Paper/patches/server/0251-Add-LivingEntity-getTargetEntity.patch

From 0000000000000000000000000000000000000000 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/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 7a89c25fcd1c76e4b176c257600db89788aa0f21..3bcf2ba5f065d946ded4020b9882bc4e19af0e08 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -4176,6 +4176,38 @@ public abstract class LivingEntity extends Entity implements Attackable {
         return this.level().clip(raytrace);
     }
 
+    public @Nullable net.minecraft.world.phys.EntityHitResult getTargetEntity(int maxDistance) {
+        if (maxDistance < 1 || maxDistance > 120) {
+            throw new IllegalArgumentException("maxDistance must be between 1-120");
+        }
+
+        Vec3 start = this.getEyePosition(1.0F);
+        Vec3 direction = this.getLookAngle();
+        Vec3 end = start.add(direction.x * maxDistance, direction.y * maxDistance, direction.z * maxDistance);
+
+        List<Entity> entityList = this.level().getEntities(this, getBoundingBox().expandTowards(direction.x * maxDistance, direction.y * maxDistance, direction.z * maxDistance).inflate(1.0D, 1.0D, 1.0D), EntitySelector.NO_SPECTATORS.and(Entity::isPickable));
+
+        double distance = 0.0D;
+        net.minecraft.world.phys.EntityHitResult result = null;
+
+        for (Entity entity : entityList) {
+            final double inflationAmount = (double) entity.getPickRadius();
+            AABB aabb = entity.getBoundingBox().inflate(inflationAmount, inflationAmount, inflationAmount);
+            Optional<Vec3> rayTraceResult = aabb.clip(start, end);
+
+            if (rayTraceResult.isPresent()) {
+                Vec3 rayTrace = rayTraceResult.get();
+                double distanceTo = start.distanceToSqr(rayTrace);
+                if (distanceTo < distance || distance == 0.0D) {
+                    result = new net.minecraft.world.phys.EntityHitResult(entity, rayTrace);
+                    distance = distanceTo;
+                }
+            }
+        }
+
+        return result;
+    }
+
     public int shieldBlockingDelay = this.level().paperConfig().misc.shieldBlockingDelay;
 
     public int getShieldBlockingDelay() {
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
index 0c7bf4124d67258ebca9b9b73b92c2e0efbdaa86..c4c83b4e17aac23794fdb51acfba4e7ef8451e2c 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
@@ -232,6 +232,39 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
         }
         return null;
     }
+
+    public Entity getTargetEntity(int maxDistance, boolean ignoreBlocks) {
+        net.minecraft.world.phys.EntityHitResult rayTrace = rayTraceEntity(maxDistance, ignoreBlocks);
+        return rayTrace == null ? null : rayTrace.getEntity().getBukkitEntity();
+    }
+
+    public com.destroystokyo.paper.entity.TargetEntityInfo getTargetEntityInfo(int maxDistance, boolean ignoreBlocks) {
+        net.minecraft.world.phys.EntityHitResult rayTrace = rayTraceEntity(maxDistance, ignoreBlocks);
+        return rayTrace == null ? null : new com.destroystokyo.paper.entity.TargetEntityInfo(rayTrace.getEntity().getBukkitEntity(), new org.bukkit.util.Vector(rayTrace.getLocation().x, rayTrace.getLocation().y, rayTrace.getLocation().z));
+    }
+
+    @Override
+    public RayTraceResult rayTraceEntities(int maxDistance, boolean ignoreBlocks) {
+        net.minecraft.world.phys.EntityHitResult rayTrace = this.rayTraceEntity(maxDistance, ignoreBlocks);
+        return rayTrace == null ? null : new org.bukkit.util.RayTraceResult(org.bukkit.craftbukkit.util.CraftVector.toBukkit(rayTrace.getLocation()), rayTrace.getEntity().getBukkitEntity());
+    }
+
+    public net.minecraft.world.phys.EntityHitResult rayTraceEntity(int maxDistance, boolean ignoreBlocks) {
+        net.minecraft.world.phys.EntityHitResult rayTrace = getHandle().getTargetEntity(maxDistance);
+        if (rayTrace == null) {
+            return null;
+        }
+        if (!ignoreBlocks) {
+            net.minecraft.world.phys.HitResult rayTraceBlocks = getHandle().getRayTrace(maxDistance, net.minecraft.world.level.ClipContext.Fluid.NONE);
+            if (rayTraceBlocks != null) {
+                net.minecraft.world.phys.Vec3 eye = getHandle().getEyePosition(1.0F);
+                if (eye.distanceToSqr(rayTraceBlocks.getLocation()) <= eye.distanceToSqr(rayTrace.getLocation())) {
+                    return null;
+                }
+            }
+        }
+        return rayTrace;
+    }
     // Paper end
 
     @Override