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• recent unreliable wireless connection

  - by gabkdlly

  Recently, my internet connection over wireless ( via a Netgear KWGR614 router ) has become unreliable, on both a Dell laptop running Ubuntu 10.04 as well as my Desktop running Ubuntu 10.10 . The problem does not seem to occur on a laptop running Windows Vista, nor on a Desktop running Windows 7 ( this machine is connected with an ethernet cable ). The problem does not seem to occur on my Openmoko Freerunner ( running Android 1.5 ), though I hardly ever use this device to connect over WLAN, so the problem may have just slipped by. On my main Ubuntu Desktop, I have tried the following wireless devices: a Longshine PCI card ( an old device with an RTL8180L chip ) a D-Link DWL-510 PCI card ( this device threw warnings in dmesg ) a USB device from MSI ( US54EX ). Usually my wireless network shows up in the network manager with a normal signal strength, even when the connection speed is slow or the connection gets reset ( asking me to click connect to re-authenticate my wireless connection ). I have observed this problem with a Netgear KWGR614 Router ( with the manufacturers firmware ), as well as with a TP-LINK TL-WR741ND router running OpenWrt. Taking a look at my routers logs, I find many instances of the following line: Tuesday,04 Jan 2011 03:53:01 [TCP SYN Flood][Deny access policy matched, dropping packet] I know that the Netgear router is susceptible to denial of service attacks, as I have previously been able to disrupt its operation by putting an nmap scan into a while loop. I use WEP or WPA to encrypt the wireless network. Is it possible that someone is jamming my signal ?

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• How to manage Areas/Levels in an RPG?

  - by Hexlan

  I'm working on an RPG and I'm trying to figure out how to manage the different levels/areas in the game. Currently I create a new state (source file) for every area, defining its unique aspects. My concern is that as the game grows the number of class files will become unmanageable with all the towns, houses, shops, dungeons, etc. that I need to keep track of. I would also prefer to separate my levels from the source code because non-programmer members of the team will be creating levels, and I would like the engine to be as free from game specific code as possible. I'm thinking of creating a class that provides all the functions that will be the same between all the levels/areas with a unique member variable that can be used to look up level specifics from data. This way I only need to define level/area once in the code, but can create multiple instances each with its own unique aspects provided by data. Is this a good way to go about solving the issue? Is there a better way to handle a growing number of levels?

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• How can I pass an external instance to the constructor of an object that's being created using the default XNA XML content loader?

  - by Michael

  I'm trying to understand how to use the XNA XML content importer to instantiate non-trivial objects that are more than a collection of basic properties (e.g., a class that inherits from DrawableGameObject or GameObject and requires other things to be passed into its constructor). Is it possible to pass existing external instances (e.g., an instance of the current Game) to the constructor of an object that's being created using the default XNA XML content loader? For example, imagine that I have the following class, inheriting from DrawableGameComponent: public class Character : DrawableGameComponent { public string Name { get; set; } public Character(Game game) : base(game) { } public override void Update(GameTime gameTime) { } public override void Draw(GameTime gameTime) { } } If I had a simple class that did not need other parameters in its constructor (i.e., the Game instance), then I could simply use this XML: <XnaContent> <Asset Type="MyNamespace.Character"> <Name>John Doe</Name> </Asset> </XnaContent> ...and then create an instance of Character using this code: var character = Content.Load<Character>("MyXmlAssetName"); But that won't work because I need to pass the need to pass the Game into the constructor. What's the best way to handle this situation? Is there a way to pass in things like the current Game using the default XNA XML content loader? Do I need to write my own XML loader? (If so, how?) Is there a better object-oriented design that I should be using for my classes? Note: Although I used Game in this example, I'm really just asking how to pass any type of existing instance to my constructors. (For example, I'm using the Farseer Physics Engine, and some of my classes also need a reference to the Farseer World object too.) Thanks in advance.

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• You may be tempted by IaaS, but you should PaaS on that or your database cloud journey will be a short one

  - by B R Clouse

  Before we examine Consolidation, the next step in the journey to cloud, let's take a short detour to address a critical choice you will face at the outset of your journey: whether to deploy your databases in virtual machines or not. A common misconception we've encountered is the belief that moving to cloud computing can be accomplished by simply hosting one's current operating environment as-is within virtual machines, and then stacking those VMs together in a consolidated environment.  This solution is often described as "Infrastructure as a Service" (IaaS) because the building block for deployments is a VM, which behaves like a full complement of infrastructure.  This approach is easy to understand and may feel like a good first step, but it won't take your databases very far in the journey to cloud computing.  In fact, if you follow the IaaS fork in the road, your journey will end quickly, without realizing the full benefits of cloud computing.  The better option to is to rationalize the deployment stack so that VMs are needed only for exceptional cases.  By settling on a standard operating system and patch level, you create an infrastructure that potentially all of your databases can share.  Now, the building block will be database instances or possibly schemas within databases.  These components are the platforms on which you will deploy workloads, hence this is known as "Platform as a Service" (PaaS). PaaS opens the door to higher degrees of consolidation than IaaS, because with PaaS you will not need to accommodate the footprint (operating system, hypervisor, processes, ...) that each VM brings with it.  You will also reduce your maintenance overheard if you move forward without the VMs and their O/Ses to patch and monitor.  So while IaaS simply shuffles complex and varied environments into VMs,  PaaS actually reduces complexity by rationalizing to the small possible set of components.  Now we're ready to look at the consolidation options that PaaS provides -- in our next blog posting.

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• Service layer coupling

  - by Justin

  I am working on writing a service layer for an order system in php. It's the typical scenario, you have an Order that can have multiple Line Items. So lets say a request is received to store a line item with pictures and comments. I might receive a json request such as { 'type': 'Bike', 'color': 'Red', 'commentIds': [3193,3194] 'attachmentIds': [123,413] } My idea was to have a Service_LineItem_Bike class that knows how to take the json data and store an entity for a bike. My question is, the Service_LineItem class now needs to fetch comments and file attachments, and store the relationships. Service_LineItem seems like it should interact with a Service_Comment and a Service_FileUpload. Should instances of these two other services be instantiated and passed to the Service_LineItem constructor,or set by getters and setters? Dependency injection seems like the right solution, allowing a service access to a 'service fetching helper' seems wrong, and this should stay at the application level. I am using Doctrine 2 as a ORM, and I can technically write a dql query inside Service_LineItem to fetch the comments and file uploads necessary for the association, but this seems like it would have a tighter coupling, rather then leaving this up to the right service object.

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• SOA performance on SPARC T5 benchmark results

  - by JuergenKress

  The brand NEW super fast SPARC T5 servers are available. The platform is superb to run large SOA Suite environments or to consolidate your whole middleware platform. Some performance advices, recommended for all workloads: Performance profile for SOA apps on Oracle Solaris 11 BPEL (Fusion Order Demo) instances per second OSB (messages / transformations per second) Crypto acceleration study for SOA transformations SPARC T4 and T5 platform testing, pre-tuning Performance suitable for mid-to-high range enterprise in stand-alone SOA deployment or virtualized consolidation environment shared with Oracle applications 2.2x to 5x faster than SPARC T3 servers 25% faster SOA throughput, core to core than Intel 5600-series servers (running Exalogic software) SPARC T5 has 2x the consolidation density of Intel 5600-class processors 2x faster initial deployment time using Optimized Solutions pre-tested configuration steps Over 200 Application adapters for easiest Oracle software integration Would you like to get details? We can share with you on 1:1 bases T5 SOA Suite performance benchmarks, please contact your local partner manager or myself! SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Mix Forum Technorati Tags: T5,TS Sparc,T5 SOA,bechmark,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

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• Oracle NoSQL Database: Cleaner Performance

  - by Charles Lamb

  In an earlier post I noted that Berkeley DB Java Edition cleaner performance had improved significantly in release 5.x. From an Oracle NoSQL Database point of view, this is important because Berkeley DB Java Edition is the core storage engine for Oracle NoSQL Database. Many contemporary NoSQL Databases utilize log based (i.e. append-only) storage systems and it is well-understood that these architectures also require a "cleaning" or "compaction" mechanism (effectively a garbage collector) to free up unused space. 10 years ago when we set out to write a new Berkeley DB storage architecture for the BDB Java Edition ("JE") we knew that the corresponding compaction mechanism would take years to perfect. "Cleaning", or GC, is a hard problem to solve and it has taken all of those years of experience, bug fixes, tuning exercises, user deployment, and user feedback to bring it to the mature point it is at today. Reports like Vinoth Chandar's where he observes a 20x improvement validate the maturity of JE's cleaner. Cleaner performance has a direct impact on predictability and throughput in Oracle NoSQL Database. A cleaner that is too aggressive will consume too many resources and negatively affect system throughput. A cleaner that is not aggressive enough will allow the disk storage to become inefficient over time. It has to Work well out of the box, and Needs to be configurable so that customers can tune it for their specific workloads and requirements. The JE Cleaner has been field tested in production for many years managing instances with hundreds of GBs to TBs of data. The maturity of the cleaner and the entire underlying JE storage system is one of the key advantages that Oracle NoSQL Database brings to the table -- we haven't had to reinvent the wheel.

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• IRQ Conflicts Causing Video Card and Boot Problems?

  - by sanpatricio

  tl;dr - I have 4 devices sharing 1 IRQ. Is this bad and how do I tell the BIOS to stop it? Background: I have an old Dell GX280 dual Pentium 4 that I (semi) resurrected last weekend with an installation of Ubuntu 12.04. Everything was going fine the first several hours until a problem that plagued me when WinXP was on that machine happened -- it froze. Completely froze. None of the myriad of ways I have found here on askubuntu helped me to regain control except a long-press of the power button to shut it off. Clearly, this wasn't a software/WinXP issue. After much googling, I found that hardware conflicts can often cause this sort of total lock-up and with all the odd blocks of yellow and flecks of color showing on my screen (both WinXP and Ubuntu) I figured my old GeForce 7600 was failing and causing me these odd issues. (A good canned-air dusting of the entire interior fixed the color fleck problem) Again, through much googling and numerous answers found on askubuntu, I somehow stumbled my way onto the lshw command. After going through it, line by line, I found that I have four devices sharing IRQ 16: eth0, wlan0, ide0 (DVD-RW), and my video card. In hindsight, I can recall weird instances of my Ethernet connection to another computer not working when I thought it should. I never full troubleshot those issues so it could be a coincidence. The other thing that has been plaguing me since installing Ubuntu (wasn't there during WinXP) has been periodic moments of my monitor getting no signal from Ubuntu during boot. The first couple days, it would disappear after the Dell boot screen and reappear at Ubuntu login. Now, it disappears after the Dell boot screen and doesn't return at all -- I have to hit F12 where I can load a safe mode version of Ubuntu and get more details like dmesg and lsdev. I also ran memtest86 overnight and woke up to zero errors, so failing RAM is out. Where do I go from here?

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• Static DataTable or DataSet in a class - bad idea?

  - by Superbest

  I have several instances of a class. Each instance stores data in a common database. So, I thought "I'll make the DataTable table field static, that way every instance can just add/modify rows to its own table field, but all the data will actually be in one place!" However, apparently it's a bad idea to do use static fields, especially if it's databases: Don't Use "Static" in C#? Is this a bad idea? Will I run into problems later on if I use it? This is a small project so I can accept no testing as a compromise if that is the only drawback. The benefit of using a static database is that there can be many objects of type MyClass, but only one table they all talk to, so a static field seems to be an implementation of exactly this, while keeping syntax concise. I don't see why I shouldn't use a static field (although I wouldn't really know) but if I had to, the best alternative I can think of is creating one DataTable, and passing a reference to it when creating each instance of MyClass, perhaps as a constructor parameter. But is this really an improvement? It seems less intuitive than a static field.

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• Models, collections...and then what? Processes?

  - by Dan

  I'm a LAMP-stack dev who's been more on the JavaScript side the last few years and really enjoying the Model + Collection approach to data entities that BackboneJS, etc. uses. It's helped me organize my code in such a way that it is extremely portable, keeping all my properties and methods in the scope (model, collection, etc.) in which they apply. One thing that keeps bugging me though is how to organize the next level up, the 'process layer' as you might call it, that can potentially operate on instances of either models or collections or whatever else. Where should methods like find() (which returns a collection) and create() (which returns a model) reside? I know some people would put a create() in the Collection prototype, but while a collection operates on models I don't think it's exactly right to create them. And while a find() would return a collection I don't think it correct to have that action within the collection prototype itself (it should be a layer up). Can anyone offer some examples of any patterns that employ some kind of OOP-friendly 'process' layer? I'm sorry if this is a fairly well-known discussion but I'm afraid I can't seem to find the terminology to search for.

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• Should I make a seperate unit test for a method, if it only modifies the parent state?

  - by Dante

  Should classes, that modify the state of the parent class, but not itself, be unit tested separately? And by separately, I mean putting the test in the corresponding unit test class, that tests that specific class. I'm developing a library based on chained methods, that return a new instance of a new type in most cases, where a chained method is called. The returned instances only modify the root parent state, but not itself. Overly simplified example, to get the point across: public class BoxedRabbits { private readonly Box _box; public BoxedRabbits(Box box) { _box = box; } public void SetCount(int count) { _box.Items += count; } } public class Box { public int Items { get; set; } public BoxedRabbits AddRabbits() { return new BoxedRabbits(this); } } var box = new Box(); box.AddRabbits().SetCount(14); Say, if I write a unit test under the Box class unit tests: box.AddRabbits().SetCount(14) I could effectively say, that I've already tested the BoxedRabbits class as well. Is this the wrong way of approaching this, even though it's far simpler to first write a test for the above call, then to first write a unit test for the BoxedRabbits separately?

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• How to identify process that's sending error messages to terminal?

  - by kjo

  The following error message occasionally appears in my terminal: Failed to open VDPAU backend libvdpau_nvidia.so: cannot open shared object file: No such file or directory ...which is pretty annoying. I have searched online for solutions to this error, without success. Is there any way to at least identify the process responsible for sending these error messages to my terminal? EDIT: Let me clarify that, as far as I can tell, these error messages appear "out of the blue". In fact, they appear asynchronously with respect to my interactions with the terminal (more often than not see them for the first time when I return to a terminal window that has been unattended for some time). I'm sure there's a definite, deterministic cause for these messages, but it is not one that I can readily identify. In short, I have not noticed any pattern or regularity to their occurrence. In particular, in my case their occurrence has nothing to do with running mplayer, or any other video playback program. (Please my earlier post about it here.) For one thing, the machine in question is a work machine, and I rarely watch any videos with it. In the very few instances in which I've watched a video on this machine I've used VLC, not mplayer, and these errors never appeared in these rare occasions that I used VLC.

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• Business Forces: SOA Adoption

  The only constant in today’s business environment is change. Businesses that continuously foresee change and adapt quickly will gain market share and increased growth. In our ever growing global business environment change is driven by data in regards to collecting, maintaining, verifying and distributing data.  Companies today are made and broken over data. Would anyone still use Google if they did not have one of the most accurate search indexes on the internet? No, because their value is in their data and the quality of their data. Due to the increasing focus on data, companies have been adopting new methodologies for gaining more control over their data while attempting to reduce the costs of maintaining it. In addition, companies are also trying to reduce the time it takes to analyze data in regards to various market forces to foresee changes prior to them actually occurring.   Benefits of Adopting SOA Services can be maintained separately from other services and applications so that a change in one service will only affect itself and client services or applications. The advent of services allows for system functionality to be distributed across a network or multiple networks. The costs associated with maintain business functionality is much higher in standard application development over SOA due to the fact that one Services can be maintained and shared to other applications instead of multiple instances of business functionality being duplicated via hard coding in to several applications. When multiple applications use a single service for a specific business function then the all of the data being processed will be consistent in terms of quality and accuracy through the applications. Disadvantages of Adopting SOA Increased initial costs and timelines are associated with SOA due to the fact that services need to be created as well as applications need to be modified to call the services In order for an SOA project to be successful the project must obtain company and management support in order to gain the proper exposure, funding, and attention. If SOA is new to a company they must also support the proper training in order for the project to be designed, and implemented correctly. References: Tews, R. (2007). Beyond IT: Exploring the Business Value of SOA. SOA Magazine Issue XI.

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• To Virtual or Not to Virtual

  - by Kevin Shyr

  I recently made a comment "I hate everything virtual" while responding to a SQL server performance question.  I then promptly fired up my Hyper-V development environment to do my proof of concept stuff, and realized that I made the cardinal sin of making a generalized comment about something, instead of saying "It depends". The bottom line is if the virtual environment gives the throughput that the server needs, then it is not that big of a deal.  I just have seen so many environment set up with SQL server sitting in virtual environment sitting in a SAN, so on top of having to plan for loss data, I now have to plan for my virtual environment failing for so many different reasons, thought SQL 2012 High Availability Group should make that easier.  To me, a virtual environment makes sense for a stateless application with big scalibility requirement, but doesn't give much benefit to an application where performance and data integrity are both important.  If security is not a concern, I would just build servers with multiple instances on them to balance the workload. Maybe this is also too generalized a comment, and I'll confess that I'm not a DBA by trade.  I'd love to hear the pros and cons of virtualizing a SQL server, or other examples where virtualization makes total sense (not just money, but recovery, rollback, etc.)

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• Are there legitimate reasons for returning exception objects instead of throwing them?

  - by stakx

  This question is intended to apply to any OO programming language that supports exception handling; I am using C# for illustrative purposes only. Exceptions are usually intended to be raised when an problem arises that the code cannot immediately handle, and then to be caught in a catch clause in a different location (usually an outer stack frame). Q: Are there any legitimate situations where exceptions are not thrown and caught, but simply returned from a method and then passed around as error objects? This question came up for me because .NET 4's System.IObserver<T>.OnError method suggests just that: exceptions being passed around as error objects. Let's look at another scenario, validation. Let's say I am following conventional wisdom, and that I am therefore distinguishing between an error object type IValidationError and a separate exception type ValidationException that is used to report unexpected errors: partial interface IValidationError { } abstract partial class ValidationException : System.Exception { public abstract IValidationError[] ValidationErrors { get; } } (The System.Component.DataAnnotations namespace does something quite similar.) These types could be employed as follows: partial interface IFoo { } // an immutable type partial interface IFooBuilder // mutable counterpart to prepare instances of above type { bool IsValid(out IValidationError[] validationErrors); // true if no validation error occurs IFoo Build(); // throws ValidationException if !IsValid(…) } Now I am wondering, could I not simplify the above to this: partial class ValidationError : System.Exception { } // = IValidationError + ValidationException partial interface IFoo { } // (unchanged) partial interface IFooBuilder { bool IsValid(out ValidationError[] validationErrors); IFoo Build(); // may throw ValidationError or sth. like AggregateException<ValidationError> } Q: What are the advantages and disadvantages of these two differing approaches?

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• C# Threading Background Process - Programming - How to?

  - by Magic

  Hello...I have been given the horrible task of doing this. Launch the website Take a screenshot Fill in the form details, click on Next Take a screenshot ... ... ... Rinse. Repeat. Now, with various combinations, this comes up to 300 screenshots. And I have to do this for 4 different browsers. Chrome, Firefox, IE 6 and IE 7. I cannot use tools which will capture the screenshot and store them, such as, SnagIT. I need to take a screenshot, copy it to a Word Document and take the second screenshot and take it to a Word Document. I thought, I will write a tiny utility which will help me do this. Here is the requirement spec that I put up for it - An executable which once launched seats itself in the System Tray. While it is active, all instances of Key Press (Print Scrn), it should write the contents to a Word Document as defined (either a default path or a user defined one). Save the document periodically. Now, my question is - if I am going to develop this using C# (Winforms application), how do I go about doing this. I can do a fair bit of C# programming and I am willing to learn. But I am not able to locate the references for how to do a background process so that it runs in the background. And while it runs, it has to capture the Print Scrn command. Can you folks point me to the right material where I can learn this? Theoretical references should suffice. But if there are practical references, then nothing like it. Thanks!

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• digital magazine publishing engine licensing question

  - by nosarious

  I have a publishing engine I have been developing for thirty months but find myself being unable to work on it during my masters degree. I would like to make it open source in the interim to get others to use it and improve how it works. I would like to consider a licensing system that allows for multiple instances of the software for singular users (ie, a newspaper/magazine or zine hosting the code on their own). I would like to limit it from becoming the basis of a larger magazine hosting service right now because it is intended to be an integral part of a much larger publishing ecosystem which allows for the creation, dissemination and collection of publications as a free or very inexpensive service. Right now there is no license associated with it, which is why I am not posting a link here. (This system was developed to counter implied censorship for digital magazines and remove costly and confusing 'barriers to entry' for creators wishing to make interactive digital content. It is intended to be useful for free, but I would like to prevent people taking the code and using it to take advantage of others. It needs a bit of work to separate the content from the page itself to allow the access of multiple which I cannot develop right now) Any help or suggestion on how to handle licensing this code for contributions and use would be appreciated, and if anyone would like to see examples or the github I would be happy to send it.

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• Cookie access within a HTTP Class

  - by James Jeffery

  I have a HTTP class that has a Get, and Post, method. It's a simple class I created to encapsulate Post and Get requests so I don't have to repeat the get/post code throughout the application. In C#: class HTTP { private CookieContainer cookieJar; private String userAgent = "..."; public HTTP() { this.cookieJar = new CookieContainer(); } public String get(String url) { // Make get request. Return the JSON } public String post(String url, String postData) { // Make post request. Return the JSON } } I've made the CookieJar a property because I want to preserve the cookie values throughout the session. If the user is logged into Twitter with my application, each request I make (be it get or post) I want to use the cookies so they remain logged in. That's the basics of it anyway. But, I don't want to return a string in all instances. Sometimes I may want the cookie, or a header value, or something else from the request. Ideally I'd like to be able to do this in my code: Cookie cookie = http.get("http://google.com").cookie("g_user"); String g_user = cookie.value; or String source = http.get("http://google.com").body; My question - To do this, would I need to have a Get class, and a Post class, that are included within the HTTP class and are accessible via accessors? Within the Get and Post class I would then have the Cookie method, and the body property, and whatever else is needed. Should I also use an interface, or create a Request class and have Post and Get extend it so that common methods and properties are available to both classes? Or, am I thinking totally wrong?

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• What are some ways to separate game logic from animations and the draw loop?

  - by TMV

  I have only previously made flash games, using MovieClips and such to separate out my animations from my game logic. Now I am getting into trying my hand at making a game for Android, but the game programming theory around separating these things still confuses me. I come from a background of developing non game web applications so I am versed in more MVC like patterns and am stuck in that mindset as I approach game programming. I want to do things like abstract my game by having, for example, a game board class that contains the data for a grid of tiles with instances of a tile class that each contain properties. I can give my draw loop access to this and have it draw the game board based on the properties of each tile on the game board, but I don't understand where exactly animation should go. As far as I can tell, animation sort of sits between the abstracted game logic (model) and the draw loop (view). With my MVC mindset, it's frustrating trying to decide where animation is actually supposed to go. It would have quite a bit of data associated with it like a model, but seemingly needs to be very closely coupled with the draw loop in order to have things like frame independent animation. How can I break out of this mindset and start thinking about patterns that make more sense for games?

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• Performance impact of Zones.

  - by nospam(at)example.com (Joerg Moellenkamp)

  I was really astonished when i saw this question. Because this question was a old acquaintance from years ago, that i didn't heard for a long time. However there was it again. The question: "What's the overhead of Zones?". Sun was and Oracle is not saying "zero". We saying saying minimal. However during all the performance analysis gigs on customer systems i made since the introduction of Zones i failed to measure any overhead caused by zones. What i saw however, was additional load intoduced by processes that wouldn't be there when you would use only one zone Like additional monitoring daemons, like additional daemons having a controlling or supervising job for the application that resulted in slighly longer runtimes of processes, because such additional daemons wanted some cycles on the CPU as well. So i ask when someone wants to tell me that he measured a slight slowdown, if he or she has really measured the impact of the virtualization layer or of a side effect described above. It seems to be a little bit hard to believe, that a virtualisation technology has no overhead, however keep in mind that there is no hypervisor and just one kernel running that looks and behaves like many operating system instances to apps and users. While this imposes some limits to the technology (because there is just one kernel running you can't have zones with different kernels versions running ... obvious even to the cursory observer), but that is key to it's lightweightness and thus to the low overhead. Continue reading "Performance impact of Zones."

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• Implementing my Entity System. Questions about some problems I have found.

  - by Notbad

  Hi!, Well during this week I have deciding about implementation of my entity system. It is a big topic so it has been difficult to take one option from the whole. This has been my decision: 1) I don't have an entity class it is just an id. 2) I have systems that contain a list of components (the list is homegenous, I mean, RenderSystem will just have RenderComponents). 3) Compones will be just data. 4) There would be some kind of "entity prototypes" in a manager or something from we will create entity instances.Ideally they will define the type of components it has and initialization data. 5) Prototype code to create an entity (this is from the top of my head): int id=World::getInstance()->createEntity("entity template"); 6) This will notify all systems that a new entity has been created, and if the entity needs a component that the system handles it will add it to the entity. Ok, this are the ideas. Let's see if some can help with the problems: 1) The main problem is this templates that are sent to the systems in creation process to populate the entity with needed components. What would you use, an OR(ed) int?, a list of strings?. 2) How to do initialization for components when the entity has been created? How to store this in the template? I have thought about having a function in the template that is virtual and after entity is created an populated, gets the components and sets initialization values. 3) Don't you think this is a lot of work for just an entity creation?. Sorry for the long post, I have tried to expose my ideas and finding in order other could have a start beside exposing my problems. Thanks in advance, Notbad.

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• Are specific types still necessary?

  - by MKO

  One thing that occurred to me the other day, are specific types still necessary or a legacy that is holding us back. What I mean is: do we really need short, int, long, bigint etc etc. I understand the reasoning, variables/objects are kept in memory, memory needs to be allocated and therefore we need to know how big a variable can be. But really, shouldn't a modern programming language be able to handle "adaptive types", ie, if something is only ever allocated in the shortint range it uses fewer bytes, and if something is suddenly allocated a very big number the memory is allocated accordinly for that particular instance. Float, real and double's are a bit trickier since the type depends on what precision you need. Strings should however be able to take upp less memory in many instances (in .Net) where mostly ascii is used buth strings always take up double the memory because of unicode encoding. One argument for specific types might be that it's part of the specification, ie for example a variable should not be able to be bigger than a certain value so we set it to shortint. But why not have type constraints instead? It would be much more flexible and powerful to be able to set permissible ranges and values on variables (and properties). I realize the immense problem in revamping the type architecture since it's so tightly integrated with underlying hardware and things like serialization might become tricky indeed. But from a programming perspective it should be great no?

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• A few questions about how JavaScript works

  - by KayoticSully

  I originally posted on Stack Overflow and was told I might get some better answers here. I have been looking deeply into JavaScript lately to fully understand the language and have a few nagging questions that I can not seem to find answers to (Specifically dealing with Object Oriented programming. I know JavaScript is meant to be used in an OOP manner I just want to understand it for the sake of completeness). Assuming the following code: function TestObject() { this.fA = function() { // do stuff } this.fB = testB; function testB() { // do stuff } } TestObject.prototype = { fC : function { // do stuff } } What is the difference between functions fA and fB? Do they behave exactly the same in scope and potential ability? Is it just convention or is one way technically better or proper? If there is only ever going to be one instance of an object at any given time, would adding a function to the prototype such as fC even be worthwhile? Is there any benefit to doing so? Is the prototype only really useful when dealing with many instances of an object or inheritance? And what is technically the "proper" way to add methods to the prototype the way I have above or calling TestObject.prototype.functionName = function(){} every time? I am looking to keep my JavaScript code as clean and readable as possible but am also very interested in what the proper conventions for Objects are in the language. I come from a Java and PHP background and am trying to not make any assumptions about how JavaScript works since I know it is very different being prototype based. Also are there any definitive JavaScript style guides or documentation about how JavaScript operates at a low level? Thanks!

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• Complex string matching with fuzzywuzzy

  - by That1Guy

  I'm attempting to write a process that matches obscure strings to a single 'master string' for further processing. I have a lot of data that looks something like this: Basketball Basket Ball Football BasketBallR BBall BBall - r FootB ...and so on. These need to be mapped to a master record like so: Basketball = Basket Ball, BBall Basketball - R = BasketBallR, BBall - r I also have instances of data resembling this format: Football -r FootBall - r-g/H,Q,HH These situations need to be separated into different categories before being mapped. For example FootBall - r-g/H,Q,HH should be: Football - r Football - g Football - H Football - Q Football - HH At this point, it still needs to be mapped to a master record... I've tried several different combinations of fuzzywuzzy matching methods, Levenshtein Distance measurements, regex, etc. and can't seem to find a reliable method to logically associate different naming styles of a single item with a master name. I'm throwing my hands up in desperation. Are there any existing python resources than can help sort out my problem? Are there other options? Can anybody point out an obvious option that I might have overlooked? Basically, any suggestion, solution, resource or alternative method is greatly appreciated.

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• Space Invaders-type game: Keeping the enemies aligned with each other as they turn around?

  - by CorundumGames

  OK, so here's the lowdown of the problem I'm trying to solve. I'm developing a game in PyGame that's a cross between Space Invaders and Columns. I'm trying to make the motion of the enemies similar to that of the aliens in Space Invaders; that is, they're all clustered in a grid, and if even one hits the side of the screen, the entire formation moves down and turns around. However, the motion of these aliens is continuous (as continuous as a monitor can be, anyway), not on a discrete grid like in the original. The enemies are instances of an Enemy class, and in turn they're held by a 2D array in a enemysquadron module (which, if you don't use Python, is in this case essentially a singleton due to the way Python modules work). Inside the Enemy class I have a class-scope velocity vector that is reversed every time an Enemy object touches the edge of the screen. This won't do, though, because as time goes on the enemies just become disorganized and jumbled (i.e. not in a grid as planned). I haven't implemented the Enemies going downward yet, so let's not worry about that right now. Any tips?

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