Fix: Piston listener on Fabric/NeoForge (#4899)

* Fix: Sticky pistons not retracting on Geyser-Spigot/turning visually into normal pistons on all other platforms

* Initial attempt: Mod piston listener

* fix piston retracting

bootstrap/mod/build.gradle.kts

@@ -16,7 +16,8 @@ afterEvaluate {
 dependencies {
     api(projects.core)
     compileOnly(libs.mixin)
+    compileOnly(libs.mixinextras)
 
     // Only here to suppress "unknown enum constant EnvType.CLIENT" warnings. DO NOT USE!
     compileOnly(libs.fabric.loader)
-}
+}

bootstrap/mod/src/main/java/org/geysermc/geyser/platform/mod/mixin/server/PistonBaseBlockMixin.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2024 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.platform.mod.mixin.server;
+
+import com.llamalad7.mixinextras.injector.ModifyExpressionValue;
+import com.llamalad7.mixinextras.sugar.Share;
+import com.llamalad7.mixinextras.sugar.ref.LocalRef;
+import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.piston.PistonBaseBlock;
+import net.minecraft.world.level.block.state.BlockState;
+import org.cloudburstmc.math.vector.Vector3i;
+import org.geysermc.geyser.GeyserImpl;
+import org.geysermc.geyser.session.GeyserSession;
+import org.geysermc.geyser.session.cache.PistonCache;
+import org.geysermc.geyser.translator.level.block.entity.PistonBlockEntity;
+import org.geysermc.mcprotocollib.protocol.data.game.level.block.value.PistonValueType;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+@Mixin(PistonBaseBlock.class)
+public class PistonBaseBlockMixin {
+
+    @Shadow
+    @Final
+    private boolean isSticky;
+
+    @ModifyExpressionValue(method = "moveBlocks",
+        at = @At(value = "INVOKE", target = "Lcom/google/common/collect/Maps;newHashMap()Ljava/util/HashMap;")
+    )
+    private HashMap<BlockPos, BlockState> geyser$onMapCreate(HashMap<BlockPos, BlockState> original, @Share("pushBlocks") LocalRef<Map<BlockPos, BlockState>> localRef) {
+        localRef.set(original);
+        return original;
+    }
+
+    @Inject(method = "moveBlocks",
+        at = @At(value = "INVOKE", target = "Lnet/minecraft/world/level/block/piston/PistonStructureResolver;getToDestroy()Ljava/util/List;")
+    )
+    private void geyser$onBlocksMove(Level level, BlockPos blockPos, Direction direction, boolean isExtending, CallbackInfoReturnable<Boolean> cir, @Share("pushBlocks") LocalRef<Map<BlockPos, BlockState>> localRef) {
+        PistonValueType type = isExtending ? PistonValueType.PUSHING : PistonValueType.PULLING;
+        boolean sticky = this.isSticky;
+
+        Object2ObjectMap<Vector3i, org.geysermc.geyser.level.block.type.BlockState> attachedBlocks = new Object2ObjectArrayMap<>();
+        boolean blocksFilled = false;
+
+        for (Map.Entry<UUID, GeyserSession> entry : GeyserImpl.getInstance().getSessionManager().getSessions().entrySet()) {
+            Player player = level.getPlayerByUUID(entry.getKey());
+            //noinspection resource
+            if (player == null || !player.level().equals(level)) {
+                continue;
+            }
+            GeyserSession session = entry.getValue();
+
+            int dX = Math.abs(blockPos.getX() - player.getBlockX()) >> 4;
+            int dZ = Math.abs(blockPos.getZ() - player.getBlockZ()) >> 4;
+            if ((dX * dX + dZ * dZ) > session.getServerRenderDistance() * session.getServerRenderDistance()) {
+                // Ignore pistons outside the player's render distance
+                continue;
+            }
+
+            // Trying to grab the blocks from the world like other platforms would result in the moving piston block
+            // being returned instead.
+            if (!blocksFilled) {
+                Map<BlockPos, net.minecraft.world.level.block.state.BlockState> blocks = localRef.get();
+                for (Map.Entry<BlockPos, BlockState> blockStateEntry : blocks.entrySet()) {
+                    int blockStateId = Block.BLOCK_STATE_REGISTRY.getId(blockStateEntry.getValue());
+                    org.geysermc.geyser.level.block.type.BlockState state = org.geysermc.geyser.level.block.type.BlockState.of(blockStateId);
+                    attachedBlocks.put(geyser$fromBlockPos(blockStateEntry.getKey()), state);
+                }
+                blocksFilled = true;
+            }
+
+            org.geysermc.geyser.level.physics.Direction orientation = org.geysermc.geyser.level.physics.Direction.VALUES[direction.ordinal()];
+
+            Vector3i position = geyser$fromBlockPos(blockPos);
+            session.executeInEventLoop(() -> {
+                PistonCache pistonCache = session.getPistonCache();
+                PistonBlockEntity blockEntity = pistonCache.getPistons().computeIfAbsent(position, pos ->
+                    new PistonBlockEntity(session, position, orientation, sticky, !isExtending));
+                blockEntity.setAction(type, attachedBlocks);
+            });
+        }
+    }
+
+    @Unique
+    private static Vector3i geyser$fromBlockPos(BlockPos pos) {
+        return Vector3i.from(pos.getX(), pos.getY(), pos.getZ());
+    }
+
+}

bootstrap/mod/src/main/resources/geyser.mixins.json

@@ -5,6 +5,7 @@
   "compatibilityLevel": "JAVA_17",
   "mixins": [
     "server.BlockPlaceMixin",
+    "server.PistonBaseBlockMixin",
     "server.ServerConnectionListenerMixin"
   ],
   "server": [

core/src/main/java/org/geysermc/geyser/registry/populator/BlockRegistryPopulator.java

@@ -129,7 +129,7 @@ public final class BlockRegistryPopulator {
                     NbtMapBuilder builder = vanillaBlockStates.get(i).toBuilder();
                     builder.remove("version"); // Remove all nbt tags which are not needed for differentiating states
                     builder.remove("name_hash"); // Quick workaround - was added in 1.19.20
-                    builder.remove("network_id"); // Added in 1.19.80 - ????
+                    builder.remove("network_id"); // Added in 1.19.80
                     builder.remove("block_id"); // Added in 1.20.60
                     //noinspection UnstableApiUsage
                     builder.putCompound("states", statesInterner.intern((NbtMap) builder.remove("states")));

core/src/main/java/org/geysermc/geyser/translator/level/block/entity/PistonBlockEntity.java

@@ -37,7 +37,6 @@ import org.cloudburstmc.math.vector.Vector3i;
 import org.cloudburstmc.nbt.NbtMap;
 import org.cloudburstmc.nbt.NbtMapBuilder;
 import org.cloudburstmc.protocol.bedrock.packet.UpdateBlockPacket;
-import org.geysermc.geyser.api.util.PlatformType;
 import org.geysermc.geyser.level.block.BlockStateValues;
 import org.geysermc.geyser.level.block.Blocks;
 import org.geysermc.geyser.level.block.property.Properties;
@@ -230,8 +229,8 @@ public class PistonBlockEntity {
         BlockState state = session.getGeyser().getWorldManager().blockAt(session, blockInFront);
         if (state.is(Blocks.PISTON_HEAD)) {
             ChunkUtils.updateBlock(session, Block.JAVA_AIR_ID, blockInFront);
-        } else if ((session.getGeyser().getPlatformType() == PlatformType.SPIGOT || session.getErosionHandler().isActive()) && state.is(Blocks.AIR)) {
+        } else if ((session.getGeyser().getWorldManager().hasOwnChunkCache() || session.getErosionHandler().isActive()) && state.is(Blocks.AIR)) {
-            // Spigot removes the piston head from the cache, but we need to send the block update ourselves
+            // The platform removes the piston head from the cache, but we need to send the block update ourselves
             ChunkUtils.updateBlock(session, Block.JAVA_AIR_ID, blockInFront);
         }
     }

core/src/main/java/org/geysermc/geyser/translator/protocol/java/level/JavaBlockEventTranslator.java

@@ -82,16 +82,22 @@ public class JavaBlockEventTranslator extends PacketTranslator<ClientboundBlockE
             Direction direction = Direction.fromPistonValue(pistonValue.getDirection());
             PistonCache pistonCache = session.getPistonCache();
 
-            if (session.getGeyser().getPlatformType() == PlatformType.SPIGOT || session.getErosionHandler().isActive()) {
+            if (session.getGeyser().getWorldManager().hasOwnChunkCache() || session.getErosionHandler().isActive()) {
-                // Mostly handled in the GeyserPistonEvents class
+                // Mostly handled in the GeyserPistonEvents class (Spigot) / the PistonBlockBaseMixin (Mod platforms)
-                // Retracting sticky pistons is an exception, since the event is not called on Spigot from 1.13.2 - 1.17.1
+                // However, the retracting event is not fully covered. (Spigot)
-                // See https://github.com/PaperMC/Paper/blob/6fa1983e9ce177a4a412d5b950fd978620174777/patches/server/0304-Fire-BlockPistonRetractEvent-for-all-empty-pistons.patch
+                // Mod platforms only handle pistons moving blocks; not the retracting of pistons.
                 if (action == PistonValueType.PULLING || action == PistonValueType.CANCELLED_MID_PUSH) {
                     BlockState pistonBlock = session.getGeyser().getWorldManager().blockAt(session, position);
-                    if (!isSticky(pistonBlock)) {
+
+                    // Retracting sticky pistons is an exception, since the event is not called on Spigot from 1.13.2 - 1.17.1
+                    // See https://github.com/PaperMC/Paper/blob/6fa1983e9ce177a4a412d5b950fd978620174777/patches/server/0304-Fire-BlockPistonRetractEvent-for-all-empty-pistons.patch
+                    boolean isSticky = isSticky(pistonBlock);
+                    if (session.getGeyser().getPlatformType() == PlatformType.SPIGOT && !isSticky) {
                         return;
                     }
-                    if (action != PistonValueType.CANCELLED_MID_PUSH) {
+
+                    // Only sticky pistons that don't pull any blocks are affected
+                    if (action != PistonValueType.CANCELLED_MID_PUSH && isSticky) {
                         Vector3i blockInFrontPos = position.add(direction.getUnitVector());
                         int blockInFront = session.getGeyser().getWorldManager().getBlockAt(session, blockInFrontPos);
                         if (blockInFront != Block.JAVA_AIR_ID) {
@@ -99,7 +105,7 @@ public class JavaBlockEventTranslator extends PacketTranslator<ClientboundBlockE
                             return;
                         }
                     }
-                    PistonBlockEntity blockEntity = pistonCache.getPistons().computeIfAbsent(position, pos -> new PistonBlockEntity(session, pos, direction, true, true));
+                    PistonBlockEntity blockEntity = pistonCache.getPistons().computeIfAbsent(position, pos -> new PistonBlockEntity(session, pos, direction, isSticky, true));
                     if (blockEntity.getAction() != action) {
                         blockEntity.setAction(action, Object2ObjectMaps.emptyMap());
                     }

gradle/libs.versions.toml

@@ -33,6 +33,7 @@ fabric-api = "0.100.1+1.21"
 fabric-permissions = "0.2-SNAPSHOT"
 neoforge-minecraft = "21.0.0-beta"
 mixin = "0.8.5"
+mixinextras = "0.3.5"
 minecraft = "1.21"
 
 # plugin versions
@@ -89,6 +90,7 @@ folia-api = { group = "dev.folia", name = "folia-api", version.ref = "folia" }
 paper-mojangapi = { group = "io.papermc.paper", name = "paper-mojangapi", version.ref = "folia" }
 
 mixin = { group = "org.spongepowered", name = "mixin", version.ref = "mixin" }
+mixinextras = { module = "io.github.llamalad7:mixinextras-common", version.ref = "mixinextras" }
 
 minecraft = { group = "com.mojang", name = "minecraft", version.ref = "minecraft" }