Overlap bitmaps (WIP)

gistfile1.txt

var colors = {
  0: 'transparent',
  1: 'white',
  2: '#aaa'
}

var planetMap = [
  [ 0, 0, 1, 9, 1 ],
  [ 0, 0, 1, 8, 1 ],
  [ 1, 1, 1, 7, 1 ],
  [ 0, 0, 1, 6, 1 ],
  [ 1, 1, 1, 5, 1 ]
]

var craterMap = [
  [ 2, 3 ],
  [ 0, 5 ]
]

function overlap(map1, map2, x, y) {
  return map1.map((row, bitY) => {
    return row.map((col, bitX) => {
      if (y > bitY || x > bitX || !map2[bitY - y]) {
        return col
      }
      return map2[bitY - y][bitX - x] || col
    })
  })
}

overlap(planetMap, craterMap, 3, 2)