A.D.A. Amiga Demoscene Archive

Hi,
did anyone made a vertical copperscroll or knows how to do this? I want to make a game scrolling vertical like swiv or Xenon.
I'm not very familiar with asm because I'm a BB2-coder. but afaik it has an inline assembler.
those tutorials in the web and in this forum couldn't help me. it seems like i have to write my own copperlist for that. so its just a wait for a y-position and then setting a new position to where the bitmap starts. don't sound that hard but all this copper stuff confuses me.
any idea?

Hi

Exactly what are you confused over? The method you're describing is the correct one, though it implies some additional logic since any bitmap object crossing the line between the bottom of your bitmap memory and the top will have to be split in two and drawn in different parts of the memory.

There's another simpler method where you switch between two full backgrounds and display one typically over the course of 8 or 16 frames while the other "pre-scrolled" background is progressively drawn. This method needs more memory and drawing operations but frees you from managing copper lists and complicated blits.