With regards to to the border, should you not just copy the pixels out to the edge (depending on the amount of border) ? But then if you do that it would lose its seamlessness? The same would happen if you copied from the opposite edge if you had a larger then 1 border. I think anyway… I might be getting confused (which I probably am!) but I’m starting to think that borders are only really useful for tilemaps, whereas this is just creating seamless textures which could be sorted by clamping uvs? or something…
Copying images out of the tile sheet is incredibly inefficient as it’ll require changing the texture between draw calls if each sprite uses a different frame, right now I can just change the UV for each rect(or vertex, for point sprites) and simply draw hundreds of animated particles in one go, which is very efficient. However, this also means that the whole animation is shared across the texture, so clamping doesn’t do anything useful. This is why having a border that has the tiling built in saves some computation, right now I’m offsetting the UVs into each cell by half a pixel so it’s not an issue for me. It just struck me as strange, as I don’t see how a transparent border would be useful. I’ve seen coloured(i.e. pink) borders used in complex animation sheets for characters and stuff, but these particle sheets always contain different sized cells, TimelineFX exports each cell as the same size so I’m not sure how useful such a border would be.