Yay, fps boost
My bucket sort was a total success: about 1/3 more fps than before! Yep, was totally worth I'd say. I was able to increase the number of automatically sorted sprites up to 2080 with around 30 compared to the 20 I got with no bucket sorting. The higher the amount of sprites goes, the more one will notice the speed gain (for around 8000 sprites it's four times faster than insertion sort variant) but I doubt I'll render THAT much stuff on screen. It's for simple stuff after all - totally enough. I'll update the demo as soon as I get a bit of rest, worked all night on that stuff. Also, one can now define the z axis ordering on his own, choosing the best behaviour for his own code.