Gridlocked.lua

function love.load()
  player = {
    grid_x = 256,
    grid_y = 256,
    act_x = 256,
    act_y = 256,
    speed = 10
  }

  map = {
    { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
    { 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 },
    { 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1 },
    { 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1 },
    { 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1 },
    { 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 },
    { 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
    { 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
    { 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
    { 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1 },
    { 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 },
    { 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 },
    { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }
  }

  -- this makes a 2d array the same size as the map 2d array
  seen_tiles = {}
  for yindex,column in ipairs(map) do
    seen_tiles[yindex] = {}
    for xindex,tile in ipairs(column) do
      seen_tiles[yindex][xindex] = 0
    end
  end
end

function love.update(dt)
  player.act_y = player.act_y - ((player.act_y - player.grid_y) * player.speed * dt)
  player.act_x = player.act_x - ((player.act_x - player.grid_x) * player.speed * dt)
end

function love.draw()
  love.graphics.rectangle("fill", player.act_x, player.act_y, 32, 32)

  -- draw the seen tiles if they have been marked as seen
  for y=1, #seen_tiles do
        for x=1, #seen_tiles[y] do
            if seen_tiles[y][x] == 1 then
                love.graphics.rectangle("line", x * 32, y * 32, 32, 32)
            end
        end
    end
end

function love.keypressed (key)
  if key == "up" then
    if testMap (0, -1) then
      player.grid_y = player.grid_y - 32
    end
  elseif key == "down" then
    if testMap (0, 1) then
      player.grid_y = player.grid_y + 32
    end
  elseif key == "left" then
    if testMap (-1, 0) then
      player.grid_x = player.grid_x - 32
    end
  elseif key == "right" then
    if testMap (1, 0) then
      player.grid_x = player.grid_x + 32
    end
  end
end

function testMap (x, y)
  if map[(player.grid_y / 32) + y][(player.grid_x / 32) + x] == 1 then
    -- mark a tile as seen by setting it to a value of 1
    seen_tiles[(player.grid_y / 32) + y][(player.grid_x / 32) + x] = 1
    return false
  end
  return true
end