For a game I'm making (similar to games like Terraria, Starbound etc.) I want to ensure that the framework is as modder friendly as possible. This leads me to wonder if it would be too inhibitive to modders if I only allowed them to create one sprite, then the game flips the sprite depending on what direction you're walking/facing. The only reason I want to make the game flip sprites is because my file structure is already horrible, and I feel like creating another right/left folder would make the whole think even worse.
Using an atlas:
You can pack the left and right versions into a single texture for each sprite, and only swap UV's based on the player's direction.
Although you may put only left/right images into the textures, will your modders?
A few descriptors to think about:
bool AutoFlip; //Swap UV's based on L/R? bool ReverseTextures; //Reverse standard "autoflip" direction - who know's why... bool MirrorUVx; //Backwards? - who know's why... bool MirrorUVy; //Upside-down? - who know's why...