local overlays = {}

function get_main_color(tint)
  if tint == BLUE then
    return 12
  elseif tint == YELLOW then
    return 9
  else
    return 1
  end
end

function get_shade_color(tint)
  if tint == BLUE then
    return 13
  elseif tint == YELLOW then
    return 4
  else
    return 1
  end
end

function spawn_tile_transition(x, y, w, h, from_tint, to_tint)
  local p = #patterns
  local from_color = get_main_color(from_tint)
  local to_color = get_main_color(to_tint)
  add(
    overlays, {
      _draw = function(self)
        fillp()
        rectfill(x, y, x + w, y + h, from_color)
        fillp(patterns[p \ 1] + 0b0.1)
        rectfill(x, y, x + w, y + h, to_color)
        p -= 1
        if p < 1 then
          del(overlays, self)
        end
      end
    }
  )
end