More on dinamyc maps...

Well people,
i have spent most of yesterday thinking about this. And the conclusion is that there is no wasy way, nor perfect solution.

This is the approach i am going to follow:
1) reduced chunks to 9 (3x3 matrix) and increased size to square chunks as big as the main window
 2) reload chunks from disk as in previous post

This will ensure that maps fitting into memory (about 1800x1800px on S60v5 devices, something more on Symbian^3) will still be as fast as possible (no reloads), bigger maps will be loaded albeit quite slowly.

One possible optimization is to cache the image chunks as uchar buffers (after reducing to 8bit and such to save disk), to avoid very slow jpeg decompressions...

I could use libjpeg, which has been ported to Symbian, but what about PNGs? So i prefer to avoid this right now. For very large bitmaps (above 3000x3000px) probably BMPs are faster?

Still, i have to implement the zoom...