[OSM-dev] Map rendering code... API or database direct?

Richard Fairhurst richard at systemeD.net
Thu Mar 30 12:47:44 BST 2006


Tom wrote:

> On 3/30/06, Raphaël Jacquot <sxpert at esitcom.org> wrote:
>>
>> there is another better way yet, available at the sql level...
>> select all line segments that have a "foot" in the tile you're
>> interested in.
>
> No, the problem is that some segments don't have any "feet" in the 
> current tile.

SELECT id,path FROM segments WHERE
    ((xmin BETWEEN $bbox_xmin AND $bbox_xmax) OR
     (xmax BETWEEN $bbox_xmin AND $bbox_xmax) OR
     (xmin<$bbox_xmin AND xmax>$bbox_xmax)) AND
    ((ymin BETWEEN $bbox_ymin AND $bbox_ymax) OR
     (ymax BETWEEN $bbox_ymin AND $bbox_ymax) OR
     (ymin<$bbox_ymin AND ymax>$bbox_ymax))

where xmin, xmax, ymin and ymax are the bounding box of each segment, 
and $bbox_xmin, $bbox_xmax etc. are the bounding box of the current map 
view (tile).

Richard




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