mapgen_rivers/load.lua

101 lines
2.0 KiB
Lua
Raw Normal View History

local worldpath = mapgen_rivers.world_data_path
function mapgen_rivers.load_map(filename, bytes, signed, size, converter)
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()
if converter then
for i=1, size do
map[i] = converter(map[i])
end
end
return map
end
local sbyte = string.byte
local loader_mt = {
__index = function(loader, i)
local file = loader.file
local bytes = loader.bytes
file:seek('set', (i-1)*bytes)
local strnum = file:read(bytes)
local n = sbyte(strnum, 1)
if loader.signed and n >= 128 then
n = n - 256
end
for j=2, bytes do
n = n*256 + sbyte(strnum, j)
end
if loader.conv then
n = loader.conv(n)
end
loader[i] = n
return n
end,
}
function mapgen_rivers.interactive_loader(filename, bytes, signed, size, converter)
local file = io.open(worldpath .. filename, 'rb')
if file then
minetest.register_on_shutdown(function()
file:close()
end)
converter = converter or false
return setmetatable({file=file, bytes=bytes, signed=signed, size=size, conv=converter}, loader_mt)
end
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