#include <FastLED.h>

#define LED_PIN  3

#define COLOR_ORDER GRB
#define CHIPSET     WS2811

#define BRIGHTNESS 254

const uint8_t kMatrixWidth = 16;
const uint8_t kMatrixHeight = 16;
uint8_t hue;

const bool    kMatrixSerpentineLayout = true;

int potpin1 = 0;  // analog pin used to connect the potentiometer
int potpin2 = 1;
int potpin3 = 2;
int val1;    // variable to read the value from the analog pin
int val2;
int val3;

uint16_t XY( uint8_t x, uint8_t y)
{
  uint16_t i;

  if( kMatrixSerpentineLayout == false) {
    i = (y * kMatrixWidth) + x;
  }

  if( kMatrixSerpentineLayout == true) {
    if( y & 0x01) {
      // Odd rows run backwards
      uint8_t reverseX = (kMatrixWidth - 1) - x;
      i = (y * kMatrixWidth) + reverseX;
    } else {
      // Even rows run forwards
      i = (y * kMatrixWidth) + x;
    }
  }

  return i;
}


#define NUM_LEDS (kMatrixWidth * kMatrixHeight)
CRGB leds_plus_safety_pixel[ NUM_LEDS + 1];
CRGB* const leds( leds_plus_safety_pixel + 1);

uint16_t XYsafe( uint8_t x, uint8_t y)
{
  if( x >= kMatrixWidth) return -1;
  if( y >= kMatrixHeight) return -1;
  return XY(x,y);
}


void loop()
{
    val1 = map(analogRead(potpin1), 0, 1023, 0, 10);
    val2 = map(analogRead(potpin2), 0, 1023, 0, 10);
    val3 = map(analogRead(potpin3), 0, 1023, 0, 10);
    spirograph(val1,val2,val3);

}


void setup() {
  Serial.begin(115200);
  FastLED.addLeds<CHIPSET, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection(TypicalSMD5050);
  FastLED.setBrightness( BRIGHTNESS );
}

float Sp = 0;
void spirograph(int fixed, //outer ring radius
                int moving, //inner, moving ring radius
                int offSet //pen offset from inner ring (like the holes in the toy)
                ){
  //int Sp =  millis()*.03;
  Sp = Sp+.03;
  int cX = kMatrixWidth/2;
  int cY = kMatrixHeight/2;

  int thisX = (fixed+moving) * cos(Sp) - (moving+offSet)*cos(((fixed+moving)/moving)*Sp);
  int thisY = (fixed+moving) * sin(Sp) - (moving+offSet)*sin(((fixed+moving)/moving)*Sp);
  leds[XYsafe(thisX+cX,thisY+cY)] = CHSV( 0, 0, 255);
  Serial.print(val1);
  Serial.print(", ");
  Serial.print(val2);
  Serial.print(", ");
  Serial.println(val3);
  //Serial.print(thisX+cX);
  //Serial.print(", ");
  //Serial.println(thisY+cY);

  fadeToBlackBy(leds, NUM_LEDS, 1);
  FastLED.show();
  leds[XYsafe(thisX+cX,thisY+cY)] = CHSV( 16, 255, 255);
}