[mapserver-dev] Server-side Simplication Speed-up

[Paul Ramsey]

Sandro working on MapNik says that this change

https://github.com/mapnik/mapnik/issues/1136

running an "appropriate" st_simplify on the geometries before sending
them over the wire to the renderer, gave up to 75% speedups on
rendering complicated items.

In order to try it out on MapServer, the PostGIS driver needs to know
two things:
- what's the resolution being rendered to? this I can pick up out of
the mapObj easily I think, tracing back up from the layerObj passed
into the driver
- is this a rendering call to the driver, or a feature access call?
this is harder... I need to distinguish between calls to the driver
that are going to use the features for rendering and those that are
going to send them back to the requester as data. Is there an obvious
global way to figure this out from the driver level?

P.