Block Tracking

Block Tracking

The block tracking system tracks which player placed blocks and maintains placement counts per chunk.

Package Location

• Components: com.hypixel.hytale.server.core.modules.interaction.components
• Block Track: com.hypixel.hytale.server.core.modules.interaction.blocktrack

Overview

When blocks are placed via the interaction system, two tracking mechanisms are available:

1. PlacedByInteractionComponent - Tracks who placed a specific block
2. TrackedPlacement + BlockCounter - Counts placements by block type

PlacedByInteractionComponent

Tracks which player placed a block:

package com.hypixel.hytale.server.core.modules.interaction.components;

public class PlacedByInteractionComponent implements Component<ChunkStore> {
    // Constructor
    public PlacedByInteractionComponent(UUID whoPlacedUuid);

    // Get placer UUID
    public UUID getWhoPlacedUuid();

    // Get component type
    public static ComponentType<ChunkStore, PlacedByInteractionComponent>
        getComponentType();
}

Usage Example

import com.hypixel.hytale.server.core.modules.interaction.components.PlacedByInteractionComponent;
import com.hypixel.hytale.server.core.modules.interaction.InteractionModule;
import java.util.UUID;

// Get component from block
Ref<ChunkStore> blockRef = /* block reference */;
PlacedByInteractionComponent placedBy = commandBuffer.getComponent(
    blockRef,
    InteractionModule.get().getPlacedByComponentType()
);

if (placedBy != null) {
    UUID placerUuid = placedBy.getWhoPlacedUuid();

    // Find the player who placed it
    Ref<EntityStore> placerRef = entityStore.getRefFromUUID(placerUuid);
    if (placerRef != null && placerRef.isValid()) {
        // Player is online
    }
}

Listening for Block Placements

import com.hypixel.hytale.component.system.RefChangeSystem;
import com.hypixel.hytale.server.core.modules.interaction.components.PlacedByInteractionComponent;

public class BlockPlaceListener
    extends RefChangeSystem<ChunkStore, PlacedByInteractionComponent> {

    @Override
    public void onComponentAdded(
        Ref<ChunkStore> blockRef,
        PlacedByInteractionComponent placedBy,
        Store<ChunkStore> chunkStore,
        CommandBuffer<ChunkStore> commandBuffer
    ) {
        UUID placerUuid = placedBy.getWhoPlacedUuid();

        // Get block info
        BlockModule.BlockStateInfo blockInfo = chunkStore.getComponent(
            blockRef,
            BlockModule.BlockStateInfo.getComponentType()
        );

        String blockType = blockInfo.getBlockTypeName();

        // React to placement
        getLogger().info(placerUuid + " placed " + blockType);
    }

    @Override
    public void onComponentRemoved(
        Ref<ChunkStore> blockRef,
        PlacedByInteractionComponent placedBy,
        Store<ChunkStore> chunkStore,
        CommandBuffer<ChunkStore> commandBuffer
    ) {
        // Block was destroyed
    }
}

TrackedPlacement

Tracks block type for counting:

package com.hypixel.hytale.server.core.modules.interaction.blocktrack;

public class TrackedPlacement implements Component<ChunkStore> {
    // Constructor
    public TrackedPlacement(String blockName);

    // Get block name
    public String getBlockName();

    // Get component type
    public static ComponentType<ChunkStore, TrackedPlacement> getComponentType();
}

BlockCounter

Resource maintaining per-chunk block placement counts:

package com.hypixel.hytale.server.core.modules.interaction.blocktrack;

public class BlockCounter implements Resource<ChunkStore> {
    // Track a block placement
    public void trackBlock(String blockName);

    // Untrack a block (when destroyed)
    public void untrackBlock(String blockName);

    // Get count for block type
    public int getBlockPlacementCount(String blockName);
}

Usage Example

import com.hypixel.hytale.server.core.modules.interaction.blocktrack.BlockCounter;
import com.hypixel.hytale.server.core.modules.interaction.InteractionModule;

// Get block counter for chunk
BlockCounter counter = commandBuffer.getResource(
    InteractionModule.get().getBlockCounterResourceType()
);

// Check how many stone blocks placed
int stoneCount = counter.getBlockPlacementCount("Stone");

// Check grass blocks
int grassCount = counter.getBlockPlacementCount("Grass");

// Total player-placed blocks
int total = stoneCount + grassCount; // etc.

Automatic Tracking

The system automatically:

1. Adds TrackedPlacement when a block is placed via interaction
2. Updates BlockCounter when TrackedPlacement is added/removed
3. Removes tracking when blocks are destroyed

Block Placed → TrackedPlacement Added → BlockCounter.trackBlock()
Block Broken → TrackedPlacement Removed → BlockCounter.untrackBlock()

Practical Example: Protected Blocks

Track blocks that only the placer can break:

import com.hypixel.hytale.server.core.event.events.ecs.BreakBlockEvent;

@Override
protected void setup() {
    getEventRegistry().register(BreakBlockEvent.class, this::onBreakBlock);
}

private void onBreakBlock(BreakBlockEvent event) {
    // Get block reference
    Ref<ChunkStore> blockRef = event.getBlockRef();

    // Check who placed it
    PlacedByInteractionComponent placedBy = getComponent(
        blockRef,
        InteractionModule.get().getPlacedByComponentType()
    );

    if (placedBy != null) {
        UUID placerUuid = placedBy.getWhoPlacedUuid();
        UUID breakerUuid = event.getPlayerUuid();

        // Only placer can break
        if (!placerUuid.equals(breakerUuid)) {
            event.setCancelled(true);
            // Send message to player
        }
    }
}

Practical Example: Placement Limits

Limit how many blocks of a type can be placed:

import com.hypixel.hytale.server.core.event.events.ecs.PlaceBlockEvent;

private static final int MAX_TNT_PER_CHUNK = 10;

private void onPlaceBlock(PlaceBlockEvent event) {
    BlockType blockType = event.getBlockType();

    if (blockType.getId().equals("tnt")) {
        // Get block counter
        BlockCounter counter = getBlockCounter(event.getChunk());

        int tntCount = counter.getBlockPlacementCount("TNT");

        if (tntCount >= MAX_TNT_PER_CHUNK) {
            event.setCancelled(true);
            // Send limit message
        }
    }
}

Serialization

Both components serialize with entity/chunk data:

PlacedByInteractionComponent:

{
  "PlacedByInteraction": {
    "UUID": "550e8400-e29b-41d4-a716-446655440000"
  }
}

TrackedPlacement:

{
  "TrackedPlacement": {
    "BlockName": "Stone"
  }
}

BlockCounter:

{
  "BlockCounter": {
    "Stone": 42,
    "Grass": 15,
    "Wood": 23
  }
}

Related

• Interaction System - Interaction overview
• Event System - Block events
• Block System - Block types