PaperMC/patches/server/Add-EntityKnockbackByEntityEvent-and-EntityPushedByE.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Brokkonaut <hannos17@gmx.de>
Date: Mon, 18 Jun 2018 15:46:23 +0200
Subject: [PATCH] Add EntityKnockbackByEntityEvent and
 EntityPushedByEntityAttackEvent

Co-authored-by: aerulion <aerulion@gmail.com>

This event is called when an entity receives knockback by another entity.

diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -0,0 +0,0 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
     }
 
     public void push(double deltaX, double deltaY, double deltaZ) {
-        this.setDeltaMovement(this.getDeltaMovement().add(deltaX, deltaY, deltaZ));
+        // Paper start - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
+        this.push(deltaX, deltaY, deltaZ, null);
+    }
+
+    public void push(double deltaX, double deltaY, double deltaZ, @org.jetbrains.annotations.Nullable Entity pushingEntity) {
+        org.bukkit.util.Vector delta = new org.bukkit.util.Vector(deltaX, deltaY, deltaZ);
+        if (pushingEntity != null) {
+            io.papermc.paper.event.entity.EntityPushedByEntityAttackEvent event = new io.papermc.paper.event.entity.EntityPushedByEntityAttackEvent(getBukkitEntity(), pushingEntity.getBukkitEntity(), delta);
+            if (!event.callEvent()) {
+                return;
+            }
+            delta = event.getAcceleration();
+        }
+        this.setDeltaMovement(this.getDeltaMovement().add(delta.getX(), delta.getY(), delta.getZ()));
         this.hasImpulse = true;
+        // Paper end - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
     }
 
     protected void markHurt() {
diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -0,0 +0,0 @@ public abstract class LivingEntity extends Entity implements Attackable {
     }
 
     protected void blockedByShield(LivingEntity target) {
-        target.knockback(0.5D, target.getX() - this.getX(), target.getZ() - this.getZ(), null, EntityKnockbackEvent.KnockbackCause.SHIELD_BLOCK); // CraftBukkit
+        target.knockback(0.5D, target.getX() - this.getX(), target.getZ() - this.getZ(), this, EntityKnockbackEvent.KnockbackCause.SHIELD_BLOCK); // CraftBukkit // Paper - fix attacker
     }
 
     private boolean checkTotemDeathProtection(DamageSource source) {
@@ -0,0 +0,0 @@ public abstract class LivingEntity extends Entity implements Attackable {
                 return;
             }
 
+            // Paper start - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
+            final org.bukkit.util.Vector currentMovement = this.getBukkitEntity().getVelocity();
+            org.bukkit.util.Vector resultingMovement = event.getFinalKnockback();
+            final org.bukkit.util.Vector deltaMovement = resultingMovement.clone().subtract(currentMovement);
+            if (attacker != null) {
+                final com.destroystokyo.paper.event.entity.EntityKnockbackByEntityEvent knockbackEvent = new com.destroystokyo.paper.event.entity.EntityKnockbackByEntityEvent((org.bukkit.entity.LivingEntity) getBukkitEntity(), attacker.getBukkitEntity(), (float) event.getForce(), deltaMovement);
+                if (!knockbackEvent.callEvent()) {
+                    return;
+                }
+
+                // Back from delta to the absolute vector
+                resultingMovement = currentMovement.add(knockbackEvent.getAcceleration());
+            }
             this.hasImpulse = true;
-            this.setDeltaMovement(event.getFinalKnockback().getX(), event.getFinalKnockback().getY(), event.getFinalKnockback().getZ());
+            this.setDeltaMovement(resultingMovement.getX(), resultingMovement.getY(), resultingMovement.getZ());
+            // Paper end - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
             // CraftBukkit end
         }
     }
diff --git a/src/main/java/net/minecraft/world/entity/ai/behavior/RamTarget.java b/src/main/java/net/minecraft/world/entity/ai/behavior/RamTarget.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/ai/behavior/RamTarget.java
+++ b/src/main/java/net/minecraft/world/entity/ai/behavior/RamTarget.java
@@ -0,0 +0,0 @@ public class RamTarget extends Behavior<Goat> {
             float f = 0.25F * (float)(i - j);
             float g = Mth.clamp(entity.getSpeed() * 1.65F, 0.2F, 3.0F) + f;
             float h = livingEntity.isDamageSourceBlocked(world.damageSources().mobAttack(entity)) ? 0.5F : 1.0F;
-            livingEntity.knockback((double)(h * g) * this.getKnockbackForce.applyAsDouble(entity), this.ramDirection.x(), this.ramDirection.z());
+            livingEntity.knockback((double)(h * g) * this.getKnockbackForce.applyAsDouble(entity), this.ramDirection.x(), this.ramDirection.z(), entity, org.bukkit.event.entity.EntityKnockbackEvent.KnockbackCause.ENTITY_ATTACK); // Paper - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
             this.finishRam(world, entity);
             world.playSound((Player)null, entity, this.getImpactSound.apply(entity), SoundSource.NEUTRAL, 1.0F, 1.0F);
         } else if (this.hasRammedHornBreakingBlock(world, entity)) {
diff --git a/src/main/java/net/minecraft/world/entity/ai/behavior/warden/SonicBoom.java b/src/main/java/net/minecraft/world/entity/ai/behavior/warden/SonicBoom.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/ai/behavior/warden/SonicBoom.java
+++ b/src/main/java/net/minecraft/world/entity/ai/behavior/warden/SonicBoom.java
@@ -0,0 +0,0 @@ public class SonicBoom extends Behavior<Warden> {
                 target.hurt(world.damageSources().sonicBoom(entity), 10.0F);
                 double d = 0.5D * (1.0D - target.getAttributeValue(Attributes.KNOCKBACK_RESISTANCE));
                 double e = 2.5D * (1.0D - target.getAttributeValue(Attributes.KNOCKBACK_RESISTANCE));
-                target.push(vec33.x() * e, vec33.y() * d, vec33.z() * e);
+                target.push(vec33.x() * e, vec33.y() * d, vec33.z() * e, entity); // Paper - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
             });
         }
     }
diff --git a/src/main/java/net/minecraft/world/entity/boss/enderdragon/EnderDragon.java b/src/main/java/net/minecraft/world/entity/boss/enderdragon/EnderDragon.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/boss/enderdragon/EnderDragon.java
+++ b/src/main/java/net/minecraft/world/entity/boss/enderdragon/EnderDragon.java
@@ -0,0 +0,0 @@ public class EnderDragon extends Mob implements Enemy {
                 double d3 = entity.getZ() - d1;
                 double d4 = Math.max(d2 * d2 + d3 * d3, 0.1D);
 
-                entity.push(d2 / d4 * 4.0D, 0.20000000298023224D, d3 / d4 * 4.0D);
+                entity.push(d2 / d4 * 4.0D, 0.20000000298023224D, d3 / d4 * 4.0D, this); // Paper - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
                 if (!this.phaseManager.getCurrentPhase().isSitting() && ((LivingEntity) entity).getLastHurtByMobTimestamp() < entity.tickCount - 2) {
                     entity.hurt(this.damageSources().mobAttack(this), 5.0F);
                     this.doEnchantDamageEffects(this, entity);
diff --git a/src/main/java/net/minecraft/world/entity/monster/Ravager.java b/src/main/java/net/minecraft/world/entity/monster/Ravager.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/monster/Ravager.java
+++ b/src/main/java/net/minecraft/world/entity/monster/Ravager.java
@@ -0,0 +0,0 @@ public class Ravager extends Raider {
         double d1 = entity.getZ() - this.getZ();
         double d2 = Math.max(d0 * d0 + d1 * d1, 0.001D);
 
-        entity.push(d0 / d2 * 4.0D, 0.2D, d1 / d2 * 4.0D);
+        entity.push(d0 / d2 * 4.0D, 0.2D, d1 / d2 * 4.0D, this); // Paper - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/entity/monster/hoglin/HoglinBase.java b/src/main/java/net/minecraft/world/entity/monster/hoglin/HoglinBase.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/monster/hoglin/HoglinBase.java
+++ b/src/main/java/net/minecraft/world/entity/monster/hoglin/HoglinBase.java
@@ -0,0 +0,0 @@ public interface HoglinBase {
             double j = f * (double)(attacker.level().random.nextFloat() * 0.5F + 0.2F);
             Vec3 vec3 = (new Vec3(g, 0.0D, h)).normalize().scale(j).yRot(i);
             double k = f * (double)attacker.level().random.nextFloat() * 0.5D;
-            target.push(vec3.x, k, vec3.z);
+            target.push(vec3.x, k, vec3.z, attacker); // Paper - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
             target.hurtMarked = true;
         }
     }
diff --git a/src/main/java/net/minecraft/world/entity/player/Player.java b/src/main/java/net/minecraft/world/entity/player/Player.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/player/Player.java
+++ b/src/main/java/net/minecraft/world/entity/player/Player.java
@@ -0,0 +0,0 @@ public abstract class Player extends LivingEntity {
                             if (target instanceof LivingEntity) {
                                 ((LivingEntity) target).knockback((double) ((float) i * 0.5F), (double) Mth.sin(this.getYRot() * 0.017453292F), (double) (-Mth.cos(this.getYRot() * 0.017453292F)), this, EntityKnockbackEvent.KnockbackCause.ENTITY_ATTACK); // CraftBukkit
                             } else {
-                                target.push((double) (-Mth.sin(this.getYRot() * 0.017453292F) * (float) i * 0.5F), 0.1D, (double) (Mth.cos(this.getYRot() * 0.017453292F) * (float) i * 0.5F));
+                                target.push((double) (-Mth.sin(this.getYRot() * 0.017453292F) * (float) i * 0.5F), 0.1D, (double) (Mth.cos(this.getYRot() * 0.017453292F) * (float) i * 0.5F), this); // Paper - Add EntityKnockbackByEntityEvent and EntityPushedByEntityAttackEvent
                             }
 
                             this.setDeltaMovement(this.getDeltaMovement().multiply(0.6D, 1.0D, 0.6D));
diff --git a/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java b/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
+++ b/src/main/java/net/minecraft/world/entity/projectile/AbstractArrow.java
@@ -0,0 +0,0 @@ public abstract class AbstractArrow extends Projectile {
                     Vec3 vec3d = this.getDeltaMovement().multiply(1.0D, 0.0D, 1.0D).normalize().scale((double) this.knockback * 0.6D * d0);
 
                     if (vec3d.lengthSqr() > 0.0D) {
-                        entityliving.push(vec3d.x, 0.1D, vec3d.z);
+                        entityliving.push(vec3d.x, 0.1D, vec3d.z, this); // Paper
                     }
                 }