documentation update (mapformat.txt mainly)

This commit is contained in:
Perttu Ahola 2011-06-04 16:54:26 +03:00
parent bf22dba687
commit 6bd4cb2562
2 changed files with 81 additions and 0 deletions

75
doc/mapformat.txt Normal file

@ -0,0 +1,75 @@
I'll try to quickly document the newest block format in here (might contain
errors). Refer to the mapgen or minetestmapper script for the directory
structure and file naming. There are two sector namings possible,
sector/XXXXZZZZ and sector/XXX/ZZZ.
There also exists files map_meta.txt and chunk_meta, that are used by the
generator. If they are not found or invalid, the generator will currently
behave quite strangely.
The MapBlock file format (sectors2/XXX/ZZZ/YYYY):
NOTE: Byte order is MSB first.
u8 version
- map format version number, this one is version 17
u8 flags
- Flag bitmasks:
- 0x01: is_underground: Should be set to 0 if there will be no light
obstructions above the block. If/when sunlight of a block is updated and
there is no block above it, this value is checked for determining whether
sunlight comes from the top.
- 0x02: day_night_differs: Whether the lighting of the block is different on
day and night. Only blocks that have this bit set are updated when day
transforms to night.
- 0x04: lighting_expired: If true, lighting is invalid and should be updated.
If you can't calculate lighting in your generator properly, you could try
setting this 1 to everything and setting the uppermost block in every
sector as is_underground=0. I am quite sure it doesn't work properly,
though.
zlib-compressed map data:
- content:
u8[4096]: content types
u8[4096]: param1 values
u8[4096]: param2 values
zlib-compressed node metadata
- content:
u16 version (=1)
u16 count of metadata
foreach count:
u16 position (= p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X)
u16 type_id
u16 content_size
u8[content_size] misc. stuff contained in the metadata
u16 mapblockobject_count
- always write as 0.
- if read != 0, just fail.
foreach mapblockobject_count:
- deprecated, should not be used. Length of this data can only be known by
properly parsing it. Just hope not to run into any of this.
u8 static object version:
- currently 0
u16 static_object_count
foreach static_object_count:
u8 type (object type-id)
s32 pos_x * 1000
s32 pos_y * 1000
s32 pos_z * 1000
u16 data_size
u8[data_size] data
u32 timestamp
- Timestamp when last saved, as seconds from starting the game.
- 0xffffffff = invalid/unknown timestamp, nothing will be done with the time
difference when loaded (recommended)
// END

@ -174,6 +174,12 @@ TODO: Better control of draw_control.wanted_max_blocks
TODO: Block mesh generator to tile properly on smooth lighting
TODO: Further investigate the use of GPU lighting in addition to the
current one
TODO: Quick drawing of huge distances according to heightmap has to be
tested once again.
Configuration:
--------------