visit(callback, collection)

Iterates cells in row-major order and calls callback({ row, col, value }) for each cell whose value is contained in collection (Array or Set). Reading and mutating the grid inside the callback is allowed.

Example

(move mouse to highlight 🐸 filled cells in the hovered col, and click to randomize q)

code

Quadrille.cellLength = 50;
let q, hint;

const monkeys = ['🙈', '🙉', '🙊', '🦧'];
const birds = ['🐍', '🦜', '🦚', '🐤'];
const emojis = [...monkeys, ...birds, '🐸', '🐯', '🐱', '🐶', '🐮'];

function setup() {
  createCanvas(8 * Quadrille.cellLength, 8 * Quadrille.cellLength);
  highlight();
}

function draw() {
  background('#DAF7A6');
  drawQuadrille(q);
  drawQuadrille(hint);
}

function mousePressed() {
  highlight();
}

function highlight() {
  q = createQuadrille(8, 8);
  // fill q with random emojis
  q.visit(({ row, col }) => q.fill(row, col, random(emojis)));
  hint = createQuadrille(8, 8);
  // mark monkey positions
  q.visit(({ row, col }) => hint.fill(row, col, color(0, 140)), monkeys);
}

The first loop fills all cells with random emojis using visit(callback).
The second loop visits only monkey cells, marking them in a separate quadrille.

Syntax

visit(callback, collection)

Parameters

Param	Description
`callback`	Function called for each visited cell, receiving an object `{ row, col, value }`. Its return value is ignored
`collection`	An `Array` or `Set` of values. Only cells whose value is in the collection are visited

visit(callback)visit(callback, predicate)