Sorry for not describing my problem better.
What I want to do is to have multiple "shaded" textures at the same time.
So for instance, I want to not only be able to have this tutorial's "shaded" texture rendered, but another texture too, a character for example.
See here for example:
The background wall and the character are both "shaded", whereas the tutorial shows us how to do this for just one texture. How can I accomplish this in an effective way?
I'm pretty sure my problem is that I don't understand GLSL that good yet, but if someone explained this to me it would really help me understand it.