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  • Modularity through HTTP

    - by Michael Williamson
    As programmers, we strive for modularity in the code we write. We hope that splitting the problem up makes it easier to solve, and allows us to reuse parts of our code in other applications. Object-orientation is the most obvious of many attempts to get us closer to this ideal, and yet one of the most successful approaches is almost accidental: the web. Programming languages provide us with functions and classes, and plenty of other ways to modularize our code. This allows us to take our large problem, split it into small parts, and solve those small parts without having to worry about the whole. It also makes it easier to reason about our code. So far, so good, but now that we’ve written our small, independent module, for example to send out e-mails to my customers, we’d like to reuse it in another application. By creating DLLs, JARs or our platform’s package container of choice, we can do just that – provided our new application is on the same platform. Want to use a Java library from C#? Well, good luck – it might be possible, but it’s not going to be smooth sailing. Even if a library exists, it doesn’t mean that using it going to be a pleasant experience. Say I want to use Java to write out an XML document to an output stream. You’d imagine this would be a simple one-liner. You’d be wrong: import org.w3c.dom.*; import java.io.*; import javax.xml.transform.*; import javax.xml.transform.dom.*; import javax.xml.transform.stream.*; private static final void writeDoc(Document doc, OutputStream out) throws IOException { try { Transformer t = TransformerFactory.newInstance().newTransformer(); t.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, doc.getDoctype().getSystemId()); t.transform(new DOMSource(doc), new StreamResult(out)); } catch (TransformerException e) { throw new AssertionError(e); // Can't happen! } } Most of the time, there is a good chance somebody else has written the code before, but if nobody can understand the interface to that code, nobody’s going to use it. The result is that most of the code we write is just a variation on a theme. Despite our best efforts, we’ve fallen a little short of our ideal, but the web brings us closer. If we want to send e-mails to our customers, we could write an e-mail-sending library. More likely, we’d use an existing one for our language. Even then, we probably wouldn’t have niceties like A/B testing or DKIM signing. Alternatively, we could just fire some HTTP requests at MailChimp, and get a whole slew of features without getting anywhere near the code that implements them. The web is inherently language agnostic. So long as your language can send and receive text over HTTP, and probably parse some JSON, you’re about as well equipped as anybody. Instead of building libraries for a specific language, we can build a service that almost every language can reuse. The text-based nature of HTTP also helps to limit the complexity of the API. As SOAP will attest, you can still make a horrible mess using HTTP, but at least it is an obvious horrible mess. Complex data structures are tedious to marshal to and from text, providing a strong incentive to keep things simple. By contrast, spotting the complexities in a class hierarchy is often not as easy. HTTP doesn’t solve every problem. It probably isn’t such a good idea to use it inside an inner loop that’s executed thousands of times per second. What’s more, the HTTP approach might introduce some new problems. We often need to add a thin shim to each application that we wish to communicate over HTTP. For instance, we might need to write a small plugin in PHP if we want to integrate WordPress into our system. Suddenly, instead of a system written in one language, we’re maintaining a system with several distinct languages and platforms. Even then, we should strive to avoid re-implementing the same old thing. As programmers, we consistently underestimate both the cost of building a system and the ongoing maintenance. If we allow ourselves to integrate existing applications, even if they’re in unfamiliar languages, we save ourselves those development and maintenance costs, as well as being able to pick the best solution for our problem. Thanks to the web, HTTP is often the easiest way to get there.

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  • How is the gimbal locked problem solved using accumulative matrix transformations

    - by Luke San Antonio
    I am reading the online "Learning Modern 3D Graphics Programming" book by Jason L. McKesson As of now, I am up to the gimbal lock problem and how to solve it using quaternions. However right here, at the Quaternions page. Part of the problem is that we are trying to store an orientation as a series of 3 accumulated axial rotations. Orientations are orientations, not rotations. And orientations are certainly not a series of rotations. So we need to treat the orientation of the ship as an orientation, as a specific quantity. I guess this is the first spot I start to get confused, the reason is because I don't see the dramatic difference between orientations and rotations. I also don't understand why an orientation cannot be represented by a series of rotations... Also: The first thought towards this end would be to keep the orientation as a matrix. When the time comes to modify the orientation, we simply apply a transformation to this matrix, storing the result as the new current orientation. This means that every yaw, pitch, and roll applied to the current orientation will be relative to that current orientation. Which is precisely what we need. If the user applies a positive yaw, you want that yaw to rotate them relative to where they are current pointing, not relative to some fixed coordinate system. The concept, I understand, however I don't understand how if accumulating matrix transformations is a solution to this problem, how the code given in the previous page isn't just that. Here's the code: void display() { glClearColor(0.0f, 0.0f, 0.0f, 0.0f); glClearDepth(1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glutil::MatrixStack currMatrix; currMatrix.Translate(glm::vec3(0.0f, 0.0f, -200.0f)); currMatrix.RotateX(g_angles.fAngleX); DrawGimbal(currMatrix, GIMBAL_X_AXIS, glm::vec4(0.4f, 0.4f, 1.0f, 1.0f)); currMatrix.RotateY(g_angles.fAngleY); DrawGimbal(currMatrix, GIMBAL_Y_AXIS, glm::vec4(0.0f, 1.0f, 0.0f, 1.0f)); currMatrix.RotateZ(g_angles.fAngleZ); DrawGimbal(currMatrix, GIMBAL_Z_AXIS, glm::vec4(1.0f, 0.3f, 0.3f, 1.0f)); glUseProgram(theProgram); currMatrix.Scale(3.0, 3.0, 3.0); currMatrix.RotateX(-90); //Set the base color for this object. glUniform4f(baseColorUnif, 1.0, 1.0, 1.0, 1.0); glUniformMatrix4fv(modelToCameraMatrixUnif, 1, GL_FALSE, glm::value_ptr(currMatrix.Top())); g_pObject->Render("tint"); glUseProgram(0); glutSwapBuffers(); } To my understanding, isn't what he is doing (modifying a matrix on a stack) considered accumulating matrices, since the author combined all the individual rotation transformations into one matrix which is being stored on the top of the stack. My understanding of a matrix is that they are used to take a point which is relative to an origin (let's say... the model), and make it relative to another origin (the camera). I'm pretty sure this is a safe definition, however I feel like there is something missing which is blocking me from understanding this gimbal lock problem. One thing that doesn't make sense to me is: If a matrix determines the difference relative between two "spaces," how come a rotation around the Y axis for, let's say, roll, doesn't put the point in "roll space" which can then be transformed once again in relation to this roll... In other words shouldn't any further transformations to this point be in relation to this new "roll space" and therefore not have the rotation be relative to the previous "model space" which is causing the gimbal lock. That's why gimbal lock occurs right? It's because we are rotating the object around set X, Y, and Z axes rather than rotating the object around it's own, relative axes. Or am I wrong? Since apparently this code I linked in isn't an accumulation of matrix transformations can you please give an example of a solution using this method. So in summary: What is the difference between a rotation and an orientation? Why is the code linked in not an example of accumulation of matrix transformations? What is the real, specific purpose of a matrix, if I had it wrong? How could a solution to the gimbal lock problem be implemented using accumulation of matrix transformations? Also, as a bonus: Why are the transformations after the rotation still relative to "model space?" Another bonus: Am I wrong in the assumption that after a transformation, further transformations will occur relative to the current? Also, if it wasn't implied, I am using OpenGL, GLSL, C++, and GLM, so examples and explanations in terms of these are greatly appreciated, if not necessary. The more the detail the better! Thanks in advance...

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  • Yippy &ndash; the F# MVVM Pattern

    - by MarkPearl
    I did a recent post on implementing WPF with F#. Today I would like to expand on this posting to give a simple implementation of the MVVM pattern in F#. A good read about this topic can also be found on Dean Chalk’s blog although my example of the pattern is possibly simpler. With the MVVM pattern one typically has 3 segments, the view, viewmodel and model. With the beauty of WPF binding one is able to link the state based viewmodel to the view. In my implementation I have kept the same principles. I have a view (MainView.xaml), and and a ViewModel (MainViewModel.fs).     What I would really like to illustrate in this posting is the binding between the View and the ViewModel so I am going to jump to that… In Program.fs I have the following code… module Program open System open System.Windows open System.Windows.Controls open System.Windows.Markup open myViewModels // Create the View and bind it to the View Model let myView = Application.LoadComponent(new System.Uri("/FSharpWPF;component/MainView.xaml", System.UriKind.Relative)) :?> Window myView.DataContext <- new MainViewModel() :> obj // Application Entry point [<STAThread>] [<EntryPoint>] let main(_) = (new Application()).Run(myView) You can see that I have simply created the view (myView) and then created an instance of my viewmodel (MainViewModel) and then bound it to the data context with the code… myView.DataContext <- new MainViewModel() :> obj If I have a look at my viewmodel (MainViewModel) it looks like this… module myViewModels open System open System.Windows open System.Windows.Input open System.ComponentModel open ViewModelBase type MainViewModel() = // private variables let mutable _title = "Bound Data to Textbox" // public properties member x.Title with get() = _title and set(v) = _title <- v // public commands member x.MyCommand = new FuncCommand ( (fun d -> true), (fun e -> x.ShowMessage) ) // public methods member public x.ShowMessage = let msg = MessageBox.Show(x.Title) () I have exposed a few things, namely a property called Title that is mutable, a command and a method called ShowMessage that simply pops up a message box when called. If I then look at my view which I have created in xaml (MainView.xaml) it looks as follows… <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="F# WPF MVVM" Height="350" Width="525"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition Height="Auto"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <TextBox Text="{Binding Path=Title, Mode=TwoWay}" Grid.Row="0"/> <Button Command="{Binding MyCommand}" Grid.Row="1"> <TextBlock Text="Click Me"/> </Button> </Grid> </Window>   It is also very simple. It has a button that’s command is bound to the MyCommand and a textbox that has its text bound to the Title property. One other module that I have created is my ViewModelBase. Right now it is used to store my commanding function but I would look to expand on it at a later stage to implement other commonly used functions… module ViewModelBase open System open System.Windows open System.Windows.Input open System.ComponentModel type FuncCommand (canExec:(obj -> bool),doExec:(obj -> unit)) = let cecEvent = new DelegateEvent<EventHandler>() interface ICommand with [<CLIEvent>] member x.CanExecuteChanged = cecEvent.Publish member x.CanExecute arg = canExec(arg) member x.Execute arg = doExec(arg) Put this all together and you have a basic project that implements the MVVM pattern in F#. For me this is quite exciting as it turned out to be a lot simpler to do than I originally thought possible. Also because I have my view in XAML I can use the XAML designer to design forms in F# which I believe is a much cleaner way to go rather than implementing it all in code. Finally if I look at my viewmodel code, it is actually quite clean and compact…

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  • Using Resources the Right Way

    - by BuckWoody
    It’s an interesting time in computing technology. At one point there was a dearth of information available for solving a given problem, or educating ourselves on broader topics so that we can solve problems in the future. With dozens, perhaps hundreds or thousands of web sites and content available (for free, in many cases) from vendors, peers, even colleges and universities, it seems like there is actually too much information. Who has the time to absorb all this information and training? Even if you had the inclination, where to start? In fact, it seems so overwhelming that I often hear people saying that they can’t find the training they need, or that vendor X or Y “doesn’t help their users”. On questioning these folks, however, I often find that they – and sometimes I - haven’t put in the effort to learn what resources we have. That’s where blogs, like this one, can help. If you follow a blog, either by checking it often or perhaps subscribing to the Really Simple Syndication (RSS) feed, you’ll be able to spread out the search or create a mental filter for the information you need. But it’s not enough just read a blog or a web page. The creators need real feedback – what doesn’t work, and what does. Yes, you’re allowed to tell a vendor or writer “This helped me because…” so that you reinforce the positives. To be sure, bring up what doesn’t work as well –  that’s fine. But be specific, and be constructive. You’d be surprised at how much it matters. I know for a fact at Microsoft we listen – there is a real live person that reads your comments. I’m sure this is true of other vendors, and I also know that most blog authors – yours truly most especially – wants to know what you think.   In this blog entry I’d to call your attention to three resources you have at your disposal, and how you can use them to help. I’ll try to bring up things like this from time to time that I find useful, and cover in them in more depth like this. Think of this as a synopsis of a longer set of resources that you can use to filter whether you want to research further, bookmark, or forward on to a circle of friends where you think it might help them.   Data Driven Design Concepts http://msdn.microsoft.com/en-us/library/windowsazure/jj156154 I’ll start with a great site that walks you through the process of designing a solution from a data-first perspective. As you know, I believe all computing is merely re-arranging data. If you follow that logic as well, you’ll realize that whenever you create a solution, you should start at the data-end of the application. This resource helps you do that. Even if you don’t use the specific technologies the instructions use, the concepts hold for almost any other technology that deals with data. This should be a definite bookmark for a developer, DBA, or Data Architect. When I mentioned my admiration for this resource here at Microsoft, the team that created it contacted me and asked if I’d share an e-mail address to my readers so that you can comment on it. You’re guaranteed to be heard – you can suggest changes, talk about how useful – or not – it is, and so on. Here’s that address:  [email protected]   End-to-End Example of a complete Hybrid Application – with Live Demo https://azurestocktrader.cloudapp.net/Default.aspx I learn by example. I also like having ready-made, live, functional demos that show the completed solution at work. If you’ve ever wanted to learn how a complex, complete, hybrid application that bridges on-premises systems with cloud-based databases, code, functions and more, this is it. It’s a stock-trading simulator, and you can get everything from the design to the code itself, or you can just play with the application. It’s running on Windows Azure, the actual production servers we use for everything else. Using a Cloud-Based Service https://azureconfigweb.cloudapp.net/Default.aspx Along with that stock-trading application, you have a full demonstration and usable code sample of a web-based service available. If you’re a developer, this is a style of code you need to understand for everything from iPhone development to a full Service-Oriented Architecture (SOA) environment. So check out these resources. I’ll post more from time to time as I run across them. Hopefully they’ll be as useful to you as they are to me. Oh, and if you have a comment on any of the resources, let them know. And if you have any comments about these or any of my entries, feel free to post away. To quote a famous TV Show: “Hello Seattle – I’m listening…”

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  • Mixing Forms and Token Authentication in a single ASP.NET Application (the Details)

    - by Your DisplayName here!
    The scenario described in my last post works because of the design around HTTP modules in ASP.NET. Authentication related modules (like Forms authentication and WIF WS-Fed/Sessions) typically subscribe to three events in the pipeline – AuthenticateRequest/PostAuthenticateRequest for pre-processing and EndRequest for post-processing (like making redirects to a login page). In the pre-processing stage it is the modules’ job to determine the identity of the client based on incoming HTTP details (like a header, cookie, form post) and set HttpContext.User and Thread.CurrentPrincipal. The actual page (in the ExecuteHandler event) “sees” the identity that the last module has set. So in our case there are three modules in effect: FormsAuthenticationModule (AuthenticateRequest, EndRequest) WSFederationAuthenticationModule (AuthenticateRequest, PostAuthenticateRequest, EndRequest) SessionAuthenticationModule (AuthenticateRequest, PostAuthenticateRequest) So let’s have a look at the different scenario we have when mixing Forms auth and WS-Federation. Anoymous request to unprotected resource This is the easiest case. Since there is no WIF session cookie or a FormsAuth cookie, these modules do nothing. The WSFed module creates an anonymous ClaimsPrincipal and calls the registered ClaimsAuthenticationManager (if any) to transform it. The result (by default an anonymous ClaimsPrincipal) gets set. Anonymous request to FormsAuth protected resource This is the scenario where an anonymous user tries to access a FormsAuth protected resource for the first time. The principal is anonymous and before the page gets rendered, the Authorize attribute kicks in. The attribute determines that the user needs authentication and therefor sets a 401 status code and ends the request. Now execution jumps to the EndRequest event, where the FormsAuth module takes over. The module then converts the 401 to a redirect (302) to the forms login page. If authentication is successful, the login page sets the FormsAuth cookie.   FormsAuth authenticated request to a FormsAuth protected resource Now a FormsAuth cookie is present, which gets validated by the FormsAuth module. This cookie gets turned into a GenericPrincipal/FormsIdentity combination. The WS-Fed module turns the principal into a ClaimsPrincipal and calls the registered ClaimsAuthenticationManager. The outcome of that gets set on the context. Anonymous request to STS protected resource This time the anonymous user tries to access an STS protected resource (a controller decorated with the RequireTokenAuthentication attribute). The attribute determines that the user needs STS authentication by checking the authentication type on the current principal. If this is not Federation, the redirect to the STS will be made. After successful authentication at the STS, the STS posts the token back to the application (using WS-Federation syntax). Postback from STS authentication After the postback, the WS-Fed module finds the token response and validates the contained token. If successful, the token gets transformed by the ClaimsAuthenticationManager, and the outcome is a) stored in a session cookie, and b) set on the context. STS authenticated request to an STS protected resource This time the WIF Session authentication module kicks in because it can find the previously issued session cookie. The module re-hydrates the ClaimsPrincipal from the cookie and sets it.     FormsAuth and STS authenticated request to a protected resource This is kind of an odd case – e.g. the user first authenticated using Forms and after that using the STS. This time the FormsAuth module does its work, and then afterwards the session module stomps over the context with the session principal. In other words, the STS identity wins.   What about roles? A common way to set roles in ASP.NET is to use the role manager feature. There is a corresponding HTTP module for that (RoleManagerModule) that handles PostAuthenticateRequest. Does this collide with the above combinations? No it doesn’t! When the WS-Fed module turns existing principals into a ClaimsPrincipal (like it did with the FormsIdentity), it also checks for RolePrincipal (which is the principal type created by role manager), and turns the roles in role claims. Nice! But as you can see in the last scenario above, this might result in unnecessary work, so I would rather recommend consolidating all role work (and other claims transformations) into the ClaimsAuthenticationManager. In there you can check for the authentication type of the incoming principal and act accordingly. HTH

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  • MERGE gives better OUTPUT options

    - by Rob Farley
    MERGE is very cool. There are a ton of useful things about it – mostly around the fact that you can implement a ton of change against a table all at once. This is great for data warehousing, handling changes made to relational databases by applications, all kinds of things. One of the more subtle things about MERGE is the power of the OUTPUT clause. Useful for logging.   If you’re not familiar with the OUTPUT clause, you really should be – it basically makes your DML (INSERT/DELETE/UPDATE/MERGE) statement return data back to you. This is a great way of returning identity values from INSERT commands (so much better than SCOPE_IDENTITY() or the older (and worse) @@IDENTITY, because you can get lots of rows back). You can even use it to grab default values that are set using non-deterministic functions like NEWID() – things you couldn’t normally get back without running another query (or with a trigger, I guess, but that’s not pretty). That inserted table I referenced – that’s part of the ‘behind-the-scenes’ work that goes on with all DML changes. When you insert data, this internal table called inserted gets populated with rows, and then used to inflict the appropriate inserts on the various structures that store data (HoBTs – the Heaps or B-Trees used to store data as tables and indexes). When deleting, the deleted table gets populated. Updates get a matching row in both tables (although this doesn’t mean that an update is a delete followed by an inserted, it’s just the way it’s handled with these tables). These tables can be referenced by the OUTPUT clause, which can show you the before and after for any DML statement. Useful stuff. MERGE is slightly different though. With MERGE, you get a mix of entries. Your MERGE statement might be doing some INSERTs, some UPDATEs and some DELETEs. One of the most common examples of MERGE is to perform an UPSERT command, where data is updated if it already exists, or inserted if it’s new. And in a single operation too. Here, you can see the usefulness of the deleted and inserted tables, which clearly reflect the type of operation (but then again, MERGE lets you use an extra column called $action to show this). (Don’t worry about the fact that I turned on IDENTITY_INSERT, that’s just so that I could insert the values) One of the things I love about MERGE is that it feels almost cursor-like – the UPDATE bit feels like “WHERE CURRENT OF …”, and the INSERT bit feels like a single-row insert. And it is – but into the inserted and deleted tables. The operations to maintain the HoBTs are still done using the whole set of changes, which is very cool. And $action – very convenient. But as cool as $action is, that’s not the point of my post. If it were, I hope you’d all be disappointed, as you can’t really go near the MERGE statement without learning about it. The subtle thing that I love about MERGE with OUTPUT is that you can hook into more than just inserted and deleted. Did you notice in my earlier query that my source table had a ‘src’ field, that wasn’t used in the insert? Normally, this would be somewhat pointless to include in my source query. But with MERGE, I can put that in the OUTPUT clause. This is useful stuff, particularly when you’re needing to audit the changes. Suppose your query involved consolidating data from a number of sources, but you didn’t need to insert that into the actual table, just into a table for audit. This is now very doable, either using the INTO clause of OUTPUT, or surrounding the whole MERGE statement in brackets (parentheses if you’re American) and using a regular INSERT statement. This is also doable if you’re using MERGE to just do INSERTs. In case you hadn’t realised, you can use MERGE in place of an INSERT statement. It’s just like the UPSERT-style statement we’ve just seen, except that we want nothing to match. That’s easy to do, we just use ON 1=2. This is obviously more convoluted than a straight INSERT. And it’s slightly more effort for the database engine too. But, if you want the extra audit capabilities, the ability to hook into the other source columns is definitely useful. Oh, and before people ask if you can also hook into the target table’s columns... Yes, of course. That’s what deleted and inserted give you.

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  • Xobni Plus for Outlook [Review]

    - by The Geek
    Overview Xobni Plus is an addin that will bring a sidebar to Outlook which allows you to search through your inbox and contacts a lot easier. It provides the ability to search and keep track of your favorite social networks. Searching with Xobni is a lot more powerful than the default search feature in Outlook. It let’s you drill down your searches to conversations, email, links, and attachments. It now supports Outlook 2010 both 32 & 64-bit versions. Installation & Setup Installation is easy following the wizard. After completing the wizard you can tell you’re friends on Facebook and Twitter that you are now using it. You can also decide to join their Product Improvement Program if you want. After installation when you open Outlook, Xobni appears as a sidebar on the right side. Don’t worry about it always being in the way, as you can hide it if you need more room for other Outlook functions. After Xobni free is installed, you can upgrade to the Plus version at any time. A new window will open up and you can use your Credit Card, PayPal, or redeem a code if you have one. Features & Use Where to begin with the amount of features available in Xobni Plus? It really has an amazing amount of cool features. Of course you’ll have all of the features of the Free Version which we previously covered…and a lot more. After Xobni is installed you’ll notice a section for it on the Ribbon. From here you can search Xobni, show or hide the Sidebar, and change other options. It allows you to easily keep up with various social networks like Facebook, Twitter, and LinkedIn… Check out email analytics and contact ranks. Click on the Files Exchanged tab to search for specific attachments. Quickly search links exchanged with your contacts. Hover over a link to get a preview of what it entails. It gives you the ability to index all of your Yahoo mail as well, without the need for purchasing Yahoo Plus! Then your Yahoo messages appear in the Xobni sidebar. When you select a contact you can see related messages from you Yahoo account. Easily index all of your mail…including Yahoo mail for better organization and faster search results. There are several options you can select to change the way Xobni works. From setting up your Yahoo email, Indexing options, and much more. Additional Features of Xobni Plus Advanced Search Capabilities – Filter results, Boolean & Phrase Search, Ability to search Appointments & Tasks, Advanced Search Builder Search unlimited PST data files Xobni contacts in the compose screen Find links exchanged with your contacts View calendar appointments One year premium tech support No Ads! Performance We ran Xobni Plus on Outlook 2010 32-bit on a Dual-Core AMD Athlon system with 4GB of RAM and found it to run quite smoothly. However, we did notice it would sometimes slow down launching Outlook, especially if other apps are running at the same time. Product Support When you buy a license for Xobni Plus you get a full year of premium tech support. They provide a Questions and Answers page on their site where you can run a search query and answers appear instantly. You can contact support directly as a Plus member through their web form and they advise the turn around time is 2 business days. However, when we tested it, we received a response within 24 hours. They also provide FAQ, Community forum, and you can download the Owners Manual in PDF format from the support page. Conclusion Xobni Plus is a very powerful addin for Outlook and includes a lot more features that we didn’t cover in this review. You can download Xobni free edition which includes an 8 day free trial of the Plus version. This provides a good way to start getting familiar with it. Then upgrade to Xobni Plus at any time for $29.95. Once you get started, you’ll find the sidebar is nicely laid out and intuitive to use. If you live out of Outlook during the day, Xobni Plus is a great addition for fast and powerful searches. It provides an easy way to keep all of your contacts and messages well organized and easy to find. Xobni Plus works with XP, Vista, and Windows 7 (32 & 64-bit editions) Outlook 2003, 2007 and both 32 & 64-bit editions of Outlook 2010. Download Xobni Plus Download Xobni Free Edition Rating Installation: 8 Ease of Use: 8 Features: 9 Performance: 8 Product Support: 8 Similar Articles Productive Geek Tips Xobni Free Powers Up Outlook’s Search and ContactsCreate an Email Template in Outlook 2003Add Social Elements to Your Gmail Contacts with RapportiveChange Outlook Startup FolderClear Outlook Searches and MRU (Most Recently Used) Lists TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Xobni Plus for Outlook All My Movies 5.9 CloudBerry Online Backup 1.5 for Windows Home Server Snagit 10 10 Superb Firefox Wallpapers OpenDNS Guide Google TV The iPod Revolution Ultimate Boot CD can help when disaster strikes Windows Firewall with Advanced Security – How To Guides

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  • How customers view and interact with a company

    The Harvard Business Review article written by Rayport and Jaworski is aptly titled “Best Face Forward” because it sheds light on how customers view and interact with a company. In the past most business interaction between customers was performed in a face to face meeting where one party would present an item for sale and then the other would decide whether to purchase the item. In addition, if there was a problem with a purchased item then they would bring the item back to the person who sold the item for resolution. One of my earliest examples of witnessing this was when I was around 6 or 7 years old and I was allowed to spend the summer in Tennessee with my Grandparents. My Grandfather had just written a book about the local history of his town and was selling them to his friends and local bookstores. I still remember he offered to pay me a small commission for every book I helped him sell because I was carrying the books around for him. Every sale he made was face to face with his customers which allowed him to share his excitement for the book with everyone. In today’s modern world there is less and less human interaction as the use of computers and other technologies allow us to communicate within seconds even though both parties may be across the globe or just next door. That being said, customers view a company through multiple access points called faces that represent the ability to interact without actually seeing a human face. As a software engineer this is a good and a bad thing because direct human interaction and technology based interaction have both good and bad attributes based on the customer. How organizations coordinate business and IT functions, to provide quality service varies based on each individual business and the goals and directives put in place by its management. According to Rayport and Jaworski, the type of interaction used through a particular access point may lend itself to be people-dominate, machine-dominate, or a combination of both. The method by which a company communicates information through an access point is a strategic choice that relates costs and customer outcomes. To simplify this, the choice is based on what can give the customer the best experience interacting with the company when the cost of the interaction is also a factor. I personally see examples of this every day at work. The company website is machine-dominate with people updating and maintaining information, our groups department is people dominate because most of the customer interaction is done at the customers location and is backed up by machine based data sources, and our sales/member service department is a hybrid because employees work in tandem with machines in order for them to assist customers with signing up or any other issue they may have. The positive and negative aspects of human and machine interfaces are a key aspect in deciding which interface to use when allowing customers to access a company or a combination of the two. Rayport and Jaworski also used MIT professor Erik Brynjolfsson preliminary catalog of human and machine strengths. He stated that humans outperform machines in judgment, pattern recognition, exception processing, insight, and creativity. I have found this to be true based on the example of how sales and member service reps at my company handle a multitude of questions and various situations with a lot of unknown variables. A machine interface could never effectively be able to handle these scenarios because there are too many variables to consider and would not have the built-in logic to process each customer’s claims and needs. In addition, he also stated that machines outperform humans in collecting, storing, transmitting and routine processing. An example of this would be my employer’s website. Customers can simply go online and purchase a product without even talking to a sales or member services representative. The information is then stored in a database so that the customer can always go back and review there order, and access their selected services. A human, no matter how smart they are would never be able to keep track of hundreds of thousands of customers let alone know what they purchased or how much they paid. In today’s technology driven economy every company must offer their customers multiple methods of accessibly in order to survive. The more of an opportunity a company has to create a positive experience for their customers, in my opinion, they more likely the customer will return to that company again. I have noticed this with my personal shopping habits and experiences. References Rayport, J., & Jaworski, B. (2004). Best Face Forward. Harvard Business Review, 82(12), 47-58. Retrieved from Business Source Complete database.

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  • Upgrading to Code Based Migrations EF 4.3.1 with Connector/Net 6.6

    - by GABMARTINEZ
    Entity Framework 4.3.1 includes a new feature called code first migrations.  We are adding support for this feature in our upcoming 6.6 release of Connector/Net.  In this walk-through we'll see the workflow of code-based migrations when you have an existing application and you would like to upgrade to this EF 4.3.1 version and use this approach, so you can keep track of the changes that you do to your database.   The first thing we need to do is add the new Entity Framework 4.3.1 package to our application. This should via the NuGet package manager.  You can read more about why EF is not part of the .NET framework here. Adding EF 4.3.1 to our existing application  Inside VS 2010 go to Tools -> Library Package Manager -> Package Manager Console, this will open the Power Shell Host Window where we can work with all the EF commands. In order to install this library to your existing application you should type Install-Package EntityFramework This will make some changes to your application. So Let's check them. In your .config file you'll see a  <configSections> which contains the version you have from EntityFramework and also was added the <entityFramework> section as shown below. This section is by default configured to use SQL Express which won't be necesary for this case. So you can comment it out or leave it empty. Also please make sure you're using the Connector/Net 6.6.x version which is the one that has this support as is shown in the previous image. At this point we face one issue; in order to be able to work with Migrations we need the __MigrationHistory table that we don't have yet since our Database was created with an older version. This table is used to keep track of the changes in our model. So we need to get it in our existing Database. Getting a Migration-History table into an existing database First thing we need to do to enable migrations in our existing application is to create our configuration class which will set up the MySqlClient Provider as our SQL Generator. So we have to add it with the following code: using System.Data.Entity.Migrations;     //add this at the top of your cs file public class Configuration : DbMigrationsConfiguration<NameOfYourDbContext>  //Make sure to use the name of your existing DBContext { public Configuration() { this.AutomaticMigrationsEnabled = false; //Set Automatic migrations to false since we'll be applying the migrations manually for this case. SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator());     }   }  This code will set up our configuration that we'll be using when executing all the migrations for our application. Once we have done this we can Build our application so we can check that everything is fine. Creating our Initial Migration Now let's add our Initial Migration. In Package Manager Console, execute "add-migration InitialCreate", you can use any other name but I like to set this as our initial create for future reference. After we run this command, some changes were done in our application: A new Migrations Folder was created. A new class migration call InitialCreate which in most of the cases should have empty Up and Down methods as long as your database is up to date with your Model. Since all your entities already exists, delete all duplicated code to create any entity which exists already in your Database if there is any. I found this easier when you don't have any pending updates to do to your database. Now we have our empty migration that will make no changes in our database and represents how are all the things at the begining of our migrations.  Finally, let's create our MigrationsHistory table. Optionally you can add SQL code to delete the edmdata table which is not needed anymore. public override void Up() { // Just make sure that you used 4.1 or later version         Sql("DROP TABLE EdmMetadata"); } From our Package Manager Console let's type: Update-database; If you like to see the operations made on each Update-database command you can use the flag -verbose after the Update-database. This will make two important changes.  It will execute the Up method in the initial migration which has no changes in the database. And second, and very important,  it will create the __MigrationHistory table necessary to keep track of your changes. And next time you make a change to your database it will compare the current model to the one stored in the Model Column of this table. Conclusion The important thing of this walk through is that we must create our initial migration before we start doing any changes to our model. This way we'll be adding the necessary __MigrationsHistory table to our existing database, so we can keep our database up to date with all the changes we do in our context model using migrations. Hope you have found this information useful. Please let us know if you have any questions or comments, also please check our forums here where we keep answering questions in general for the community.  Happy MySQL/Net Coding!

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  • #OOW 2012 @PARIS...talking Oracle and Clouds, and Optimized Datacenter

    - by Eric Bezille
    For those of you who want to get most out of Oracle technologies to evolve your IT to the Next Wave, I encourage you to register to the up coming Oracle Optimized Datacenter event that will take place in Paris on November 28th. You will get the opportunity to exchange with Oracle experts and customers having successfully evolve their IT by leveraging Oracle technologies. You will also get the latest news on some of the Oracle systems announcements made during OOW 2012. During this event we will make an update about Oracle and Clouds, from private to public and hybrid models. So in preparing this session, I thought it was a good start to make a status of Cloud Computing in France, and CIO requirements in particular. Starting in 2009 with the first Cloud Camp in Paris, the market has evolved, but the basics are still the same : think hybrid. From Traditional IT to Clouds One size doesn't fit all, and for big companies having already an IT in place, there will be parts eligible to external (public) cloud, and parts that would be required to stay inside the firewalls, so ability to integrate both side is key.  None the less, one of the major impact of Cloud Computing trend on IT, reported by Forrester, is the pressure it makes on CIO to evolve towards the same model that end-users are now used to in their day to day life, where self-service and flexibility are paramount. This is what is driving IT to transform itself toward "a Global Service Provider", or for some as "IT "is" the Business" (see : Gartner Identifies Four Futures for IT and CIO), and for both models toward a Private Cloud Service Provider. In this journey, there is still a big difference between most of existing external Cloud and a firm IT : the number of applications that a CIO has to manage. Most cloud providers today are overly specialized, but at the end of the day, there are really few business processes that rely on only one application. So CIOs has to combine everything together external and internal. And for the internal parts that they will have to make them evolve to a Private Cloud, the scope can be very large. This will often require CIOs to evolve from their traditional approach to more disruptive ones, the time has come to introduce new standards and processes, if they want to succeed. So let's have a look at the different Cloud models, what type of users they are addressing, what value they bring and most importantly what needs to be done by the  Cloud Provider, and what is left over to the user. IaaS, PaaS, SaaS : what's provided and what needs to be done First of all the Cloud Provider will have to provide all the infrastructure needed to deliver the service. And the more value IT will want to provide, the more IT will have to deliver and integrate : from disks to applications. As we can see in the above picture, providing pure IaaS, left a lot to cover for the end-user, that’s why the end-user targeted by this Cloud Service is IT people. If you want to bring more value to developers, you need to provide to them a development platform ready to use, which is what PaaS is standing for, by providing not only the processors power, storage and OS, but also the Database and Middleware platform. SaaS being the last mile of the Cloud, providing an application ready to use by business users, the remaining part for the end-users being configuring and specifying the application for their specific usage. In addition to that, there are common challenges encompassing all type of Cloud Services : Security : covering all aspect, not only of users management but also data flows and data privacy Charge back : measuring what is used and by whom Application management : providing capabilities not only to deploy, but also to upgrade, from OS for IaaS, Database, and Middleware for PaaS, to a full Business Application for SaaS. Scalability : ability to evolve ALL the components of the Cloud Provider stack as needed Availability : ability to cover “always on” requirements Efficiency : providing a infrastructure that leverage shared resources in an efficient way and still comply to SLA (performances, availability, scalability, and ability to evolve) Automation : providing the orchestration of ALL the components in all service life-cycle (deployment, growth & shrink (elasticity), upgrades,...) Management : providing monitoring, configuring and self-service up to the end-users Oracle Strategy and Clouds For CIOs to succeed in their Private Cloud implementation, means that they encompass all those aspects for each component life-cycle that they selected to build their Cloud. That’s where a multi-vendors layered approach comes short in terms of efficiency. That’s the reason why Oracle focus on taking care of all those aspects directly at Engineering level, to truly provide efficient Cloud Services solutions for IaaS, PaaS and SaaS. We are going as far as embedding software functions in hardware (storage, processor level,...) to ensure the best SLA with the highest efficiency. The beauty of it, as we rely on standards, is that the Oracle components that you are running today in-house, are exactly the same that we are using to build Clouds, bringing you flexibility, reversibility and fast path to adoption. With Oracle Engineered Systems (Exadata, Exalogic & SPARC SuperCluster, more specifically, when talking about Cloud), we are delivering all those components hardware and software already engineered together at Oracle factory, with a single pane of glace for the management of ALL the components through Oracle Enterprise Manager, and with high-availability, scalability and ability to evolve by design. To give you a feeling of what does that bring in terms just of implementation project timeline, for example with Oracle SPARC SuperCluster, we have a consistent track of record to have the system plug into existing Datacenter and ready in a week. This includes Oracle Database, OS, virtualization, Database Storage (Exadata Storage Cells in this case), Application Storage, and all network configuration. This strategy enable CIOs to very quickly build Cloud Services, taking out not only the complexity of integrating everything together but also taking out the automation and evolution complexity and cost. I invite you to discuss all those aspect in regards of your particular context face2face on November 28th.

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  • Where would a spam bot be located?

    - by Tim
    I have a hosted website using a free hosting service, I received an email this afternoon saying that I have been suspended because my account has been compromised. Basically, someone is using my email account to mass send spam. I've changed all the passwords and everything but when my Gmail pulls the emails from the host it's still downloading loads of spam messages that show like this: This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: [email protected] SMTP error from remote mail server after end of data: host 198.91.80.251 [198.91.80.251]: 554 5.6.0 id=23634-03 - Rejected by MTA on relaying, from MTA([127.0.0.1]:10030): 554 Error: This email address has lost rights to send email from the system ------ This is a copy of the message, including all the headers. ------ Return-path: <[email protected]> Received: from keenesystems.com ([66.135.33.211]:2370 helo=server211) by absolut.x10hosting.com with esmtpsa (TLSv1:RC4-MD5:128) (Exim 4.77) (envelope-from <[email protected]>) id 1TGwSW-002hHe-Lc for [email protected]; Wed, 26 Sep 2012 13:35:44 -0500 MIME-Version: 1.0 Date: Wed, 26 Sep 2012 13:35:43 -0500 X-Priority: 3 (Normal) X-Mailer: Ximian Evolution 3.9.9 (8.5.3-6) Subject: New staff members wanted at Auction It Online From: [email protected] Reply-To: [email protected] To: "Nadia Monti" <[email protected]> Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Message-ID: <OUTLOOK-IDM-9aed7054-6a3e-e1a4-1d5c-3e73377652a6@server211> Date : 26 September 2012=0ATime : 13:35=0ASender : Dennise Halcomb Head = Office Manager of RJ Auction Drop-Off Int.=0A=0ANice to meet you Nadia M= onti=0A=0ARJ ADO Ltd., a USA based company, offers a significant amount = of goods worldwide for our customers on eBay and other auction venues. = Our company's main target is to provide a suitable and cost-effective se= rvice for any person, company or fundraising company. The main purpose o= f the administrative assistant / sales support representative is to cont= ribute to the sales force and add convenience to our cost-effective serv= ice dedicated to individuals, businesses, and organizations worldwide. O= ur HR department obtained your resume from one of the various job-orient= ed websites just to offer you this post.=0A=0AWorking Schedule: This is = a part time and home-based offer. You won't need to spend more than 3 ho= urs each day. Your =0Aschedule will be flexible.=0A=0ASalary: At the end= of the trial period (it lasts for 1 month) you will be paid 1,800 EUR. = With the average volume of clients your overall income will raise up to = 3,000 EUR per month. After the trial period is over your base salary wil= l grow up to 2,500 EUR per month, so you will earn 5% commission from th= e transactions completed.=0A=0AWhere?: Italy Wide. As it is a stay at ho= me position all the communication will be carried out via email and via = phone.=0A=0ARequirements: Access to the internet during the workday and = basic microsoft office skills are needed. Basic knowledge of English is = required (most of the contacts will be in English).=0A=0ACosts and Fees:= There are NO costs at any time for our employees. All fees related to t= his position are covered by the RJ ADO Co. Ltd..=0A=0AFurther Hiring Pro= cess: If you are interested in position we offer, please reply to this e= mail and send us the copy of your resume for verification.=0A=0AAfter re= viewing all of the received applications we will reply to successful app= licants only. Then we'll offer to these successful applicants a position= within our firm on a trial period basis for one month beginning from th= e date you sign a trial agreement. During this trial period you will rec= eive full guidance and support. Employees on a one monthly trial period = are evaluated at least one week prior to the end of their trial. During = the trial, your supervisor can recommend termination. At the end of the = trial period, the supervisor can offer continued employment, extension o= f trial period, or termination. After the trial period you may ask for m= ore hours or continue full-time.=0A=0AIf you are interested in this posi= tion, just reply to this email and send any questions you have and the c= opy of your resume for verification.=0A=0AThank You,=0AHR-Manager of RJ = ADO Co. Ltd.=0A=0APermission Settings=0AYou have been referred to RJ Auc= tion Drop-Off If you feel you received this email in error or do not wis= h to receive future messages, please reply to this message with "remove"= in the subject field. We will immediately update our database according= ly. =0AWe apologize for any inconvenience caused.=0A=0ARJ Auction Drop-O= ff Co. Ltd. I'm not aware of how this has happened. I'm not sure how anyone could have got hold of my password. It's a simple wordpress install, at some point recently my host went down and there was a fresh install of wordpress with default admin accounts, I have a feeling it could be something to do with this. My question is, even though I've changed all my passwords it's all still happening, is there annywhere in paticular this script would be stored on my host. I really can't deal with having my hosting account suspended and my email account sending all this spam.

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  • 7-Eleven Improves the Digital Guest Experience With 10-Minute Application Provisioning

    - by MichaelM-Oracle
    By Vishal Mehra - Director, Cloud Computing, Oracle Consulting Making the Cloud Journey Matter There’s much more to cloud computing than cutting costs and closing data centers. In fact, cloud computing is fast becoming the engine for innovation and productivity in the digital age. Oracle Consulting Services contributes to our customers’ cloud journey by accelerating application provisioning and rapidly deploying enterprise solutions. By blending flexibility with standardization, our Middleware as a Service (MWaaS) offering is ensuring the success of many cloud initiatives. 10-Minute Application Provisioning Times at 7-Eleven As a case in point, 7-Eleven recently highlighted the scope, scale, and results of a cloud-powered environment. The world’s largest convenience store chain is rolling out a Digital Guest Experience (DGE) program across 8,500 stores in the U.S. and Canada. Everyday, 7-Eleven connects with tens of millions of customers through point-of-sale terminals, web sites, and mobile apps. Promoting customer loyalty, targeting promotions, downloading digital coupons, and accepting digital payments are all part of the roadmap for a comprehensive and rewarding customer experience. And what about the time required for deploying successive versions of this mission-critical solution? Ron Clanton, 7-Eleven's DGE Program Manager, Information Technology reported at Oracle Open World, " We are now able to provision new environments in less than 10 minutes. This includes the complete SOA Suite on Exalogic, and Enterprise Manager managing both the SOA Suite, Exalogic, and our Exadata databases ." OCS understands the complex nature of innovative solutions and has processes and expertise to help clients like 7-Eleven rapidly develop technology that enhances the customer experience with little more than the click of a button. OCS understood that the 7-Eleven roadmap required careful planning, agile development, and a cloud-capable environment to move fast and perform at enterprise scale. Business Agility Today’s business-savvy technology leaders face competing priorities as they confront the digital disruptions of the mobile revolution and next-generation enterprise applications. To support an innovation agenda, IT is required to balance competing priorities between development and operations groups. Standardization and consolidation of computing resources are the keys to success. With our operational and technical expertise promoting business agility, Oracle Consulting's deep Middleware as a Service experience can make a significant difference to our clients by empowering enterprise IT organizations with the computing environment they seek to keep up with the pace of change that digitally driven business units expect. Depending on the needs of the organization, this environment runs within a private, public, or hybrid cloud infrastructure. Through on-demand access to a shared pool of configurable computing resources, IT delivers the standard tools and methods for developing, integrating, deploying, and scaling next-generation applications. Gold profiles of predefined configurations eliminate the version mismatches among databases, application servers, and SOA suite components, delivered both by Oracle and other enterprise ISVs. These computing resources are well defined in business terms, enabling users to select what they need from a service catalog. Striking the Balance between Development and Operations As a result, development groups have the flexibility to choose among a menu of available services with descriptions of standard business functions, service level guarantees, and costs. Faced with the consumerization of enterprise IT, they can deliver the innovative customer experiences that seamlessly integrate with underlying enterprise applications and services. This cloud-powered development and testing environment accelerates release cycles to ensure agile development and rapid deployments. At the same time, the operations group is relying on certified stacks and frameworks, tuned to predefined environments and patterns. Operators can maintain a high level of security, and continue best practices for applications/systems monitoring and management. Moreover, faced with the challenges of delivering on service level agreements (SLAs) with the business units, operators can ensure performance, scalability, and reliability of the infrastructure. The elasticity of a cloud-computing environment – the ability to rapidly add virtual machines and storage in response to computing demands -- makes a difference for hardware utilization and efficiency. Contending with Continuous Change What does it take to succeed on the promise of the cloud? As the engine for innovation and productivity in the digital age, IT must face not only the technical transformations but also the organizational challenges of the cloud. Standardizing key technologies, resources, and services through cloud computing is only one part of the cloud journey. Managing relationships among multiple department and projects over time – developing the management, governance, and monitoring capabilities within IT – is an often unmentioned but all too important second part. In fact, IT must have the organizational agility to contend with continuous change. This is where a skilled consulting services partner can play a pivotal role as a trusted advisor in the successful adoption of cloud solutions. With a lifecycle services approach to delivering innovative business solutions, Oracle Consulting Services has expertise and a portfolio of services to help enterprise customers succeed on their cloud journeys as well as other converging mega trends .

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  • Null Values And The T-SQL IN Operator

    - by Jesse
    I came across some unexpected behavior while troubleshooting a failing test the other day that took me long enough to figure out that I thought it was worth sharing here. I finally traced the failing test back to a SELECT statement in a stored procedure that was using the IN t-sql operator to exclude a certain set of values. Here’s a very simple example table to illustrate the issue: Customers CustomerId INT, NOT NULL, Primary Key CustomerName nvarchar(100) NOT NULL SalesRegionId INT NULL   The ‘SalesRegionId’ column contains a number representing the sales region that the customer belongs to. This column is nullable because new customers get created all the time but assigning them to sales regions is a process that is handled by a regional manager on a periodic basis. For the purposes of this example, the Customers table currently has the following rows: CustomerId CustomerName SalesRegionId 1 Customer A 1 2 Customer B NULL 3 Customer C 4 4 Customer D 2 5 Customer E 3   How could we write a query against this table for all customers that are NOT in sales regions 2 or 4? You might try something like this: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE SalesRegionId NOT IN (2,4)   Will this work? In short, no; at least not in the way that you might expect. Here’s what this query will return given the example data we’re working with: CustomerId CustomerName SalesRegionId 1 Customer A 1 5 Customer E 5   I was expecting that this query would also return ‘Customer B’, since that customer has a NULL SalesRegionId. In my mind, having a customer with no sales region should be included in a set of customers that are not in sales regions 2 or 4.When I first started troubleshooting my issue I made note of the fact that this query should probably be re-written without the NOT IN clause, but I didn’t suspect that the NOT IN clause was actually the source of the issue. This particular query was only one minor piece in a much larger process that was being exercised via an automated integration test and I simply made a poor assumption that the NOT IN would work the way that I thought it should. So why doesn’t this work the way that I thought it should? From the MSDN documentation on the t-sql IN operator: If the value of test_expression is equal to any value returned by subquery or is equal to any expression from the comma-separated list, the result value is TRUE; otherwise, the result value is FALSE. Using NOT IN negates the subquery value or expression. The key phrase out of that quote is, “… is equal to any expression from the comma-separated list…”. The NULL SalesRegionId isn’t included in the NOT IN because of how NULL values are handled in equality comparisons. From the MSDN documentation on ANSI_NULLS: The SQL-92 standard requires that an equals (=) or not equal to (<>) comparison against a null value evaluates to FALSE. When SET ANSI_NULLS is ON, a SELECT statement using WHERE column_name = NULL returns zero rows even if there are null values in column_name. A SELECT statement using WHERE column_name <> NULL returns zero rows even if there are nonnull values in column_name. In fact, the MSDN documentation on the IN operator includes the following blurb about using NULL values in IN sub-queries or expressions that are used with the IN operator: Any null values returned by subquery or expression that are compared to test_expression using IN or NOT IN return UNKNOWN. Using null values in together with IN or NOT IN can produce unexpected results. If I were to include a ‘SET ANSI_NULLS OFF’ command right above my SELECT statement I would get ‘Customer B’ returned in the results, but that’s definitely not the right way to deal with this. We could re-write the query to explicitly include the NULL value in the WHERE clause: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE (SalesRegionId NOT IN (2,4) OR SalesRegionId IS NULL)   This query works and properly includes ‘Customer B’ in the results, but I ultimately opted to re-write the query using a LEFT OUTER JOIN against a table variable containing all of the values that I wanted to exclude because, in my case, there could potentially be several hundred values to be excluded. If we were to apply the same refactoring to our simple sales region example we’d end up with: 1: DECLARE @regionsToIgnore TABLE (IgnoredRegionId INT) 2: INSERT @regionsToIgnore values (2),(4) 3:  4: SELECT 5: c.CustomerId, 6: c.CustomerName, 7: c.SalesRegionId 8: FROM Customers c 9: LEFT OUTER JOIN @regionsToIgnore r ON r.IgnoredRegionId = c.SalesRegionId 10: WHERE r.IgnoredRegionId IS NULL By performing a LEFT OUTER JOIN from Customers to the @regionsToIgnore table variable we can simply exclude any rows where the IgnoredRegionId is null, as those represent customers that DO NOT appear in the ignored regions list. This approach will likely perform better if the number of sales regions to ignore gets very large and it also will correctly include any customers that do not yet have a sales region.

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  • Trouble with AABB collision response and physics

    - by WCM
    I have been racking my brain trying to figure out a problem I am having with physics and basic AABB collision response. I am fairly close as the physics are mostly right. Gravity feels good and movement is solid. The issue I am running into is that when I land on the test block in my project, I can jump off of it most of the time. If I repeatedly jump in place, I will eventually get stuck one or two pixels below the surface of the test block. If I try to jump, I can become free of the other block, but it will happen again a few jumps later. I feel like I am missing something really obvious with this. I have two functions that support the detection and function to return a vector for the overlap of the two rectangle bounding boxes. I have a single update method that is processing the physics and collision for the entity. I feel like I am missing something very simple, like an ordering of the physics vs. collision response handling. Any thoughts or help can be appreciated. I apologize for the format of the code, tis prototype code mostly. The collision detection function: public static bool Collides(Rectangle source, Rectangle target) { if (source.Right < target.Left || source.Bottom < target.Top || source.Left > target.Right || source.Top > target.Bottom) { return false; } return true; } The overlap function: public static Vector2 GetMinimumTranslation(Rectangle source, Rectangle target) { Vector2 mtd = new Vector2(); Vector2 amin = source.Min(); Vector2 amax = source.Max(); Vector2 bmin = target.Min(); Vector2 bmax = target.Max(); float left = (bmin.X - amax.X); float right = (bmax.X - amin.X); float top = (bmin.Y - amax.Y); float bottom = (bmax.Y - amin.Y); if (left > 0 || right < 0) return Vector2.Zero; if (top > 0 || bottom < 0) return Vector2.Zero; if (Math.Abs(left) < right) mtd.X = left; else mtd.X = right; if (Math.Abs(top) < bottom) mtd.Y = top; else mtd.Y = bottom; // 0 the axis with the largest mtd value. if (Math.Abs(mtd.X) < Math.Abs(mtd.Y)) mtd.Y = 0; else mtd.X = 0; return mtd; } The update routine (gravity = 0.001f, jumpHeight = 0.35f, moveAmount = 0.15f): public void Update(GameTime gameTime) { Acceleration.Y = gravity; Position += new Vector2((float)(movement * moveAmount * gameTime.ElapsedGameTime.TotalMilliseconds), (float)(Velocity.Y * gameTime.ElapsedGameTime.TotalMilliseconds)); Velocity.Y += Acceleration.Y; Vector2 previousPosition = new Vector2((int)Position.X, (int)Position.Y); KeyboardState keyboard = Keyboard.GetState(); movement = 0; if (keyboard.IsKeyDown(Keys.Left)) { movement -= 1; } if (keyboard.IsKeyDown(Keys.Right)) { movement += 1; } if (Position.Y + 16 > GameClass.Instance.GraphicsDevice.Viewport.Height) { Velocity.Y = 0; Position = new Vector2(Position.X, GameClass.Instance.GraphicsDevice.Viewport.Height - 16); IsOnSurface = true; } if (Collision.Collides(BoundingBox, GameClass.Instance.block.BoundingBox)) { Vector2 mtd = Collision.GetMinimumTranslation(BoundingBox, GameClass.Instance.block.BoundingBox); Position += mtd; Velocity.Y = 0; IsOnSurface = true; } if (keyboard.IsKeyDown(Keys.Space) && !previousKeyboard.IsKeyDown(Keys.Space)) { if (IsOnSurface) { Velocity.Y = -jumpHeight; IsOnSurface = false; } } previousKeyboard = keyboard; } This is also a full download to the project. https://www.box.com/s/3rkdtbso3xgfgc2asawy P.S. I know that I could do this with the XNA Platformer Starter Kit algo, but it has some deep flaws that I am going to try to live without. I'd rather go the route of collision response via an overlay function. Thanks for any and all insight!

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  • How to break out of if statement

    - by TheBroodian
    I'm not sure if the title is exactly an accurate representation of what I'm actually trying to ask, but that was the best I could think of. I am experiencing an issue with my character class. I have developed a system so that he can perform chain attacks, and something that was important to me was that 1)button presses during the process of an attack wouldn't interrupt the character, and 2) at the same time, button presses should be stored so that the player can smoothly queue up chain attacks in the middle of one so that gameplay doesn't feel rigid or unresponsive. This all begins when the player presses the punch button. Upon pressing the punch button, the game checks the state of the dpad at the moment of the button press, and then translates the resulting combined buttons into an int which I use as an enumerator relating to a punch method for the character. The enumerator is placed into a List so that the next time the character's Update() method is called, it will execute the next punch in the list. It only executes the next punch if my character is flagged with acceptInput as true. All attacks flag acceptInput as false, to prevent the interruption of attacks, and then at the end of an attack, acceptInput is set back to true. While accepting input, all other actions are polled for, i.e. jumping, running, etc. In runtime, if I attack, and then queue up another attack behind it (by pressing forward+punch) I can see the second attack visibly execute, which should flag acceptInput as false, yet it gets interrupted and my character will stop punching and start running if I am still holding down the dpad. Included is some code for context. This is the input region for my character. //Placed this outside the if (acceptInput) tree because I want it //to be taken into account whether we are accepting input or not. //This will queue up attacks, which will only be executed if we are accepting input. //This creates a desired effect that helps control the character in a // smoother fashion for the player. if (Input.justPressed(buttonManager.Punch)) { int dpadPressed = Input.DpadState(0); if (attackBuffer.Count() < 1) { attackBuffer.Add(CheckPunch(dpadPressed)); } else { attackBuffer.Clear(); attackBuffer.Add(CheckPunch(dpadPressed)); } } if (acceptInput) { if (attackBuffer.Count() > 0) { ExecutePunch(attackBuffer[0]); attackBuffer.RemoveAt(0); } //If D-Pad left is being held down. if (Input.DpadDirectionHeld(0, buttonManager.Left)) { flipped = false; if (onGround) { newAnimation = "run"; } velocity = new Vector2(velocity.X - acceleration, velocity.Y); if (walking == true && velocity.X <= -walkSpeed) { velocity.X = -walkSpeed; } else if (walking == false && velocity.X <= -maxSpeed) { velocity.X = -maxSpeed; } } //If D-Pad right is being held down. if (Input.DpadDirectionHeld(0, buttonManager.Right)) { flipped = true; if (onGround) { newAnimation = "run"; } velocity = new Vector2(velocity.X + acceleration, velocity.Y); if (walking == true && velocity.X >= walkSpeed) { velocity.X = walkSpeed; } else if (walking == false && velocity.X >= maxSpeed) { velocity.X = maxSpeed; } } //If jump/accept button is pressed. if (Input.justPressed(buttonManager.JumpAccept)) { if (onGround) { Jump(); } } //If toggle element next button is pressed. if (Input.justPressed(buttonManager.ToggleElementNext)) { if (elements.Count != 0) { elementInUse++; if (elementInUse >= elements.Count) { elementInUse = 0; } } } //If toggle element last button is pressed. if (Input.justPressed(buttonManager.ToggleElementLast)) { if (elements.Count != 0) { elementInUse--; if (elementInUse < 0) { elementInUse = Convert.ToSByte(elements.Count() - 1); } } } //If character is in the process of jumping. if (jumping == true) { if (Input.heldDown(buttonManager.JumpAccept)) { velocity.Y -= fallSpeed.Y; maxJumpTime -= elapsed; } if (Input.justReleased(buttonManager.JumpAccept) || maxJumpTime <= 0) { jumping = false; maxJumpTime = 0; } } //Won't execute abilities if input isn't being accepted. foreach (PlayerAbility ability in playerAbilities) { if (buffer.Matches(ability)) { if (onGround) { ability.Activate(); } if (!onGround && ability.UsableInAir) { ability.Activate(); } else if (!onGround && !ability.UsableInAir) { buffer.Clear(); } } } } When the attackBuffer calls ExecutePunch(int) method, ExecutePunch() will call one of the following methods: private void NeutralPunch1() //0 { acceptInput = false; busy = true; newAnimation = "punch1"; numberOfAttacks++; timeSinceLastAttack = 0; } private void ForwardPunch2(bool toLeft) //true == 7, false == 4 { forwardPunch2Timer = 0f; acceptInput = false; busy = true; newAnimation = "punch2begin"; numberOfAttacks++; timeSinceLastAttack = 0; if (toLeft) { velocity.X -= 800; } if (!toLeft) { velocity.X += 800; } } I assume the attack is being interrupted due to the fact that ExecutePunch() is in the same if statement as running, but I haven't been able to find a suitable way to stop this happening. Thank you ahead of time for reading this, I apologize for it having become so long winded.

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  • Sass interface in HTML6 for upload files.

    - by Anirudha
    Originally posted on: http://geekswithblogs.net/anirugu/archive/2013/11/04/sass-interface-in-html6-for-upload-files.aspx[This post is about experiment & imagination] From Windows XP (ever last OS I tried) I have seen a feature that is about send file to pen drive and make shortcut on Desktop. In XP, Win7 (Win8 have this too, not removed) just select the file right click > send to and you can send this file to many places. In my menu it’s show me Skype because I have installed it. this skype confirm that we can add our own app here to make it more easy for user to send file in our app. Nowadays Many people use Cloud or online site to store the file. In case of html5 drag and drop you need to have site opened and have opened that page which is about file upload. You need to select all  and drag and drop. after drag and drop file is simply uploaded to server and site show you on list (if no error happen). but this file upload is seriously not worthy since I have to open the site when I do this operation.   Through this post I want to describe a feature that can make this thing better.  This API is simply called SASS FILE UPLOAD API Through This API when you surf the site and come into file upload page then the page will tell you that we also have SASS FILE API support. Enable it for better result.   How this work This API feature are activated on 2 basis. 1. Feature are disabled by default on site (or you can change it if it’s not) 2. This API allow specific site to upload the files. Files upload may have some rule. For example (minimum or maximum size of file to uploaded, which format the site allowed you to upload). In case of resume site you will be allowed to use .doc (according to code of site)   How browser recognize that Site have SASS service. In HTML source of  the site, the code have a meta tag similar to this <meta name=”sass-upload-api” path=”/upload.json”/> Remember that upload.json is one file that has define the value of many settings {   "cookie_name": "ck_file",   "maximum_allowed_perday": 24,   "allowed_file_extensions","*.png,*.jpg,*.jpeg,*.gif",   "method": [       {           "get": "file/get",           "routing":"/file/get/{fileName}"       },       {           "post": "file/post",           "routing":"/file/post/{fileName}"       },       {           "delete": "file/delete",           "routing":"/file/delete/{fileName}"       },         {           "put": "file/put",           "routing":"/file/put/{fileName}"       },        {           "all": "file/all",           "routing":"/file/all/{fileName}"       }    ] } cookie name is simply a cookie which should be stored in browser and define in json. we define the cookie_name so we can easily share then with service in Windows system. This cookie will be accessible with the service so it’s security based safe. other cookie will not be shared.   The cookie will be post,put, get from this location. The all location will be simply about showing a whole list of file. This will gave a treeview kind of json to show the directories on sever.   for example example.com if you have activated the API with this site then you will seen a send to option in your explorer.exe when you send you will got a windows open which folder you want to use to send the file. The windows will also describe the limit and how much you can upload. This thing never required site to opened. When you upload the file this will be uploaded through FTP protocol. FTP protocol are better for performance.   How this API make thing faster. Suppose you want to ask a question and want to post image. you just do it and get it ready when you open stackoverflow.com now stackoverflow will only tell you which file you want to put on your current question that you asking for. second use is about people use cloud app.   There is no need of drag and drop anymore. we just need to do it without drag and drop it. we doesn’t need to open the site either. This thing is still in experiment level. I will update this post when I got some progress on this API.

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  • Part 8: How to name EBS Customizations

    - by volker.eckardt(at)oracle.com
    You might wonder why I am discussing this here. The reason is simple: nearly every project has a bit different naming conventions, which makes a the life always a bit complicated (for developers, but also setup responsible, and also for consultants).  Although we always create a document to describe the technical object naming conventions, I have rarely seen a dedicated document  with functional naming conventions. To be precisely, from my stand point, there should always be one global naming definition for an implementation! Let me discuss some related questions: What is the best convention for the customization reference? How to name database objects (tables, packages etc.)? How to name functional objects like Value Sets, Concurrent Programs, etc. How to separate customizations from standard objects best? What is the best convention for the customization reference? The customization reference is the key you use to reference your customization from other lists, from the project plan etc. Usually it is something like XXHU_CONV_22 (HU=customer abbreviation, CONV=Conversion object #22) or XXFA_DEPRN_RPT_02 (FA=Fixed Assets, DEPRN=Short object group, here depreciation, RPT=Report, 02=2nd report in this area) As this is just a reference (not an object name yet), I would prefer the second option. XX=Customization, FA=Main EBS Module linked (you may have sometimes more, but FA is the main) DEPRN_RPT=Short name to specify the customization 02=a unique number Important here is that the HU isn’t used, because XX is enough to mark a custom object, and the 3rd+4th char can be used by the EBS module short name. How to name database objects (tables, packages etc.)? I was leading different developer teams, and I know that one common way is it to take the Customization reference and add more chars behind to classify the object (like _V for view and _T1 for triggers etc.). The only concern I have with this approach is the reusability. If you name your view XXFA_DEPRN_RPT_02_V, no one will by choice reuse this nice view, as it seams to be specific for this CEMLI. My suggestion is rather to name the view XXFA_DEPRN_PERIODS_V and allow herewith reusability for other CEMLIs (although the view will be deployed primarily with CEMLI package XXFA_DEPRN_RPT_02). (check also one of the following Blogs where I will talk about deployment.) How to name Value Sets, Concurrent Programs, etc. For Value Sets I would go with the same convention as for database objects, starting with XX<Module> …. For Concurrent Programs the situation is a bit different. This “object” is seen and used by a lot of users, and they will search for. In many projects it is common to start again with the company short name, or with XX. My proposal would differ. If you have created your own report and you name it “XX: Invoice Report”, the user has to remember that this report does not start with “I”, it starts with X. Would you like typing an X if you are looking for an Invoice report? No, you wouldn’t! So my advise would be to name it:   “Invoice Report (XXAP)”. Still we know it is custom (because of the XXAP), but the end user will type the key “i” to get it (and will see similar reports starting also with “i”). I hope that the general schema behind has now become obvious. How to separate customizations from standard objects best? I would not have this section here if the naming would not play an important role. Unfortunately, we can not always link a custom application to our own object, therefore the naming is really important. In the file system structure we use our $XXyy_TOP, in JAVA_TOP it is perhaps also “xx” in front. But in the database itself? Although there are different concepts in place, still many implementations are using the standard “apps” approach, means custom objects are stored in the apps schema (which should not cause any trouble). Final advise: review the naming conventions regularly, once a month. You may have to add more! And, publish them! To summarize: Technical and functional customized objects should always follow a naming convention. This naming convention should be project wide, and only one place shall be used to maintain (like in a Wiki). If the name is for the end user, rather put a customization identifier at the end; if it is an internal name, start with XX…

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  • ADF Business Components

    - by Arda Eralp
    ADF Business Components and JDeveloper simplify the development, delivery, and customization of business applications for the Java EE platform. With ADF Business Components, developers aren't required to write the application infrastructure code required by the typical Java EE application to: Connect to the database Retrieve data Lock database records Manage transactions   ADF Business Components addresses these tasks through its library of reusable software components and through the supporting design time facilities in JDeveloper. Most importantly, developers save time using ADF Business Components since the JDeveloper design time makes typical development tasks entirely declarative. In particular, JDeveloper supports declarative development with ADF Business Components to: Author and test business logic in components which automatically integrate with databases Reuse business logic through multiple SQL-based views of data, supporting different application tasks Access and update the views from browser, desktop, mobile, and web service clients Customize application functionality in layers without requiring modification of the delivered application The goal of ADF Business Components is to make the business services developer more productive.   ADF Business Components provides a foundation of Java classes that allow your business-tier application components to leverage the functionality provided in the following areas: Simplifying Data Access Design a data model for client displays, including only necessary data Include master-detail hierarchies of any complexity as part of the data model Implement end-user Query-by-Example data filtering without code Automatically coordinate data model changes with business services layer Automatically validate and save any changes to the database   Enforcing Business Domain Validation and Business Logic Declaratively enforce required fields, primary key uniqueness, data precision-scale, and foreign key references Easily capture and enforce both simple and complex business rules, programmatically or declaratively, with multilevel validation support Navigate relationships between business domain objects and enforce constraints related to compound components   Supporting Sophisticated UIs with Multipage Units of Work Automatically reflect changes made by business service application logic in the user interface Retrieve reference information from related tables, and automatically maintain the information when the user changes foreign-key values Simplify multistep web-based business transactions with automatic web-tier state management Handle images, video, sound, and documents without having to use code Synchronize pending data changes across multiple views of data Consistently apply prompts, tooltips, format masks, and error messages in any application Define custom metadata for any business components to support metadata-driven user interface or application functionality Add dynamic attributes at runtime to simplify per-row state management   Implementing High-Performance Service-Oriented Architecture Support highly functional web service interfaces for business integration without writing code Enforce best-practice interface-based programming style Simplify application security with automatic JAAS integration and audit maintenance "Write once, run anywhere": use the same business service as plain Java class, EJB session bean, or web service   Streamlining Application Customization Extend component functionality after delivery without modifying source code Globally substitute delivered components with extended ones without modifying the application   ADF Business Components implements the business service through the following set of cooperating components: Entity object An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. These are basically your 1 to 1 representation of a database table. Each table in the database will have 1 and only 1 EO. The EO contains the mapping between columns and attributes. EO's also contain the business logic and validation. These are you core data services. They are responsible for updating, inserting and deleting records. The Attributes tab displays the actual mapping between attributes and columns, the mapping has following fields: Name : contains the name of the attribute we expose in our data model. Type : defines the data type of the attribute in our application. Column : specifies the column to which we want to map the attribute with Column Type : contains the type of the column in the database   View object A view object represents a SQL query. You use the full power of the familiar SQL language to join, filter, sort, and aggregate data into exactly the shape required by the end-user task. The attributes in the View Objects are actually coming from the Entity Object. In the end the VO will generate a query but you basically build a VO by selecting which EO need to participate in the VO and which attributes of those EO you want to use. That's why you have the Entity Usage column so you can see the relation between VO and EO. In the query tab you can clearly see the query that will be generated for the VO. At this stage we don't need it and just use it for information purpose. In later stages we might use it. Application module An application module is the controller of your data layer. It is responsible for keeping hold of the transaction. It exposes the data model to the view layer. You expose the VO's through the Application Module. This is the abstraction of your data layer which you want to show to the outside word.It defines an updatable data model and top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task. While the base components handle all the common cases through built-in behavior, customization is always possible and the default behavior provided by the base components can be easily overridden or augmented. When you create EO's, a foreign key will be translated into an association in our model. It defines the type of relation and who is the master and child as well as how the visibility of the association looks like. A similar concept exists to identify relations between view objects. These are called view links. These are almost identical as association except that a view link is based upon attributes defined in the view object. It can also be based upon an association. Here's a short summary: Entity Objects: representations of tables Association: Relations between EO's. Representations of foreign keys View Objects: Logical model View Links: Relationships between view objects Application Model: interface to your application  

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  • #OOW 2012 : IaaS, Private Cloud, Multitenant Database, and X3H2M2

    - by Eric Bezille
    The title of this post is a summary of the 4 announcements made by Larry Ellison today, during the opening session of Oracle Open World 2012... To know what's behind X3H2M2, you will have to wait a little, as I will go in order, beginning with the IaaS - Infrastructure as a Service - announcement. Oracle IaaS goes Public... and Private... Starting in 2004 with Fusion development, Oracle Cloud was launch last year to provide not only SaaS Application, based on standard development, but also the underlying PaaS, required to build the specifics, and required interconnections between applications, in and outside of the Cloud. Still, to cover the end-to-end Cloud  Services spectrum, we had to provide an Infrastructure as a Service, leveraging our Servers, Storage, OS, and Virtualization Technologies, all "Engineered Together". This Cloud Infrastructure, was already available for our customers to build rapidly their own Private Cloud either on SPARC/Solaris or x86/Linux... The second announcement made today bring that proposition a big step further : for cautious customers (like Banks, or sensible industries) who would like to benefits from the Cloud value of "as a Service", but don't want their Data out in the Cloud... We propose to them to operate the same systems, Exadata, Exalogic & SuperCluster, that are providing our Public Cloud Infrastructure, behind their firewall, in a Private Cloud model. Oracle 12c Multitenant Database This is also a major announcement made today, on what's coming with Oracle Database 12c : the ability to consolidate multiple databases with no extra additional  cost especially in terms of memory needed on the server node, which is often THE consolidation limiting factor. The principle could be compare to Solaris Zones, where, you will have a Database Container, who is "owning" the memory and Database background processes, and "Pluggable" Database in this Database Container. This particular feature is a strong compelling event to evaluate rapidly Oracle Database 12c once it will be available, as this is major step forward into true Database consolidation with Multitenancy on a shared (optimized) infrastructure. X3H2M2, enabling the new Exadata X3 in-Memory Database Here we are :  X3H2M2 stands for X3 (the new version of Exadata announced also today) Heuristic Hierarchical Mass Memory, providing the capability to keep most if not all the Data in the memory cache hierarchy. Of course, this is the major software enhancement of the new X3 Exadata machine, but as this is a software, our current customers would be able to benefit from it on their existing systems by upgrading to the new release. But that' not the only thing that we did with X3, at the same time we have upgraded everything : the CPUs, adding more cores per server node (16 vs. 12, with the arrival of Intel E5 / Sandy Bridge), the memory with 512GB memory as well per node,  and the new Flash Fire card, bringing now up to 22 TB of Flash cache. All of this 4TB of RAM + 22TB of Flash being use cleverly not only for read but also for write by the X3H2M2 algorithm... making a very big difference compare to traditional storage flash extension. But what does those extra performances brings to you on an already very efficient system: double your performances compare to the fastest storage array on the market today (including flash) and divide you storage price x10 at the same time... Something to consider closely this days... Especially that we also announced the availability of a new Exadata X3-2 8th rack : a good starting point. As you have seen a major opening for this year again with true innovation. But that was not the only thing that we saw today, as before Larry's talk, Fujitsu did introduce more in deep the up coming new SPARC processor, that they are co-developing with us. And as such Andrew Mendelsohn - Senior Vice President Database Server Technologies came on stage to explain that the next step after I/O optimization for Database with Exadata, was to accelerate the Database at execution level by bringing functions in the SPARC processor silicium. All in all, to process more and more Data... The big theme of the day... and of the Oracle User Groups Conferences that were also happening today and where I had the opportunity to attend some interesting sessions on practical use cases of Big Data one in Finances and Fraud profiling and the other one on practical deployment of Oracle Exalytics for Data Analytics. In conclusion, one picture to try to size Oracle Open World ... and you can understand why, with such a rich content... and this only the first day !

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  • Avoiding coupling

    - by Seralize
    It is also true that a system may become so coupled, where each class is dependent on other classes that depend on other classes, that it is no longer possible to make a change in one place without having a ripple effect and having to make subsequent changes in many places.[1] This is why using an interface or an abstract class can be valuable in any object-oriented software project. Quote from Wikipedia Starting from scratch I'm starting from scratch with a project that I recently finished because I found the code to be too tightly coupled and hard to refactor, even when using MVC. I will be using MVC on my new project aswell but want to try and avoid the pitfalls this time, hopefully with your help. Project summary My issue is that I really wish to keep the Controller as clean as possible, but it seems like I can't do this. The basic idea of the program is that the user picks wordlists which is sent to the game engine. It will pick random words from the lists until there are none left. Problem at hand My main problem is that the game will have 'modes', and need to check the input in different ways through a method called checkWord(), but exactly where to put this and how to abstract it properly is a challenge to me. I'm new to design patterns, so not sure whether there exist any might fit my problem. My own attempt at abstraction Here is what I've gotten so far after hours of 'refactoring' the design plans, and I know it's long, but it's the best I could do to try and give you an overview (Note: As this is the sketch, anything is subject to change, all help and advice is very welcome. Also note the marked coupling points): Wordlist class Wordlist { // Basic CRUD etc. here! // Other sample methods: public function wordlistCount($user_id) {} // Returns count of how many wordlists a user has public function getAll($user_id) {} // Returns all wordlists of a user } Word class Word { // Basic CRUD etc. here! // Other sample methods: public function wordCount($wordlist_id) {} // Returns count of words in a wordlist public function getAll($wordlist_id) {} // Returns all words from a wordlist public function getWordInfo($word_id) {} // Returns information about a word } Wordpicker class Wordpicker { // The class needs to know which words and wordlists to exclude protected $_used_words = array(); protected $_used_wordlists = array(); // Wordlists to pick words from protected $_wordlists = array(); /* Public Methods */ public function setWordlists($wordlists = array()) {} public function setUsedWords($used_words = array()) {} public function setUsedWordlists($used_wordlists = array()) {} public function getRandomWord() {} // COUPLING POINT! Will most likely need to communicate with both the Wordlist and Word classes /* Protected Methods */ protected function _checkAvailableWordlists() {} // COUPLING POINT! Might need to check if wordlists are deleted etc. protected function _checkAvailableWords() {} // COUPLING POINT! Method needs to get all words in a wordlist from the Word class } Game class Game { protected $_session_id; // The ID of a game session which gets stored in the database along with game details protected $_game_info = array(); // Game instantiation public function __construct($user_id) { if (! $this->_session_id = $this->_gameExists($user_id)) { // New game } else { // Resume game } } // This is the method I tried to make flexible by using abstract classes etc. // Does it even belong in this class at all? public function checkWord($answer, $native_word, $translation) {} // This method checks the answer against the native word / translation word, depending on game mode public function getGameInfo() {} // Returns information about a game session, or creates it if it does not exist public function deleteSession($session_id) {} // Deletes a game session from the database // Methods dealing with game session information protected function _gameExists($user_id) {} protected function _getProgress($session_id) {} protected function _updateProgress($game_info = array()) {} } The Game /* CONTROLLER */ /* "Guess the word" page */ // User input $game_type = $_POST['game_type']; // Chosen with radio buttons etc. $wordlists = $_POST['wordlists']; // Chosen with checkboxes etc. // Starts a new game or resumes one from the database $game = new Game($_SESSION['user_id']); $game_info = $game->getGameInfo(); // Instantiates a new Wordpicker $wordpicker = new Wordpicker(); $wordpicker->setWordlists((isset($game_info['wordlists'])) ? $game_info['wordlists'] : $wordlists); $wordpicker->setUsedWordlists((isset($game_info['used_wordlists'])) ? $game_info['used_wordlists'] : NULL); $wordpicker->setUsedWords((isset($game_info['used_words'])) ? $game_info['used_words'] : NULL); // Fetches an available word if (! $word_id = $wordpicker->getRandomWord()) { // No more words left - game over! $game->deleteSession($game_info['id']); redirect(); } else { // Presents word details to the user $word = new Word(); $word_info = $word->getWordInfo($word_id); } The Bit to Finish /* CONTROLLER */ /* "Check the answer" page */ // ?????????????????? ( http://pastebin.com/cc6MtLTR ) Make sure you toggle the 'Layout Width' to the right for a better view. Thanks in advance. Questions To which extent should objects be loosely coupled? If object A needs info from object B, how is it supposed to get this without losing too much cohesion? As suggested in the comments, models should hold all business logic. However, as objects should be independent, where to glue them together? Should the model contain some sort of "index" or "client" area which connects the dots? Edit: So basically what I should do for a start is to make a new model which I can more easily call with oneliners such as $model->doAction(); // Lots of code in here which uses classes! How about the method for checking words? Should it be it's own object? I'm not sure where I should put it as it's pretty much part of the 'game'. But on another hand, I could just leave out the 'abstraction and OOPness' and make it a method of the 'client model' which will be encapsulated from the controller anyway. Very unsure about this.

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  • Space invaders clone not moving properly

    - by ThePlan
    I'm trying to make a basic space invaders clone in allegro 5, I've got my game set up, basic events and such, here is the code: #include <allegro5/allegro.h> #include <allegro5/allegro_image.h> #include <allegro5/allegro_primitives.h> #include <allegro5/allegro_font.h> #include <allegro5/allegro_ttf.h> #include "Entity.h" // GLOBALS ========================================== const int width = 500; const int height = 500; const int imgsize = 3; bool key[5] = {false, false, false, false, false}; bool running = true; bool draw = true; // FUNCTIONS ======================================== void initSpaceship(Spaceship &ship); void moveSpaceshipRight(Spaceship &ship); void moveSpaceshipLeft(Spaceship &ship); void initInvader(Invader &invader); void moveInvaderRight(Invader &invader); void moveInvaderLeft(Invader &invader); void initBullet(Bullet &bullet); void fireBullet(); void doCollision(); void updateInvaders(); void drawText(); enum key_t { UP, DOWN, LEFT, RIGHT, SPACE }; enum source_t { INVADER, DEFENDER }; int main(void) { if(!al_init()) { return -1; } Spaceship ship; Invader invader; Bullet bullet; al_init_image_addon(); al_install_keyboard(); al_init_font_addon(); al_init_ttf_addon(); ALLEGRO_DISPLAY *display = al_create_display(width, height); ALLEGRO_EVENT_QUEUE *event_queue = al_create_event_queue(); ALLEGRO_TIMER *timer = al_create_timer(1.0 / 60); ALLEGRO_BITMAP *images[imgsize]; ALLEGRO_FONT *font1 = al_load_font("arial.ttf", 20, 0); al_register_event_source(event_queue, al_get_keyboard_event_source()); al_register_event_source(event_queue, al_get_display_event_source(display)); al_register_event_source(event_queue, al_get_timer_event_source(timer)); images[0] = al_load_bitmap("defender.bmp"); images[1] = al_load_bitmap("invader.bmp"); images[2] = al_load_bitmap("explosion.bmp"); al_convert_mask_to_alpha(images[0], al_map_rgb(0, 0, 0)); al_convert_mask_to_alpha(images[1], al_map_rgb(0, 0, 0)); al_convert_mask_to_alpha(images[2], al_map_rgb(0, 0, 0)); initSpaceship(ship); initBullet(bullet); initInvader(invader); al_start_timer(timer); while(running) { ALLEGRO_EVENT ev; al_wait_for_event(event_queue, &ev); if(ev.type == ALLEGRO_EVENT_TIMER) { draw = true; if(key[RIGHT] == true) moveSpaceshipRight(ship); if(key[LEFT] == true) moveSpaceshipLeft(ship); } else if(ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE) running = false; else if(ev.type == ALLEGRO_EVENT_KEY_DOWN) { switch(ev.keyboard.keycode) { case ALLEGRO_KEY_ESCAPE: running = false; break; case ALLEGRO_KEY_LEFT: key[LEFT] = true; break; case ALLEGRO_KEY_RIGHT: key[RIGHT] = true; break; case ALLEGRO_KEY_SPACE: key[SPACE] = true; break; } } else if(ev.type == ALLEGRO_KEY_UP) { switch(ev.keyboard.keycode) { case ALLEGRO_KEY_LEFT: key[LEFT] = false; break; case ALLEGRO_KEY_RIGHT: key[RIGHT] = false; break; case ALLEGRO_KEY_SPACE: key[SPACE] = false; break; } } if(draw && al_is_event_queue_empty(event_queue)) { draw = false; al_draw_bitmap(images[0], ship.pos_x, ship.pos_y, 0); al_flip_display(); al_clear_to_color(al_map_rgb(0, 0, 0)); } } al_destroy_font(font1); al_destroy_event_queue(event_queue); al_destroy_timer(timer); for(int i = 0; i < imgsize; i++) al_destroy_bitmap(images[i]); al_destroy_display(display); } // FUNCTION LOGIC ====================================== void initSpaceship(Spaceship &ship) { ship.lives = 3; ship.speed = 2; ship.pos_x = width / 2; ship.pos_y = height - 20; } void initInvader(Invader &invader) { invader.health = 100; invader.count = 40; invader.speed = 0.5; invader.pos_x = 300; invader.pos_y = 300; } void initBullet(Bullet &bullet) { bullet.speed = 10; } void moveSpaceshipRight(Spaceship &ship) { ship.pos_x += ship.speed; if(ship.pos_x >= width) ship.pos_x = width-30; } void moveSpaceshipLeft(Spaceship &ship) { ship.pos_x -= ship.speed; if(ship.pos_x <= 0) ship.pos_x = 0+30; } However it's not behaving the way I want it to behave, in fact the behavior for the ship movement is un-normal. Basically I specified that the ship only moves when the right/left key is down, however the ship is moving constantly to the direction of the key pressed, it never stops although it should only move while my key is down. Even more weird behavior, when I press the opposite key the ship completely stops no matter what else I press. What's wrong with the code? Why does the ship move constantly even after I specified it only moves when a key is down?

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  • Managing text-maps in a 2D array on to be painted on HTML5 Canvas

    - by weka
    So, I'm making a HTML5 RPG just for fun. The map is a <canvas> (512px width, 352px height | 16 tiles across, 11 tiles top to bottom). I want to know if there's a more efficient way to paint the <canvas>. Here's how I have it right now. How tiles are loaded and painted on map The map is being painted by tiles (32x32) using the Image() piece. The image files are loaded through a simple for loop and put into an array called tiles[] to be PAINTED on using drawImage(). First, we load the tiles... and here's how it's being done: // SET UP THE & DRAW THE MAP TILES tiles = []; var loadedImagesCount = 0; for (x = 0; x <= NUM_OF_TILES; x++) { var imageObj = new Image(); // new instance for each image imageObj.src = "js/tiles/t" + x + ".png"; imageObj.onload = function () { console.log("Added tile ... " + loadedImagesCount); loadedImagesCount++; if (loadedImagesCount == NUM_OF_TILES) { // Onces all tiles are loaded ... // We paint the map for (y = 0; y <= 15; y++) { for (x = 0; x <= 10; x++) { theX = x * 32; theY = y * 32; context.drawImage(tiles[5], theY, theX, 32, 32); } } } }; tiles.push(imageObj); } Naturally, when a player starts a game it loads the map they last left off. But for here, it an all-grass map. Right now, the maps use 2D arrays. Here's an example map. [[4, 1, 4, 1, 4, 1, 4, 1, 4, 1, 4, 1, 1, 1, 1, 1], [1, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 1, 1, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 1, 1, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 13, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 13, 11, 11, 11, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 1, 1, 1, 1, 1, 1, 1, 13, 13, 13, 13, 13, 1], [1, 1, 1, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 1, 1, 1]]; I get different maps using a simple if structure. Once the 2d array above is return, the corresponding number in each array will be painted according to Image() stored inside tile[]. Then drawImage() will occur and paint according to the x and y and times it by 32 to paint on the correct x-y coordinate. How multiple map switching occurs With my game, maps have five things to keep track of: currentID, leftID, rightID, upID, and bottomID. currentID: The current ID of the map you are on. leftID: What ID of currentID to load when you exit on the left of current map. rightID: What ID of currentID to load when you exit on the right of current map. downID: What ID of currentID to load when you exit on the bottom of current map. upID: What ID of currentID to load when you exit on the top of current map. Something to note: If either leftID, rightID, upID, or bottomID are NOT specific, that means they are a 0. That means they cannot leave that side of the map. It is merely an invisible blockade. So, once a person exits a side of the map, depending on where they exited... for example if they exited on the bottom, bottomID will the number of the map to load and thus be painted on the map. Here's a representational .GIF to help you better visualize: As you can see, sooner or later, with many maps I will be dealing with many IDs. And that can possibly get a little confusing and hectic. The obvious pros is that it load 176 tiles at a time, refresh a small 512x352 canvas, and handles one map at time. The con is that the MAP ids, when dealing with many maps, may get confusing at times. My question Is this an efficient way to store maps (given the usage of tiles), or is there a better way to handle maps? I was thinking along the lines of a giant map. The map-size is big and it's all one 2D array. The viewport, however, is still 512x352 pixels. Here's another .gif I made (for this question) to help visualize: Sorry if you cannot understand my English. Please ask anything you have trouble understanding. Hopefully, I made it clear. Thanks.

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  • Indexed Drawing in OpenGL not working

    - by user2050846
    I am trying to render 2 types of primitives- - points ( a Point Cloud ) - triangles ( a Mesh ) I am rendering points simply without any index arrays and they are getting rendered fine. To render the meshes I am using indexed drawing with the face list array having the indices of the vertices to be rendered as Triangles. Vertices and their corresponding vertex colors are stored in their corresponding buffers. But the indexed drawing command do not draw anything. The code is as follows- Main Display Function: void display() { simple->enable(); simple->bindUniform("MV",modelview); simple->bindUniform("P", projection); // rendering Point Cloud glBindVertexArray(vao); // Vertex buffer Point Cloud glBindBuffer(GL_ARRAY_BUFFER,vertexbuffer); glEnableVertexAttribArray(0); glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0); // Color Buffer point Cloud glBindBuffer(GL_ARRAY_BUFFER,colorbuffer); glEnableVertexAttribArray(1); glVertexAttribPointer(1,3,GL_FLOAT,GL_FALSE,0,0); // Render Colored Point Cloud //glDrawArrays(GL_POINTS,0,model->vertexCount); glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); // ---------------- END---------------------// //// Floor Rendering glBindBuffer(GL_ARRAY_BUFFER,fl); glEnableVertexAttribArray(0); glEnableVertexAttribArray(1); glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0); glVertexAttribPointer(1,4,GL_FLOAT,GL_FALSE,0,(void *)48); glDrawArrays(GL_QUADS,0,4); glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); // -----------------END---------------------// //Rendering the Meshes //////////// PART OF CODE THAT IS NOT DRAWING ANYTHING //////////////////// glBindVertexArray(vid); for(int i=0;i<NUM_MESHES;i++) { glBindBuffer(GL_ARRAY_BUFFER,mVertex[i]); glEnableVertexAttribArray(0); glEnableVertexAttribArray(1); glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0); glVertexAttribPointer(1,3,GL_FLOAT,GL_FALSE,0,(void *)(meshes[i]->vertexCount*sizeof(glm::vec3))); //glDrawArrays(GL_TRIANGLES,0,meshes[i]->vertexCount); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,mFace[i]); //cout<<gluErrorString(glGetError()); glDrawElements(GL_TRIANGLES,meshes[i]->faceCount*3,GL_FLOAT,(void *)0); glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); } glUseProgram(0); glutSwapBuffers(); glutPostRedisplay(); } Point Cloud Buffer Allocation Initialization: void initGLPointCloud() { glGenBuffers(1,&vertexbuffer); glGenBuffers(1,&colorbuffer); glGenBuffers(1,&fl); //Populates the position buffer glBindBuffer(GL_ARRAY_BUFFER,vertexbuffer); glBufferData(GL_ARRAY_BUFFER, model->vertexCount * sizeof (glm::vec3), &model->positions[0], GL_STATIC_DRAW); //Populates the color buffer glBindBuffer(GL_ARRAY_BUFFER, colorbuffer); glBufferData(GL_ARRAY_BUFFER, model->vertexCount * sizeof (glm::vec3), &model->colors[0], GL_STATIC_DRAW); model->FreeMemory(); // To free the not needed memory, as the data has been already // copied on graphic card, and wont be used again. glBindBuffer(GL_ARRAY_BUFFER,0); } Meshes Buffer Initialization: void initGLMeshes(int i) { glBindBuffer(GL_ARRAY_BUFFER,mVertex[i]); glBufferData(GL_ARRAY_BUFFER,meshes[i]->vertexCount*sizeof(glm::vec3)*2,NULL,GL_STATIC_DRAW); glBufferSubData(GL_ARRAY_BUFFER,0,meshes[i]->vertexCount*sizeof(glm::vec3),&meshes[i]->positions[0]); glBufferSubData(GL_ARRAY_BUFFER,meshes[i]->vertexCount*sizeof(glm::vec3),meshes[i]->vertexCount*sizeof(glm::vec3),&meshes[i]->colors[0]); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,mFace[i]); glBufferData(GL_ELEMENT_ARRAY_BUFFER,meshes[i]->faceCount*sizeof(glm::vec3), &meshes[i]->faces[0],GL_STATIC_DRAW); meshes[i]->FreeMemory(); //glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0); } Initialize the Rendering, load and create shader and calls the mesh and PCD initializers. void initRender() { simple= new GLSLShader("shaders/simple.vert","shaders/simple.frag"); //Point Cloud //Sets up VAO glGenVertexArrays(1, &vao); glBindVertexArray(vao); initGLPointCloud(); //floorData glBindBuffer(GL_ARRAY_BUFFER, fl); glBufferData(GL_ARRAY_BUFFER, sizeof(floorData), &floorData[0], GL_STATIC_DRAW); glBindBuffer(GL_ARRAY_BUFFER,0); glBindVertexArray(0); //Meshes for(int i=0;i<NUM_MESHES;i++) { if(i==0) // SET up the new vertex array state for indexed Drawing { glGenVertexArrays(1, &vid); glBindVertexArray(vid); glGenBuffers(NUM_MESHES,mVertex); glGenBuffers(NUM_MESHES,mColor); glGenBuffers(NUM_MESHES,mFace); } initGLMeshes(i); } glEnable(GL_DEPTH_TEST); } Any help would be much appreciated, I have been breaking my head on this problem since 3 days, and still it is unsolved.

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  • Defining scope for Record Count functoid:

    - by ArunManick
    Defining scope for Record Count functoid: Problem: One of the most common scenarios in BizTalk is calculating the record count of repeating structure. BizTalk has come up with an advanced functoid called Record Count functoid which will give the record count for the repeating structure however you cannot define the scope for a Record Count functoid. Because Record Count functoid accepts exactly one parameter which can be repeating record or field element.   If somebody don’t know what “scope” means I will explain with a simple example. Consider that we have a source schema having a structure Country -> State -> City. Country will have various states and each state will have different cities. Now you want to calculate no. of cities present in each state. Here scope is defined at the parent node “State”. Traditional Record Count functoid will give the total no. of cities present in the source message and not the State level city count.   Source Schema:   Destination Schema:   Soultion #1: As the title indicates we are not going to add one more parameter to the record count functoid. Instead of that, we are going to achieve the solution with the help of Scripting functoid with Inline XSLT script. XSLT is basically the transformation language used in the mapping.     “No.OfCities” indicates the destination field name to which we are going to send the value. In count(City), “count” refers to built in XPath function used in XSLT and “City” refers to source schema record name. Here you can find the list of built-in functions available in XSLT.   The mapping will look like as follows:   The 2 Record Count functoids used in this map will give the total number of states and total number of cities as that of input message.   Soultion #2:  If someone doesn’t like XSLT code and they wish to achieve the solution using functoids alone, then here is another solution.   Use logical Existence functoid to check whether “City” exist or not Connect the output of Logical Existence functoid to the Value Mapping functoid with second parameter as constant “1”. Hence if the first parameter is TRUE it will give the output as “1”. Connect the output of Value Mapping functoid to the Cumulative Sum functoid with scope as “1”   This will calculate the City count at the state level. The mapping will look like as follows:     Let us see the sample input and the map output.   Input: <?xml version="1.0" encoding="utf-8"?> <ns0:Country xmlns:ns0="http://RecordCount.Source">   <State>     <StateName>Tamilnadu</StateName>     <City>       <CityName>Pollachi</CityName>     </City>     <City>       <CityName>Coimbatore</CityName>     </City>     <City>       <CityName>Chennai</CityName>     </City>   </State>   <State>     <StateName>Kerala</StateName>     <City>       <CityName>Palakad</CityName>     </City>   </State>   <State>     <StateName>Karnataka</StateName>     <City>       <CityName>Bangalore</CityName>     </City>     <City>       <CityName>Mangalore</CityName>     </City>   </State> </ns0:Country>     Output: <ns0:Country xmlns:ns0="http://RecordCount.Destination">           <No.OfStates>3</No.OfStates>           <No.OfCities>6</No.OfCities>           <States>                    <No.OfCities>3</No.OfCities>           </States>           <States>                    <No.OfCities>1</No.OfCities>           </States>           <States>                    <No.OfCities>2</No.OfCities>           </States> </ns0:Country>   Conclusion: This is my first post and I hope you enjoyed it.   -Arun

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  • Draw Bug 2D player Camera

    - by RedShft
    I have just implemented a 2D player camera for my game, everything works properly except the player on the screen jitters when it moves between tiles. What I mean by jitter, is that if the player is moving the camera updates the tileset to be drawn and if the player steps to the right, the camera snaps that way. The movement is not smooth. I'm guessing this is occurring because of how I implemented the function to calculate the current viewable area or how my draw function works. I'm not entirely sure how to fix this. This camera system was entirely of my own creation and a first attempt at that, so it's very possible this is not a great way of doing things. My camera class, pulls information from the current tileset and calculates the viewable area. Right now I am targettng a resolution of 800 by 600. So I try to fit the appropriate amount of tiles for that resolution. My camera class, after calculating the current viewable tileset relative to the players location, returns a slice of the original tileset to be drawn. This tileset slice is updated every frame according to the players position. This slice is then passed to the map class, which draws the tile on screen. //Map Draw Function //This draw function currently matches the GID of the tile to it's location on the //PNG file of the tileset and then draws this portion on the screen void Draw(SDL_Surface* background, int[] _tileSet) { enforce( tilesetImage != null, "Tileset is null!"); enforce( background != null, "BackGround is null!"); int i = 0; int j = 0; SDL_Rect DestR, SrcR; SrcR.x = 0; SrcR.y = 0; SrcR.h = 32; SrcR.w = 32; foreach(tile; _tileSet) { //This code is matching the current tiles ID to the tileset image SrcR.x = cast(short)(tileWidth * (tile >= 11 ? (tile - ((tile / 10) * 10) - 1) : tile - 1)); SrcR.y = cast(short)(tileHeight * (tile > 10 ? (tile / 10) : 0)); //Applying the tile to the surface SDL_BlitSurface( tilesetImage, &SrcR, background, &DestR ); //this keeps track of what column/row we are on i++; if ( i == mapWidth ) { i = 0; j++; } DestR.x = cast(short)(i * tileWidth); DestR.y = cast(short)(j * tileHeight); } } //Camera Class class Camera { private: //A rectangle representing the view area SDL_Rect viewArea; //In number of tiles int viewAreaWidth; int viewAreaHeight; //This is the x and y coordinate of the camera in MAP SPACE IN PIXELS vect2 cameraCoordinates; //The player location in map space IN PIXELS vect2 playerLocation; //This is the players location in screen space; vect2 playerScreenLoc; int playerTileCol; int playerTileRow; int cameraTileCol; int cameraTileRow; //The map is stored in a single array with the tile ids //this corresponds to the index of the starting and ending tile int cameraStartTile, cameraEndTile; //This is a slice of the current tile set int[] tileSetCopy; int mapWidth; int mapHeight; int tileWidth; int tileHeight; public: this() { this.viewAreaWidth = 25; this.viewAreaHeight = 19; this.cameraCoordinates = vect2(0, 0); this.playerLocation = vect2(0, 0); this.viewArea = SDL_Rect (0, 0, 0, 0); this.tileWidth = 32; this.tileHeight = 32; } void Init(vect2 playerPosition, ref int[] tileSet, int mapWidth, int mapHeight ) { playerLocation = playerPosition; this.mapWidth = mapWidth; this.mapHeight = mapHeight; CalculateCurrentCameraPosition( tileSet, playerPosition ); //writeln( "Tile Set Copy: ", tileSetCopy ); //writeln( "Orginal Tile Set: ", tileSet ); } void CalculateCurrentCameraPosition( ref int[] tileSet, vect2 playerPosition ) { playerLocation = playerPosition; playerTileCol = cast(int)((playerLocation.x / tileWidth) + 1); playerTileRow = cast(int)((playerLocation.y / tileHeight) + 1); //writeln( "Player Tile (Column, Row): ","(", playerTileCol, ", ", playerTileRow, ")"); cameraTileCol = playerTileCol - (viewAreaWidth / 2); cameraTileRow = playerTileRow - (viewAreaHeight / 2); CameraMapBoundsCheck(); //writeln( "Camera Tile Start (Column, Row): ","(", cameraTileCol, ", ", cameraTileRow, ")"); cameraStartTile = ( (cameraTileRow - 1) * mapWidth ) + cameraTileCol - 1; //writeln( "Camera Start Tile: ", cameraStartTile ); cameraEndTile = cameraStartTile + ( viewAreaWidth * viewAreaHeight ) * 2; //writeln( "Camera End Tile: ", cameraEndTile ); tileSetCopy = tileSet[cameraStartTile..cameraEndTile]; } vect2 CalculatePlayerScreenLocation() { cameraCoordinates.x = cast(float)(cameraTileCol * tileWidth); cameraCoordinates.y = cast(float)(cameraTileRow * tileHeight); playerScreenLoc = playerLocation - cameraCoordinates + vect2(32, 32);; //writeln( "Camera Coordinates: ", cameraCoordinates ); //writeln( "Player Location (Map Space): ", playerLocation ); //writeln( "Player Location (Screen Space): ", playerScreenLoc ); return playerScreenLoc; } void CameraMapBoundsCheck() { if( cameraTileCol < 1 ) cameraTileCol = 1; if( cameraTileRow < 1 ) cameraTileRow = 1; if( cameraTileCol + 24 > mapWidth ) cameraTileCol = mapWidth - 24; if( cameraTileRow + 19 > mapHeight ) cameraTileRow = mapHeight - 19; } ref int[] GetTileSet() { return tileSetCopy; } int GetViewWidth() { return viewAreaWidth; } }

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