Testting multiple coplist in the 1 display

Longer time past than I expected.

I saw multiple coplist in a single diplay when I see the source code of ACE. The ACE is one of blliliant game in Amiga Blitz Basic Jam 2022.

The first cop is used for main screen of the game and another one is used for game dock. The game dock displays life, pause state, etc. My shooter game doesn't split score&life area and main game area. This means, I should check shapes and sprites are not overwrite to score&life area for every frame. I'm not sure, but I think to separate those area to multiple coplist probably good for performance. At least no more boundary check myself (I hope). 

So, I tested how to use multiple coplist in 1 display. Here is a test screen. Upper area displayed boxes is height=16, and below area displayed circles is  height 200-16 (NTSC). I saw there is a 2pix gap between 2 coplists. This test code doesn't use dualfield, smoothscroll, sprite yet.

One more thing I tested. The ACE creates one more coplist for title screen. So, it looks switching display from title to game stage and vice versa. I could not find how to switch 2 display below in the manual.

CreateDisplay 0        ;Coplist#0 for title screen

CreateDisplay 1, 2   ;Coplist#1 for game dock and #2 for game stage

->>how to switch?

Maybe I can use single display in blitz mode (?) and the first display will gone (or re-initialized by) when I call another CreateDisplay. For now, I would switch like this,

When game mode changes -> if gamemode=0 then CreateDisplay 0 else CreateDisplay 1,2