I totally want to add texture packing support to nxPascal. Important thing just is that it has an editor that is full featured and free. I made one such simple packer for bmp files many years ago so there is some code base.

I also discovered the difficulty of making such algorithm that would make the tightest possible fit... and it really is a complex mathematical problem. Because there may be 1000 sprites where each have millions of choices for possible location. So what i did was simple "magnetic pull" on sprites towards top left corner and was able to move obstacle sprites around with cursor Because for some problems human eye can see things quicker.