Fix glitch that jolts players up edges

[jordan4ibanez]

• Goal of the PR
  Fixes a glitch that jolts players up edges of nodes. "The Boink™"
• How does the PR work?
  Makes sure that the thing is firmly on the ground before committing to step up.
• Does it resolve any reported issue?
  No idea

To do

This PR is Ready for Review.

How to test

Try to make "The Boink™" happen with this change.

Here's a youtube video showing it in action for some reason. https://youtu.be/38UbIPhHimk?feature=shared

[SmallJoker]

This may look like it causes some strange side-effect in gameplay but I found that there's no difference in the maximal node climbing height with or without the sneak glitch being active.

[Desour]

Shouldn't there be a physics override or so for this? I can imagine players complaining about pvp or parkour disadvantages with the new version.

[SmallJoker]

@Desour Would you please be so nice to provide an example where this change breaks a specific movement? If the node is too high to jump onto, the code will be executed when the player is about to fall down. I can imagine that the hiccup (that is already present in master) would only be delayed by a few milliseconds, thus not break anything. The player (or entity for the matter) would still be put on top of the node.

Unless there's a clear negative difference in gameplay, I think that customizing this behaviour introduces unnecessary code and maintenance bloat.

[Desour]

Example:

• Build a staircase (with normal cube nodes).
• Hold jump and forward, to jump upwards.
• => You're faster in master. (Haven't measured, but it definitely feels faster.)

[SmallJoker]

Right. Teleporting up (what step-up does) effectively makes you move faster. That is a logical consequence of getting rid of the hiccup.

[jordan4ibanez]

I just came back to say hi again

[Zughy]

So is OP expected to add a physics override option (due to the label) or is it fine and we can proceed?

As someone who follows speedruns, it happens many times that new games get patched and speedrunners have to find a new way (shorter or longer) for a new record. I think this is no big deal, especially if we consider that it means more code burden for us - and it's not like there aren't many movement bug issues already. It takes no time to a server admin to remove one sec from the scoreboard to everyone (and frankly I don't know servers that feature time trial parkours anyway)

[jordan4ibanez]

So is OP expected to add a physics override option (due to the label) or is it fine and we can proceed?

As someone who follows speedruns, it happens many times that new games get patched and speedrunners have to find a new way (shorter or longer) for a new record. I think this is no big deal, especially if we consider that it means more code burden for us - and it's not like there aren't many movement bug issues already. It takes no time to a server admin to remove one sec from the scoreboard to everyone (and frankly I don't know servers that feature time trial parkours anyway)

Please let me just merge this in so we can stop dealing with bugs and not harbor them anymore

[Desour]

I don't remember having seen any speedrunning in minetest either. But as said, this gives a pvp disadvantage. For some users it will be a reason to not upgrade.
We already have similar physics override flags, I don't see why there shouldn't be a new one for this case.

[Warr1024]

For parkour games, the big impact won't be stair climbing times, but jumps that used to be barely possible due to the "ledge grab" no longer being possible and requiring entire map areas to be reworked.

If an override is available for this, I would enable it and keep the legacy behavior at least in NodeCore (though I would try the new physics first in my other games), since hyper realistic movement is not a design goal and excess realism is likely to distract from the game. If no override is available then I will probably just have to tell players that it's something outside of my control and they need to either adapt to it, or file an issue here.

[sfan5]

There have been enough uproars about the engine changing existing behaviour or "pulling the rug".
Proposing to just stop dealing with bugs and merge a breaking change anyway is not productive.

[appgurueu]

I think a physics override is insufficient: The code modified by Jordan applies to entities and players alike; this patch would hence also apply to entities with a stepheight > 0. We'd need an object property.

[Zughy]

@jordan4ibanez still want to work on this? @minetest/engine thoughts about what appguru has said?

[jordan4ibanez]

@jordan4ibanez still want to work on this? @minetest/engine thoughts about what appguru has said?

You can steal it if you want

[Zughy]

No no, just wanted to know if I had to close it

[jordan4ibanez]

Oh yeah go for it