[1.9.4] Making a weapon apply a potion effect randomly?

[T-10a]

Hello,

After making a new custom item apply slowness when I hit an enemy, how would I make it so it randomly applies the effect?

For example, when the player hits another entity with this item, it has a 1 in 4 chance to apply Slowness on hit to the target.

[American2050]

If I understand correctly, you already made it to apply slowness when an enemy is hit.

 

I think you can do the same way, but choosing a random from 0 to 3, and if it is 0 then apply the effect.

[T-10a]

Yes, I have been able to make it apply on hit. I'm just not sure how to implement a random number generator in Java code, as all the online examples seem fairly complex.

[Choonster]

Use the

Random

class, you already have access to an instance of it stored in

Item.itemRand

.

[T-10a]

I'm just not sure how to use that to create a random number generator. I'm also not familiar with making random number generators in Java either.

(I know this forum isn't a Java school. I do know basic Java programming.)

 

Screw it, had a shot at making one. Didn't quite turn out well, went from applying all the time to never.

Here's the code:

 

 

package com.t10a.minedran.item.weapons;

import java.util.List;
import java.util.Random;
import java.util.Set;

import com.google.common.collect.Sets;
import com.t10a.minedran.reference.Reference;

import net.minecraft.block.Block;
import net.minecraft.block.state.IBlockState;
import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Blocks;
import net.minecraft.init.MobEffects;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.item.ItemTool;
import net.minecraft.potion.PotionEffect;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.World;

import com.t10a.minedran.reference.EventHandler;

public class ItemMace extends ItemTool 
{
//Dummy set to get the tool class to shut up. Also, stops the crashing. 
private static final Set<Block> MaceBlocks = Sets.newHashSet(new Block[] {Blocks.BEDROCK});


public ItemMace(ToolMaterial material) {
	super(1.0F, -2.8F, material, MaceBlocks);
	setMaxStackSize(1);
	this.efficiencyOnProperMaterial = 0.0F;

	setCreativeTab(CreativeTabs.COMBAT);
	setUnlocalizedName(Reference.ItemBase.MACE.getUnlocalizedName() + "_" + getToolMaterialName().toLowerCase());
	setRegistryName(Reference.ItemBase.MACE.getRegistryName()  + "_" + getToolMaterialName().toLowerCase());
}

@Override
public void addInformation(ItemStack stack, EntityPlayer player, List<String> list, boolean par4)
{
list.add("Hit enemies to stun them w/ Slowness!");
}

@Override
public boolean hitEntity(ItemStack stack, EntityLivingBase target, EntityLivingBase attacker) 
{
	int pow=(int)(Math.random()*4+1);
	if ( pow==0 )
		target.addPotionEffect(new PotionEffect(MobEffects.SLOWNESS, 80));
	stack.damageItem(1, attacker);
	return super.hitEntity(stack, target, attacker);
}

@Override
    public boolean onBlockDestroyed(ItemStack stack, World worldIn, IBlockState state, BlockPos pos, EntityLivingBase entityLiving)
    {
        if ((double)state.getBlockHardness(worldIn, pos) != 0.0D)
        {
            stack.damageItem(2, entityLiving);
        }

        return true;
    }
}

 

How can I fix this?

[Choonster]

Random

is a (pseudo-)random number generator. Call

Random#nextInt

to get a random integer in the specified range.

 

Math.random

returns a random number in the range

[0, 1)

(i.e. greater than or equal to 0, less than 1). If you multiply by 4 and add 1, the new range is

[1, 5)

; which means that it will never be 0 and your potion effect will never be applied.

[T-10a]

Fixed it by replacing 'pow == 0' with 'pow == 1' and it works flawlessly. Thanks for the help!