projection time loss

[Stephen Woodbridge]

Kevin Flanders wrote:
> 
> 
> I have several annotation shapefiles with several thousand labels each 
> that I need to either project on-the-fly or pre-process and project 
> beforehand.  Would anyone care to comment on the performance hit this 
> level of projection on the fly might have on my Mapserver application….

Hi Kevin,

The cost to project points should be relatively small. On the other hand 
the cost to display the label irrespective of a projection is probably 
taking 40-60% of you display time, guessing from my past experience 
unless you have tuned the number of labels you are trying to display at 
any given scale.

If you are concerned, build mapserver with DEBUG option with ./configure 
--enable-debug and add DEBUG ON to the MAP object and to the LAYER 
object and draw a map while watch the apache error.log. Timing stats 
will got there for each layer and the label cache. If your label cache 
time is big, you need to filter down the number of labels you are 
throwing at mapserver.

-Steve