[mapserver-dev] Per-layer choice of graphical rendering engine - possible?

Toby Rahilly toby.rahilly at gmail.com
Fri Dec 19 00:35:36 EST 2008

Hi Håvard,

These are my thoughts from the perspective of optimised OpenGL rendering.

This would require some sort of common buffer to render the layers
into. This would kill the performance of OpenGL as copying buffers
from the video memory to main memory is a huge bottleneck, doing it
per layer would slow the rendering to a crawl.

Alternatively,  GD and AGG layers could be rendered onto textures and
then moved onto an OpenGL buffer in video memory. But this means there
would need to be two different implementations, for when OpenGL is and
isn't used.


On Thu, Dec 18, 2008 at 8:09 PM, Havard Tveite <havard.tveite at umb.no> wrote:
> I have been experimenting a bit with Mapserver, using both
> GD and AGG (and now comes OpenGL!).
> I have experienced that some types of layers are best
> rendered using AGG, and some using GD, with quite a bit of
> difference in both performance and graphical quality.
> It would therefore have been nice to be able to choose
> graphical rendering engine on a per-layer basis.
> Would it be possible to have a per-layer choice of graphical
> rendering engine (AGG, GD, OpenGL, ...) in Mapserver?
> Håvard
> --
> Håvard Tveite
> Department of Mathematical Sciences and Technology, UMB
> Drøbakveien 31, POBox 5003, N-1432 Ås, NORWAY
> Phone: +47 64965483 Fax: +47 64965401 http://www.umb.no/imt/
> _______________________________________________
> mapserver-dev mailing list
> mapserver-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-dev

More information about the mapserver-dev mailing list