Originally Posted by invent
Copper Effect (Is this possible?).
If I had a 4 colour background can each scanline be changed (darker/lighter) to give the illusion of a gradient like shading? The left panel is the original image, the second panel has shading every 16 pixels, and the third panel is every 1 pixel scanline.
Does this copper effect slow down games in anyway or are there particular limits I need to be aware of.
Sure, a lot of games do this. The Copper has no built-in concept of backgrounds or gradients, and what you're doing is giving the Copper a program that basically says change this and that palette entry on this and that line, which means any other graphics using those palette entries will be affected in the same way.
The Copper programs do eat up a little amount of time, but unless you're changing f.ex. 16 colors on every single scanline (which is about the limit before it flows into the beginning of the next scanline so to speak) it won't matter much. In your case, changing the shades of blue one at a time at every 5 scanlines would probably look good enough.