create-phaser-app/src/plugins/lightrays/clumpy.js

A boiler plate to start your phaser app with webpack4, babel7+ and Phaser 3

/*
This file is a set of functions whose purpose is to find
'islands' or 'clumps'
Of tiles in a tilemap with a simple recursive flodfill
*/

function tileIsInBounds(tileX, tileY, layer) {
  return (
    tileX >= 0 && tileX < layer.width && tileY >= 0 && tileY < layer.height
  );
}

function getTileAt(tileX, tileY, layer) {
  let tile = null;
  if (tileIsInBounds(tileX, tileY, layer)) {
    tile = layer.data[tileY][tileX];
    if (tile.index === -1) {
      tile = null;
    }
  }
  return tile;
}

function tilemapLayerToTileClumps(tilemapLayer) {
  const clumps = [];

  let tlW = tilemapLayer.width;
  let tlH = tilemapLayer.height;

  for (let x = 0; x < tlW; x++) {
    for (let y = 0; y < tlH; y++) {
      const tile = getTileAt(x, y, tilemapLayer);
      const shouldAddTile = tile && !clumpThatHasTile(tile, clumps);

      if (shouldAddTile) {
        const clump = [];
        gatherNeighbors({
          x,
          y,
          clump,
          tilemapLayer
        });
        clumps.push(clump);
      }
    }
  }
  return clumps;
}

function gatherNeighbors({ x, y, clump, tilemapLayer }) {
  const tile = getTileAt(x, y, tilemapLayer);
  const shouldAddTile = tile && clump.indexOf(tile) === -1;
  if (shouldAddTile) {
    clump.push(tile);
    let origin = {
      x,
      y,
      clump,
      tilemapLayer
    };
    const north = { ...origin, ...{ y: y + 1 } };
    const south = { ...origin, ...{ y: y - 1 } };
    const east = { ...origin, ...{ x: x + 1 } };
    const west = { ...origin, ...{ x: x - 1 } };
    gatherNeighbors(north);
    gatherNeighbors(south);
    gatherNeighbors(east);
    gatherNeighbors(west);
  }
}

function clumpThatHasTile(tile, clumps) {
  let clumpsLength = clumps.length;
  for (let ci = 0; ci < clumpsLength; ci++) {
    let clump = clumps[ci];
    let tilesLength = clump.length;
    for (let ti = 0; ti < tilesLength; ti++) {
      let _tile = clump[ti];

      if (tile === _tile) {
        return clump;
      }
    }
  }
  return null;
}

export default tilemapLayerToTileClumps;