[Qgis-developer] Student Projects

[Manuel Massing]

Hi,

> - read in the window for the raster to match the current map view (which is
> resampled to match the display resolution and fetching only the required
> bands for display) using gdal (as currently implemented in QGIS) but with
> an additional bit to account for post reprojection rotation. - reproject
> by internally using the same api calls that gdal_warp uses - display

I suspect this is what's already happening when opening a rotated raster,
or a raster with GCPs (see QgsRasterLayer::readFile). Such files are
wrapped in a VRT file by readFile. This leads the gdal VRT driver to
transparently apply on-the-fly reprojection. 

If I recall the VRT implementation correctly, it does already choose 
reprojection windows adaptively, and so should be usable if nearest
neighbor resampling  is used and pyramids are available.

It might be worth a shot to just extend the VRT wrapping case to
include coordinate system transforms for a quick implementation.

Regards,

	Manuel