[Tilesathome] Blank tiles...

[Łukasz Jernaś]

On Sun, Oct 12, 2008 at 10:58 AM, spaetz <osm at sspaeth.de> wrote:
> On Sat, Oct 11, 2008 at 08:44:31PM +0200, ??ukasz Jerna?? wrote:
>> So the format has unused fields? Quoting
>> http://wiki.openstreetmap.org/index.php/Tiles%40home/Tileset_as_one_file_v2:
>> "Each index denotes an unsigned 32-bit integer and either contains the
>> blankness information of the tile in question (0=unknown, 1=sea,
>> 2=land, 3=transparent), or the offset to the spot in the file where
>> the PNG data of that tile starts."
>>
>> Does it mean that only the offset is stored in the tileset file or the
>> integer value for empty tiles is somehow magically computed?
>
> Sorry, I don't get at all what you are aiming at. These are the possibilities:
>
> 1) There is a tileset file in place for a z0, z6, or z12 tileset. In this case all tiles of it have been rendered and if a tile *from this tileset* is empty it will be denoted by an blankness value of "1,2,3".
> If the tileset file exists the emptyness value of all tiles within that tileset ome from whatever the client told us.
>
> 2)If there is no tileset file at all (recognizable by the text oceantiles.dat is used on the details page), then there is no way of knowing whether it's really a totally empty tileset or just has never been rendered (although the "has never been rendered" should pretty much not occur anymore).
> In this case the oceantiles.dat on the server is being used to determine the blankness value of the tileset.
>
> Does this answer your question?

Partially, but nevermind - I shouldn't have stuck my nose into it anyway.

-- 
Łukasz