mapgen_rivers/load.lua

58 lines
1.1 KiB
Lua
Raw Normal View History

local worldpath = mapgen_rivers.world_data_path
function mapgen_rivers.load_map(filename, bytes, signed, size)
local file = io.open(worldpath .. filename, 'rb')
local data = file:read('*all')
if #data < bytes*size then
data = minetest.decompress(data)
end
local sbyte = string.byte
local map = {}
for i=1, size do
local i0 = (i-1)*bytes+1
local elements = {data:byte(i0, i1)}
local n = sbyte(data, i0)
if signed and n >= 128 then
n = n - 256
end
for j=1, bytes-1 do
n = n*256 + sbyte(data, i0+j)
end
map[i] = n
end
file:close()
return map
end
function mapgen_rivers.write_map(filename, data, bytes)
local size = #data
local file = io.open(worldpath .. filename, 'wb')
local mfloor = math.floor
local schar = string.char
local upack = unpack
local bytelist = {}
for j=1, bytes do
bytelist[j] = 0
end
for i=1, size do
local n = mfloor(data[i])
data[i] = n
for j=bytes, 2, -1 do
bytelist[j] = n % 256
n = mfloor(n / 256)
end
bytelist[1] = n % 256
file:write(schar(upack(bytelist)))
end
file:close()
end