[Tilesathome] Blank tile handling

[Sebastian Spaeth]

Rob Reid wrote:
> spaetz wrote the following on 14/08/2008 21:57:
>> The server has to recreate those empty tiles recursively and I am not sure whether it's more costly to the server to process those 1500 tile files or whether to recreate the blankness state by recursing down. We will still not create blank tiles if the whole parent tile was empty,
>>
>> ------------------------------------------------------------------------
>> r9818 | spaetz | 2008-08-14 11:56:17 +0200 (Thu, 14 Aug 2008) | 1 line
>>
>> Do away with the whole "do we need to create a blank tile here" optimization. The server needs those anyway, it's less work for the client. Tileset uploads are only slightly bigger, and we still skip empty sub-regions.
>> ------------------------------------------------------------------------
>>
>> I have rerendered your test case and it looks good now.
>>   
> Thanks for fixing that.
> While we are on the subject of blank tiles, is there any way to optimise 
> the blank tile handling for maplint tiles. I understand it gets forced 
> to produce a full tileset by the RenderFullTileset option in layers.conf 
> but I find it a little depressing when watching it rendering a 
> completely blank tileset when it flys through the tile layer only 
> creating one blank tile and then chugs through maplint layer creating 
> 341 blank tiles.

I am still no expert of the client, and especially not a maplint expert, 
but here's my opinion:

problem is, that maplint can usually show stuff at levels z16 but would 
not show anything at higher zoom levels, such as z12, right?

In that case, we cannot shortcut the rendering as we need to crunch 
through to z16 to see if there's something. If the above is wrong, and a 
maplint tile that displays something in z16 will also display something 
in z12, then there is indeed no need for the RenderFullTileset option.

I guess, somebody who knows the maplint layer will have to answer that 
question.

spaetz