[Tilesathome] Blank tiles...

[spaetz]

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?
spaetz