Just wondered if there was a penaly for passing textures to my shader in four seperate textures or is it measurably faster to pass as a single (larger) texture ? I am miles away from exhausting my texture registers so have the "room" to take either approach.
I have buffered all my effectParameters, and am only updating my shader parameters when something has changed, and as I think I've read that "changing one value is roughly the same cost as changing multiple values, so if you do need to change a value, do them all". On that basis I am leaning toward keeping my textures in seperate Texture2D and avoiding the slight complexity of making a texture atlas with associated margin mipmap problems.
Please be aware I'm still stuck in Dx9 XNA4 territory, but I dont think that makes a difference from reading around the subject.