I'm trying to find in the code which class or classes trigger mob spawns. For example if I wanted to change the Y at which slimes spawn or allow a custom mob like an elephant spawn on the Savannah biome.
Intent is to do this for a forge mod, but I assume the answer is standard for minecraft?
Thanks!
For mod-added entities, EntityRegistry.addSpawn(...) is used to register which biomes the entity will spawn in using the existing per-biome spawn rules.
For slimes, the class EntitySlime controls what Y heights it is allowed to spawn at, see the getCanSpawnHere() method. However, you cannot modify this class. In order to override what heights are valid, you would need to subscribe to the LivingSpawnEvent (there are three subclasses, you would want to subscribe to one of the three) and set the result to Result.ALLOW to force the entity to spawn regardless of its usual spawn checks (conversely, Result.DENY to prevent it).
Related
I cannot see any of the command pattern classes e.g. invoker, receiver manifesting in the accepted answer of the following link Long list of if statements in Java. I have gone with the accepted answer to solve my 30+ if/else statements.
I have one repository that I am trying to pass DTOs to save to the database. I want the repository to invoke the correct save method for the DTO so I am checking the instance type at runtime.
Here is the implementation in Repository
private Map<Class<?>, Command> commandMap;
public void setCommandMap(Map<Class<?>, Command> commandMap) {
this.commandMap = commandMap;
}
and a method that will populate the commandMap
commandMap.put(Address.class, new CommandAddress());
commandMap.put(Animal.class, new CommandAnimal());
commandMap.put(Client.class, new CommandClient());
and finally the method that saves
public void getValue(){
commandMap.get(these.get(0).getClass()).save();
}
The service class that uses the Repo registers the commandMap.
Does the accepted answer represent a sort of (approximate) implementation of the Command pattern?
It seems like an enum that implements an exec interface will eliminate your if/else problem or turn it into a switch.
It does not look like you need a command patterm.
Gof says:
Use the Command pattern when you want to
parameterize objects by an action to perform, as MenuItem objects did above. You can express such parameterization in a procedural language with a callback function, that is, a function that's registered somewhere to be called at a later point. Commands are an object-oriented replacement for callbacks.
specify, queue, and execute requests at different times. A Command object can have a lifetime independent of the original request. If the receiver of a request can be represented in an address space-independent way, then you can transfer a command object for the request to a different process and fulfill the request there.
support undo. The Command's Execute operation can store state for reversing its effects in the command itself. The Command interface must have an added Unexecute operation that reverses the effects of a previous call to Execute. Executed commands are stored in a history list. Unlimited-level undo and redo is achieved by traversing this list backwards and forwards calling Unexecute and Execute, respectively.
support logging changes so that they can be reapplied in case of a system crash. By augmenting the Command interface with load and store operations, you can keep a persistent log of changes. Recovering from a crash involves reloading logged commands from disk and reexecuting them with the Execute operation.
structure a system around high-level operations built on primitives operations. Such a structure is common in information systems that support transactions. A transaction encapsulates a set of changes to data. The Command pattern offers a way to model transactions. Commands have a common interface, letting you invoke all transactions the same way. The pattern also makes it easy to extend the system with new transactions.
Which of the above do you want to do?
Sure, I can do it by using functional global variable(FGV). At the very beginning of the code, I read the state(booleans, nemeric values, etc.) from FGV and wire the data into shift register in Facade.vi. After while loop terminate itself, I write the data into FGV and I can reuse it next time.
But there is a problem when I use multiple instances of X Control in a VI instead of single instance. The Non-reentrant FGVs used by different instance of X Control share there common state.
Is there a way that I can keep internal states independently from instances of X Control?
Thanks for any help.
You can use State ability and/or Custom Properties to store any variable used to control the appearance and/or behaviour of the X Control.
In both cases each instance of the X Control will have different State values.
I have faced the same problem and solved by using DVRs.
Upon code initiation, you should initiate DVR and store the reference in the global variable. By doing this you can set "FGV"s to be reentrant, but still function correctly.
Here is my colleague's answer. He actually keeps internal states independently from instances of XControl.
He uses FGV but one shift register contains VI clone name and the other one contains array of cluster(states) of XControl instance respectively. The FGV is still Non-reentrant and multiple instances use a common FGV. When one of instances want to read its own states, it just passes its VI clone name into FGV and then FGV gives it states according to VI clone name. In the other hand, if one of instances completes the works, it passes its VI clone name and states into FGV after terminates while loop. The FGV will stack VI clone name and according states separately into shift registers. This method will keep internal states independently from instances of XControl.
Stack method used in FGV
Just make the FGVs be full reentrant.
I working on high-scalability web site for learning purpose. I decided to use CQS pattern and some ideas of CQRS. I have separate write and read layers used by command handlers and event handlers which system sends and receives from message buses (two separate message- buses).
I have some problem dealing with commands. I read that command shouldn't return anything. And now the point is: for example I have a form on with user can create an event or for example change something in his profile (photo or name). After user clicked save i want to show him, his profile or add a new event to his wall. But how can I know that his profile has been already updated when command is only send to the bus ? I How connect idea of command and CRUD operations ? Or maybe this wrong idea at all ?
Well first off, the split should not be between commands and events, but rather between domain and read models. You can't really map CQRS commands to CRUD operations as a general rule, although most of the commands in your system will change the state of your repositories. I will give you a general overview of how this works. Say you want to add a user, you create a command AddUserCommand and assign an id to that message. On the back end, you have an handler for that command and you're right that the command does not return nothing. Once that command is handled you should publish and event reflecting the change: UserWasAddedEvent. The id of this message will be unique, but it can and should have an id related to the command which you created in the UI. Your read models should handle the event and update a read model with the command status (waiting, processing, completedOnError, completedSuccessfully) depending on the event you published. On the UI after you submited the command, you should start querying the read models whith the ID of the command you created to get the status and then update your UI accordigly.
Your right that CQRS handlers return void, but you should bear in mind that typically in an architecture like this, the backend should return the validation results of the submited commands, not the handler itself but the infrastucture around your cqrs handlers.
Just update te UI on the assumption the command succeeds - which most of the time it will.
If validation is required on the user input, you could run validation as the user types or tabs to increase the likelyhood the command will succeed.
I'd like to write a Minecraft mod which adds a new type of mob. Is that possible? I see that, in Bukkit, EntityType is a predefined enum, which leads me to believe there may not be a way to add a new type of entity. I'm hoping that's wrong.
Yes, you can!
I'd direct you to some tutorials on the Bukkit forums. Specifically:
Creating a Meteor Entity
Modifying the Behavior of a Mob or Entity
Disclaimer: the first is written by me.
You cannot truly add an entirely new mob just via Bukkit. You'd have to use Spout to give it a different skin. However, in the case you simply want a mob, and are content with sharing a skin of another entity, then it can be done.
The idea is injecting the EntityType values via Java's Reflection API. It would look something like this:
public static void load() {
try {
Method a = EntityTypes.class.getDeclaredMethod("a", Class.class, String.class, int.class);
a.setAccessible(true);
a.invoke(a, YourEntityClass.class, "Your identifier, can be anything", id_map);
} catch (Exception e) {
//Insert handling code here
}
}
I think the above is fairly straightforward. We get a handle to the private method, make it public, and invoke its registration method.id_map contains the entity id to map your entity to. 12 is that of a fireball. The mapping can be found in EntityType.class. Note that these ids should not be confused with their packet designations. The two are completely different.
Lastly, you actually need to spawn your entity. MC will continue spawning the default entity, since we haven't removed it from the map. But its just a matter of calling the net.minecraft.server.spawnEntity(your_entity, SpawnReason.CUSTOM).
If you need a skin, I suggest you look into SpoutPlugin. It does require running the Spout client to join to such a server, but the possibilities at that point are literally infinite.
It would only be possible with client-side mods as well, sadly. You could look into Spout, (http://www.spout.org/) which is a client mod which provides an API for server-side plugins to do more on the client, but without doing something client side, this is impossible.
It's not possible to add new entities, but it is possible to edit entity behaviors for example one time, I made it so that you could tame iron golems and they followed you around.
Also you can sort of achieve custom looking human entities by accessing player entities and tweaking network packets
It's expensive as you need to create a player account to achieve this that then gets used to act as a mob. You then spawn a named entity and give it the same behaviour AI as you would with an existing mob. Keep in mind however you will need to write the AI yourself (you could borrow code straight from craftbukkit/bukkit) and you will need to push the movement and events of this mob to players within sight .. As technically speaking all your doing is pushing packets to the client from the serve on what's actually happening but if your outside that push list nothing will happen as other players will see you being knocked around by invisible something :) it's a bit of a mental leap :)
I'm using this concept to create Npc that act as friendly and factional armies. I've also used mobs themselves as friendly entities (if you belong to a dark faction)
I'd like to personally see future server API that can push model instructions to the client for server specific cache as well as the ability to tell a client where to download mob skins ..
It's doable today but I'd have to create a plugin for the client to achieve this which is then back to a game of annoyance especially when mojang push out a new release and all the plugins take forever to rise with its tide
In all honesty this entire ecosystem could be managed more strategically but right now I think it's just really ad hoc product management (speaking as a former product manager of .net I'd love to work on this strategy it would be such a fun gig)
I'm working on a small application using C++/wxWidgets, where several parts of the GUI need to be updated based on e.g. received UDP datagrams. More specifically, a secondary thread tries to keep a list of available "clients" in the network (which may come and go away) and e.g. corresponding comboboxes in the UI need to be updated to reflect the changes.
The documentation mentions that for this kind of thing EVT_UPDATE_UI would be a good choice. As far as I can understand from the sparse documentation, this event is sent automatically by the system and provides some support for assisted UI change.
However, I'd feel more comfortable using a more direct approach, i.e. where e.g. a window object could register/subscribe to receive notifications (either events or callbacks) upon particular events and another part of the code is sending out these notifications when required. I could do this in C++ using my own code, however I guess if wxWidgets already supports something like that, I should make use of it. However I haven't found anything in that regards.
So, the question is: does wxWidgets support this kind of notification system (or similar alternatives) or would I be best served coding my own?
AFAIK there is nothing directly usable in wxWidgets, but doing it on your own seems easy.
What I would do:
Create a wxEvtHandler-descendent class to hold the list of available "clients" in the network. Let this class have a wxCriticalSection, and use a wxCriticalSectionLocker for that in all methods that add or delete "clients".
Create a worker thread class by inheriting wxThread to handle your UDP datagrams, using blocking calls. The thread should directly call methods of the client list object whenever a client has to be added or removed. In these methods update the list of clients, and ::wxPostEvent() an event to itself (this will execute the whole notification calls in the main GUI thread).
Handle the event in the client list class, and notify all listeners that the list of clients has changed. The observer pattern seems to me a good fit. You could either call a method of all registered listeners directly, or send a wxCommandEvent to them.
Have you tried calling Update() on the widget(s) that change? Once you update the contents of the combo box, call Update(), and the contents should update.