#include "FastLED.h"

#define NUM_ROWS 17 
#define NUM_COLS 17
#define DATA_PIN 3
#define BRIGHTNESS 255
#define NUM_LEDS NUM_ROWS * NUM_COLS
CRGB leds[NUM_LEDS+1];


void setup() {
  FastLED.addLeds<NEOPIXEL, DATA_PIN>(leds, NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);
}

void loop() {
static byte hue =0;
EVERY_N_MILLISECONDS(30) { hue++; }  

byte x1 = beatsin8 (18, 0, (NUM_COLS-1));
byte x2 = beatsin8 (23, 0, (NUM_COLS-1)); 
byte x3 = beatsin8 (27, 0, (NUM_COLS-1)); 
byte x4 = beatsin8 (31, 0, (NUM_COLS-1)); 
byte x5 = beatsin8 (33, 0, (NUM_COLS-1)); 

byte y1 = beatsin8 (20, 0, (NUM_ROWS-1)); 
byte y2 = beatsin8 (26, 0, (NUM_ROWS-1));
byte y3 = beatsin8 (15, 0, (NUM_ROWS-1));
byte y4 = beatsin8 (27, 0, (NUM_ROWS-1));
byte y5 = beatsin8 (30, 0, (NUM_ROWS-1));

CRGB color = CHSV (hue,255,BRIGHTNESS);

fadeToBlackBy (leds,NUM_LEDS, 30 );

mydrawLine(x1, y1,  x2, y2, color,1);
mydrawLine(x2, y2,  x3, y3, color,1);
mydrawLine(x2, y2,  x4, y4, color,1);
mydrawLine(x3, y3,  x4, y4, color,1);
mydrawLine(x3, y3,  x1, y1, color,1);
mydrawLine(x4, y4,  x1, y1, color,1);

blur2d (leds,NUM_COLS, NUM_ROWS, 64 );
FastLED.show();

} 

void mydrawLine (byte x, byte y, byte x1, byte y1, CRGB color, bool dot){   

byte xsteps = abs8(x-x1)+1;  
byte ysteps = abs8(y-y1)+1;
byte steps =  xsteps >= ysteps? xsteps:ysteps;

for (byte i = 1; i <= steps; i++) {
byte dx = lerp8by8 (x, x1, i*255/steps);
byte dy = lerp8by8 (y, y1, i*255/steps);
leds[XY(dx, dy)] += color;    
}

if (dot) {     
    leds[XY(x,y)] += CRGB ::White;
    leds[XY(x1,y1)] += CRGB ::White;
         }
}

byte XY (byte x, byte y) {
static byte PlanarLookTable [] = {             
241, 53, 54, 55, 56, 57, 58, 59, 0, 1, 2, 3, 4, 5, 6, 7, 241,
52, 241, 241, 103, 104, 105, 106, 107, 60, 61, 62, 63, 64, 65, 241, 241, 8,
51, 241, 102, 241, 144, 145, 146, 147, 108, 109, 110, 111, 112, 241, 66, 241, 9,
50, 101, 241, 143, 241, 177, 178, 179, 148, 149, 150, 151, 241, 113, 241, 67, 10,
49, 100, 142, 241, 176, 241, 202, 203, 180, 181, 182, 241, 152, 241, 114, 68, 11,
48, 99, 141, 175, 241, 201, 241, 219, 204, 205, 241, 183, 241, 153, 115, 69, 12,
47, 98, 140, 174, 200, 241, 218, 231, 220, 221, 206, 241, 184, 154, 116, 70, 13,
46, 97, 139, 173, 199, 217, 230, 239, 232, 233, 222, 207, 185, 155, 117, 71, 14,
45, 96, 138, 172, 198, 216, 229, 238, 241, 234, 223, 208, 186, 156, 118, 72, 15,
44, 95, 137, 171, 197, 215, 228, 237, 236, 235, 224, 209, 187, 157, 119, 73, 16,
43, 94, 136, 170, 196, 241, 214, 227, 226, 225, 210, 241, 188, 158, 120, 74, 17,
42, 93, 135, 169, 241, 195, 241, 213, 212, 211, 241, 189, 241, 159, 121, 75, 18,
41, 92, 134, 241, 168, 241, 194, 193, 192, 191, 190, 241, 160, 241, 122, 76, 19,
40, 91, 241, 133, 241, 167, 166, 165, 164, 163, 162, 161, 241, 123, 241, 77, 20,
39, 241, 90, 241, 132, 131, 130, 129, 128, 127, 126, 125, 124, 241, 78, 241, 21,
38, 241, 241, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 241, 241, 22,
241, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 241};
return (PlanarLookTable[y*NUM_COLS+x])