NumbSin

#include "FastLED.h"

#define NUM_LEDS 60
#define DATA_PIN 6
#define POT_PIN A1
#define buttonPin 10
int sinVal = 0; // global for numbSin()
int buttonState = 0; // I bet you can guess what this is for


int palette[]={109,132}; // an array to hold colro values
int paletteCt = (sizeof(palette) / sizeof(palette[0]));  // count palette values


CRGB leds[NUM_LEDS]; // Define the array of leds

void setup() {
      FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);
      FastLED.clear();
      FastLED.show();
      Serial.begin(9600);
      pinMode(buttonPin, INPUT);

}

void loop() {
  buttonState = digitalRead(buttonPin); //read the state of the button
  palette[paletteCt-1] = potmap(); //assign the mapped malue from the pot to the last position in the array
  if(buttonState==HIGH) palette[paletteCt-2] = potmap(); // if the button is down, set the second to last position in the array to the current pot value
  leds[numbSin(NUM_LEDS,500,0,0)]=CHSV(palette[random(paletteCt)],255,random(10,80)); // pick the current led using the numbSin funtion, set the color to a random palette position, fully saturated with clamped random brightness
  Serial.println(numbSin(NUM_LEDS,500,0,0)); // for some reason calling this a second time fixes everything
  FastLED.show(); // display what is currently in the led array
}

int potmap(){ // map a reading from to pot to 0-255
  int sensorValue = analogRead(POT_PIN);
  sensorValue = map(sensorValue,0,1023,0,255);
  return sensorValue;
}

int numbSin( int amp, int waveL,int offset,int delayval){ // offset -right +left , returns the current position on a sin wave
  int i = sinVal;
  i = i + offset;
  int half = amp/2;
  i++;
  int mysin = (half*sin(i*((PI*2)/waveL))+half);
  sinVal = i;
  delay(delayval);
  if (sinVal > waveL) sinVal = 0;
  return mysin;
}