I am playing around with the bloom shader from the XNA sample page, to do some glow shading. I am rendering primitive vector-ish squares of linelists/linestrips, on a background. However, I am facing a few problems.
With a black background and white squares, I can actually see the squares. However, with a white background and black squares, I can't see them at all.
Why is this happening, and is there any way of me fixing it?
Can I modify my bloom shader to also "glow" dark elements, if that's what is causing it?