[Qgis-developer] Approximate reprojection for vectors

[Martin Dobias]

On Sun, Oct 2, 2011 at 4:33 PM, Marco Hugentobler
<marco.hugentobler at sourcepole.ch> wrote:
> I did a lot of profiling for the FOSS4G WMS benchmark (osm data, reprojected to
> google crs, complex symbology with a lot of rules). The pattern was mostly the
> following:
> the rendering itself (QPainter->drawPolyline) was the most time consuming
> operation (appr. 50% of rendering time), next was evaluation in rule based
> renderer (20% of time), getNextFeature in PostgresProvider 10%, coordinate
> transformation 10%.

Marco,

how did you profile? Using callgind, oprofile or directly measuring
time? If you used callgrind the results may be significantly skewed:
the time spent within postgres provider while waiting for server to
return the features may not be considered.

Regards
Martin