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  • Where should "display functions" live in an MVC web app?

    - by User
    I'm using the Yii Framework which is an MVC php framework that is pretty similar to your standard web-based MVC framework. I want to display the related data from a many-to-many table as a list of strings in my view. Assuming a table schema like: tag { id, name } post { id, title, content, date } post_tag { post_id, tag_id } A post will display like: Date: 9/27/2012 Title: Some Title Content: blah blah blah... Tags: Smart Funny Cool Informative I can achieve this by doing something like this in my Post view: <?php echo join(' ', array_map(function($tag) { return $tag->name; }, $model->tags)); ?> (where $model->tags is an array of Tag objects associated with my model) My questions are: Is this amount of code/logic okay in the view? (Personally I think I'd rather just reference a property or call a single function.) If not, where should this code live? In the model? the controller? a helper? Potentially I may want to use in in other views as well. Ultimately I think its purely a display issue which would make me think it should be in the view, but then I have to repeat the code in any view I want to use it in.

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  • What are some techniques I can use to refactor Object Oriented code into Functional code?

    - by tieTYT
    I've spent about 20-40 hours developing part of a game using JavaScript and HTML5 canvas. When I started I had no idea what I was doing. So it started as a proof of concept and is coming along nicely now, but it has no automated tests. The game is starting to become complex enough that it could benefit from some automated testing, but it seems tough to do because the code depends on mutating global state. I'd like to refactor the whole thing using Underscore.js, a functional programming library for JavaScript. Part of me thinks I should just start from scratch using a Functional Programming style and testing. But, I think refactoring the imperative code into declarative code might be a better learning experience and a safer way to get to my current state of functionality. Problem is, I know what I want my code to look like in the end, but I don't know how to turn my current code into it. I'm hoping some people here could give me some tips a la the Refactoring book and Working Effectively With Legacy Code. For example, as a first step I'm thinking about "banning" global state. Take every function that uses a global variable and pass it in as a parameter instead. Next step may be to "ban" mutation, and to always return a new object. Any advice would be appreciated. I've never taken OO code and refactored it into Functional code before.

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  • GTK app: How do I create a working indicator with Qt/C++?

    - by hakermania
    I've tried in 2 forums, but I had no luck so far. So, I am using Qt IDE in order to build my application so as to participate to the Ubuntu Showdown contest. In my application, I've done the following: void show_app(MainWindow *data) { //this works fine: app_indicator_set_status(appindicator, APP_INDICATOR_STATUS_PASSIVE); //this crashes the application: data->show(); } void MainWindow::make_indicator() { if(appindicator){ //appindicator has already been created return; } appindicator = app_indicator_new("Format Junkie Indicator", "formatjunkie", APP_INDICATOR_CATEGORY_APPLICATION_STATUS); GtkWidget* showapp_option; GtkWidget* indicatormenu = gtk_menu_new(); GtkWidget* item = gtk_menu_item_new_with_label("Format Junkie main menu"); gtk_menu_item_set_submenu(GTK_MENU_ITEM(item), indicatormenu); showapp_option = gtk_menu_item_new_with_label("Show App!"); g_signal_connect(showapp_option, "activate", G_CALLBACK(show_app), this); gtk_menu_shell_append(GTK_MENU_SHELL(indicatormenu), showapp_option); gtk_widget_show_all(indicatormenu); app_indicator_set_status(appindicator, APP_INDICATOR_STATUS_ACTIVE); app_indicator_set_attention_icon(appindicator, "dialog-warning"); app_indicator_set_menu(appindicator, GTK_MENU (indicatormenu)); } So, basically I am trying to make a simple indicator entry, which, on click, it will hide the indicator and display the application. The indicator can be successfully hidden using the PASSIVE thingy over there, but, during the call data-show();, the application crashes. Any help on what I am doing wrong would be appreciated! Also, please help me to correct this problem I'm facing (alternatively, I will migrate to the old and good tray icon (it works fine in 12.04, anyway) which I can handle very easily and efficiently)

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  • PDF export printing in Internet Explorer [closed]

    - by user619804
    protected static byte[] exportReportToPdf(JasperPrint jasperPrint) throws JRException { JRPdfExporter exporter = new JRPdfExporter(); ByteArrayOutputStream baos = new ByteArrayOutputStream(); exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint); exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, baos); exporter.setParameter(JRPdfExporterParameter.PDF_JAVASCRIPT, "this.print({bUI: true,bSilent: false,bShrinkToFit: true});"); exporter.exportReport(); return baos.toByteArray(); } We are using code like this to export a PDF document from a Jasper application. The line exporter.setParameter(JRPdfExporterParameter.PDF_JAVASCRIPT, "this.print({bUI: true,bSilent: false,bShrinkToFit: true});"); adds JavaScript to send the PDF document directly to the printer. The expected behavior is that a print dialog will come up with a preview of the PDF document. This works fine most of the time - except I am having problems about one out of every 5-6 times in Internet Explorer 8 and Firefox. What happens is - the print preview dialog with the PDF document does not appear or it appears with a blank document in the preview window. -I've tried a number of different JavaScripts (different params to this.print() via exporter.setParameter -I've tried setting different response headers such as response.setContentType("application/pdf"); response.setHeader("Content-disposition","inline; filename=\"" + reportName + "\""); response.setContentLength(baos.size()); these did not seem to help This seems to be an IE and FF issue. Has anyone ever dealt with this problem? I need to get it to work across all browsers 100% of the time. Perhaps a different approach to accomplish the goal of sending the PDF document export directly to the printer? or a third party library that will work across browsers?

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  • What should be the path for storing Maildir e-mails?

    - by Thufir
    Am I storing e-mails to the correct path? Working from the dovecot-postfix package I'm able to deliver e-mails to myself as so: thufir@dur:~$ thufir@dur:~$ telnet localhost 25 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 dur.bounceme.net ESMTP Postfix (Ubuntu) HELO me 250 dur.bounceme.net mail from:<[email protected]> 250 2.1.0 Ok rcpt to:<thufir@localhost> 250 2.1.5 Ok data 354 End data with <CR><LF>.<CR><LF> subject: to evolution mail we'll see if this goes through. . 250 2.0.0 Ok: queued as 43D6F2A07C1 quit 221 2.0.0 Bye Connection closed by foreign host. thufir@dur:~$ and then here's the message: thufir@dur:~$ ll Maildir/new/ total 20 drwx------ 2 thufir thufir 4096 Nov 16 18:56 ./ drwx------ 5 thufir thufir 4096 Nov 16 18:56 ../ -rw------- 1 thufir thufir 410 Nov 16 11:57 1353095866.M305477P3932.dur,S=410,W=422 -rw------- 1 thufir thufir 424 Nov 16 17:20 1353115248.M841336P2990.dur,S=424,W=436 -rw------- 1 thufir thufir 445 Nov 16 18:56 1353121003.M187706P3838.dur,S=445,W=457 thufir@dur:~$ thufir@dur:~$ nl Maildir/new/1353121003.M187706P3838.dur\,S\=445\,W\=457 1 Return-Path: <[email protected]> 2 X-Original-To: thufir@localhost 3 Delivered-To: thufir@localhost 4 Received: from me (localhost [127.0.0.1]) 5 by dur.bounceme.net (Postfix) with SMTP id 43D6F2A07C1 6 for <thufir@localhost>; Fri, 16 Nov 2012 18:55:55 -0800 (PST) 7 subject: to evolution mail 8 Message-Id: <[email protected]> 9 Date: Fri, 16 Nov 2012 18:55:55 -0800 (PST) 10 From: [email protected] 11 we'll see if this goes through. thufir@dur:~$ Do I perhaps have postfix misconfigured? I ask because evolution seems to use a different path for mail.

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  • Embedded Nashorn in JEditorPane

    - by Geertjan
    Here's a prototype for some kind of backoffice content management system. Several interesting goodies are included, such as an embedded JavaScript editor, as can be seen in the screenshot: Key items of interest in the above are as follows: Embedded JavaScript editor (i.e., the latest and greatest Nashorn technology, look it up, if you're not aware of what that is.) The way that's done is to include the relevant JavaScript modules in your NetBeans Platform application. Make very sure to include "Lexer to NetBeans Bridge", which does a bunch of critical stuff under the hood. The JEditorPane is defined as follows, along the lines that I blogged about recently thanks to Steven Yi: javaScriptPane.setContentType("text/javascript"); EditorKit kit = CloneableEditorSupport.getEditorKit("text/javascript"); javaScriptPane.setEditorKit(kit); javaScriptPane.getDocument().putProperty("mimeType", "text/javascript"); Note that "javaScriptPane" above is simply a JEditorPane. Timon Veenstra's excellent solution for integrating Nodes with MultiViewElements, which is described here by Timon, and nowhere else in the world. The tab you see above is within a pluggable container, so anyone else could create a new module and register their own MultiViewElement such that it will be incorporated into the editor. A small trick to ensure that only one window opens per news item: @NbBundle.Messages("OpenNews=Open") private class OpenNewsAction extends AbstractAction { public OpenNewsAction() { super(Bundle.OpenNews()); } @Override public void actionPerformed(ActionEvent e) { News news = getLookup().lookup(News.class); Mode editorMode = WindowManager.getDefault().findMode("editor"); for (TopComponent tc : WindowManager.getDefault().getOpenedTopComponents(editorMode)) { if (tc.getDisplayName().equals(news.getTitle())) { tc.requestActive(); return; } } TopComponent tc = MultiViews.createMultiView("application/x-newsnode", NewsNode.this); tc.open(); tc.requestActive(); } } The rest of what you see above is all standard NetBeans Platform stuff. The sources of everything you see above is here: http://java.net/projects/nb-api-samples/sources/api-samples/show/versions/7.3/misc/CMSBackOffice

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  • Install a i386 printer driver into an amd64 distribution or how can I find a good printer based on features?

    - by Yanick Rochon
    Hi, I just bought a Lexmark Interpret S408 all-in-one printer. The box said that it supported Ubuntu 8.04, but I told myself it should work with Lucid... well no. The only driver I have found is for i386 while I have a amd64 image installed; the architecture is incompatible. So, the quesiton is : Is it possible to install that driver anyway, somehow? Or do I need to take that printer back to the store and buy another one? If the latter is the only alternative, I need a printer that has wireless connection capability can do color printing is of good price (less than $200 CAD) Thank you for your answers, help, and tips. ** UPDATE ** The driver was given in the form of deb package (for Debian distributions) and I managed to extract the actual deb package driver out of the install program. I ran sudo dpkg -i --force-all lexmark-inkjet-09-driver-1.5-1.i386.deb and the driver installed, and I was able to print something out. But that pretty much ends there; I cannot access anymore of the printer settings, etc. (i.g. scanner, fax, wifi settings, etc.) I should suffice for now as I'm satisfied with the printer's features (and size, and prince), but if I could have a full-linux-supported printer like that one, I would return this one in exchange for the other.

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  • Calculating the correct particle angle in an outwards explosion

    - by Sun
    I'm creating a simple particle explosion but am stuck in finding the correct angle to rotate my particle. The effect I'm going for is similar to this: Where each particle is going outwards from the point of origin and at the correct angle. This is what I currently have: As you can see, each particle is facing the same angle, but I'm having a little difficulty figuring out the correct angle. I have the vector for the point of emission and the new vector for each particle, how can I use this to calculate the angle? Some code for reference: private Particle CreateParticle() { ... Vector2 velocity = new Vector2(2.0f * (float)(random.NextDouble() * 2 - 1), 2.0f * (float)(random.NextDouble() * 2 - 1)); direction = velocity - ParticleLocation; float angle = (float)Math.Atan2(direction.Y, direction.X); ... return new Particle(texture, position, velocity, angle, angularVelocity, color, size, ttl, EmitterLocation); } I am then using the angle created as so in my particles Draw method: spriteBatch.Draw(Texture, Position, null, Color, Angle, origin, Size, SpriteEffects.None, 0f);

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  • MOS Community rewards Ram Kasthuri w/ FREE OOW Pass!

    - by cwarticki
    Congratulations Ram Kasthuri on Receiving a Free Full Conference Pass to Oracle OpenWorld!  Thank you for helping other members through your participation in My Oracle Support Community My Oracle Support Community member Ram Kasthuri received a free Oracle OpenWorld Pass from the My Oracle Support Community in appreciation for his work in answering questions posted by other Community members. Ram, an independent consultant, is an Application Solution Architect with Canon. He has been a valued Oracle customer for over 13 years. Ram is an active member in several of the Oracle EBS communities. He has achieved the Expert Level of recognition through his active participation.   Ram described the value he receives from My Oracle Support Community when he said what “I like best about the communities is the vicarious learning from real business scenarios posted by other Community members. The questions are real opportunities to learn all things Oracle, and EBS especially.” Ram is one of those member's who answers more questions than he posts, so he must get a lot of that vicarious learning. Oracle Premier Support customers can get answers and learn from both peers who have faced similar situations and Oracle experts. Join us in My Oracle Support Community. Look for Ram this week at Oracle OpenWorld and join him in My Oracle Support Community when you return to work. And while you’re at Oracle OpenWorld, Oracle Customer Support Services invites you to expand your knowledge by meeting with Oracle Support experts. Learn more about our sessions and network opportunities today!

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  • Using ASP.NET, Membership, and jQuery to Determine Username Availability

    Chances are, at some point you've tried creating a new user account on a website and were told that the username you selected was already taken. This is especially common on very large websites with millions of members, but can happen on smaller websites with common usernames, such as people's names or popular words or phrases in the lexicon of the online community that frequents the website. If the user registration process is short and sweet, most users won't balk when they are told their desired username has already been taken - they'll just try a new one. But if the user registration process is long, involving several questions and scrolling, it can be frustrating to complete the registration process only to be told you need to return to the top of the page to try a different username. Many websites use Ajax techniques to check whether a visitor's desired username is available as soon as they enter it (rather than waiting for them to submit the form). This article shows how to implement such a feature in an ASP.NET website using Membership and jQuery. This article includes a demo available for download that implements this behavior in an ASP.NET WebForms application that uses the CreateUserWizard control to register new users. However, the concepts in this article can be applied to ad-hoc user registration pages and ASP.NET MVC. Read on to learn more! Read More >

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  • Looking for a better Factory pattern (Java)

    - by Sam Goldberg
    After doing a rough sketch of a high level object model, I am doing iterative TDD, and letting the other objects emerge as a refactoring of the code (as it increases in complexity). (That whole approach may be a discussion/argument for another day.) In any case, I am at the point where I am looking to refactor code blocks currently in an if-else blocks into separate objects. This is because there is another another value combination which creates new set of logical sub-branches. To be more specific, this is a trading system feature, where buy orders have different behavior than sell orders. Responses to the orders have a numeric indicator field which describes some event that occurred (e.g. fill, cancel). The combination of this numeric indicator field plus whether it is a buy or sell, require different processing buy the code. Creating a family of objects to separate the code for the unique handling each of the combinations of the 2 fields seems like a good choice at this point. The way I would normally do this, is to create some Factory object which when called with the 2 relevant parameters (indicator, buysell), would return the correct subclass of the object. Some times I do this pattern with a map, which allows to look up a live instance (or constructor to use via reflection), and sometimes I just hard code the cases in the Factory class. So - for some reason this feels like not good design (e.g. one object which knows all the subclasses of an interface or parent object), and a bit clumsy. Is there a better pattern for solving this kind of problem? And if this factory method approach makes sense, can anyone suggest a nicer design?

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  • Java - Using Linear Coordinates to Check Against AI [closed]

    - by Oliver Jones
    I'm working on some artificial intelligence, and I want my AI not to run into given coordinates as these are references of a wall/boundary. To begin with, every time my AI hits a wall, it makes a reference to that position (x,y). When it hits the same wall three times, it uses linear check points to 'imagine' there is a wall going through these coordinates. I want to now prevent my AI from going into that wall again. To detect if my coordinates make a straight line, i use: private boolean collinear(double x1, double y1, double x2, double y2, double x3, double y3) { return (y1 - y2) * (x1 - x3) == (y1 - y3) * (x1 - x2); } This returns true is the given points are linear to one another. So my problems are: How do I determine whether my robot is approaching the wall from its current trajectory? Instead of Java 'imagining' theres a line from 1, to 3. But to 'imagine' a line all the way through these linear coordinantes, until infinity (or close). I have a feeling this is going to require some confusing trigonometry? (REPOST: http://stackoverflow.com/questions/13542592/java-using-linear-coordinates-to-check-against-ai)

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  • Windows domain full hostnames cannot be resolved resulting in intranet not working

    - by OpethR
    the domain: is foo.bar.local full hostname is: bla.foo.bar.local short hostname is: bla I installed winbind. here is my smb.conf: name resolve order = lmhosts host wins bcast here is my nsswitch.conf: hosts: files mdns4_minimal [NOTFOUND=return] dns wins mdns4 when I try to ping full hostname, I get: "ping: unknown host" when I ping short hostname it works and shows me PING bla.foo.bar.local (10.11.20.135) 56(84) bytes of data. 64 bytes from bla.foo.bar.local (10.11.20.135): icmp_req=1 ttl=62 time=49.7 ms *notice that it manages to get the full hostname!? :S now the only reason I need it is cuz I'm trying to reach intranet websites. when I type short hostname "bla" in firefox address bar, it automatically changes it to the full hostname (which is good, right?!) but then it says: Server not found Firefox can't find the server at bla.foo.bar.local. what am I doing wrong? it's driving me nutz. so if you are wandering then yes, it is company intranet I'm trying to reach from ubuntu. If I use my crappy winxp everything is working perfectly well.

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  • Get Func-y v2.0

    - by PhubarBaz
    In my last post I talked about using funcs in C# to do async calls in WinForms to free up the main thread for the UI. In that post I demonstrated calling a method and then waiting until the value came back. Today I want to talk about calling a method and then continuing on and handling the results of the async call in a callback.The difference is that in the previous example although the UI would not lock up the user couldn't really do anything while the other thread was working because it was waiting for it to finish. This time I want to allow the user to continue to do other stuff while waiting for the thread to finish.Like before I have a service call I want to make that takes a long time to finish defined in a method called MyServiceCall. We need to define a callback method takes an IAsyncResult parameter.public ServiceCallResult MyServiceCall(int param1)...public int MyCallbackMethod(IAsyncResult ar)...We start the same way by defining a delegate to the service call method using a Func. We need to pass an AsyncCallback object into the BeginInvoke method. This will tell it to call our callback method when MyServiceCall finishes. The second parameter to BeginInvoke is the Func delegate. This will give us access to it in our callback.Func<int, ServiceCallResult> f = MyServiceCall;AsyncCallback callback =   new AsyncCallback(MyCallbackMethod);IAsyncResult async = f.BeginInvoke(23, callback, f); Now let's expand the callback method. The IAsyncResult parameter contains the Func delegate in its AsyncState property. We call EndInvoke on that Func to get the return value.public int MyCallbackMethod(IAsyncResult ar){    Func<int, ServiceCallResult> delegate =        (Func<int, ServiceCallResult>)ar.AsyncState;    ServiceCallResult result = delegate.EndInvoke(ar);}There you have it. Now you don't have to make the user wait for something that isn't critical to the loading of the page.

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

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

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  • Command Pattern refactor for input processing?

    - by Casey
    According to Game Coding Complete 4th. ed. processing input via the following is considered unmanagable and inflexible. But does not show an example. I've used the Command pattern to represent GUI button commands but could not figure out how to represent the input from the keyboard and/or mouse. if(g_keyboard->KeyDown(KEY_ESC)) { quit = true; return; } //Processing if(g_keyboard->KeyDown(KEY_T)) { g_show_test_gateway = !g_show_test_gateway; } if(g_mouse->ButtonDown(a2de::Mouse::BUTTON2)) { g_selected_part = GWPart::PART_NONE; SetMouseImageToPartImage(); } ResetButtonStates(); g_prevButton = g_curButton; g_curButton = GetButtonHovered(); if(g_curButton) { g_mouse->SetImageToDefault(); if(g_mouse->ButtonDown(a2de::Mouse::BUTTON1) || g_mouse->ButtonPress(a2de::Mouse::BUTTON1)) { ButtonPressCommand curCommand(g_curButton); curCommand.Execute(); } else if(g_mouse->ButtonUp(a2de::Mouse::BUTTON1)) { if(g_prevButton == g_curButton) { ButtonReleaseCommand curCommand(g_curButton); curCommand.Execute(); if(g_curButton->GetType() == "export") { ExportCommand curCommand(g_curButton, *g_gateway); curCommand.Execute(); } } else { ResetButtonStates(); } } else { ButtonHoverCommand curCommand(g_curButton); curCommand.Execute(); } } else { g_status_message.clear(); SetMouseImageToPartImage(); if(g_mouse->ButtonDown(a2de::Mouse::BUTTON1)) { CreatePartCommand curCommand(*g_gateway, g_selected_part, a2de::Vector2D(g_mouse->GetX(), g_mouse->GetY())); curCommand.Execute(); } }

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  • How do I draw a dotted or dashed line?

    - by Gagege
    I'm trying to draw a dashed or dotted line by placing individual segments(dashes) along a path and then separating them. The only algorithm I could come up with for this gave me a dash length that was variable based on the angle of the line. Like this: private function createDashedLine(fromX:Float, fromY:Float, toX:Float, toY:Float):Sprite { var line = new Sprite(); var currentX = fromX; var currentY = fromY; var addX = (toX - fromX) * 0.0075; var addY = (toY - fromY) * 0.0075; line.graphics.lineStyle(1, 0xFFFFFF); var count = 0; // while line is not complete while (!lineAtDestination(fromX, fromY, toX, toY, currentX, currentY)) { /// move line draw cursor to beginning of next dash line.graphics.moveTo(currentX, currentY); // if dash is even if (count % 2 == 0) { // draw the dash line.graphics.lineTo(currentX + addX, currentY + addY); } // add next dash's length to current cursor position currentX += addX; currentY += addY; count++; } return line; } This just happens to be written in Haxe, but the solution should be language neutral. What I would like is for the dash length to be the same no matter what angle the line is. As is, it's just adding 75 thousandths of the line length to the x and y, so if the line is and a 45 degree angle you get pretty much a solid line. If the line is at something shallow like 85 degrees then you get a nice looking dashed line. So, the dash length is variable, and I don't want that. How would I make a function that I can pass a "dash length" into and get that length of dash, no matter what the angle is? If you need to completely disregard my code, be my guest. I'm sure there's a better solution.

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  • Tail-recursive implementation of take-while

    - by Giorgio
    I am trying to write a tail-recursive implementation of the function take-while in Scheme (but this exercise can be done in another language as well). My first attempt was (define (take-while p xs) (if (or (null? xs) (not (p (car xs)))) '() (cons (car xs) (take-while p (cdr xs))))) which works correctly but is not tail-recursive. My next attempt was (define (take-while-tr p xs) (let loop ((acc '()) (ys xs)) (if (or (null? ys) (not (p (car ys)))) (reverse acc) (loop (cons (car ys) acc) (cdr ys))))) which is tail recursive but needs a call to reverse as a last step in order to return the result list in the proper order. I cannot come up with a solution that is tail-recursive, does not use reverse, only uses lists as data structure (using a functional data structure like a Haskell's sequence which allows to append elements is not an option), has complexity linear in the size of the prefix, or at least does not have quadratic complexity (thanks to delnan for pointing this out). Is there an alternative solution satisfying all the properties above? My intuition tells me that it is impossible to accumulate the prefix of a list in a tail-recursive fashion while maintaining the original order between the elements (i.e. without the need of using reverse to adjust the result) but I am not able to prove this. Note The solution using reverse satisfies conditions 1, 3, 4.

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  • The idea of functionN in Scala / Functionaljava

    - by Luke Murphy
    From brain driven development It turns out, that every Function you’ll ever define in Scala, will become an instance of an Implementation which will feature a certain Function Trait. There is a whole bunch of that Function Traits, ranging from Function1 up to Function22. Since Functions are Objects in Scala and Scala is a statically typed language, it has to provide an appropriate type for every Function which comes with a different number of arguments. If you define a Function with two arguments, the compiler picks Function2 as the underlying type. Also, from Michael Froh's blog You need to make FunctionN classes for each number of parameters that you want? Yes, but you define the classes once and then you use them forever, or ideally they're already defined in a library (e.g. Functional Java defines classes F, F2, ..., F8, and the Scala standard library defines classes Function1, ..., Function22) So we have a list of function traits (Scala), and a list of interfaces (Functional-java) to enable us to have first class funtions. I am trying to understand exactly why this is the case. I know, in Java for example, when I write a method say, public int add(int a, int b){ return a + b; } That I cannot go ahead and write add(3,4,5); ( error would be something like : method add cannot be applied to give types ) We simply have to define an interface/trait for functions with different parameters, because of static typing?

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  • XNA 4: RenderTarget2D textures getting transparent on fullscreen

    - by Shashwat
    I'm generating a Texture2D object using RenderTarget2D as in the following code public static Texture2D GetTextTexture(string text, Vector2 position, SpriteFont font, Color foreColor, Color backColor, Texture2D background=null) { int width = (int)font.MeasureString(text).X; int height = (int)font.MeasureString(text).Y; GraphicsDevice device = Settings.game.GraphicsDevice; SpriteBatch spriteBatch = Settings.game.spriteBatch; RenderTarget2D renderTarget = new RenderTarget2D(device, width, height, false, SurfaceFormat.Color, DepthFormat.Depth24Stencil8, device.PresentationParameters.MultiSampleCount, RenderTargetUsage.DiscardContents); device.SetRenderTarget(renderTarget); device.Clear(backColor); spriteBatch.Begin(SpriteSortMode.Immediate, BlendState.Opaque); if (background != null) spriteBatch.Draw(background, new Rectangle(0, 0, 70, 70), Color.White); spriteBatch.End(); spriteBatch.Begin(); spriteBatch.DrawString(font, text, position, foreColor, 0, new Vector2(0), 0.8f, SpriteEffects.None, 0); spriteBatch.End(); device.SetRenderTarget(null); ResetGraphicsDeviceSettings(); return (Texture2D)renderTarget; } It's working all fine. But when I ToggleFullScreen() (and vice-versa), the previous textures are getting transparent. However, the new textures after that are being generated correctly. What can be the reason for this?

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  • Serializing network messages

    - by mtsvetkov
    I am writing a network wrapper around boost::asio and was wondering what is a good and simple way to serialize my messages. I have a message factory which can take care of dispatching the data to the correct builder, but I want to know if there are any established solutions for getting the binary data on the sender side and consequently passing the data for deserialization on the receiver end. Some options I've explored are: passing a pointer to a char[] to the serialize/deserialize functions (for serialize to write to, and deserialize to read from), but it's difficult to enforce buffer size this way; building on that, I decided to have the serialize function return a boost::asio::mutable_buffer, however ownership of the memory gets blurred between multiple classes, as the network wrapper needs to clean up the memory allocated by the message builder. I have also seen solutions involving streambuf's and stringstream's, but manipulating binary data in terms of its string representation is something I want to avoid. Is there some sort of binary stream I can use instead? What I am looking for is a solution (preferrably using boost libs) that lets the message builder dictate the amount of memory allocated during serialization and what that would look like in terms of passing the data around between the wrapper and message factory/message builders. PS. Messages contain almost exclusively built-in types and PODs and form a shallow but wide hierarchy for the sake of going through a factory. Note: a link to examples of using boost::serialization for something like this would be appreciated as I'm having difficulties figuring out the relation between it and buffers.

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  • How to debug a fatal system crash - [graphical loop DOTA2]?

    - by Huw
    Whilst playing DOTA2, I occasionally and apparently randomly seem to be experiencing a fatal crash where the display freezes fixed and the audio loops over approx the last .5 of a second. Now, I'm interested in resolving this - but my trouble is I don't know where to start. The error appears non-reproducible (I've tried returning to games and deploying the same combination of events in hopes of pinning to to a certain shader etc), and I don't know which part of 'the stack' it might be coming from. Variables that occur to me: I custom build this system, did I do something wrong - is my PSU not providing enough power to the graphics card? I am running Steam and DOTA under Linux, could this new software have a bug Might it be something to do with my ATI Catalyst graphics drivers Is some other background process interfering I'm usually mid game when this occurs, so i quickly kill the power and reboot (when i'm lucky i can get back in with only 1-2 mins lost!). So my question here relates to logs. Where should I start to look or how might I set up logs to help me pin down a fatal crash of this kind by recording moments up to / before a crash and is this likely to be something I should push Steam to do, or is there something at a system level? Then perhaps I can return with a more specific question and perhaps even a bug report :) Many thanks in advance.

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  • Text on a model

    - by alecnash
    I am trying to put some text on a Model and I want it to be dynamic. Did some research and came up with drawing the text on the texture and then set it on the model. I use something like this: public static Texture2D SpriteFontTextToTexture(SpriteFont font, string text, Color backgroundColor, Color textColor) { Size = font.MeasureString(text); RenderTarget2D renderTarget = new RenderTarget2D(GraphicsDevice, (int)Size.X, (int)Size.Y); GraphicsDevice.SetRenderTarget(renderTarget); GraphicsDevice.Clear(Color.Transparent); Spritbatch.Begin(); //have to redo the ColorTexture Spritbatch.Draw(ColorTexture.Create(GraphicsDevice, 1024, 1024, backgroundColor), Vector2.Zero, Color.White); Spritbatch.DrawString(font, text, Vector2.Zero, textColor); Spritbatch.End(); GraphicsDevice.SetRenderTarget(null); return renderTarget; } When I was working with primitives and not models everything worked fine because I set the texture exactly where I wanted but with the model (RoundedRect 3D button). It now looks like that: Is there a way to have the text centered only on one side?

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  • Animating sprites in HTML5 canvas

    - by fnx
    I'm creating a 2D platformer game with HTML5 canvas and javascript. I'm having a bit of a struggle with animations. Currently I animate by getting preloaded images from an array, and the code is really simple, in player.update() I call a function that does this: var animLength = this.animations[id].length; this.counter++; this.counter %= 3; if (this.counter == 2) this.spriteCounter++; this.spriteCounter %= animLength; return this.animations[id][this.spriteCounter]; There are a couple of problems with this one: When the player does 2 actions that require animating at the same time, animation speed doubles. Apparently this.counter++ is working twice at the same time. I imagine that if I start animating multiple sprites with this, the animation speed will multiply by the amount of sprites. Other issue is that I couldn't make the animation run only once instead of looping while key is held down. Someone told me that I should create a function Animation(animation id, isLooped boolean) and the use something like player.sprite = new Animation("explode", false) but I don't know how to make it work. Yes I'm a noob... :)

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  • ERROR #342: DEVICE_SHADER_LINKAGE_SEMANTICNAME_NOT_FOUND

    - by Telanor
    I've stared at this for at least half an hour now and I cannot figure out what directx is complaining about. I know this error normally means you put float3 instead of a float4 or something like that, but I've checked over and over and as far as I can tell, everything matches. This is the full error message: D3D11: ERROR: ID3D11DeviceContext::DrawIndexed: Input Assembler - Vertex Shader linkage error: Signatures between stages are incompatible. The input stage requires Semantic/Index (COLOR,0) as input, but it is not provided by the output stage. [ EXECUTION ERROR #342: DEVICE_SHADER_LINKAGE_SEMANTICNAME_NOT_FOUND ] This is the vertex shader's input signature as seen in PIX: // Input signature: // // Name Index Mask Register SysValue Format Used // -------------------- ----- ------ -------- -------- ------ ------ // POSITION 0 xyz 0 NONE float xyz // NORMAL 0 xyz 1 NONE float // COLOR 0 xyzw 2 NONE float The HLSL structure looks like this: struct VertexShaderInput { float3 Position : POSITION0; float3 Normal : NORMAL0; float4 Color: COLOR0; }; The input layout, from PIX, is: The C# structure holding the data looks like this: [StructLayout(LayoutKind.Sequential)] public struct PositionColored { public static int SizeInBytes = Marshal.SizeOf(typeof(PositionColored)); public static InputElement[] InputElements = new[] { new InputElement("POSITION", 0, Format.R32G32B32_Float, 0), new InputElement("NORMAL", 0, Format.R32G32B32_Float, 0), new InputElement("COLOR", 0, Format.R32G32B32A32_Float, 0) }; Vector3 position; Vector3 normal; Vector4 color; #region Properties ... #endregion public PositionColored(Vector3 position, Vector3 normal, Vector4 color) { this.position = position; this.normal = normal; this.color = color; } public override string ToString() { StringBuilder sb = new StringBuilder(base.ToString()); sb.Append(" Position="); sb.Append(position); sb.Append(" Color="); sb.Append(Color); return sb.ToString(); } } SizeInBytes comes out to 40, which is correct (4*3 + 4*3 + 4*4 = 40). Can anyone find where the mistake is?

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