AW: [Qgis-developer] Raster rendering difference tracked down

[Hugentobler Marco]

Hi Peter,

Ok, looks like it is an issue introduced by me. I will investigate.

The raster scale factor for rendering should always be 1.0 in the main map canvas (it is different only for map composer).

Regards,
Marco



-----Ursprüngliche Nachricht-----
Von: qgis-developer-bounces at lists.osgeo.org im Auftrag von Peter Ersts
Gesendet: Mo 14.07.2008 16:47
An: QGIS Developer Mailing List
Betreff: [Qgis-developer] Raster rendering difference tracked down
 
Tim and Marco,

Here is a little update. I have tracked down the difference in rendering 
behavior, which is causing the two units tests to fail, to revision 
8440. This was the merge into the trunk of the Render Context Branch. 
More specifically, I believe the difference has to do with the scale 
factors that are being computed in QgsMapRender.cpp.

As it is right now, I will say the test results for the landsat_basic 
looks like it has artifacts compared to the expected result in the area 
being marked as different. However, when you load the original raster 
data for the landsat_basic test and 'Zoom to best scale' the displayed 
result does not exhibit any artifacts. So I think the next logical place 
to start digging around is the QgsMapRender->setExtent() and looking 
more at the scale factors, unless anyone has other ideas.

-pete

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Peter J. Ersts, Project Specialist
American Museum of Natural History
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