[Fixed][Bug][Player/Editor] Flipped/Face Left hatches have a different behavior

[IchoTolot]

This is probably a sideeffect from the intended change to merge "face left" and "flip".

I strangely noticed more and more replays failing out of nowhere not changing the converted level and the old replays even passed several times before.
After more investigations I found the cause: I usually set my left facing hatches to "face left" in the old format  -- they kept their original apperance but spawned to the other side. Now this option seem to be replaced with "flip graphic" entirely. So far so good. This causes levels to fail because some of the now flipped hatches have different spawn points now as it's not in the same spot anymore after the flip.

So far still acceptable -- a few failing replays but managable.

BUT: This is extra devious here as those breaking levels are not detected naturally by the checker! No, the cases will only fail (as with the pick-up stuff: https://www.lemmingsforums.net/index.php?topic=3711.0) after you manually load the level into the editor after the conversion and then save it again --- the hatch is now flipped, the spawn has changed and the replay fails.

So I would advice to bring back the "face left" behavior at least for hatches. Or we simply have to manually check and save all of our levels one at a time to identify errors making mass conversion mostly pointless and increase the conversion workload dramatically.

EDIT:
Idea: "Flip" only does the old "face left" for hatches.
To clarify again -- the main problem I would still call is that the automatic replay check doesn't cover this. With that working fixing replays won't be much of an issue. I just figured that my idea is easier to do than getting the checker to cover this.

[Nepster]

Again the problem is not the merge of "flip" and "face left", it is that the NL player still allows only "face left" without a "flip". For the next update I plan to add this to the player, so that this breacking change will already be detected by the mass replay checker.

[IchoTolot]

That would be nice, thanks!

Redoing a few replays if you know exactly where you need to act won't be much of a problem then. Also I think not every hatch seems to be affected as some flipped ones still have the same physics as the non flipped version.

[GigaLem]

Again the problem is not the merge of "flip" and "face left", it is that the NL player still allows only "face left" without a "flip". For the next update I plan to add this to the player, so that this breacking change will already be detected by the mass replay checker.

Thinking about this now, it might help in the long run. They both mean the same thing so I say go for it

[Proxima]

One issue I can see is that it's possible there may be hatches -- currently existing or in the future -- in shapes, for instance a house with a door at the side, where you would want to flip the graphic as well as the spawning direction; but with the hatches from the L1 sets, you'd want the graphic to remain unflipped. So I think it's worth keeping "flip" and "face left" separate. Simon correctly points out: in my "house with door" example, it would be better to make two objects, so that you can have both a left-hatch and a right-hatch with correct shading. So I prefer hatch graphics to never be flipped, and can't see any major downside to that solution.

[Simon]

Interesting issue.

What is the exact history here? 2016 NL allowed all 4 possible combinations of face-left and mirror-image, then 2017 NL pruned it to 2 of the 4, no-flags and face-left-and-mirror-image? Do level designers accept that face-left then breaks the shading/lighting of the tile?

-- Simon

[IchoTolot]

Interesting issue.

What is the exact history here? 2016 NL allowed all 4 possible combinations of face-left and mirror-image, then 2017 NL pruned it to 2 of the 4, no-flags and face-left-and-mirror-image? Do level designers accept that face-left then breaks the shading/lighting of the tile?

-- Simon

It breaks the shading/lighting of the tile yes, therefore I always used the old "face left" option  ---> I now have the trigger area issues. I still prefer the old way as you had total control over this matter. But I now just assumed here that Nepsters implementation and decision was final and I didn't want to cause another controversy.

[Nepster]

First of all: I want to restrict the designer's options to one flipping option and not have two options "flip" and "face left" that may confuse level designers (at least it has confused me). There have to be a lot more important issues than the shading of hatches (which is only one type of objects!), before I will even consider going back to the old options.

Regarding the hatch issue: While we have the arrows that appear when hovering over the hatches, I prefer to have an always visible way to distinguish them. And the easiest way of doing so is to tightly couple the lemming direction with the flipping of the graphics.

Moreover if you have all hatches facing left in your level, then just mark everything in the new editor and click "flip". This will flip the whole level (not just each piece separately!) and you will get correctly shaded hatches (though you might have to slightly adapt some other object positions). So the hatch shading is only an issue, when there are both left-facing and right-facing hatches. And especially in such cases a direct visual clue to this fact is important in my opinion. 

[Proxima]

Regarding the hatch issue: While we have the arrows that appear when hovering over the hatches, I prefer to have an always visible way to distinguish them.

We discussed that point in the chat last night. The shading being wrong is too minute a difference to be a good distinguisher; most players won't notice it, and for those that do, we don't want to be teaching players that paying attention to minute details of graphics is a big part of the game.

[Nepster]

We discussed that point in the chat last night.

Sorry, but I could only find your discussion with Nessy, who is indifferent about this.

The shading being wrong is too minute a difference to be a good distinguisher; most players won't notice it, and for those that do, we don't want to be teaching players that paying attention to minute details of graphics is a big part of the game.

If most players won't notice the shading, then flipping the graphics won't hurt them, so we can keep the current behavior.

[IchoTolot]

I think they will notice the wrong shading, but won't connect it with left-spawing hatches, leaving just an odd sight.

[Simon]

I wouldn't mirror the sprite and let the flag change only the spawn direction. If hatch direction must be visible even during the first 3 seconds of a map, consider extra markers. Reason:

• If players don't see the difference in shading, then mirroring the sprite has no effect at all, and both mirror-sprite and never-mirror are equally good solutions.
  
• If the shading is subtly wrong, then some players will notice, and it won't shine well on the level designer -- did they really not catch such a visual error during design? And the marking is still unclear for other players, thus doesn't tell apart left-facing hatches from right-facing hatches. I assume most hatches will have such subtly wrong shading if mirrored. The discussion should focus on this case.
  
• If the tile is clearly mirrored, then it might reflect weirdly on the level designer, but not in every case. Direction will be easily apparent. Some hatches have this: The medieval dragon and the highland barrel. This is the best possible case for merge-mirror-and-face-left.

-- Simon

[IchoTolot]

If hatch direction must be visible even during the first 3 seconds of a map, consider extra markers.

Maybe do a sort of like solution related to: https://www.lemmingsforums.net/index.php?topic=3711.msg69356#msg69356

Display the direction with an arrow directly in the first 3 seconds of a map. After that let the arrow disappear again as the lem flow will show the info after that.

So basically the old "face left" behavior combined with these temporal arrow markers I would call a solution that solves all problems -- visual correctness, stable physics and info displaying.

Right now the forced flip for those hatches seems like a "Verschlimmbesserung" (improvement in one part, downgrade in another).

[IchoTolot]

Thinking more about my solution: I found another thing were this temporal arrow display method (preferably a few pixels under the hatch's trigger area) is vastly superior than the graphic flip.

Hatches on top of each other that spawn in different directions! With the arrow display a <--> should be appearing (combination of <-- and -->), giving a correct display of the situation even before the level starts. The graphic flip doesn't cover this.

[Ryemanni]

I was going to post a rant inspired by yesterdays Lix session, but now anymore since the arrow idea has been presented. I highly suppor the arrow instead of flipping the entire hatch graphics.