Viable objects for Parallaxing?

Pretty simple; what objects/extensions can be displayed behind the backdrop layer? Assume my game can only use a single layer, and *has* to draw the level with backdrops, not using text blitters or overlays (it really does have to), then what objects can I display behind the backdrops in order to do parallax? I've been putting together the Backdrop Images object, but I'm not too sure about it, since it reduces my project from 50 FPS to 48 or so FPS, with spikes down to 45. Perfectly acceptable for an end product I guess, but theres tons of work to be done, and that means it will be even slower.


so what objects have that 'Displays as Backdrop' option?

Anything "dynamic" drawing as backdrop is going to be a speed hit, especially if you have other backdrops on top as well.

Why can't you use layers?

The trouble with layers and scrolling at the moment is that Layer 1 is always the "base" layer with a pre-calculated collision mask and everything else is moved around on top of it, which results in a lot of slowdown if you have a complex and large level over the top.

I've reverted to using the Background System Object for some of my backgrounds... other than that I get a bit stuck.

I managed to fix the problem in a sort by using *no* overlays or text blitters, and instead drawing the level entirely as Added Backdrops from the Active Picture object; all on the same layer, pasted in order of back to front, with just one being the obstactle layer, and then heres the key bit;

I just deactivated "Check Collision Mask in Invisible Playfield"

Since the collision mask array would have to be *huge*, since most of the level is covered with 32x32 pasted obstactles, over 15000 of them perhaps, then making it only check the 640x640 play area sped it up a ton. Just means I'll have to deactivate monsters offscreen, but thats something I'm not opposed to, terribly. Elsewise, I could write a hybrid system that just checks the array for collision, so fine detail inside each 32x32 square is lost, but you wouldn't notice much because these enemies are offscreen!

But I don't know about the Background System Object. How can you load images into it at runtime? Am I missing something? :( So I guess I'll stick with the Bacground Images Object, which is working pretty fast even with 2 of them with 640x640 patterned images each, even under rotation effects.