Struggling a little with client-side vs server-side in a very simple mod

[kriNon]

Hey all,

So I'm working on what is pretty much my first mod, and I am aiming for some very simple functionality. What I want to do is make it so that if the player is in dimension 3 the mod will set event.player.capabilities.isFlying = true.

Here's the code for the class that I'm working on:

package kriNon.mods.ModpackMod;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraft.util.ITickable;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.fml.common.gameevent.TickEvent;

public class DimensionFlight
{
    @SubscribeEvent
    public void onPlayerTickEvent(TickEvent.PlayerTickEvent event)
    {
        if (event.player instanceof EntityPlayer) {
            if (!event.player.getEntityWorld().isRemote) {
                return;
            }
                if(event.player.dimension == 3){
                    event.player.capabilities.isFlying = true;
                }
        }
    }
}

Now the issue I'm having is that the third if statement (the one that checks if the player dimension == 3) will crash the game. I believe I may be going wrong because the client side does not know what dimension it is in (i believe this might be handled only on the server side). How would I best be able to combat this problem? A simple solution would be ideal so that I may better understand it!

 

Thanks!

Edited May 29, 2018 by kriNon
updated code

[Animefan8888]

Please post the crash report and always post the crash report when there is one.

[kriNon]

Alright, so after compiling the code again it no longer causes crashes however the crash I was getting was this: https://pastebin.com/yNgNKfdU

I'm not quite sure what I did to fix the crashes, but nonetheless the code works fine without the 

if(event.player.dimension == 3){}

(albeit flight occurs in all dimensions)

However with the if statement flight will never occur (not even in dimension 3)

[Animefan8888]

Try changing

if (!event.player.getEntityWorld.isRemote)
  //to
if (event.player.getEntityWorld.isRemote)

 

[kriNon]

Yeah doing that does nothing, I suspect that

event.player.capabilities.isFlying = true;

needs to be done on the client, not the server.

[Animefan8888]

Just now, kriNon said:

Yeah doing that does nothing, I suspect that

event.player.capabilities.isFlying = true;

needs to be done on the client, not the server.

That is not possible because the Server manages all of that information. Did you crash when you changed that, was it the exact same? Does the crash change or occur when you launch it without other mods?

[kriNon]

So just for simplicity, ignoring the second if statement.

This works:

if (event.player instanceof EntityPlayer) {
            if (!event.player.getEntityWorld().isRemote) {
                return;
            }
            event.player.capabilities.isFlying = true;
        }

But this does nothing:

if (event.player instanceof EntityPlayer) {
            if (event.player.getEntityWorld().isRemote) {
                return;
            }
            event.player.capabilities.isFlying = true;
        }

No crash. The crash did occur with other mods, but I rechecked it and it is no longer an issue (no idea why, maybe I changed the code somewhere and forgot), but the crash is no longer happening under any circumstance.

[Animefan8888]

Just now, kriNon said:

So just for simplicity, ignoring the second if statement.

This works:

if (event.player instanceof EntityPlayer) {
            if (!event.player.getEntityWorld().isRemote) {
                return;
            }
            event.player.capabilities.isFlying = true;
        }

But this does nothing:

if (event.player instanceof EntityPlayer) {
            if (event.player.getEntityWorld().isRemote) {
                return;
            }
            event.player.capabilities.isFlying = true;
        }

No crash. The crash did occur with other mods, but I rechecked it and it is no longer an issue (no idea why, maybe I changed the code somewhere and forgot), but the crash is no longer happening under any circumstance.

You forgot to add back the if statement for the dimension.

[kriNon]

What I meant was, if we ignore the if statement for dimension. Just to simplify the code (incremental testing), flight does occur in the first one, but not the second. Neither does anything with the if statement for the dimension.

[Animefan8888]

17 minutes ago, kriNon said:

What I meant was, if we ignore the if statement for dimension. Just to simplify the code (incremental testing), flight does occur in the first one, but not the second. Neither does anything with the if statement for the dimension.

Through a bit of testing, I have figured out how to solve your issue. Brain power is hard to come by at almost 3 AM, but the solution is to not check the isRemote at all. This is the code I used tested on both a dedicated and integrated server.

	@SubscribeEvent
	public void tickPlayer(TickEvent.PlayerTickEvent event) {
		if (event.player.dimension == 0) {
			event.player.capabilities.allowFlying= true;
			event.player.capabilities.isFlying = true;
		} else {
			event.player.capabilities.allowFlying = event.player.capabilities.isCreativeMode;
			event.player.capabilities.isFlying = event.player.capabilities.isCreativeMode;
		}
	}

Though I did not test it with your mods. (Also change the dimension check to your choice).

[kriNon]

Okay, so I tested it and it works perfectly! Thanks!

Sadly, I've now realized that despite the mod working correctly, it doesn't do what I needed it to. I'll go into a bit more detail, but it looks like i'm going to have to try a different method.

 

So, the purpose of my mod was to give the player creative flight in that specific dimension (dimension 3) because the mod that creates the dimension (galacticraft) has different movement mechanics in creative mode to survival mode in that dimension. I had assumed that the different mechanics were caused by a isFlying check, however it turns out that it is actually an isCreative check.

 

Is there any good way of editing a class in another mod, without compiling a custom version of that mod? Kind of like patching the class upon runtime?

 

Thanks a lot for your help!

[Animefan8888]

1 minute ago, kriNon said:

Okay, so I tested it and it works perfectly! Thanks!

Sadly, I've now realized that despite the mod working correctly, it doesn't do what I needed it to. I'll go into a bit more detail, but it looks like i'm going to have to try a different method.

 

So, the purpose of my mod was to give the player creative flight in that specific dimension (dimension 3) because the mod that creates the dimension (galacticraft) has different movement mechanics in creative mode to survival mode in that dimension. I had assumed that the different mechanics were caused by a isFlying check, however it turns out that it is actually an isCreative check.

 

Is there any good way of editing a class in another mod, without compiling a custom version of that mod? Kind of like patching the class upon runtime?

 

Thanks a lot for your help!

What different movement mechanics does it have that you are trying to replicate? And I'm sorry there is no way of 'patching' a mods class on runtime.

[kriNon]

So in space (dimension 3) when the player is in Freefall (floating not near any blocks) then the player is unable to move using A or D (only able to move forwards or backwards), as well as speed and acceleration works differently.

 

I might need to make my mod depend on Galacticraft, and then modify movement too based on which state the player is in.

 

Their movement mechanics are a little complicated in space, but they can be seen here: https://github.com/micdoodle8/Galacticraft/blob/master/src/main/java/micdoodle8/mods/galacticraft/core/entities/player/FreefallHandler.java

Edited May 29, 2018 by kriNon

[Animefan8888]

4 minutes ago, kriNon said:

I might need to make my mod depend on Galacticraft, and then modify movement too based on which state the player is i.

1

You can definitely make it depended on Galacticraft and just subscribed to one of its events and cancel it to cancel the motion and limitations I believe I didn't look too far.

[kriNon]

As in subscribe to the event and then cancel the event, preventing section of galacticraft code from running?

[jabelar]

Although you can't "replace" another mod's classes, you can usually intercept their behavior using events. For example, you could make your own player capability "flyLikeGalactiCraft" and when that is true you could intercept the movement using events and run code that is similar/copied from GalactiCraft but without putting the player fully into creative mode.

 

Regarding the dependency, you only have to do that if you're interacting with their classes. If you just want to know if their mod is loaded you can check that.