calculate_lightray = (x1, y1, x2, y2, type) =>
  switch type
    when 'enemy' then window.selected_layer = enemy_layer
    else window.selected_layer = shadow_layer

  pixel_x1 = x1*config.pixelsize + (config.pixelsize/2)
  pixel_y1 = y1*config.pixelsize + (config.pixelsize/2)
  pixel_x2 = x2*config.pixelsize + (config.pixelsize/2)
  pixel_y2 = y2*config.pixelsize + (config.pixelsize/2)

  dx = Math.abs(pixel_x1 - pixel_x2)
  dy = Math.abs(pixel_y1 - pixel_y2)
  
  s = 0.99 / (if dx>dy then dx else dy)
  t = 0.0

  # show me the rays
  if config.debug
    context.beginPath()
    context.strokeStyle = 'blue'
    context.moveTo(pixel_x1+config.map.origin.x,pixel_y1+config.map.origin.y)
    context.lineTo(pixel_x2+config.map.origin.x,pixel_y2+config.map.origin.y)
    context.stroke()

  hit_wall = false
  while t < 1.0
    dx = Math.round((1.0-t)*pixel_x1 + t*pixel_x2)
    dy = Math.round((1.0-t)*pixel_y1 + t*pixel_y2)

    dx = Math.floor(dx/config.pixelsize)
    dy = Math.floor(dy/config.pixelsize)

    # FLOOR?
    if level[dy*config.map.width + dx] is 0
      break if hit_wall and !config.debug
      
      if selected_layer[dy*config.map.width + dx] == 0
        if t > 0.5
          selected_layer[dy*config.map.width + dx] += map_range([0.5, 1], [1, 0], t)
        else
          selected_layer[dy*config.map.width + dx] += 1
    # WALL?
    else if level[dy*config.map.width + dx] is 3
      break if type is 'enemy'
      if t > 0.5
        selected_layer[dy*config.map.width + dx] += map_range([0.5, 1], [1, 0], t)
      else
        selected_layer[dy*config.map.width + dx] += 1
        
      hit_wall = true
    # ENTITIY?
    else if level[dy*config.map.width + dx] in blocks.entities
      if t > 0.5
        selected_layer[dy*config.map.width + dx] += map_range([0.5, 1], [1, 0], t)
      else
        selected_layer[dy*config.map.width + dx] += 1
      break if !config.debug and level[dy*config.map.width + dx] isnt 1 and level[dy*config.map.width + dx] isnt 8
    else
      selected_layer[dy*config.map.width + dx] = .5
      break if !config.debug
        
    t += s

illuminate = (x1, y1, range, type = 'shadow') =>
  r = 0

  while r < Math.PI*2
    x2 = range*Math.cos(r) + x1
    y2 = range*Math.sin(r) + y1
    
    # bug: edge blurry stuff    
    #x2 = config.map.width-1 if x2 > config.map.width-1
    #y2 = config.map.height-1 if y2 > config.map.height-1
    #
    #x2 = 0 if x2 < 0
    #y2 = 0 if y2 < 0
    
    calculate_lightray(x1, y1, x2, y2, type)
    r += 0.03

calculate_lights = () =>
  #illuminate(8, 8, 5)
  illuminate(toxy(player.position).x, toxy(player.position).y, player.lightrange)

  for block, position in level
    switch block
      # 6 = LIGHT
      # CAMERA
      when 8
        illuminate(toxy(position).x, toxy(position).y, 4, 'enemy')

draw_lights = (type) =>
  switch type
    when 'enemy'
      color = '255, 0, 0'
      window.selected_layer = enemy_layer
    else
      color = '0, 0, 0'
      window.selected_layer = shadow_layer
  
  for brightness, position in selected_layer
    switch type
      when 'enemy'
        alpha = brightness*.5
      else
        alpha = 1-brightness

    if level[position] in blocks.entities
      if alpha < 0.4 then alpha = 0

    pixel(position, config.pixelsize, config.pixelsize, 'rgba('+color+', '+alpha+')')