Hi!

Java veteran, but new to modding. I'm working on ny very first mod experiments and I'm playing with increasing the reach of a pickaxe by following veins of ore and other fun things. 

Whenever I break a block and have a certain custom enchantment on my pickaxe, I want to break a few additional nearby blocks as well. Seems simple enough. I also want it to kind of "ripple" through the environment, so my thought was to put the blocks to be destroyed on a queue and let a tick event subscriber pick them up, one for each tick.

I have this:

@SubscribeEvent
  public static void onTick(final TickEvent e) {
    if (MegaMinerEvents.queue.isEmpty()) {
      return;
    }
    final BlockToBreak b = MegaMinerEvents.queue.removeFirst();
    final BlockState bs = b.world.getBlockState(b.pos);
    bs.getBlock()
        .playerDestroy(b.player.getLevel(), b.player, b.pos, bs, null, b.player.getMainHandItem());
    b.player.getLevel().removeBlock(b.pos, false);
  }

 

As you can see, I simply pop a block from the queue every tick and break it. It sort of works. 

However, I'm wondering if Block::playerDestroy is the right method to call. First of all, it doesn't actually remove the block. Second, it doesn't trigger any events from what I can see. The vanilla game itself is using ServerPlayerGameMode::destroyBlock(), but that method isn't accessible from any context I'm in.

So the question is: Is Block::playerDestroy the right method to use?
What other things, like sending events and checking things to I need to do if I use that method?
Also, is "onTick" the right place to do this?

 

Thanks!
NJSwede

Additional info: It only works sporadically. I guess TickEvent.ServerTickEvent is the wrong place to do this...

What is MegaMinerEvents? What is MegaMiner for that matter?

31 minutes ago, Draco18s said:

What is MegaMinerEvents? What is MegaMiner for that matter?

MegaMiner is just my playground mod. Here's the entire MegaMinerEvents class. It's just a static event receiver.

 

package nu.rydin.explodingarrows.common.events;

import net.minecraft.core.BlockPos;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.nbt.Tag;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.LevelAccessor;
import net.minecraft.world.level.block.Block;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraftforge.event.TickEvent;
import net.minecraftforge.event.world.BlockEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.fml.common.Mod;
import nu.rydin.explodingarrows.common.Main;
import nu.rydin.explodingarrows.common.enchantments.ModEnchantments;

import java.util.LinkedList;

@Mod.EventBusSubscriber(modid = Main.MOD_ID, bus = Mod.EventBusSubscriber.Bus.FORGE)
public class MegaMinerEvents {
  private static final class BlockToBreak {

    private final BlockPos pos;

    private final Player player;

    public BlockToBreak(final BlockPos pos, final Player player) {
      this.pos = pos;
      this.player = player;
    }
  }

  private static final LinkedList<BlockToBreak> queue = new LinkedList<>();

  @SubscribeEvent
  public static void onBreakBlock(final BlockEvent.BreakEvent e) {
    final LevelAccessor world = e.getWorld();
    if (world.isClientSide()) {
      return;
    }
    for (final Tag t : e.getPlayer().getMainHandItem().getEnchantmentTags()) {
      final CompoundTag ct = (CompoundTag) t;
      if (ct.getString("id")
          .equals(ModEnchantments.MEGA_MINER.get().getRegistryName().toString())) {
        MegaMinerEvents.mineNeighborhood(e.getPos(), e.getPlayer(), e.getState().getBlock());
      }
    }
  }

  @SubscribeEvent
  public static void onTick(final TickEvent.ServerTickEvent e) {
    if (MegaMinerEvents.queue.isEmpty()) {
      return;
    }
    final BlockToBreak b = MegaMinerEvents.queue.removeFirst();
    final Level world = b.player.level;
    final BlockState bs = world.getBlockState(b.pos);
    bs.getBlock().playerDestroy(world, b.player, b.pos, bs, null, b.player.getMainHandItem());
    world.removeBlock(b.pos, true);
    // MegaMinerEvents.mineNeighborhood(b.pos, b.player, bs.getBlock());
    System.out.println(MegaMinerEvents.queue.size());
  }

  private static void mineNeighborhood(
      final BlockPos pos, final Player player, final Block blockType) {
    final float x0 = pos.getX();
    final float y0 = pos.getY();
    final float z0 = pos.getZ();
    for (float z = z0 - 1.0F; z <= z0 + 1; z += 1.0) {
      for (float y = y0 - 1.0F; y <= y0 + 1; y += 1.0) {
        for (float x = x0 - 1.0F; x <= x0 + 1; x += 1.0) {
          final BlockState b = player.getLevel().getBlockState(pos);
          if (b.is(blockType)) {
            MegaMinerEvents.queue.addLast(new BlockToBreak(pos, player));
          }
        }
      }
    }
  }
}

 

Edited January 26, 20223 yr by NJSwede

You should absolutely call ForgeHooks.canHarvestBlock(state, entityPlayer, world, pos) before attempting to do anything to a block. If the return is false, skip that block.

As for the proper way to dig it out, dig around in the vanilla blocks class and look for where ForgeHooks.modifyLoot is called. Once you find that spot you might have to go up the call stack a little bit before you find the exact thing to call, and if might be several things. Been a while since I looked at it.

It turned out that ServerPlayerGameMode was accessible after all. All I had to do was to cast my player to a ServerPlayer and ask for the game mode. Calling destroyBlock on that class seems to do all the proper tests and fire the right events. It all works now! Now I can mine an entire vein of diamonds or fell an entire tree in one stroke. Whohooo!