[1.14.4] Any way to hook into Elytras code?

[SkylorBeck]

Sorry if you've seen this many times before. I've been looking for days about how to make an item work like Elytra. I found many posts where people have said it's not possible and many more where people have successfully done it. But not a single person has posted their code or explained how they did it. I've already stared at the ElytraItem.java and scoured through PlayerEntity.java and I just cannot figure it out.

 

So anyone have any ideas?

 

Thank you.

[MoxLotus]

Have you searched for usages of Items.ELYTRA?

In PlayerEntity I find a reference to a flag for "elytra flying".

There is also logic in ClientPlayerEntity that appears to submit a request for that flag to be set when the right conditions are met.

[SkylorBeck]

  On 2/6/2020 at 6:30 AM, MoxLotus said:

Have you searched for usages of Items.ELYTRA?

In PlayerEntity I find a reference to a flag for "elytra flying".

There is also logic in ClientPlayerEntity that appears to submit a request for that flag to be set when the right conditions are met.

Expand  

I did search for Items.Elytra and I also found that flag. I cannot seem to figure out how to trigger it though. 

Ah I see. 

if (this.movementInput.jump && !flag && !this.onGround && this.getMotion().y < 0.0D && !this.isElytraFlying() && !this.abilities.isFlying) {
   ItemStack itemstack = this.getItemStackFromSlot(EquipmentSlotType.CHEST);
   if (itemstack.getItem() == Items.ELYTRA && ElytraItem.isUsable(itemstack)) {
      this.connection.sendPacket(new CEntityActionPacket(this, CEntityActionPacket.Action.START_FALL_FLYING));
   }
}

FALL_FLYING appears to be a pose as I can only find it referenced here and in a pose list.

Here is what I have 

 

public class elytron extends ArmorItem{
    public elytron(IArmorMaterial p_i48534_1_, EquipmentSlotType p_i48534_2_, Properties p_i48534_3_) {
        super(p_i48534_1_, p_i48534_2_, p_i48534_3_);
        setRegistryName("elytron");}


    private void glide(PlayerEntity entity) {
        if (!entity.onGround && !entity.isElytraFlying() && !entity.isInWater()) {
            ItemStack itemstack = entity.getItemStackFromSlot(EquipmentSlotType.CHEST);
            if (itemstack.getItem() == elytronitem.elytronitem){
//MYSTERY ELYTRA CODE GOES HERE
            }
        }
    }


    @Override
    public void onArmorTick(ItemStack stack, World world, PlayerEntity player) {


        if (!player.onGround) {
            glide(player);

        }

    }
}

[SkylorBeck]

public void setElytraFlying() {
   this.setFlag(7, true);
}

 

Well I found this in ServerPlayerEntity.java. Right below it is 

public void clearElytraFlying() {
   this.setFlag(7, true);
   this.setFlag(7, false);
}

Seems like I need to trigger these.

[MoxLotus]

I'm looking at the 1.15 code, but it's substantially similar. My understanding is that when a player jumps in midair while Elytra are equipped, the client sends that packet to the server. The server receives the packet and double checks the criteria for flying.

public void processEntityAction(CEntityActionPacket packetIn) {

...

case START_FALL_FLYING:
   if (!this.player.func_226566_ei_()) {
      this.player.func_226568_ek_();
   }
   break;

The server calls another function which sets flag 7.

public void func_226568_ek_() {
   this.setFlag(7, true);
   this.setFlag(7, false);
}

[Draco18s]

See this bit?

  On 2/6/2020 at 6:59 AM, SkylorBeck said:

itemstack.getItem() == Items.ELYTRA

Expand  

This is the troublesome bit.

[SkylorBeck]

  On 2/6/2020 at 8:49 PM, MoxLotus said:

I'm looking at the 1.15 code, but it's substantially similar. My understanding is that when a player jumps in midair while Elytra are equipped, the client sends that packet to the server. The server receives the packet and double checks the criteria for flying.

public void processEntityAction(CEntityActionPacket packetIn) {

...

case START_FALL_FLYING:
   if (!this.player.func_226566_ei_()) {
      this.player.func_226568_ek_();
   }
   break;

The server calls another function which sets flag 7.

public void func_226568_ek_() {
   this.setFlag(7, true);
   this.setFlag(7, false);
}

Expand  

Yes exactly. In my mappings 

public void setElytraFlying() {
   this.setFlag(7, true);
}

public void clearElytraFlying() {
   this.setFlag(7, true);
   this.setFlag(7, false);
}

is what I need to trigger. I cannot find Fall_Flying in anything but 

 public static enum Action {
      START_SNEAKING,
      STOP_SNEAKING,
      STOP_SLEEPING,
      START_SPRINTING,
      STOP_SPRINTING,
      START_RIDING_JUMP,
      STOP_RIDING_JUMP,
      OPEN_INVENTORY,
      START_FALL_FLYING;
   }
}

 

  On 2/6/2020 at 8:52 PM, Draco18s said:

See this bit?

This is the troublesome bit.

Expand  

Ah, the guy who always tells everyone it can't be done is here. I am aware. That is why I replicated that code in my code shown above. I know it can be done and I know to use the search function. I know minecraft calls from PlayerEntity and not from Elytra. I've seen every comment you've posted about Elytra and if you're going to tell me that it's not possible like you have everyone else who tried, please leave.

Edited February 6, 2020 by SkylorBeck

[SkylorBeck]

  On 2/6/2020 at 8:49 PM, MoxLotus said:

I'm looking at the 1.15 code, but it's substantially similar. My understanding is that when a player jumps in midair while Elytra are equipped, the client sends that packet to the server. The server receives the packet and double checks the criteria for flying.

public void processEntityAction(CEntityActionPacket packetIn) {

...

case START_FALL_FLYING:
   if (!this.player.func_226566_ei_()) {
      this.player.func_226568_ek_();
   }
   break;

The server calls another function which sets flag 7.

public void func_226568_ek_() {
   this.setFlag(7, true);
   this.setFlag(7, false);
}

Expand  

Can you tell me where you found that Fall_Flying case? That seems like a good missing piece of my puzzle.

[Draco18s]

  On 2/6/2020 at 9:11 PM, SkylorBeck said:

I know minecraft calls from PlayerEntity and not from Elytra. I've seen every comment you've posted about Elytra and if you're going to tell me that it's not possible like you have everyone else who tried, please leave.

Expand  

I have never said it's not possible, I've said that you have to replicate the behavior yourself in an event handler because the vanilla code cannot be used.

Edited February 6, 2020 by Draco18s

[SkylorBeck]

  On 2/6/2020 at 9:25 PM, Draco18s said:

I have never said it's not possible, I've said that you have to replicate the behavior yourself in an event handler because the vanilla code cannot be used.

Expand  

and as you can see, I have already done that. 

  On 2/6/2020 at 6:59 AM, SkylorBeck said:

 

    private void glide(PlayerEntity entity) {
        if (!entity.onGround && !entity.isElytraFlying() && !entity.isInWater()) {
            ItemStack itemstack = entity.getItemStackFromSlot(EquipmentSlotType.CHEST);
            if (itemstack.getItem() == elytronitem.elytronitem){
//MYSTERY ELYTRA CODE GOES HERE
            }
        }
    }


    @Override
    public void onArmorTick(ItemStack stack, World world, PlayerEntity player) {


        if (!player.onGround) {
            glide(player);

        }

    }
}

Expand  

Please stop derailing the thread by being a jerk for no reason.

[MoxLotus]

  On 2/6/2020 at 9:19 PM, SkylorBeck said:

Can you tell me where you found that Fall_Flying case? That seems like a good missing piece of my puzzle.

Expand  

In ServerPlayNetHandler::processEntityAction

 

But if you call that setElytraFlying method from PlayerEntity does that have the desired effect? The setFlag method is protected, but all setElytraFlying appears to do is set it. I don't see any additional checks after it is called. It won't fully replicate the behavior of Elytra, but my guess is that it is in charge of the flying part.

[SkylorBeck]

  On 2/6/2020 at 9:39 PM, MoxLotus said:

In ServerPlayNetHandler::processEntityAction

 

But if you call that setElytraFlying method from PlayerEntity does that have the desired effect? The setFlag method is protected, but all setElytraFlying appears to do is set it. I don't see any additional checks after it is called. It won't fully replicate the behavior of Elytra, but my guess is that it is in charge of the flying part.

Expand  

Thanks for the info/idea.

 

If I try to call setElytraFlying like so,

public void glide(PlayerEntity player) {
    if (!player.onGround && !player.isElytraFlying() && !player.isInWater()) {
        ItemStack itemstack = player.getItemStackFromSlot(EquipmentSlotType.CHEST);
        if (itemstack.getItem() == elytronitem.elytronitem) {
            player.setElytraFlying();
        }
    }
}

I cannot resolve setElytraFlying in PlayerEntity. If I change it to 

public void glide(ServerPlayerEntity player) {

then it calls but then the onArmorTick doesn't function anymore as 

@Override
        public void onArmorTick (ItemStack stack, World world, PlayerEntity player){
            if (!player.onGround) {
                glide(player); }

}

is calling for a PlayerEntity. If I changed that to ServerPlayerEntity then the @Override stops working because Method does not override Method from Super.

 

I really feel like I'm missing something here. 

[larsgerrits]

Check if the player is an instanceof ServerPlayerEntity, then cast.

[MoxLotus]

ServerPlayerEntity extends PlayerEntity. No idea where which one is used, but you can run an instanceof and try casting. And yes, changing the method signature would invalidate the @Override, but basic Java is normally outside the scope of this forum.

You can try:

if (player instanceof ServerPlayerEntity){
    ServerEntityPlayer serverPlayer = (ServerEntityPlayer)player;
    glide(serverPlayer);
}else {System.out.println("player is not a ServerPlayerEntity :(");}

and feel free to look up appropriate Java tutorials for casting and polymorphism.

 

But like I said, I'm not sure exactly when PlayerEntity is or is not an instance of ServerPlayerEntity.