Basic networking

src/main/java/com/youpe/test/Testing.java

@@ -2,9 +2,13 @@ package com.youpe.test;
 
 import net.fabricmc.api.ModInitializer;
 import net.fabricmc.fabric.api.client.rendering.v1.HudRenderCallback;
+import net.fabricmc.fabric.api.event.player.PlayerBlockBreakEvents;
 import net.fabricmc.fabric.api.item.v1.FabricItemSettings;
 import net.fabricmc.fabric.api.itemgroup.v1.ItemGroupEvents;
+import net.fabricmc.fabric.api.networking.v1.PacketByteBufs;
+import net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking;
 import net.fabricmc.fabric.api.registry.FuelRegistry;
+import net.minecraft.block.Blocks;
 import net.minecraft.client.render.BufferBuilder;
 import net.minecraft.client.render.GameRenderer;
 import net.minecraft.client.render.Tessellator;
@@ -12,16 +16,19 @@ import net.minecraft.client.render.VertexFormat;
 import net.minecraft.client.render.VertexFormats;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemGroups;
+import net.minecraft.network.PacketByteBuf;
 import net.minecraft.registry.Registries;
 import net.minecraft.registry.Registry;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.Rarity;
 
-import org.joml.Matrix4f;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.mojang.blaze3d.systems.RenderSystem;
+import com.youpe.test.server.PlayerData;
+import com.youpe.test.server.StateSaverAndLoader;
 
 public class Testing implements ModInitializer {
 	// This logger is used to write text to the console and the log file.
@@ -30,6 +37,8 @@ public class Testing implements ModInitializer {
     public static final Logger LOGGER = LoggerFactory.getLogger("testing");
 	public static final Item CUSTOM_ITEM = new CustomItem(new FabricItemSettings().rarity(Rarity.COMMON));
 
+	public static final Identifier DIRT_BROKEN = new Identifier("testing", "dirt_broken");
+
 	@Override
 	public void onInitialize() {
 		// This code runs as soon as Minecraft is in a mod-load-ready state.
@@ -42,22 +51,27 @@ public class Testing implements ModInitializer {
 		ItemGroupEvents.modifyEntriesEvent(ItemGroups.BUILDING_BLOCKS).register(content -> {
 			content.add(CUSTOM_ITEM);
 		});
-		HudRenderCallback.EVENT.register((drawContext, tickDelta) -> {
+		PlayerBlockBreakEvents.AFTER.register((world, player, pos, state, entity) -> {
-			Matrix4f positionMatrix = drawContext.getMatrices().peek().getPositionMatrix();
+            if (state.getBlock() == Blocks.GRASS_BLOCK || state.getBlock() == Blocks.DIRT) {
-			Tessellator tessellator = Tessellator.getInstance();
+                StateSaverAndLoader serverState = StateSaverAndLoader.getServerState(world.getServer());
-			BufferBuilder buffer = tessellator.getBuffer();
+                // Increment the amount of dirt blocks that have been broken
+                serverState.totalDirtBlocksBroken += 1;
  
-			buffer.begin(VertexFormat.DrawMode.QUADS, VertexFormats.POSITION_COLOR_TEXTURE);
+                PlayerData playerState = StateSaverAndLoader.getPlayerState(player);
-			buffer.vertex(positionMatrix, 20, 20, 0).color(1f, 1f, 1f, 1f).texture(0f, 0f).next();
+                playerState.dirtBlocksBroken += 1;
-			buffer.vertex(positionMatrix, 20, 60, 0).color(1f, 0f, 0f, 1f).texture(0f, 1f).next();
-			buffer.vertex(positionMatrix, 60, 60, 0).color(0f, 1f, 0f, 1f).texture(1f, 1f).next();
-			buffer.vertex(positionMatrix, 60, 20, 0).color(0f, 0f, 1f, 1f).texture(1f, 0f).next();
  
-			RenderSystem.setShader(GameRenderer::getPositionColorTexProgram);
+                // Send a packet to the client
-			RenderSystem.setShaderTexture(0, new Identifier("testing", "icon.png"));
+                MinecraftServer server = world.getServer();
-			RenderSystem.setShaderColor(1f, 1f, 1f, 1f);
  
-			tessellator.draw();
+                PacketByteBuf data = PacketByteBufs.create();
+                data.writeInt(serverState.totalDirtBlocksBroken);
+                data.writeInt(playerState.dirtBlocksBroken);
+ 
+                ServerPlayerEntity playerEntity = server.getPlayerManager().getPlayer(player.getUuid());
+                server.execute(() -> {
+                    ServerPlayNetworking.send(playerEntity, DIRT_BROKEN, data);
+                });
+            }
         });
 	}
 }

src/main/java/com/youpe/test/TestingClient.java

@@ -3,6 +3,8 @@ package com.youpe.test;
 import com.youpe.test.event.KeyInputHandler;
 
 import net.fabricmc.api.ClientModInitializer;
+import net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking;
+import net.minecraft.text.Text;
 
 public class TestingClient implements ClientModInitializer{
 
@@ -10,6 +12,16 @@ public class TestingClient implements ClientModInitializer{
     public void onInitializeClient() {
         KeyInputHandler.register();
         KeyInputHandler.registerKeyInputs();
+
+        ClientPlayNetworking.registerGlobalReceiver(Testing.DIRT_BROKEN, (client, handler, buf, responseSender) -> {
+            int totalDirtBlocksBroken = buf.readInt();
+            int playerSpecificDirtBlocksBroken = buf.readInt();
+ 
+            client.execute(() -> {
+                client.player.sendMessage(Text.literal("Total dirt blocks broken: " + totalDirtBlocksBroken));
+                client.player.sendMessage(Text.literal("Player specific dirt blocks broken: " + playerSpecificDirtBlocksBroken));
+            });
+        });
     }
     
 }

src/main/java/com/youpe/test/server/PlayerData.java

@@ -0,0 +1,5 @@
+package com.youpe.test.server;
+
+public class PlayerData {
+    public int dirtBlocksBroken = 0;
+}

src/main/java/com/youpe/test/server/StateSaverAndLoader.java

@@ -0,0 +1,57 @@
+package com.youpe.test.server;
+
+import java.util.HashMap;
+import java.util.UUID;
+
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.nbt.NbtCompound;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.world.PersistentState;
+import net.minecraft.world.PersistentStateManager;
+import net.minecraft.world.World;
+ 
+public class StateSaverAndLoader extends PersistentState {
+ 
+    public Integer totalDirtBlocksBroken = 0;
+    public HashMap<UUID, PlayerData> players = new HashMap<>();
+ 
+    @Override
+    public NbtCompound writeNbt(NbtCompound nbt) {
+        nbt.putInt("totalDirtBlocksBroken", totalDirtBlocksBroken);
+        return nbt;
+    }
+
+    public static StateSaverAndLoader createFromNbt(NbtCompound tag) {
+        StateSaverAndLoader state = new StateSaverAndLoader();
+        state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");
+        return state;
+    }
+ 
+    public static StateSaverAndLoader getServerState(MinecraftServer server) {
+        // (Note: arbitrary choice to use 'World.OVERWORLD' instead of 'World.END' or 'World.NETHER'.  Any work)
+        PersistentStateManager persistentStateManager = server.getWorld(World.OVERWORLD).getPersistentStateManager();
+ 
+        // The first time the following 'getOrCreate' function is called, it creates a brand new 'StateSaverAndLoader' and
+        // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved
+        // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.
+        StateSaverAndLoader state = persistentStateManager.getOrCreate(StateSaverAndLoader::createFromNbt, StateSaverAndLoader::new, "testing");
+ 
+        // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.
+        // Technically it's 'cleaner' if you only mark state as dirty when there was actually a change, but the vast majority
+        // of mod writers are just going to be confused when their data isn't being saved, and so it's best just to 'markDirty' for them.
+        // Besides, it's literally just setting a bool to true, and the only time there's a 'cost' is when the file is written to disk when
+        // there were no actual change to any of the mods state (INCREDIBLY RARE).
+        state.markDirty();
+ 
+        return state;
+    }
+    
+    public static PlayerData getPlayerState(LivingEntity player) {
+        StateSaverAndLoader serverState = getServerState(player.getWorld().getServer());
+ 
+        // Either get the player by the uuid, or we don't have data for him yet, make a new player state
+        PlayerData playerState = serverState.players.computeIfAbsent(player.getUuid(), uuid -> new PlayerData());
+ 
+        return playerState;
+    }
+}