[Forge][1.11.2] Get the entity that another entity is looking at Server side

getLookedAtEntity.java

	/**
	 * Gets the entity that a entity is looking at
	 * @param blockReachDistance the distance to check
	 * @param entity the entity who is looking
	 * @return the entity found, or null if one is not found
	 * @since May 30, 2017
	 * @author Dalethium
	 */
	@Nullable
	public Entity getLookedAtEntity(double blockReachDistance, Entity entity) {
		Vec3d eyeVec = entity.getPositionEyes(0f);
		Vec3d lookVec = entity.getLook(1.0F);
		Vec3d diffVec = eyeVec.addVector(lookVec.xCoord * blockReachDistance, lookVec.yCoord * blockReachDistance, lookVec.zCoord * blockReachDistance);
		Vec3d resultVec = null;
		RayTraceResult traceA = entity.world.rayTraceBlocks(eyeVec, diffVec, false, false, true);
		double distA = blockReachDistance;
		Entity pointedEntity = null;

		if (traceA != null) {
			distA = traceA.hitVec.distanceTo(eyeVec);
		}
		
		List<Entity> list = entity.world.getEntitiesInAABBexcluding(entity, entity.getEntityBoundingBox().addCoord(lookVec.xCoord * blockReachDistance, lookVec.yCoord * blockReachDistance, lookVec.zCoord * blockReachDistance).expand(1.0D, 1.0D, 1.0D), Predicates.and(EntitySelectors.NOT_SPECTATING, new Predicate<Entity>() {
			public boolean apply(@Nullable Entity entity) {
				return entity != null && entity.canBeCollidedWith();
			}
		}));

		for (int j = 0; j < list.size(); ++j) {
			Entity currEntity = (Entity)list.get(j);
			AxisAlignedBB axisalignedbb = currEntity.getEntityBoundingBox().expandXyz((double)currEntity.getCollisionBorderSize());
			RayTraceResult raytraceresult = axisalignedbb.calculateIntercept(eyeVec, diffVec);

			if (axisalignedbb.isVecInside(eyeVec)) {
				if (distA >= 0.0D) {
					pointedEntity = currEntity;
					resultVec = raytraceresult == null ? eyeVec : raytraceresult.hitVec;
					distA = 0.0D;
				}
			} else if (raytraceresult != null) {
				double distB = eyeVec.distanceTo(raytraceresult.hitVec);

				if (distB < distA || distA == 0.0D) {
					if (currEntity.getLowestRidingEntity() == entity.getLowestRidingEntity() && !entity.canRiderInteract()) {
						if (distA == 0.0D) {
							pointedEntity = currEntity;
							resultVec = raytraceresult.hitVec;
						}
					} else {
						pointedEntity = currEntity;
						resultVec = raytraceresult.hitVec;
						distA = distB;
					}
				}
			}
		}
		return pointedEntity;
	}

I spent a lot of time looking for a way to do this and found nothing, so I figured I'd share it, it's mostly code ripped from sections of minecraft/forge code.

It's not very clean, most of it is not even refractored, sorry.

I just finished the method, and did basic functionality testing, obviously this is AS IS and WITHOUT WARRANTY.

If you find a bug or whatever feel free to correct it, I just wanted to give people a starting point.

Have a great day!