Custom Elytra

[HashtagShell]

Say I want to add elytra that behave motion-wise in a similar fashion of vanilla's but with some tweaks, say, custom colour or whatever.

Every tick almost at the end of EntityLivingBase#onLivingUpdate, EntityLivingBase#updateElytra gets called, which checks for the one and only vanilla elytra by reference comparison, and if (not) present in the chest armour slot, is sets the 7-flag (elytra-flight) to true (false).

The method updateElytra() gets called immediately before EntityLivingBase#moveEntityWithHeading, which calculates the motion of elytra flight, but only if flag-7 is true (through EntityLivingBase#isElytraFlying), so there is no point of entry to set the flag manually (in an armorTick or whatever).

One could replace the player entity with a subclass that overrides EntityLivingBase#isElytraFlying, but that seems awkward to do.

Coremodding can always be used, but never should.

The last idea I have is just bailing on the vanilla code, and applying motion calculated by an equivalent (heh, copy&paste) algorithm directly from the custom item. This doesn't seem update-proof however, what if Mojang changes the algorithm? (Probs not an issue, but still)

 

Lastly, if I decide to go with the third option, which seems the most sensible, what if the custom elytra are meant to be won in, say, the leggings slot, and the player simultaneously equips regular elytra?

 

Any other ideas or arguments pro/contra my ideas are greatly appreciated.

[Draco18s]

  On 4/16/2017 at 3:00 PM, HashtagShell said:

The last idea I have is just bailing on the vanilla code, and applying motion calculated by an equivalent (heh, copy&paste) algorithm directly from the custom item. This doesn't seem update-proof however, what if Mojang changes the algorithm? (Probs not an issue, but still)

Expand  

This until Forge patches it.

[HashtagShell]

The reference comparison is also made in NetHandlerPlayServer#processEntityAction for players.

 

Another issue with that idea is that motion isn't everything, there are the client-side controller checks to start flying, the player renderer, the elytra model... all these things check EntityLivingBase#isElytraFlying.

It just doesn't really seem feasible.

[Draco18s]

Make a Forge pull request changing the == to an instanceof check.

[HashtagShell]

Just a simple instanceof? I didn't think about that. Great, imma do that.

[Draco18s]

Mind, when it goes under review, Lex or someone else might have some comment on how to improve it, or something. Or why it won't work, or....

Be prepared for that.

And check to see if there's already a PR open for it.

[HashtagShell]

There's won't-fix about generic movement events here (https://github.com/MinecraftForge/MinecraftForge/issues/2859), but not closely related.

Other than that no issues or PRs pertaining to elytra that are at least somewhat relevant.

Can't see why instanceof wouldn't work, but it is so simple a solution there may well be some amendments.

Thanks for the support