Don't initialize in ref(), it's wasteful
Get rid of ugly pointless goto
Use a "texture atlas" for faster operation
Support multiple render passes
Don't interpolate alpha pointlessly
bleh
Initialize member variables
Don't convert to screen format, it's not being blitted to-screen
.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	main.cpp
	texture_filter.hpp
fixed merge conflict in texture_filter.hpp