Creates a quadrille by decoding a bitboard—passed as a JavaScript BigInt—into a fixed-size rectangular quadrille. Each bit in the bitboard determines whether a corresponding cell is filled (1) or empty (0). The number of columns is set by width, and the number of rows is explicitly set by height.

This function lets you control both width and height directly, making it useful for placing bitboard-defined patterns into specific regions of a larger quadrille.

Example 1 — Big-endian (default) #

let quadrille;

function setup() {
  createCanvas(300, 400);
  /*
  Bit pattern (MSB first), read row-major big-endian:
  |     |     |     |     → bits 11 10  9 = 0 0 0
  |     |  1  |     |     → bits  8  7  6 = 0 1 0
  |     |  1  |     |     → bits  5  4  3 = 0 1 0
  |     |  1  |  1  |     → bits  2  1  0 = 0 1 1
  Bit indices with values:
  (1)2⁰ + (1)2¹ + (1)2⁴ + (1)2⁷ = 1 + 2 + 16 + 128 = 147
  */
  quadrille = createQuadrille(3, 4, 147n, color('purple'));
}

function draw() {
  background('lime');
  drawQuadrille(quadrille);
}

This bitboard places an L shape into a 3×4 quadrille using row-major, big-endian order:

• Bit 11 → cell (0,0) — top-left
• Bit 0 → cell (3,2) — bottom-right

MSB (bit 11)
↓
|     |     |     |
|     |  1  |     |
|     |  1  |     |
|     |  1  |  1  |
↑
LSB (bit 0)

Example 2 — Little-endian #

let quadrille;

function setup() {
  createCanvas(300, 400);
  /*
  Little-endian: same bitboard, read in reverse order
  |  1  |  1  |     |     → bits 11 10  9 = 1 1 0
  |     |  1  |     |     → bits  8  7  6 = 0 1 0
  |     |  1  |     |     → bits  5  4  3 = 0 1 0
  |     |     |     |     → bits  2  1  0 = 0 0 0
  Bit indices with values:
  (1)2⁴ + (1)2⁷ + (1)2¹⁰ + (1)2¹¹ = 16 + 128 + 1024 + 2048 = 147
  */
  quadrille = createQuadrille(3, 4, 147n, color('purple'), true);
}

function draw() {
  background(250);
  drawQuadrille(quadrille);
}

Same bitboard (147n) as before, but read in row-major, little-endian order:

• Bit 0 → cell (0,0) — top-left
• Bit 11 → cell (3,2) — bottom-right

This results in a flipped L shape:

|  1  |  1  |     |
|     |  1  |     |
|     |  1  |     |
|     |     |     |

This layout matches little-endian rank-file ordering as used in engines like Stockfish.

Syntax #

createQuadrille(width, height, bitboard, value[, littleEndian])

Parameters #