beat, therefore 1 cycle per beat
Clemo 0:cb80470434eb 45 unsigned long lfo_starttick = 0; //tick lfo starts oscillating at
Clemo 0:cb80470434eb 46 unsigned long lfo_curtick = 0; //cur tick of lfo
Clemo 0:cb80470434eb 47
Clemo 0:cb80470434eb 48 //lets and gets
Clemo 0:cb80470434eb 49 unsigned int lfo_speed = 8191; //speed of lfo. not actual ticks, just a reference in a lookup table that is then divided to equal actual ticks.
Clemo 0:cb80470434eb 50 byte lfo_curtable = 0; //current lfo waveform
Clemo 0:cb80470434eb 51 boolean lfo_invert = false; //lfo invert mode
Clemo 0:cb80470434eb 52 signed char lfo_level = 0; //lfo output (-127 - 127)
Clemo 0:cb80470434eb 53
Clemo 0:cb80470434eb 54 //lets and gets
Clemo 0:cb80470434eb 55 //LFO speed. Stored as a lookup table of multipliers, not actual ticks
Clemo 0:cb80470434eb 56 void LFO_Let_Speed(unsigned int newspeed)
Clemo 0:cb80470434eb 57 {
Clemo 0:cb80470434eb 58 lfo_speed = newspeed;
Clemo 0:cb80470434eb 59 lfo_ticklen = ((unsigned long)lfo_speed+1) * MASTER_BEATTICK >> 13; //Calculate lfo tick length. This method is a way of calculating ticks without using slow (and memory consuming) floating point maths. e.g. 1 cycle per beat = 8192 * 500 >> 13 = 500
Clemo 0:cb80470434eb 60 if (lfo_ticklen<2){
Clemo 0:cb80470434eb 61 lfo_ticklen = 2; //Speed must be 2 or great otherwise divide by 0 in LFO_calcval
Clemo 0:cb80470434eb 62 }
Clemo 0:cb80470434eb 63 lfo_clockticklen = ((unsigned long)lfo_speed+1) * 24 >> 13; //same as above, this time for when MIDI clock is present
Clemo 0:cb80470434eb 64 if (lfo_clockticklen<2){
Clemo 0:cb80470434eb 65 lfo_clockticklen = 2; //Speed must be 2 or great otherwise divide by 0 in LFO_calcval
Clemo 0:cb80470434eb 66 }
Clemo 0:cb80470434eb 67 }
Clemo 0:cb80470434eb 68 unsigned int LFO_Get_Speed(void)
Clemo 0:cb80470434eb 69 {
Clemo 0:cb80470434eb 70 return lfo_speed;
Clemo 0:cb80470434eb 71 }
Clemo 0:cb80470434eb 72 //set and get lfo waveform
Clemo 0:cb80470434eb 73 void LFO_Let_Type(byte newtable)
Clemo 0:cb80470434eb 74 {
Clemo 0:cb80470434eb 75 lfo_curtable = newtable;
Clemo 0:cb80470434eb 76 }
Clemo 0:cb80470434eb 77 byte LFO_Get_Type(void)
Clemo 0:cb80470434eb 78 {
Clemo 0:cb80470434eb 79 return lfo_curtable;
Clemo 0:cb80470434eb 80 }
Clemo 0:cb80470434eb 81 //set and get invert mode
Clemo 0:cb80470434eb 82 void LFO_Let_Invert(boolean newinv)
Clemo 0:cb80470434eb 83 {
Clemo 0:cb80470434eb 84 lfo_invert = newinv;
Clemo 0:cb80470434eb 85 }
Clemo 0:cb80470434eb 86 boolean LFO_Get_Invert(void)
Clemo 0:cb80470434eb 87 {
Clemo 0:cb80470434eb 88 return lfo_invert;
Clemo 0:cb80470434eb 89 }
Clemo 0:cb80470434eb 90 //return current lfo level (-127 - 127)
Clemo 0:cb80470434eb 91 signed char LFO_Get_Level(void)
Clemo 0:cb80470434eb 92 {
Clemo 0:cb80470434eb 93 if (lfo_invert==true){
Clemo 0:cb80470434eb 94 return -lfo_level; //invert output if invert mode on
Clemo 0:cb80470434eb 95 }
Clemo 0:cb80470434eb 96 else{
Clemo 0:cb80470434eb 97 return lfo_level;
Clemo 0:cb80470434eb 98 }
Clemo 0:cb80470434eb 99 }
Clemo 0:cb80470434eb 100
Clemo 0:cb80470434eb 101 //LFO meat
Clemo 0:cb80470434eb 102 //reset lfo start tick. lfo is reset when first key is pressed
Clemo 0:cb80470434eb 103 void LFO_Reset(void)
Clemo 0:cb80470434eb 104 {
Clemo 0:cb80470434eb 105 if (MIDI_Get_ClockPresent()==false){
Clemo 0:cb80470434eb 106 lfo_starttick = master_tick;
Clemo 0:cb80470434eb 107 }
Clemo 0:cb80470434eb 108 }
Clemo 0:cb80470434eb 109 //calculate the current output of the lfo
Clemo 0:cb80470434eb 110 void LFO_CalcVal(void)
Clemo 0:cb80470434eb 111 {
Clemo 0:cb80470434eb 112 unsigned long pos;
Clemo 0:cb80470434eb 113 int index;
Clemo 0:cb80470434eb 114 //char lfoval;
Clemo 0:cb80470434eb 115 if (MIDI_Get_ClockPresent()==false){ //if midi clock not used:
Clemo 0:cb80470434eb 116 lfo_curtick = master_tick - lfo_starttick; //get ticks since lfo started
Clemo 0:cb80470434eb 117 pos = lfo_curtick % lfo_ticklen; //calculate position within cycle in ticks
Clemo 0:cb80470434eb 118 index = (pos * LFO_LEN) / lfo_ticklen; //convert to position within wavetable array
Clemo 0:cb80470434eb 119 }
Clemo 0:cb80470434eb 120 else{
Clemo 0:cb80470434eb 121 pos = MIDI_Get_ClockTick() % lfo_clockticklen; //calculate position within cycle in clock ticks
Clemo 0:cb80470434eb 122 index = (pos * LFO_LEN) / lfo_clockticklen; //convert to position within wavetable array
Clemo 0:cb80470434eb 123 }
Clemo 0:cb80470434eb 124 lfo_level = lfo_store[lfo_curtable][index]; //set lfo level
Clemo 0:cb80470434eb 125 }
Clemo 0:cb80470434eb 126