LivingSpawnEvent.CheckSpawn and LivingSpawnEvent.SpecialSpawn

Author: Nuclearfarts

patchwork-events-entity/src/main/java/com/patchworkmc/impl/event/entity/EntityEvents.java

@@ -23,17 +23,24 @@
 import net.minecraftforge.event.entity.EntityJoinWorldEvent;
 import net.minecraftforge.event.entity.living.LivingAttackEvent;
 import net.minecraftforge.event.entity.living.LivingDeathEvent;
+import net.minecraftforge.event.entity.living.LivingHurtEvent;
+import net.minecraftforge.event.entity.living.LivingSpawnEvent;
 import net.minecraftforge.event.entity.player.PlayerInteractEvent;
 import net.minecraftforge.eventbus.api.Event;
-import org.apache.logging.log4j.LogManager;
+import net.minecraftforge.eventbus.api.Event.Result;
 import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.LogManager;
 
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.SpawnType;
 import net.minecraft.entity.damage.DamageSource;
+import net.minecraft.entity.mob.MobEntity;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.util.ActionResult;
 import net.minecraft.util.Hand;
+import net.minecraft.world.IWorld;
+import net.minecraft.world.MobSpawnerLogic;
 import net.minecraft.world.World;
 
 import net.fabricmc.api.ModInitializer;
@@ -63,6 +70,45 @@ public static boolean onLivingAttack(LivingEntity entity, DamageSource src, floa
 		return MinecraftForge.EVENT_BUS.post(new LivingAttackEvent(entity, src, damage));
 	}
 
+	public static float onLivingHurt(LivingEntity entity, DamageSource src, float damage) {
+		LivingHurtEvent event = new LivingHurtEvent(entity, src, damage);
+		return MinecraftForge.EVENT_BUS.post(event) ? 0 : event.getAmount();
+	}
+
+	public static Result canEntitySpawn(MobEntity entity, IWorld world, double x, double y, double z, MobSpawnerLogic spawner, SpawnType spawnType) {
+		if (entity == null) {
+			return Result.DEFAULT;
+		}
+
+		LivingSpawnEvent.CheckSpawn event = new LivingSpawnEvent.CheckSpawn(entity, world, x, y, z, spawner, spawnType);
+		MinecraftForge.EVENT_BUS.post(event);
+		return event.getResult();
+	}
+
+	public static boolean canEntitySpawnFromSpawner(MobEntity entity, World world, double x, double y, double z, MobSpawnerLogic spawner) {
+		Result result = canEntitySpawn(entity, world, x, y, z, spawner, SpawnType.SPAWNER);
+
+		if (result == Result.DEFAULT) {
+			return entity.canSpawn(world, SpawnType.SPAWNER) && entity.canSpawn(world); //vanilla logic, but inverted since we're checking if it CAN spawn instead of if it CAN'T
+		} else {
+			return result == Result.ALLOW;
+		}
+	}
+
+	public static boolean canEntitySpawnNaturally(MobEntity entity, IWorld world, double x, double y, double z, MobSpawnerLogic spawner, SpawnType spawnType, double sqDistanceFromPlayer) {
+		Result result = canEntitySpawn(entity, world, x, y, z, spawner, spawnType);
+
+		if (result == Result.DEFAULT) {
+			return !(sqDistanceFromPlayer > 16384.0D && entity.canImmediatelyDespawn(sqDistanceFromPlayer)) && entity.canSpawn(world, SpawnType.NATURAL) && entity.canSpawn(world); //vanilla logic, but inverted since we're checking if it CAN spawn instead of if it CAN'T
+		} else {
+			return result == Result.ALLOW;
+		}
+	}
+
+	public static boolean doSpecialSpawn(MobEntity entity, IWorld world, double x, double y, double z, MobSpawnerLogic spawner, SpawnType spawnType) {
+		return MinecraftForge.EVENT_BUS.post(new LivingSpawnEvent.SpecialSpawn(entity, world, x, y, z, spawner, spawnType));
+	}
+
 	@Override
 	public void onInitialize() {
 		UseItemCallback.EVENT.register((player, world, hand) -> {

patchwork-events-entity/src/main/java/com/patchworkmc/mixin/event/entity/MixinLivingEntity.java

@@ -22,6 +22,7 @@
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.ModifyVariable;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
@@ -50,4 +51,19 @@ private void hookDamage(DamageSource source, float amount, CallbackInfoReturnabl
 			callback.setReturnValue(false);
 		}
 	}
+
+	// Shift back one because otherwise we inject after the value of damage is pushed onto the JVM stack, causing the modification to have no effect
+	@ModifyVariable(method = "applyDamage", at = @At(value = "INVOKE", target = "net/minecraft/entity/LivingEntity.applyArmorToDamage(Lnet/minecraft/entity/damage/DamageSource;F)F", shift = At.Shift.BEFORE))
+	private float hookApplyDamageForHurtEvent(float damage, DamageSource source) {
+		LivingEntity entity = (LivingEntity) (Object) this;
+
+		return EntityEvents.onLivingHurt(entity, source, damage);
+	}
+
+	@Inject(method = "applyDamage", at = @At(value = "INVOKE", target = "net/minecraft/entity/LivingEntity.applyArmorToDamage(Lnet/minecraft/entity/damage/DamageSource;F)F"), cancellable = true)
+	private void hookApplyDamageForHurtEventCancel(DamageSource source, float damage, CallbackInfo info) {
+		if (damage <= 0) {
+			info.cancel();
+		}
+	}
 }

patchwork-events-entity/src/main/java/com/patchworkmc/mixin/event/entity/MixinMobSpawnerLogic.java

@@ -0,0 +1,29 @@
+package com.patchworkmc.mixin.event.entity;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import net.minecraft.entity.SpawnType;
+import net.minecraft.entity.mob.MobEntity;
+import net.minecraft.world.IWorld;
+import net.minecraft.world.MobSpawnerLogic;
+import net.minecraft.world.ViewableWorld;
+import net.minecraft.world.World;
+
+import com.patchworkmc.impl.event.entity.EntityEvents;
+
+@Mixin(MobSpawnerLogic.class)
+public class MixinMobSpawnerLogic {
+	@Redirect(method = "update", at = @At(value = "INVOKE", target = "net/minecraft/entity/mob/MobEntity.canSpawn(Lnet/minecraft/world/IWorld;Lnet/minecraft/entity/SpawnType;)Z"))
+	private boolean spawnTestRedirect(MobEntity on, IWorld world, SpawnType type) {
+		MobSpawnerLogic spawner = (MobSpawnerLogic) (Object) this;
+
+		return EntityEvents.canEntitySpawnFromSpawner(on, (World) world, on.x, on.y, on.z, spawner);
+	}
+
+	@Redirect(method = "update", at = @At(value = "INVOKE", target = "net/minecraft/entity/mob/MobEntity.canSpawn(Lnet/minecraft/world/ViewableWorld;)Z"))
+	private boolean makeTheOtherMethodNotMessItUp(MobEntity on, ViewableWorld world) {
+		return true;
+	}
+}

patchwork-events-entity/src/main/java/com/patchworkmc/mixin/event/entity/MixinPlayerEntity.java

@@ -22,6 +22,7 @@
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.ModifyVariable;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
@@ -81,4 +82,19 @@ private void hookDamage(DamageSource source, float amount, CallbackInfoReturnabl
 			callback.setReturnValue(false);
 		}
 	}
+
+	// Shift back one because otherwise we inject after the value of damage is pushed onto the JVM stack, causing the modification to have no effect
+	@ModifyVariable(method = "applyDamage", at = @At(value = "INVOKE", target = "net/minecraft/entity/player/PlayerEntity.applyArmorToDamage(Lnet/minecraft/entity/damage/DamageSource;F)F", shift = At.Shift.BEFORE))
+	private float hookApplyDamageForHurtEvent(float damage, DamageSource source) {
+		LivingEntity entity = (LivingEntity) (Object) this;
+
+		return EntityEvents.onLivingHurt(entity, source, damage);
+	}
+
+	@Inject(method = "applyDamage", at = @At(value = "INVOKE", target = "net/minecraft/entity/player/PlayerEntity.applyArmorToDamage(Lnet/minecraft/entity/damage/DamageSource;F)F"), cancellable = true)
+	private void hookApplyDamageForHurtEventCancel(DamageSource source, float damage, CallbackInfo info) {
+		if (damage <= 0) {
+			info.cancel();
+		}
+	}
 }

patchwork-events-entity/src/main/java/com/patchworkmc/mixin/event/entity/MixinSpawnHelper.java

@@ -0,0 +1,49 @@
+package com.patchworkmc.mixin.event.entity;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import net.minecraft.entity.EntityData;
+import net.minecraft.entity.SpawnType;
+import net.minecraft.entity.mob.MobEntity;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.IWorld;
+import net.minecraft.world.LocalDifficulty;
+import net.minecraft.world.SpawnHelper;
+import net.minecraft.world.ViewableWorld;
+
+import com.patchworkmc.impl.event.entity.EntityEvents;
+
+@Mixin(SpawnHelper.class)
+public class MixinSpawnHelper {
+	@Unique
+	private static double playerDistanceStore;
+
+	//We re-implement the vanilla logic in the event, disable it here. Also capture the player distance.
+	@Redirect(method = "spawnEntitiesInChunk", at = @At(value = "INVOKE", target = "net/minecraft/entity/mob/MobEntity.canImmediatelyDespawn(D)Z"))
+	private static boolean disableVanillaLogicAndCaptureDistance(MobEntity entity, double distFromPlayer) {
+		playerDistanceStore = distFromPlayer;
+		return false;
+	}
+
+	@Redirect(method = "spawnEntitiesInChunk", at = @At(value = "INVOKE", target = "net/minecraft/entity/mob/MobEntity.canSpawn(Lnet/minecraft/world/IWorld;Lnet/minecraft/entity/SpawnType;)Z"))
+	private static boolean hookCheckSpawn(MobEntity entity, IWorld world, SpawnType spawnType) {
+		return EntityEvents.canEntitySpawnNaturally(entity, entity.world, entity.x, entity.y, entity.x, null, spawnType, playerDistanceStore);
+	}
+
+	@Redirect(method = "spawnEntitiesInChunk", at = @At(value = "INVOKE", target = "net/minecraft/entity/mob/MobEntity.canSpawn(Lnet/minecraft/world/ViewableWorld;)Z"))
+	private static boolean disableVanillaLogic(MobEntity entity, ViewableWorld world) {
+		return true;
+	}
+
+	@Redirect(method = "spawnEntitiesInChunk", at = @At(value = "INVOKE", target = "net/minecraft/entity/mob/MobEntity.initialize(Lnet/minecraft/world/IWorld;Lnet/minecraft/world/LocalDifficulty;Lnet/minecraft/entity/SpawnType;Lnet/minecraft/entity/EntityData;Lnet/minecraft/nbt/CompoundTag;)Lnet/minecraft/entity/EntityData;"))
+	private static EntityData hookSpecialSpawn(MobEntity entity, IWorld world, LocalDifficulty localDifficulty, SpawnType spawnType, EntityData data, CompoundTag tag) {
+		if (!EntityEvents.doSpecialSpawn(entity, world, entity.x, entity.y, entity.z, null, spawnType)) {
+			return entity.initialize(world, localDifficulty, spawnType, data, tag);
+		} else {
+			return data;
+		}
+	}
+}

patchwork-events-entity/src/main/java/net/minecraftforge/event/entity/living/LivingAttackEvent.java

@@ -25,13 +25,13 @@
 /**
  * LivingAttackEvent is fired when a living Entity is attacked.
  *
- * <p>This event is fired whenever a LivingEntity is attacked in
+ * <p>This event is fired whenever a {@link LivingEntity} is attacked in
  * {@link LivingEntity#damage(DamageSource, float)} and
  * {@link net.minecraft.entity.player.PlayerEntity#damage(DamageSource, float)}.</p>
  *
  * <p>This event is fired via the {@link com.patchworkmc.impl.event.entity.EntityEvents#onLivingAttack(EntityLivingBase, DamageSource, float)}.</p>
  *
- * <p>{@link #source} contains the DamageSource of the attack.
+ * <p>{@link #source} contains the {@link DamageSource} of the attack.
  * {@link #amount} contains the amount of damage dealt to the entity.</p>
  *
  * <p>This event is cancellable.

patchwork-events-entity/src/main/java/net/minecraftforge/event/entity/living/LivingHurtEvent.java

@@ -0,0 +1,72 @@
+/*
+ * Minecraft Forge, Patchwork Project
+ * Copyright (c) 2016-2019, 2019
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.event.entity.living;
+
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.damage.DamageSource;
+
+/**
+ * <p>LivingHurtEvent is fired when an Entity is set to be hurt.
+ * This event is fired whenever an Entity is hurt in
+ * {@link LivingEntity#applyDamage(DamageSource, float)} and
+ * {@link net.minecraft.entity.player.PlayerEntity#applyDamage(DamageSource, float)}.</p>
+ *
+ * <p>This event is fired via {@link com.patchworkmc.impl.event.entity.EntityEvents#onLivingHurt(LivingEntity, DamageSource, float)}.</p>
+ *
+ * <p>{@link #source} contains the {@link DamageSource} that caused this {@link LivingEntity} to be hurt.
+ * {@link #amount} contains the amount of damage dealt to the {@link LivingEntity} that was hurt.</p>
+ *
+ * <p>This event is cancellable.
+ * If this event is canceled, the Entity is not hurt.</p>
+ *
+ * <p>This event is fired on the {@link net.minecraftforge.common.MinecraftForge#EVENT_BUS}.</p>
+ */
+public class LivingHurtEvent extends LivingEvent {
+	private final DamageSource source;
+	private float amount;
+	// For EventBus
+	public LivingHurtEvent() {
+		this.source = null;
+		this.amount = 0;
+	}
+
+	public LivingHurtEvent(LivingEntity entity, DamageSource source, float amount) {
+		super(entity);
+		this.source = source;
+		this.amount = amount;
+	}
+
+	public DamageSource getSource() {
+		return source;
+	}
+
+	public float getAmount() {
+		return amount;
+	}
+
+	public void setAmount(float amount) {
+		this.amount = amount;
+	}
+
+	@Override
+	public boolean isCancelable() {
+		return true;
+	}
+}