[Tilesathome] Caption layer

[spaetz]

On Tue, Jul 15, 2008 at 07:49:27PM +0100, 80n wrote:
> The caption layer does not appear to be getting composited into the lowzoom
> tiles.  There used to be captions on the z8-z11 tiles.

No, there is no compositing of the caption layer yet. I had simply forgotten about this. Will add those back ASAP.
 
> The old lowzoom created each low zoom layer by combining captionless tiles
> from the next higher layer along with captions from the caption layer.  As
> far as I can tell this isn't happening at the moment.

Right now we take the z12 captionless and recursively stitch them down to z6, saving them in the 'tiles' layer. I will make it like it used to work. I am sorry to say that I had no real idea of how the lowzoom and caption thing was working.
 
> BTW Is there any mechanism for generating caption tiles at z11 and lower, or
> has that been overlooked?

It's possible on the server side now. There was no mechanism in the mainstream tah client so far, so there is nothing that I supported. 

To make things dead easy tile sets are z0-5,z6-11,z12-17. It would be possible but not trivial to convince me of the need for finer grained tile sets, BTW.
Right now, you can issue a request for the "caption" layer at min_z=6, this would cause the server to hand that request out to a tah client. The problem is that regular tah clients are not configured to actually be able to create the caption layer and that they wouldn't create a tileset from z6 - z11

spaetz