Right now when I use gradient tool, I have to create a new layer if I want to use it again. If I keep the same layer and want to add the gradient from another direction (for example if I want to do a vignette effect and want to put a gradient on all four corners of my image), it removes the gradient that was just created and replaces it with the next one I do, so that if I want to have the gradient on all four corners, I have to create a new layer for each corner. I would like them all to be on the same layer please.