My Sketch

function setup() {

  createCanvas(600, 600); // Set up a 600x600 canvas

  background(255);        // White background

  drawGrid();             // Call function to draw the board

}

​

function drawGrid() {

  background(255);        // Reset background to white

​

  var rows = 5;           // Number of rows

  var columns = 5;        // Number of columns

  var cellW = width / columns;  // Width of each cell

  var cellH = height / rows;    // Height of each cell

  var pad = 3;            // Small padding inside each cell

​

  // Loop over each cell in the grid

  for (var col = 0; col < columns; col++) {

    for (var row = 0; row < rows; row++) {

      let x = col * cellW; // X-coordinate of cell

      let y = row * cellH; // Y-coordinate of cell

​

      fill(0);             // Black cell background

      rect(x, y, cellW, cellH); // Draw cell rectangle

​

      let flippedN = random() < 0.1; // 10% chance to flip "N" shape

​

      fill(255);           // White for "N" shapes

      noStroke();          // No outline

​

      if (flippedN) {

        // Draw mirrored "N" shape

        rect(x + pad, y + pad, cellW / 5, cellH - 2 * pad); // Right vertical bar

        rect(x + cellW - pad - cellW / 5, y + pad, cellW / 5, cellH - 2 * pad); // Left vertical bar

​

        // Diagonal line from top-right to bottom-left

        beginShape();

        vertex(x + cellW - pad, y + pad);                        // Top-right

        vertex(x + cellW - pad - cellW / 5, y + pad);            // Inner top-right

        vertex(x + pad, y + cellH - pad);                        // Bottom-left

        vertex(x + pad + cellW / 5, y + cellH - pad);            // Inner bottom-left

        endShape(CLOSE);  // Complete mirrored "N"

      } else {

        // Draw regular "N" shape

        rect(x + pad, y + pad, cellW / 5, cellH - 2 * pad);      // Left vertical bar

        rect(x + cellW - pad - cellW / 5, y + pad, cellW / 5, cellH - 2 * pad); // Right vertical bar

​

        // Diagonal line from top-left to bottom-right

        beginShape();

        vertex(x + pad, y + pad);                                // Top-left

        vertex(x + pad + cellW / 5, y + pad);                    // Inner top-left

        vertex(x + cellW - pad, y + cellH - pad);                // Bottom-right

        vertex(x + cellW - pad - cellW / 5, y + cellH - pad);    // Inner bottom-right

        endShape(CLOSE); // Complete regular "N"

      }

    }

  }

}

​

function keyPressed() {

  if (key == 'r' || key == 'R') {

    drawGrid(); // Redraw board with new random "N"s on 'R' key press

  } else if (key == 's' || key == 'S') {

    saveCanvas('N_pattern', 'png'); // Save image as PNG on 'S' key press

  }

}