mods/boxes/io.lua

   1
   2 --[[
   3
   4   ITB (insidethebox) minetest game - Copyright (C) 2017-2018 sofar & nore
   5
   6   This library is free software; you can redistribute it and/or
   7   modify it under the terms of the GNU Lesser General Public License
   8   as published by the Free Software Foundation; either version 2.1
   9   of the License, or (at your option) any later version.
  10
  11   This library is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with this library; if not, write to the Free
  18   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  19   MA 02111-1307 USA
  20
  21 ]]--
  22
  23 local function bytes_to_string(bytes)
  24         local s = {}
  25         for i = 1, #bytes do
  26                 s[i] = string.char(bytes[i])
  27         end
  28         return table.concat(s)
  29 end
  30
  31 function boxes.import_box(id, box_data)
  32         local data_index = 1
  33         local function read_u8()
  34                 local c = string.byte(box_data, data_index)
  35                 data_index = data_index + 1
  36                 return c
  37         end
  38         local function read_u16()
  39                 local a = read_u8()
  40                 local b = read_u8()
  41                 return 256 * a + b
  42         end
  43         local function read_pos()
  44                 local x = read_u16()
  45                 local y = read_u16()
  46                 local z = read_u16()
  47                 return {x = x, y = y, z = z}
  48         end
  49         local version = read_u8()
  50         assert (version == 1)
  51         local type = read_u8()
  52         local size = read_pos()
  53         local entry = read_pos()
  54         local exit = read_pos()
  55         db.box_set_data(id, string.sub(box_data, data_index))
  56         db.box_set_meta(id, {
  57                 type = type,
  58                 meta = {
  59                         size = size,
  60                         entry = entry,
  61                         exit = exit,
  62                 }
  63         })
  64 end
  65
  66 function boxes.export_box(id)
  67         local data_index = 1
  68         local data = {}
  69         local function write_u8(x)
  70                 data[data_index] = x
  71                 data_index = data_index + 1
  72         end
  73         local function write_u16(x)
  74                 write_u8(math.floor(x / 256))
  75                 write_u8(x % 256)
  76         end
  77         local function write_pos(p)
  78                 write_u16(p.x)
  79                 write_u16(p.y)
  80                 write_u16(p.z)
  81         end
  82         local meta = db.box_get_meta(id)
  83         write_u8(1) -- version
  84         write_u8(meta.type)
  85         write_pos(meta.meta.size)
  86         write_pos(meta.meta.entry)
  87         write_pos(meta.meta.exit)
  88         return bytes_to_string(data) .. db.box_get_data(id)
  89 end
  90
  91 local function read_file(filename)
  92         local file = io.open(filename, "r")
  93         if file ~= nil then
  94                 local file_content = file:read("*all")
  95                 io.close(file)
  96                 return file_content
  97         end
  98         return ""
  99 end
 100
 101 --[[ -- kept for historical purposes.
 102 local function write_file(filename, data)
 103         local file, err = io.open(filename, "w")
 104         if file then
 105                 file:write(data)
 106                 io.close(file)
 107         else
 108                 error(err)
 109         end
 110 end
 111 ]]--
 112
 113 local modpath = minetest.get_modpath(minetest.get_current_modname())
 114
 115 if not db.box_exists(0) then
 116         local box_data = read_file(modpath .. "/entry.box")
 117         boxes.import_box(0, box_data)
 118 end
 119
 120 if not db.box_exists(1) then
 121         local box_data = read_file(modpath .. "/exit.box")
 122         boxes.import_box(1, box_data)
 123 end
 124
 125 if not db.box_exists(2) then
 126         local box_data = read_file(modpath .. "/box.box")
 127         boxes.import_box(2, box_data)
 128 end
 129
 130 -- local worldpath = minetest.get_worldpath()
 131 -- write_file(worldpath .. "/entry.box", boxes.export_box(0))
 132 -- write_file(worldpath .. "/exit.box", boxes.export_box(1))
 133 -- write_file(worldpath .. "/box.box", boxes.export_box(2))