地图迷雾压缩算法

使用四叉树将庞大的地图迷雾数据压缩为较小的base64字符串，以便传输和存储。

区域迷雾状态

状态	标识
全驱散	0
二者混合	1
全迷雾	2

API

• fog.create(w, h, tag) 创建指定大小的地图
• fog.encode(map) 序列化
• fog.decode(str, w, h) 反序列化(返回新的map)
• fog.dispel_fog(map, x, y, w, h) 驱散迷雾
• fog.cover_fog(map, x, y, w, h) 覆盖迷雾
• fog.is_fog(map, x, y) 检查迷雾
• fog.union(map1, map2) 求并集

Usage

local w, h = 10000, 5000
local map = fog.create(w, h)
print(fog.encode(map)) -- ouput: C
fog.dispel_fog(map, 100, 100, 10, 10)
local str = fog.encode(map)
print(str) -- ouput: ppppplaZapmkCZiJUKhGhEqVmImQmYCFhIhGhEaZioBqWEiqqqqqC
local map2 = fog.decode(str, w, h)
fog.dispel_fog(map2, 0, 0, 10000, 10000)
print(fog.encode(map2)) -- ouput: A
fog.cover_fog(map2, 0, 0, 5000, 10000)
print(fog.encode(map2)) -- ouput: JC


local w, h = 20, 20
local map1 = fog.create(w, h)
fog.dispel_fog(map1, 10, 10, 10, 10)
fog.dump(map1)
-- ouput
--[[
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
]]
local map2 = fog.create(w, h)
fog.dispel_fog(map2, 5, 5, 10, 10)
fog.dump(map2)
-- ouput
--[[
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
]]
local map3 = fog.union(map1, map2)
fog.dump(map3)
-- ouput
--[[
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ @ @ @ @ @ + + + + + + + + + +
@ @ @ @ @ + + + + + + + + + + + + + + +
@ @ @ @ @ + + + + + + + + + + + + + + +
@ @ @ @ @ + + + + + + + + + + + + + + +
@ @ @ @ @ + + + + + + + + + + + + + + +
@ @ @ @ @ + + + + + + + + + + + + + + +
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ + + + + + + + + + + @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
]]