I am working on a terraria-clone and I am aiming for it to be able to be run on most Android devices. I am able to generate a world, jump around, etc but I am not looking to add in some efficient lighting. In the past I have tried doing a tile-based lighting system but the project quickly came to an end after that because it dropped performance hugely. In that demo I was drawing a transparent black square over each tile and setting the alpha value dependent on surrounding lights. I envision that this will not be efficient on mobile so I don't even know if I want to go down that road. I don't need the shadows or anything like that (as of right now), I just need the lighting portion implemented. I have also looked at the other suggestions on the page here but am not sure which is the best option.
If tile-based lighting is the way to go I'd have to think of the best way to go about it. I don't think that it would be a problem to just have it work with a torch giving off light and only updating light values when a light source is added/removed, but when entities are incorporated I also have to think about how will I efficiently update an entities light value based off of surround light values. I have optimized the game a lot so far, with a world of 1,620,000 tiles being contained within it and getting a stable, smooth 30 fps even on mobile. I haven't attempted creating larger worlds than that but I don't see why, at this rate, it wouldn't be able to become any larger. I am trying to keep it as optimized as possible throughout development of the entire game so coming up with an efficient, optimized lighting system is essential.
Any suggestions are greatly appreciated.