Paper/Spigot-Server-Patches/0359-Improve-death-events.patch

From d245361a96aedce40893a891bf4794177f4deb1a Mon Sep 17 00:00:00 2001
From: Phoenix616 <mail@moep.tv>
Date: Tue, 21 Aug 2018 01:39:35 +0100
Subject: [PATCH] Improve death events

This adds the ability to cancel the death events and to modify the sound
an entity makes when dying. (In cases were no sound should it will be
called with shouldPlaySound set to false allowing unsilencing of silent
entities)

It makes handling of entity deaths a lot nicer as you no longer need
to listen on the damage event and calculate if the entity dies yourself
to cancel the death which has the benefit of also receiving the dropped
items and experience which is otherwise only properly possible by using
internal code.

diff --git a/src/main/java/net/minecraft/server/CombatTracker.java b/src/main/java/net/minecraft/server/CombatTracker.java
index 63bdb96db8..96dd1a7fa4 100644
--- a/src/main/java/net/minecraft/server/CombatTracker.java
+++ b/src/main/java/net/minecraft/server/CombatTracker.java
@@ -163,6 +163,7 @@ public class CombatTracker {
         this.h = null;
     }
 
+    public void reset() { this.g(); } // Paper - OBFHELPER
     public void g() {
         int i = this.f ? 300 : 100;
         if (this.g && (!this.b.isAlive() || this.b.ticksLived - this.c > i)) {
diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 2bb6c5f3c4..c45c52084a 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -1538,6 +1538,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         return false;
     }
 
+    public void runKillTrigger(Entity entity, int kills, DamageSource damageSource) { this.a(entity, kills, damageSource); } // Paper - OBFHELPER
     public void a(Entity entity, int i, DamageSource damagesource) {
         if (entity instanceof EntityPlayer) {
             CriterionTriggers.c.a((EntityPlayer) entity, this, damagesource);
@@ -2407,6 +2408,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         this.fallDistance = 0.0F;
     }
 
+    public void onKill(EntityLiving entityLiving) { this.b(entityLiving); } // Paper - OBFHELPER
     public void b(EntityLiving entityliving) {}
 
     protected boolean i(double d0, double d1, double d2) {
@@ -3077,6 +3079,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         return EnumPistonReaction.NORMAL;
     }
 
+    public SoundCategory getDeathSoundCategory() { return bV();} // Paper - OBFHELPER
     public SoundCategory bV() {
         return SoundCategory.NEUTRAL;
     }
diff --git a/src/main/java/net/minecraft/server/EntityArmorStand.java b/src/main/java/net/minecraft/server/EntityArmorStand.java
index 35afffedef..e8e7413748 100644
--- a/src/main/java/net/minecraft/server/EntityArmorStand.java
+++ b/src/main/java/net/minecraft/server/EntityArmorStand.java
@@ -629,7 +629,8 @@ public class EntityArmorStand extends EntityLiving {
     }
 
     public void killEntity() {
-        org.bukkit.craftbukkit.event.CraftEventFactory.callEntityDeathEvent(this, drops); // CraftBukkit - call event
+        org.bukkit.event.entity.EntityDeathEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callEntityDeathEvent(this, drops); // CraftBukkit - call event // Paper - make cancellable
+        if (event.isCancelled()) return; // Paper - make cancellable
         this.die();
     }
 
diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
index 1328f88898..13dd555491 100644
--- a/src/main/java/net/minecraft/server/EntityLiving.java
+++ b/src/main/java/net/minecraft/server/EntityLiving.java
@@ -76,14 +76,14 @@ public abstract class EntityLiving extends Entity {
     public float aU;
     public EntityHuman killer;
     public int lastDamageByPlayerTime; // Paper - public
-    protected boolean aX;
+    protected boolean aX; protected void setDying(boolean dying) { this.aX = dying; } protected boolean isDying() { return this.aX; } // Paper - OBFHELPER
     protected int ticksFarFromPlayer;
     protected float aZ;
     protected float ba;
     protected float bb;
     protected float bc;
     protected float bd;
-    protected int be;
+    protected int be; protected int getKillCount() { return this.be; } // Paper - OBFHELPER
     public float lastDamage;
     protected boolean bg;
     public float bh;
@@ -124,6 +124,7 @@ public abstract class EntityLiving extends Entity {
     public boolean collides = true;
     public boolean canPickUpLoot;
     public org.bukkit.craftbukkit.entity.CraftLivingEntity getBukkitLivingEntity() { return (org.bukkit.craftbukkit.entity.CraftLivingEntity) super.getBukkitEntity(); } // Paper
+    public boolean silentDeath = false; // Paper - mark entity as dying silently for cancellable death event
 
     @Override
     public float getBukkitYaw() {
@@ -1071,13 +1072,17 @@ public abstract class EntityLiving extends Entity {
 
             if (this.getHealth() <= 0.0F) {
                 if (!this.e(damagesource)) {
-                    SoundEffect soundeffect = this.cs();
+                    // Paper start - moved into CraftEventFactory event caller for cancellable death event
+                    //SoundEffect soundeffect = this.cs();
 
-                    if (flag1 && soundeffect != null) {
-                        this.a(soundeffect, this.cD(), this.cE());
-                    }
+                    //if (flag1 && soundeffect != null) {
+                    //    this.a(soundeffect, this.cD(), this.cE());
+                    //}
+                    this.silentDeath = !flag1; // mark entity as dying silently
+                    // Paper end
 
                     this.die(damagesource);
+                    this.silentDeath = false; // Paper - cancellable death event - reset to default
                 }
             } else if (flag1) {
                 this.c(damagesource);
@@ -1205,16 +1210,20 @@ public abstract class EntityLiving extends Entity {
             Entity entity = damagesource.getEntity();
             EntityLiving entityliving = this.cv();
 
-            if (this.be >= 0 && entityliving != null) {
-                entityliving.a(this, this.be, damagesource);
-            }
+            // Paper start - move down to make death event cancellable
+            //if (this.be >= 0 && entityliving != null) {
+            //    entityliving.a(this, this.be, damagesource);
+            //}
 
-            if (entity != null) {
-                entity.b(this);
-            }
+            //if (entity != null) {
+            //    entity.b(this);
+            //}
 
-            this.aX = true;
-            this.getCombatTracker().g();
+            this.aX = true; // Paper - Always set at start, unset later if cancelled - GH-1432
+            //this.getCombatTracker().g();
+
+            org.bukkit.event.entity.EntityDeathEvent deathEvent = null;
+            // Paper end
             if (!this.world.isClientSide) {
                 int i = 0;
 
@@ -1227,15 +1236,33 @@ public abstract class EntityLiving extends Entity {
 
                     this.a(flag, i, damagesource);
                     // CraftBukkit start - Call death event
-                    CraftEventFactory.callEntityDeathEvent(this, this.drops);
+                    deathEvent = CraftEventFactory.callEntityDeathEvent(this, this.drops); // Paper - cancellable death event
                     this.drops = new ArrayList<org.bukkit.inventory.ItemStack>();
                 } else {
-                    CraftEventFactory.callEntityDeathEvent(this);
+                    deathEvent = CraftEventFactory.callEntityDeathEvent(this); // Paper - cancellable death event
                     // CraftBukkit end
                 }
             }
 
-            this.world.broadcastEntityEffect(this, (byte) 3);
+            // Paper start - cancellable death event
+            if (deathEvent == null || !deathEvent.isCancelled()) {
+                // triggers and stats got moved down
+                if (this.getKillCount() >= 0 && entityliving != null) {
+                    entityliving.runKillTrigger(this, this.getKillCount(), damagesource);
+                }
+
+                if (entity != null) {
+                    entity.onKill(this);
+                }
+
+                this.getCombatTracker().reset();
+                this.setDying(true);
+                this.world.broadcastEntityEffect(this, (byte) 3);
+            } else {
+                this.setDying(false); // Paper - reset if cancelled
+                this.setHealth((float) deathEvent.getReviveHealth());
+            }
+            // Paper end
         }
     }
 
@@ -1289,6 +1316,7 @@ public abstract class EntityLiving extends Entity {
         return SoundEffects.ENTITY_GENERIC_HURT;
     }
 
+    @Nullable public SoundEffect getDeathSoundEffect() { return cs();} // Paper - OBFHELPER
     @Nullable
     protected SoundEffect cs() {
         return SoundEffects.ENTITY_GENERIC_DEATH;
@@ -1709,10 +1737,12 @@ public abstract class EntityLiving extends Entity {
 
     }
 
+    public float getDeathSoundVolume() { return cD();} // Paper - OBFHELPER
     protected float cD() {
         return 1.0F;
     }
 
+    public float getDeathSoundPitch() { return cE();} // Paper - OBFHELPER
     protected float cE() {
         return this.isBaby() ? (this.random.nextFloat() - this.random.nextFloat()) * 0.2F + 1.5F : (this.random.nextFloat() - this.random.nextFloat()) * 0.2F + 1.0F;
     }
diff --git a/src/main/java/net/minecraft/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
index 68f5842cfe..5ab4e01edf 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -75,6 +75,10 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
     public int ping;
     public boolean viewingCredits;
     private int containerUpdateDelay; // Paper
+    // Paper start - cancellable death event
+    public boolean queueHealthUpdatePacket = false;
+    public net.minecraft.server.PacketPlayOutUpdateHealth queuedHealthUpdatePacket;
+    // Paper end
 
     // CraftBukkit start
     public String displayName;
@@ -508,6 +512,15 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
 
         String deathmessage = defaultMessage.getString();
         org.bukkit.event.entity.PlayerDeathEvent event = CraftEventFactory.callPlayerDeathEvent(this, loot, deathmessage, keepInventory);
+        // Paper start - cancellable death event
+        if (event.isCancelled()) {
+            // make compatible with plugins that might have already set the health in an event listener
+            if (this.getHealth() <= 0) {
+                this.setHealth((float) event.getReviveHealth());
+            }
+            return;
+        }
+        // Paper end
 
         String deathMessage = event.getDeathMessage();
 
@@ -635,8 +648,17 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
                         }
                     }
                 }
-
-                return super.damageEntity(damagesource, f);
+                // Paper start - cancellable death events
+                //return super.damageEntity(damagesource, f);
+                this.queueHealthUpdatePacket = true;
+                boolean damaged = super.damageEntity(damagesource, f);
+                this.queueHealthUpdatePacket = false;
+                if (this.queuedHealthUpdatePacket != null) {
+                    this.playerConnection.sendPacket(this.queuedHealthUpdatePacket);
+                    this.queuedHealthUpdatePacket = null;
+                }
+                return damaged;
+                // Paper end
             }
         }
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftSound.java b/src/main/java/org/bukkit/craftbukkit/CraftSound.java
index 17fab031b4..ee8219e3ba 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftSound.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftSound.java
@@ -674,6 +674,22 @@ public enum CraftSound {
     WEATHER_RAIN_ABOVE("weather.rain.above");
     private final String minecraftKey;
 
+    // Paper start - cancellable death event
+    public static CraftSound getBySoundEffect(final SoundEffect effect) {
+        MinecraftKey key = IRegistry.SOUND_EVENT.getKey(effect);
+        Preconditions.checkArgument(key != null, "Key for sound effect %s not found?", effect.toString());
+
+        return valueOf(key.getKey().replace('.', '_').toUpperCase(java.util.Locale.ENGLISH));
+    }
+
+    public static Sound getSoundByEffect(final SoundEffect effect) {
+        return Sound.valueOf(getBySoundEffect(effect).name());
+    }
+
+    public static SoundEffect getSoundEffect(final Sound sound) {
+        return getSoundEffect(getSound(sound));
+    }
+    // Paper end
     CraftSound(String minecraftKey) {
         this.minecraftKey = minecraftKey;
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 2f9cff6e71..ac7fc0ef3e 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -1711,7 +1711,15 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
     }
 
     public void sendHealthUpdate() {
-        getHandle().playerConnection.sendPacket(new PacketPlayOutUpdateHealth(getScaledHealth(), getHandle().getFoodData().getFoodLevel(), getHandle().getFoodData().getSaturationLevel()));
+        // Paper start - cancellable death event
+        //getHandle().playerConnection.sendPacket(new PacketPlayOutUpdateHealth(getScaledHealth(), getHandle().getFoodData().getFoodLevel(), getHandle().getFoodData().getSaturationLevel()));
+        PacketPlayOutUpdateHealth packet = new PacketPlayOutUpdateHealth(getScaledHealth(), getHandle().getFoodData().getFoodLevel(), getHandle().getFoodData().getSaturationLevel());
+        if (this.getHandle().queueHealthUpdatePacket) {
+            this.getHandle().queuedHealthUpdatePacket = packet;
+        } else {
+            this.getHandle().playerConnection.sendPacket(packet);
+        }
+        // Paper end
     }
 
     public void injectScaledMaxHealth(Collection<AttributeInstance> collection, boolean force) {
diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index a553c20657..12e2c0f6e1 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -426,9 +426,16 @@ public class CraftEventFactory {
     public static EntityDeathEvent callEntityDeathEvent(EntityLiving victim, List<org.bukkit.inventory.ItemStack> drops) {
         CraftLivingEntity entity = (CraftLivingEntity) victim.getBukkitEntity();
         EntityDeathEvent event = new EntityDeathEvent(entity, drops, victim.getExpReward());
+        populateFields(victim, event); // Paper - make cancellable
         CraftWorld world = (CraftWorld) entity.getWorld();
         Bukkit.getServer().getPluginManager().callEvent(event);
 
+        // Paper start - make cancellable
+        if (event.isCancelled()) {
+            return event;
+        }
+        playDeathSound(victim, event);
+        // Paper end
         victim.expToDrop = event.getDroppedExp();
 
         for (org.bukkit.inventory.ItemStack stack : event.getDrops()) {
@@ -444,8 +451,15 @@ public class CraftEventFactory {
         CraftPlayer entity = victim.getBukkitEntity();
         PlayerDeathEvent event = new PlayerDeathEvent(entity, drops, victim.getExpReward(), 0, deathMessage);
         event.setKeepInventory(keepInventory);
+        populateFields(victim, event); // Paper - make cancellable
         org.bukkit.World world = entity.getWorld();
         Bukkit.getServer().getPluginManager().callEvent(event);
+        // Paper start - make cancellable
+        if (event.isCancelled()) {
+            return event;
+        }
+        playDeathSound(victim, event);
+        // Paper end
 
         victim.keepLevel = event.getKeepLevel();
         victim.newLevel = event.getNewLevel();
@@ -466,6 +480,31 @@ public class CraftEventFactory {
         return event;
     }
 
+    // Paper start - helper methods for making death event cancellable
+    // Add information to death event
+    private static void populateFields(EntityLiving victim, EntityDeathEvent event) {
+        event.setReviveHealth(event.getEntity().getAttribute(org.bukkit.attribute.Attribute.GENERIC_MAX_HEALTH).getValue());
+        event.setShouldPlayDeathSound(!victim.silentDeath && !victim.isSilent());
+        SoundEffect soundEffect = victim.getDeathSoundEffect();
+        event.setDeathSound(soundEffect != null ? org.bukkit.craftbukkit.CraftSound.getSoundByEffect(soundEffect) : null);
+        event.setDeathSoundCategory(org.bukkit.SoundCategory.valueOf(victim.getDeathSoundCategory().name()));
+        event.setDeathSoundVolume(victim.getDeathSoundVolume());
+        event.setDeathSoundPitch(victim.getDeathSoundPitch());
+    }
+
+    // Play death sound manually
+    private static void playDeathSound(EntityLiving victim, EntityDeathEvent event) {
+        if (event.shouldPlayDeathSound() && event.getDeathSound() != null && event.getDeathSoundCategory() != null) {
+            EntityHuman source = victim instanceof EntityHuman ? (EntityHuman) victim : null;
+            double x = event.getEntity().getLocation().getX();
+            double y = event.getEntity().getLocation().getY();
+            double z = event.getEntity().getLocation().getZ();
+            SoundEffect soundEffect = org.bukkit.craftbukkit.CraftSound.getSoundEffect(event.getDeathSound());
+            SoundCategory soundCategory = SoundCategory.valueOf(event.getDeathSoundCategory().name());
+            victim.world.sendSoundEffect(source, x, y, z, soundEffect, soundCategory, event.getDeathSoundVolume(), event.getDeathSoundPitch());
+        }
+    }
+    // Paper end
     /**
      * Server methods
      */
-- 
2.19.0