[Gdal-dev] Floating point pixel coordinates and scaling

[Rolf Magnus]

Hi!

I'm currently writing a moving map program for KDE that uses gdal. Basically, 
I just use GDALDataSet::RasterIO in my paint event handler to get the pixels 
that I need to redraw when some parts of my view get exposed. This is very 
fast, even when I let gdal scale it on a slow PC.
Anyway, I've got one specific problem with the scaling. When the image is to 
be scaled up, the input coordinates might not lie on an exact pixel boundary. 
I would need a way to specify e.g.  that I want to start at pixel coordinates 
200.125/150.25, which is not possible, because RasterIO wants integer 
coordinates. I can work around that problem somehow, but I think it might be 
a good idea to solve it in gdal itself. What do you people think about that?