* Well, of course, one box may effect 2 or 3 blocks.
160*160 block size:
Shadow Layer ~= 2kb
Light Layer ~= 1.5kb
So, both layers (48 images) would take about 84kb with 20*15 tiles map size.
I'll try to implement this method during further versions.
For now, I've driver problems that concerns Windows Vista and Win7.