[1.14.3] Is this a bad way to teleport a player?

[kwpugh]

Hi All,

 

Looking for some guidance/expert advice on my code.

 

I created an item that appears to do what I want it to (e.g. teleport the player to the location they are looking on right-click).

 

I used the source for EndermanEnity and EnderPearlEntity as a reference point.

 

I have an uneasy feeling that they way I am doing this is dangerous (or flat out wrong) and I'm looking for expert advice.  While testing the mod on a local server, I get an occasional crash.

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x0000000110ec8aa1, pid=34978, tid=0x0000000000005003
#
# JRE version: Java(TM) SE Runtime Environment (8.0_151-b12) (build 1.8.0_151-b12)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.151-b12 mixed mode bsd-amd64 compressed oops)
# Problematic frame:
# V  [libjvm.dylib+0x4c8aa1]
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /Users/kwpugh/eclipse-workspace/gobber2-1.14/run/hs_err_pid34978.log
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
#

 

Link to the client crash report:  https://gist.github.com/kwpugh/36d24c7a315e260a0417c1ebcee09bce

Link to server crash report:  https://gist.github.com/kwpugh/6dc5976977ea55c510c4db09275d3410

 

Here are my classes:

package com.kwpugh.gobber2.items.rings;

import java.util.List;

import com.kwpugh.gobber2.util.RayTraceUtil;

import net.minecraft.client.util.ITooltipFlag;
import net.minecraft.entity.LivingEntity;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.entity.player.ServerPlayerEntity;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.util.ActionResult;
import net.minecraft.util.ActionResultType;
import net.minecraft.util.Hand;
import net.minecraft.util.SoundCategory;
import net.minecraft.util.SoundEvents;
import net.minecraft.util.math.RayTraceResult;
import net.minecraft.util.text.ITextComponent;
import net.minecraft.util.text.StringTextComponent;
import net.minecraft.util.text.TextFormatting;
import net.minecraft.world.World;

public class ItemCustomRingBlink extends Item
{
	public ItemCustomRingBlink(Properties properties)
	{
		super(properties);
	}

	public ActionResult<ItemStack> onItemRightClick(World world, PlayerEntity player, Hand hand)
	{
		ItemStack stack = player.getHeldItem(hand);
		ItemStack equippedMain = player.getHeldItemMainhand();	
		
        if(equippedMain == stack)   //Only works in the main hand
        {
			if (!world.isRemote)
			{
				if(player instanceof LivingEntity)
				{
					LivingEntity livingentity = player;
					
					if(livingentity instanceof ServerPlayerEntity)
					{
						ServerPlayerEntity serverplayerentity = (ServerPlayerEntity)livingentity;
						
						RayTraceResult pos = RayTraceUtil.getNearestPositionWithAir(world, player, 100);
			            if(pos != null && (pos.getType() == RayTraceResult.Type.BLOCK || player.rotationPitch >= -5))
			            {
			            	int side = pos.getType().ordinal();
			                if(side != -1)
			                {
			                    double x = pos.getHitVec().x-(side == 4 ? 0.5 : 0)+(side == 5 ? 0.5 : 0);
			                    double y = pos.getHitVec().y-(side == 0 ? 2.0 : 0)+(side == 1 ? 0.5 : 0);
			                    double z = pos.getHitVec().z-(side == 2 ? 0.5 : 0)+(side == 3 ? 0.5 : 0);

			                    //Use the existing event for ender pearl teleport for our own purposes
			                    net.minecraftforge.event.entity.living.EnderTeleportEvent event = new net.minecraftforge.event.entity.living.EnderTeleportEvent(serverplayerentity, player.posX, player.posY, player.posZ, 5.0F);
			                    
				           		if (livingentity.isPassenger())
								{
				           			livingentity.stopRiding();
					            }
				           		
				           		//Set the target values for the event to the location the player is looking
				           		event.setTargetX(x);
				           		event.setTargetY(y);
				           		event.setTargetZ(z);
				           		
				           		livingentity.setPositionAndUpdate(event.getTargetX(), event.getTargetY(), event.getTargetZ());			           		
			                   
			                    world.playSound(null, player.posX, player.posY, player.posZ, SoundEvents.ENTITY_ENDERMAN_TELEPORT, SoundCategory.PLAYERS, 1.0F, 1.0F);
			
			                    return ActionResult.newResult(ActionResultType.SUCCESS, stack);
			                }
			            }		 
					}
				}
	        }
        }
        return new ActionResult<ItemStack>(ActionResultType.SUCCESS, stack);
	}
   
    @Override
	public void addInformation(ItemStack stack, World world, List<ITextComponent> list, ITooltipFlag flag)
	{
		super.addInformation(stack, world, list, flag);				
		list.add(new StringTextComponent(TextFormatting.BLUE + "Teleports player to the location looking at"));
		list.add(new StringTextComponent(TextFormatting.GREEN + "Right-click to use"));
		list.add(new StringTextComponent(TextFormatting.YELLOW + "Range limit: 100 blocks"));
	} 

}

 

The RayTraceUtil is outside the item because I use it elsewhere in my mod.

 

package com.kwpugh.gobber2.util;

import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.util.math.MathHelper;
import net.minecraft.util.math.RayTraceContext;
import net.minecraft.util.math.RayTraceResult;
import net.minecraft.util.math.Vec3d;
import net.minecraft.world.World;

public class RayTraceUtil
{
	public static RayTraceResult getNearestPositionWithAir(World world, PlayerEntity player, int reach)
    {
        return getMovingObjectPosWithReachDistance(world, player, reach, false, false, true);
    }

    private static RayTraceResult getMovingObjectPosWithReachDistance(World world, PlayerEntity player, double distance, boolean p1, boolean p2, boolean p3)
    {
        float f = player.rotationPitch;
        float f1 = player.rotationYaw;
        double d0 = player.posX;
        double d1 = player.posY + (double) player.getEyeHeight();
        double d2 = player.posZ;
        Vec3d vec3 = new Vec3d(d0, d1, d2);
        float f2 = MathHelper.cos(-f1 * 0.017453292F - (float) Math.PI);
        float f3 = MathHelper.sin(-f1 * 0.017453292F - (float) Math.PI);
        float f4 = -MathHelper.cos(-f * 0.017453292F);
        float f5 = MathHelper.sin(-f * 0.017453292F);
        float f6 = f3 * f4;
        float f7 = f2 * f4;
        Vec3d vec31 = vec3.add((double) f6 * distance, (double) f5 * distance, (double) f7 * distance);
        
        return world.rayTraceBlocks(new RayTraceContext(vec3, vec31, RayTraceContext.BlockMode.COLLIDER, RayTraceContext.FluidMode.ANY, player));
    }
}

 

Thank you in advance for any helpful advice.

 

Regards.

Edited July 13, 2019 by kwpugh

[kwpugh]

Ok, so I stopped looking at the screen and took a nap.

 

Looking at it again with fresh eyes, I was able to (hopefully) simplify it a bit.   I also noticed the .connection.setLocationAndUpdate in the ServerPlayNetHandler.   I was thinking my problem was I was moving the player around and not sending notice to the server of that fact (I think).  I was hoping the ".connection" was sufficient to let the server know.

 

I spent some time playing SP and on the local server, no crashes, no excess ticking.

 

Here is the current class:

package com.kwpugh.gobber2.items.rings;

import java.util.List;

import com.kwpugh.gobber2.util.RayTraceUtil;

import net.minecraft.client.util.ITooltipFlag;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.entity.player.ServerPlayerEntity;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.util.ActionResult;
import net.minecraft.util.ActionResultType;
import net.minecraft.util.Hand;
import net.minecraft.util.SoundCategory;
import net.minecraft.util.SoundEvents;
import net.minecraft.util.math.RayTraceResult;
import net.minecraft.util.text.ITextComponent;
import net.minecraft.util.text.StringTextComponent;
import net.minecraft.util.text.TextFormatting;
import net.minecraft.world.World;

public class ItemCustomRingBlink extends Item
{
	public ItemCustomRingBlink(Properties properties)
	{
		super(properties);
	}

	public ActionResult<ItemStack> onItemRightClick(World world, PlayerEntity player, Hand hand)
	{
		ItemStack stack = player.getHeldItem(hand);
		ItemStack equippedMain = player.getHeldItemMainhand();	
		
        if(equippedMain == stack)   //Only works in the main hand
        {
			if (!world.isRemote)
			{						
				RayTraceResult pos = RayTraceUtil.getNearestPositionWithAir(world, player, 100);
	            if(pos != null && (pos.getType() == RayTraceResult.Type.BLOCK || player.rotationPitch >= -5))
	            {
	            	int side = pos.getType().ordinal();
	                if(side != -1)
	                {
	                    double x = pos.getHitVec().x-(side == 4 ? 0.5 : 0)+(side == 5 ? 0.5 : 0);
	                    double y = pos.getHitVec().y-(side == 0 ? 2.0 : 0)+(side == 1 ? 0.5 : 0);
	                    double z = pos.getHitVec().z-(side == 2 ? 0.5 : 0)+(side == 3 ? 0.5 : 0);
		           		
		           		player.stopRiding();
		           		((ServerPlayerEntity)player).connection.setPlayerLocation(x, y, z, player.rotationYaw, player.rotationPitch);
	                   
	                    world.playSound(null, player.posX, player.posY, player.posZ, SoundEvents.ENTITY_ENDERMAN_TELEPORT, SoundCategory.PLAYERS, 1.0F, 1.0F);
	
	                    return ActionResult.newResult(ActionResultType.SUCCESS, stack);
	                }
	            }		 
	        }
        }
        return new ActionResult<ItemStack>(ActionResultType.SUCCESS, stack);
	}
	
    @Override
	public void addInformation(ItemStack stack, World world, List<ITextComponent> list, ITooltipFlag flag)
	{
		super.addInformation(stack, world, list, flag);				
		list.add(new StringTextComponent(TextFormatting.BLUE + "Teleports player to the location looking at"));
		list.add(new StringTextComponent(TextFormatting.GREEN + "Right-click to use"));
		list.add(new StringTextComponent(TextFormatting.YELLOW + "Range limit: 100 blocks"));
	} 

}

 

I did not make any changes to the RayTraceUtil that I had previously posted.

 

Is there anything glaringly wrong I'm doing or is this ok?

 

Regards.