LivingFallEvent and PlayerFlyableFallEvent

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

@@ -28,7 +28,9 @@
 import net.minecraftforge.event.entity.living.LivingDamageEvent;
 import net.minecraftforge.event.entity.living.LivingSpawnEvent;
 import net.minecraftforge.event.entity.living.LivingEvent;
+import net.minecraftforge.event.entity.living.LivingFallEvent;
 import net.minecraftforge.event.entity.player.PlayerEvent;
+import net.minecraftforge.event.entity.player.PlayerFlyableFallEvent;
 import net.minecraftforge.event.entity.player.PlayerInteractEvent;
 import net.minecraftforge.eventbus.api.Event;
 import net.minecraftforge.eventbus.api.Event.Result;
@@ -93,6 +95,15 @@ public static float onLivingHurt(LivingEntity entity, DamageSource src, float da
 		return MinecraftForge.EVENT_BUS.post(event) ? 0 : event.getAmount();
 	}
 
+	public static float[] onLivingFall(LivingEntity entity, float distance, float damageMultiplier) {
+		LivingFallEvent event = new LivingFallEvent(entity, distance, damageMultiplier);
+		return MinecraftForge.EVENT_BUS.post(event) ? null : new float[]{ event.getDistance(), event.getDamageMultiplier() };
+	}
+
+	public static void onFlyablePlayerFall(PlayerEntity player, float distance, float damageMultiplier) {
+		MinecraftForge.EVENT_BUS.post(new PlayerFlyableFallEvent(player, distance, damageMultiplier));
+	}
+
 	public static float onLivingDamage(LivingEntity entity, DamageSource src, float damage) {
 		LivingDamageEvent event = new LivingDamageEvent(entity, src, damage);
 		return MinecraftForge.EVENT_BUS.post(event) ? 0 : event.getAmount();

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

@@ -20,6 +20,7 @@
 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.Inject;
 import org.spongepowered.asm.mixin.injection.ModifyVariable;
@@ -33,6 +34,9 @@
 
 @Mixin(LivingEntity.class)
 public class MixinLivingEntity {
+	@Unique
+	private float[] fallData;
+
 	// TODO: Forge bug: PlayerEntity calls its super, so this event gets fired twice on the client.
 	@Inject(method = "onDeath", at = @At("HEAD"), cancellable = true)
 	private void hookDeath(DamageSource source, CallbackInfo callback) {
@@ -76,6 +80,27 @@ private void hookApplyDamageForHurtEventCancel(DamageSource source, float damage
 		}
 	}
 
+	@ModifyVariable(method = "handleFallDamage", at = @At(value = "INVOKE", target = "net/minecraft/entity/Entity.handleFallDamage(FF)V", shift = At.Shift.BEFORE), ordinal = 0)
+	private float hookHandleFallDamageDistance(float distance, float damageMultiplier) {
+		return fallData[0];
+	}
+
+	@ModifyVariable(method = "handleFallDamage", at = @At(value = "INVOKE", target = "net/minecraft/entity/Entity.handleFallDamage(FF)V", shift = At.Shift.AFTER), ordinal = 1)
+	private float hookHandleFallDamageMultiplier(float distance, float damageMultiplier) {
+		return fallData[1];
+	}
+
+	@Inject(method = "handleFallDamage", at = @At("HEAD"), cancellable = true)
+	private void hookHandleFallDamageCancel(float distance, float damageMultiplier, CallbackInfo info) {
+		LivingEntity entity = (LivingEntity) (Object) this;
+
+		fallData = EntityEvents.onLivingFall(entity, distance, damageMultiplier);
+
+		if (fallData == null) {
+			info.cancel();
+		}
+	}
+
 	// No shift, because we are specifically not modifying the value for this function call.
 	// TODO: Forge patches a bit later into the function here, being inconsistent with their patch for PlayerEntity. For the moment, I don't feel like finding an injection point for that, and this may be a Forge bug?
 	@ModifyVariable(method = "applyDamage", argsOnly = true, at = @At(value = "INVOKE", target = "net/minecraft/entity/LivingEntity.setAbsorptionAmount (F)V", ordinal = 0))

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

@@ -20,6 +20,7 @@
 package com.patchworkmc.mixin.event.entity;
 
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.ModifyVariable;
@@ -29,6 +30,7 @@
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.LivingEntity;
 import net.minecraft.entity.damage.DamageSource;
+import net.minecraft.entity.player.PlayerAbilities;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.util.ActionResult;
 import net.minecraft.util.Hand;
@@ -37,6 +39,9 @@
 
 @Mixin(PlayerEntity.class)
 public class MixinPlayerEntity {
+	@Shadow
+	public PlayerAbilities abilities;
+
 	@Inject(method = "interact", at = @At("HEAD"), cancellable = true)
 	private void hookInteractEntity(Entity entity, Hand hand, CallbackInfoReturnable<ActionResult> callback) {
 		PlayerEntity player = (PlayerEntity) (Object) this;
@@ -99,6 +104,14 @@ private void hookApplyDamageForHurtEventCancel(DamageSource source, float damage
 		}
 	}
 
+	@Inject(method = "handleFallDamage", at = @At("RETURN"))
+	private void hookHandleFallDamage(float distance, float damageMultiplier) {
+		if (abilities.allowFlying) {
+			PlayerEntity player = (PlayerEntity) (Object) this;
+			EntityEvents.onFlyablePlayerFall(player, distance, damageMultiplier);
+		}
+	}
+
 	// No shift, because we are specifically not modifying the value for this function call.
 	@ModifyVariable(method = "applyDamage", argsOnly = true, at = @At(value = "INVOKE", target = "net/minecraft/entity/player/PlayerEntity.setAbsorptionAmount (F)V", ordinal = 0))
 	private float hookApplyDamageForDamageEvent(float damage, DamageSource source) {

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

@@ -0,0 +1,77 @@
+/*
+ * Minecraft Forge, Patchwork Project
+ * Copyright (c) 2016-2020, 2019-2020
+ *
+ * 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;
+
+/**
+ * LivingFallEvent is fired when a {@link LivingEntity} is set to be falling.
+ *
+ * <p>This event is fired whenever a {@link LivingEntity} is set to fall in
+ * {@link LivingEntity#fall(float, float)}.</p>
+ *
+ * <p>For players that are able to fly, {@link net.minecraftforge.event.entity.player.PlayerFlyableFallEvent} will be fired instead.</p>
+ *
+ * <p>This event is fired via {@link com.patchworkmc.impl.event.entity.EntityEvents#onLivingFall(LivingEntity, float, float)}.</p>
+ *
+ * <p>{@link #distance} contains the distance the {@link LivingEntity} is to fall. If this event is cancelled, this value is set to 0.0F.</p>
+ *
+ * <p>This event is cancellable.
+ * If this event is cancelled, the {@link LivingEntity} does not take fall damage.</p>
+ *
+ * <p>This event is fired on the {@link MinecraftForge#EVENT_BUS}.</p>
+ */
+public class LivingFallEvent extends LivingEvent {
+	private float distance;
+	private float damageMultiplier;
+
+	// For EventBus
+	public LivingFallEvent() {
+		this(null, 0, 0);
+	}
+
+	public LivingFallEvent(LivingEntity entity, float distance, float damageMultiplier) {
+		super(entity);
+
+		this.setDistance(distance);
+		this.setDamageMultiplier(damageMultiplier);
+	}
+
+	public float getDistance() {
+		return distance;
+	}
+
+	public void setDistance(float distance) {
+		this.distance = distance;
+	}
+
+	public float getDamageMultiplier() {
+		return damageMultiplier;
+	}
+
+	public void setDamageMultiplier(float damageMultiplier) {
+		this.damageMultiplier = damageMultiplier;
+	}
+
+	@Override
+	public boolean isCancelable() {
+		return true;
+	}
+}

patchwork-events-entity/src/main/java/net/minecraftforge/event/entity/player/PlayerFlyableFallEvent.java

@@ -0,0 +1,59 @@
+/*
+ * Minecraft Forge, Patchwork Project
+ * Copyright (c) 2016-2020, 2019-2020
+ *
+ * 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.player;
+
+import net.minecraft.entity.player.PlayerEntity;
+
+/**
+ * Occurs when a player falls, but is able to fly.
+ * {@link net.minecraftforge.event.entity.living.LivingFallEvent} will be fired for players that are not able to fly.
+ */
+public class PlayerFlyableFallEvent extends PlayerEvent {
+	private float distance;
+	private float multiplier;
+
+	// For EventBus
+	public PlayerFlyableFallEvent() {
+		this(null, 0, 0);
+	}
+
+	public PlayerFlyableFallEvent(PlayerEntity player, float distance, float multiplier) {
+		super(player);
+
+		this.distance = distance;
+		this.multiplier = multiplier;
+	}
+
+	public float getDistance() {
+		return distance;
+	}
+
+	public void setDistance(float distance) {
+		this.distance = distance;
+	}
+
+	public float getMultiplier() {
+		return multiplier;
+	}
+
+	public void setMultiplier(float multiplier) {
+		this.multiplier = multiplier;
+	}
+}