Paper/Spigot-Server-Patches/0371-Add-LivingEntity-getTargetEntity.patch

From b82067ae505316dca7048faaedeb7f7565406b6e Mon Sep 17 00:00:00 2001
From: BillyGalbreath <Blake.Galbreath@GMail.com>
Date: Sat, 22 Sep 2018 00:33:08 -0500
Subject: [PATCH] Add LivingEntity#getTargetEntity


diff --git a/src/main/java/net/minecraft/server/AxisAlignedBB.java b/src/main/java/net/minecraft/server/AxisAlignedBB.java
index 1c0b783e8e..dad1ff7372 100644
--- a/src/main/java/net/minecraft/server/AxisAlignedBB.java
+++ b/src/main/java/net/minecraft/server/AxisAlignedBB.java
@@ -95,6 +95,7 @@ public class AxisAlignedBB {
         return new AxisAlignedBB(d3, d4, d5, d6, d7, d8);
     }
 
+    public AxisAlignedBB expand(double x, double y, double z) { return b(x, y, z); } // Paper - OBFHELPER
     public AxisAlignedBB b(double d0, double d1, double d2) {
         double d3 = this.minX;
         double d4 = this.minY;
@@ -124,6 +125,12 @@ public class AxisAlignedBB {
         return new AxisAlignedBB(d3, d4, d5, d6, d7, d8);
     }
 
+    // Paper start
+    public AxisAlignedBB grow(double d0) {
+        return grow(d0, d0, d0);
+    }
+    // Paper end
+
     public AxisAlignedBB grow(double d0, double d1, double d2) {
         double d3 = this.minX - d0;
         double d4 = this.minY - d1;
@@ -181,6 +188,7 @@ public class AxisAlignedBB {
         return this.minX < d3 && this.maxX > d0 && this.minY < d4 && this.maxY > d1 && this.minZ < d5 && this.maxZ > d2;
     }
 
+    public boolean contains(Vec3D vec3d) { return b(vec3d); } // Paper - OBFHELPER
     public boolean b(Vec3D vec3d) {
         return this.e(vec3d.x, vec3d.y, vec3d.z);
     }
@@ -205,6 +213,7 @@ public class AxisAlignedBB {
         return this.g(-d0);
     }
 
+    public MovingObjectPosition calculateIntercept(Vec3D vec3d, Vec3D vec3d1) { return b(vec3d, vec3d1); } // Paper - OBFHELPER
     @Nullable
     public MovingObjectPosition b(Vec3D vec3d, Vec3D vec3d1) {
         return this.a(vec3d, vec3d1, (BlockPosition) null);
diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 3db1b6bb1b..de45e3c7a8 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -1536,6 +1536,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         return new Vec3D((double) (f5 * f6), (double) (-f7), (double) (f4 * f6));
     }
 
+    public Vec3D getEyePosition(float partialTicks) { return i(partialTicks); } // Paper - OBFHELPER
     public Vec3D i(float f) {
         if (f == 1.0F) {
             return new Vec3D(this.locX, this.locY + (double) this.getHeadHeight(), this.locZ);
@@ -2183,10 +2184,12 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         return this.bP().size() < 1;
     }
 
+    public float getCollisionBorderSize() { return aM(); } // Paper - OBFHELPER
     public float aM() {
         return 0.0F;
     }
 
+    public Vec3D getLookVec() { return aN(); } // Paper - OBFHELPER
     public Vec3D aN() {
         return this.d(this.pitch, this.yaw);
     }
diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
index 3d1cdd6271..14f1029687 100644
--- a/src/main/java/net/minecraft/server/EntityLiving.java
+++ b/src/main/java/net/minecraft/server/EntityLiving.java
@@ -3,6 +3,8 @@ package net.minecraft.server;
 import com.destroystokyo.paper.event.player.PlayerArmorChangeEvent;
 import com.google.common.base.Objects;
 import com.google.common.collect.Maps;
+
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.ConcurrentModificationException;
 import java.util.Iterator;
@@ -16,6 +18,8 @@ import org.apache.logging.log4j.Logger;
 
 // CraftBukkit start
 import java.util.ArrayList;
+import java.util.stream.Collectors;
+
 import com.google.common.base.Function;
 import com.google.common.collect.Lists;
 import org.bukkit.Location;
@@ -2863,6 +2867,36 @@ public abstract class EntityLiving extends Entity {
         return world.rayTrace(start, end, fluidCollisionOption);
     }
 
+    public MovingObjectPosition getTargetEntity(int maxDistance) {
+        if (maxDistance < 1 || maxDistance > 120) {
+            throw new IllegalArgumentException("maxDistance must be between 1-120");
+        }
+
+        Vec3D start = getEyePosition(1.0F);
+        Vec3D direction = getLookVec();
+        Vec3D end = start.add(direction.x * maxDistance, direction.y * maxDistance, direction.z * maxDistance);
+
+        List<Entity> entityList = world.getEntities(this, getBoundingBox().expand(direction.x * maxDistance, direction.y * maxDistance, direction.z * maxDistance).grow(1.0D, 1.0D, 1.0D), IEntitySelector.notSpectator().and(Entity::isInteractable));
+
+        double distance = 0.0D;
+        MovingObjectPosition rayTraceResult = null;
+
+        for (Entity entity : entityList) {
+            AxisAlignedBB aabb = entity.getBoundingBox().grow((double) entity.getCollisionBorderSize());
+            MovingObjectPosition rayTrace = aabb.calculateIntercept(start, end);
+
+            if (rayTrace != null) {
+                double distanceTo = start.distanceSquared(rayTrace.pos);
+                if (distanceTo < distance || distance == 0.0D) {
+                    rayTraceResult = new MovingObjectPosition(entity, rayTrace.pos);
+                    distance = distanceTo;
+                }
+            }
+        }
+
+        return rayTraceResult;
+    }
+
     public int shieldBlockingDelay = world.paperConfig.shieldBlockingDelay;
 
     public int getShieldBlockingDelay() {
diff --git a/src/main/java/net/minecraft/server/IEntitySelector.java b/src/main/java/net/minecraft/server/IEntitySelector.java
index f6916fd455..71f08d53c7 100644
--- a/src/main/java/net/minecraft/server/IEntitySelector.java
+++ b/src/main/java/net/minecraft/server/IEntitySelector.java
@@ -19,6 +19,7 @@ public final class IEntitySelector {
     public static final Predicate<Entity> e = (entity) -> {
         return !(entity instanceof EntityHuman) || !((EntityHuman) entity).isSpectator() && !((EntityHuman) entity).u();
     };
+    public static Predicate<Entity> notSpectator() { return f; } // Paper - OBFHELPER
     public static final Predicate<Entity> f = (entity) -> {
         return !(entity instanceof EntityHuman) || !((EntityHuman) entity).isSpectator();
     };
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
index eeab59379a..d6a4bc64ae 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
@@ -186,6 +186,33 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
         net.minecraft.server.MovingObjectPosition rayTrace = getHandle().getRayTrace(maxDistance, net.minecraft.server.MCUtil.getNMSFluidCollisionOption(fluidMode));
         return rayTrace == null ? null : new com.destroystokyo.paper.block.TargetBlockInfo(org.bukkit.craftbukkit.block.CraftBlock.at(getHandle().world, rayTrace.getBlockPosition()), net.minecraft.server.MCUtil.toBukkitBlockFace(rayTrace.direction));
     }
+
+    public Entity getTargetEntity(int maxDistance, boolean ignoreBlocks) {
+        net.minecraft.server.MovingObjectPosition rayTrace = rayTraceEntity(maxDistance, ignoreBlocks);
+        return rayTrace == null ? null : rayTrace.entity.getBukkitEntity();
+    }
+
+    public com.destroystokyo.paper.entity.TargetEntityInfo getTargetEntityInfo(int maxDistance, boolean ignoreBlocks) {
+        net.minecraft.server.MovingObjectPosition rayTrace = rayTraceEntity(maxDistance, ignoreBlocks);
+        return rayTrace == null ? null : new com.destroystokyo.paper.entity.TargetEntityInfo(rayTrace.entity.getBukkitEntity(), new org.bukkit.util.Vector(rayTrace.pos.x, rayTrace.pos.y, rayTrace.pos.z));
+    }
+
+    public net.minecraft.server.MovingObjectPosition rayTraceEntity(int maxDistance, boolean ignoreBlocks) {
+        net.minecraft.server.MovingObjectPosition rayTrace = getHandle().getTargetEntity(maxDistance);
+        if (rayTrace == null) {
+            return null;
+        }
+        if (!ignoreBlocks) {
+            net.minecraft.server.MovingObjectPosition rayTraceBlocks = getHandle().getRayTrace(maxDistance, net.minecraft.server.FluidCollisionOption.NEVER);
+            if (rayTraceBlocks != null) {
+                net.minecraft.server.Vec3D eye = getHandle().getEyePosition(1.0F);
+                if (eye.distanceSquared(rayTraceBlocks.pos) <= eye.distanceSquared(rayTrace.pos)) {
+                    return null;
+                }
+            }
+        }
+        return rayTrace;
+    }
     // Paper end
 
     public List<Block> getLastTwoTargetBlocks(Set<Material> transparent, int maxDistance) {
-- 
2.21.0