BackPackCode

#include <FastLED.h>

#define LED_PIN 3
#define COLOR_ORDER GRB
#define CHIPSET WS2812B
#define BRIGHTNESS 200

const uint8_t kMatrixWidth = 12; //Maximum width of the matrix
const uint8_t kMatrixHeight = 13; //Maximum width of the matrix

#define NUM_LEDS (kMatrixWidth * kMatrixHeight)
CRGB leds[NUM_LEDS];
uint8_t brightness = BRIGHTNESS;


#define LAST_VISIBLE_LED 114

uint16_t XY (uint16_t x, uint16_t y) {
  // any out of bounds address maps to the first hidden pixel
  if ( (x >= kMatrixWidth) || (y >= kMatrixHeight) ) {
    return (LAST_VISIBLE_LED + 1);
  }

  const uint16_t XYTable[] = {
   281, 282, 283, 284, 285, 286, 287, 110, 288, 111, 289, 112, 290, 113, 291, 114, 292, 293, 294, 295, 296, 297, 298,
   280, 279, 278, 277, 276, 275, 109, 274, 108, 273, 107, 272, 106, 271, 105, 270, 104, 269, 268, 267, 266, 265, 264,
   248, 249, 250, 251, 252,  97, 253,  98, 254,  99, 255, 100, 256, 101, 257, 102, 258, 103, 259, 260, 261, 262, 263,
   247, 246, 245, 244,  96, 243,  95, 242,  94, 241,  93, 240,  92, 239,  91, 238,  90, 237,  89, 236, 235, 234, 233,
   219, 220, 221,  80, 222,  81, 223,  82, 224,  83, 225,  84, 226,  85, 227,  86, 228,  87, 229,  88, 230, 231, 232,
   218, 217,  79, 216,  78, 215,  77, 214,  76, 213,  75, 212,  74, 211,  73, 210,  72, 209,  71, 208,  70, 207, 206,
   194,  59, 195,  60, 196,  61, 197,  62, 198,  63, 199,  64, 200,  65, 201,  66, 202,  67, 203,  68, 204,  69, 205,
    58, 193,  57, 192,  56, 191,  55, 190,  54, 189,  53, 188,  52, 187,  51, 186,  50, 185,  49, 184,  48, 183,  47,
   171,  36, 172,  37, 173,  38, 174,  39, 175,  40, 176,  41, 177,  42, 178,  43, 179,  44, 180,  45, 181,  46, 182,
    35, 170,  34, 169,  33, 168,  32, 167,  31, 166,  30, 165,  29, 164,  28, 163,  27, 162,  26, 161,  25, 160,  24,
   144, 145, 146, 147, 148,  17, 149,  18, 150,  19, 151,  20, 152,  21, 153,  22, 154,  23, 155, 156, 157, 158, 159,
   143, 142, 141, 140,  16, 139,  15, 138,  14, 137,  13, 136,  12, 135,  11, 134,  10, 133,   9, 132, 131, 130, 129,
   115, 116, 117,   0, 118,   1, 119,   2, 120,   3, 121,   4, 122,   5, 123,   6, 124,   7, 125,   8, 126, 127, 128
  };

  uint16_t i = (y * kMatrixWidth) + x;
  uint16_t j = XYTable[i];
  return j;
}

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

void loop()
{
   uint32_t ms = millis();
   int32_t yHueDelta32 = ((int32_t)cos16( ms * (27/1) ) * (350 / kMatrixWidth));
   int32_t xHueDelta32 = ((int32_t)cos16( ms * (39/1) ) * (310 / kMatrixHeight));
   DrawOneFrame( ms / 65536, yHueDelta32 / 32768, xHueDelta32 / 32768);
   if( ms < 5000 ) {
      FastLED.setBrightness( scale8( BRIGHTNESS, (ms * 256) / 5000));
    } else {
      FastLED.setBrightness(BRIGHTNESS);
    }
    FastLED.show();
}

void DrawOneFrame( byte startHue8, int8_t yHueDelta8, int8_t xHueDelta8)
{
  byte  lineStartHue = startHue8;
  for( byte y = 0; y < kMatrixHeight; y++) {
    lineStartHue += yHueDelta8;
    byte pixelHue = lineStartHue;
    for( byte x = 0; x < kMatrixWidth; x++) {
      pixelHue += xHueDelta8;
      leds[ XY(x, y)]  = CHSV( pixelHue, 255, 255);
    }
  }
}