RM2K(3) BUGFIX PATCH/IPS: CONSISTENT Z-ORDER OF EVENTS WHICH ARE ON THE SAME TILE, FINALLY!

Hello guys! I came across a problem user Tor_Heyerdal had, about events which are on the same tile and "randomly" switched their priority/z-order when panning the screen.

It looks like this problem always existed in RM! In particular, it works like this: When you move events (which are on the same layer, e.g. same-layer-as-hero) onto the same tile, weird things happen. The RM will use a comparison method based on Y position, whether it is the hero or not, and X position, in that order, to determine the order in which the events are drawn. However, if all of these are the same, the actual order depends partly on the event ID, but partly on the other events in the visible area and maybe the moon phase and the size of your shoes, because it is actually undefined behavior.

For example, I have these events (below you can see the event IDs):


Now, I move the outer two events onto the middle one. What happens is this mess:


Note how the order changes when the hero walks past them! >_<

(In this simple example, only the vertical position caused the events to switch their priority, but in more complicated scenarios like the one Tor_Heyerdal had, also the horizontal position caused weird changes like that.)

My solution to bring order into this mess is to add another step in the comparison of events to determine their order: The event ID. Higher IDs are drawn on top of lower IDs (as you would expect, e.g. from pictures). So, the comparison is now Y, hero-or-not, X, event ID.

The result looks like this, and stays this way regardless of where the hero or the map are positioned:



That's much nicer, I think!

I built a patch for RM2k3 v1.08 to achieve this (works also with DynRPG). To apply the patch, download this IPS file and patch your RPG_RT.exe with it (or put it into the DynPatches folder if you use DynRPG version 0.20+): http://share.cherrytree.at/showfile-25860/rpg_rt_with_event_id_fix.ips

EDIT: Here also for RM2k v1.07: http://share.cherrytree.at/showfile-25862/rpg_rt_2k_with_event_id_fix.ips

EDIT2: On second thought, though, I'm not sure if the solution is ideal. Maybe it should use the event ID in the check instead of the X position check? Because now, with the current solution, the order will change when the event is walking around horizontally, in an unexpected way (e.g. when an event walks behind a box). However, some people may depends on the X position order in some way, when events are wider than 16 pixels... What do you think? This is what I mean:


EDIT3: Since Tor_Heyerdal actually needed it without the X check as it turns out, here is the version with only Y, hero-or-not and event ID in the comparison (no X), for RM2k3 v1.08 only: http://share.cherrytree.at/showfile-25872/rpg_rt_108_fixed_without_x.ips

(I will also add this in the next official update of RM2k3.)

Enjoy your new nice and tidy event order!
Cherry