Hi Paul,<br><br>layer->extent is used to provide data for msLayerGetExtent. If layer->extent is set then this value is used, otherwise the driver-specific implementation is called which may be much slower and some of the drivers don't implement to retrieve it. I assume layer->extent is defined in the layer coordinate system. <br>
I think you could easily use this in msLayerIsVisible (assuming it does nothing if the extent is not set ). I don't see the necessity have an RFC with this.<br><br>Best regards,<br><br>Tamas<br><br><br><br><div class="gmail_quote">
2009/6/4 Paul Ramsey <span dir="ltr"><<a href="mailto:pramsey@opengeo.org">pramsey@opengeo.org</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I see we have an EXTENT keyword under LAYER, but poking around the<br>
code, layerObj->extent is not used very much.<br>
<br>
I have a client request to use LAYER EXTENT as a processing short<br>
circuit, so that layers whose extent does not intersect the map extent<br>
can be quickly skipped (probably at the point where msLayerIsVisible()<br>
is called).<br>
<br>
First, does this feel RFC worthy? (My feeling is "no", it's just an<br>
enhancement of existing behavior)<br>
Second, what are the expected semantics of the coordinates in LAYER<br>
EXTENT. Are they in the LAYER projection or the MAP projection? (My<br>
feeling is, LAYER).<br>
<br>
Thanks,<br>
<br>
Paul<br>
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