#include <FastLED.h>

#define LED_PIN  3

#define COLOR_ORDER GRB
#define CHIPSET     WS2811

#define BRIGHTNESS 254

const uint8_t kMatrixWidth = 10;
const uint8_t kMatrixHeight = 10;
uint8_t hue;

const bool    kMatrixSerpentineLayout = true;

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()
{
    spiral(0,5,10);
    //spiral(5,5,10);
    spiral(10,5,50);
    fadeToBlackBy(leds, NUM_LEDS, 1);

}


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


void spiral(int offSet, int radMax, int speed){
  int radius = beatsin8(speed, 0, radMax);;
  int cX = kMatrixWidth/2;
  int cY = kMatrixHeight/2;

  int thisX = cX+(floor(radius*sin(millis()*.03+offSet)));
  int thisY = cY+(floor(radius*cos(millis()*.03+offSet)));
  leds[XY(thisX,thisY)] = CHSV( hue++, 255, 255);

  //fadeToBlackBy(leds, NUM_LEDS, 5);
  FastLED.show();
}