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  • Need help transforming DirectX 9 skybox hlsl shader to DirectX 11

    - by J2V
    I am in the middle of implementing a skybox to my game. I have been following this tutorial http://rbwhitaker.wikidot.com/skyboxes-2. I am using MonoGame as a framework and in order to support both Windows and Windows 8 metro I need to compile the shader with pixel and vertex shader 4. compile vs_4_0_level_9_1 compile ps_4_0_level_9_1 However some of the hlsl syntax has been updated with DX10 and DX11. I need to update this hlsl code: float4x4 World; float4x4 View; float4x4 Projection; float3 CameraPosition; Texture SkyBoxTexture; samplerCUBE SkyBoxSampler = sampler_state { texture = <SkyBoxTexture>; magfilter = LINEAR; minfilter = LINEAR; mipfilter = LINEAR; AddressU = Mirror; AddressV = Mirror; }; struct VertexShaderInput { float4 Position : POSITION0; }; struct VertexShaderOutput { float4 Position : POSITION0; float3 TextureCoordinate : TEXCOORD0; }; VertexShaderOutput VertexShaderFunction(VertexShaderInput input) { VertexShaderOutput output; float4 worldPosition = mul(input.Position, World); float4 viewPosition = mul(worldPosition, View); output.Position = mul(viewPosition, Projection); float4 VertexPosition = mul(input.Position, World); output.TextureCoordinate = VertexPosition - CameraPosition; return output; } float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0 { return texCUBE(SkyBoxSampler, normalize(input.TextureCoordinate)); } technique Skybox { pass Pass1 { VertexShader = compile vs_2_0 VertexShaderFunction(); PixelShader = compile ps_2_0 PixelShaderFunction(); } } I quess I need to change Texture into TextureCube, change sampler, swap texCUBE() with TextureCube.Sample() and change PixelShader return semantic to SV_Target0. I'm very new in shader languages and any help is appreciated!

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  • Async & Await in C# with Xamarin

    - by Wallym
     One of the great things about the .NET Framework is that Microsoft has worked long and hard to improve many features. Since the initial release of .NET 1.0, there has been support for threading via .NET threads as well as an application-level threadpool. This provided a great starting point when compared to Visual Basic 6 and classic ASP programming. The release of.NET 4 brought significant improvements in the area of threading, asynchronous operations and parallel operations. While the improvements made working with asynchronous operations easier, new problems were introduced, since many of these operations work based on callbacks. For example: How should a developer handle error checking? The program flow tends to be non-linear. Fixing bugs can be problematic. It is hard for a developer to get an understanding of what is happening within an application. The release of .NET 4.5 (and C# 5.0), in the fall of 2012, was a blockbuster update with regards to asynchronous operations and threads. Microsoft has added C# language keywords to take this non-linear callback-based program flow and turn it into a much more linear flow. Recently, Xamarin has updated Xamarin.Android and Xamarin.iOS to support async. This article will look at how Xamarin has implemented the .NET 4.5/C# 5 support into their Xamarin.iOS and Xamarin.Android productions. There are three general areas that I'll focus on: A general look at the asynchronous support in Xamarin's mobile products. This includes async, await, and the implications that this has for cross-platform code. The new HttpClient class that is provided in .NET 4.5/Mono 3.2. Xamarin's extensions for asynchronous operations for Android and iOS. FYI: Be aware that sometimes the OpenWeatherMap API breaks, for no reason.  I found this out after I shipped the article in.

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  • Should certain math classes be required for a Computer Science degree?

    - by sunpech
    For a Computer Science (CS) degree at many colleges and universities, certain math courses are required: Calculus, Linear Algebra, and Discrete Mathematics are few examples. However, since I've started working in the real world as a software developer, I have yet to truly use some the knowledge I had at once acquired from taking those classes. Discrete Math might be the only exception. My questions: Should these math classes be required to obtain a computer science degree? Or would they be better served as electives? I'm challenging even that the certain math classes even help with required CS classes. For example, I never used linear algebra outside of the math class itself. I hear it's used in Computer Graphics, but I never took those classes-- yet linear algebra was required for a CS degree. I personally think it could be better served as an elective rather than requirement because it's more specific to a branch of CS rather than general CS. From a Slashdot post CS Profs Debate Role of Math In CS Education: 'For too long, we have taught computer science as an academic discipline (as though all of our students will go on to get PhDs and then become CS faculty members) even though for most of us, our students are overwhelmingly seeking careers in which they apply computer science.'

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  • Weird CSS-behaviour [migrated]

    - by WMRKameleon
    <!DOCTYPE html> <html> <head> <title>PakHet</title> <link rel="stylesheet" type="text/css" href="css/basis.css" /> </head> <body> <div class="wrapper"> <div id='cssmenu'> <ul> <li class="active"><a href='index.html'><span>Start</span></a></li> <li><a href='pakhet.html'><span>Over PakHet</span></a></li> <li><a href='overons.html'><span>Over Ons</span></a></li> <li class='has-sub '><a href='#'><span>Uw pakket</span></a> <ul> <li><a href='aanmelden.php'><span>Aanmelden</span></a></li> <li><a href='traceren.php'><span>Traceren</span></a></li> </ul> </li> </ul> </div> <div class="header"> <h1>Hier komt de titel van de website</h1> </div> <div class="content"> <p>Dit is de tekst van de content. Dit is de indexpagina.</p> </div> </div> </body> </html> And this is the CSS: /* CSS RESET */ html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video, *{ margin: 0; padding: 0; border: 0; vertical-align: baseline; } table { border-collapse: collapse; border-spacing: 0; } /* Einde CSS RESET, nu echte code */ html, body{ background:url(../images/bg_picture.jpg) fixed no-repeat; } .wrapper{ margin:0 auto; } .header{ margin:0 auto; background-color:rgba(0, 0, 0, 0.4); } .content{ background-color:rgba(0, 0, 0, 0.4); width:600px; margin:0 auto; margin-top:50px; } .content p{ color:white; text-shadow:1px 1px 0 rgba(0,0,0, 0.5); font-family:"Lucida Grande", sans-serif; } #cssmenu{ height:37px; display:block; padding:0; margin: 0; border:1px solid; } #cssmenu > ul {list-style:inside none; padding:0; margin:0;} #cssmenu > ul > li {list-style:inside none; padding:0; margin:0; float:left; display:block; position:relative;} #cssmenu > ul > li > a{ outline:none; display:block; position:relative; padding:12px 20px; font:bold 13px/100% "Lucida Grande", Helvetica, sans-serif; text-align:center; text-decoration:none; text-shadow:1px 1px 0 rgba(0,0,0, 0.4); } #cssmenu > ul > li:first-child > a{border-radius:5px 0 0 5px;} #cssmenu > ul > li > a:after{ content:''; position:absolute; border-right:1px solid; top:-1px; bottom:-1px; right:-2px; z-index:99; } #cssmenu ul li.has-sub:hover > a:after{top:0; bottom:0;} #cssmenu > ul > li.has-sub > a:before{ content:''; position:absolute; top:18px; right:6px; border:5px solid transparent; border-top:5px solid #fff; } #cssmenu > ul > li.has-sub:hover > a:before{top:19px;} #cssmenu ul li.has-sub:hover > a{ background:#3f3f3f; border-color:#3f3f3f; padding-bottom:13px; padding-top:13px; top:-1px; z-index:999; } #cssmenu ul li.has-sub:hover > ul, #cssmenu ul li.has-sub:hover > div{display:block;} #cssmenu ul li.has-sub > a:hover{background:#3f3f3f; border-color:#3f3f3f;} #cssmenu ul li > ul, #cssmenu ul li > div{ display:none; width:auto; position:absolute; top:38px; padding:10px 0; background:#3f3f3f; border-radius:0 0 5px 5px; z-index:999; } #cssmenu ul li > ul{width:200px;} #cssmenu ul li > ul li{display:block; list-style:inside none; padding:0; margin:0; position:relative;} #cssmenu ul li > ul li a{ outline:none; display:block; position:relative; margin:0; padding:8px 20px; font:10pt "Lucida Grande", Helvetica, sans-serif; color:#fff; text-decoration:none; text-shadow:1px 1px 0 rgba(0,0,0, 0.5); } #cssmenu, #cssmenu > ul > li > ul > li a:hover{ background:#333333; background:-moz-linear-gradient(top, #333333 0%, #222222 100%); background:-webkit-gradient(linear, left top, left bottom, color-stop(0%,#333333), color-stop(100%,#222222)); background:-webkit-linear-gradient(top, #333333 0%,#222222 100%); background:-o-linear-gradient(top, #333333 0%,#222222 100%); background:-ms-linear-gradient(top, #333333 0%,#222222 100%); background:linear-gradient(top, #333333 0%,#222222 100%); filter:progid:DXImageTransform.Microsoft.gradient( startColorstr='#333333', endColorstr='#222222',GradientType=0 ); } #cssmenu{border-color:#000;} #cssmenu > ul > li > a{border-right:1px solid #000; color:#fff;} #cssmenu > ul > li > a:after{border-color:#444;} #cssmenu > ul > li > a:hover{background:#111;} #cssmenu > ul > li.active > a{ color:orange; } .header{ clear:both; } The problem is that, whenever I hover on the dropdown-menu, that a 1px margin appears in between the menu and the header. Can I solve that? I can't seem to find the solution.

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  • Display Call To Action bar on page load [migrated]

    - by dasickle
    I am using the following code to load the bar on click but I can't figure our how to load it on page load automatically. <script> var autohide; $('body').prepend('<div id="bn-bar"><b>DON\'T MISS OUT!</b> Only 9 seats remain for the Google Tag Manager training on May 22! <a href="#">Book Your Seat Today!</a><div id="hider"> </div></div>'); $(document).ready(function(){ $("#hider").click(function(){ $("#bn-bar").animate({ top: "-50" }, "fast","linear", function(){}); }) $("#bn-bar").mouseover(function(){clearTimeout(autohide);}); setTimeout(function(){$("#bn-bar").animate({top: "0"}, "slow","linear", function(){});},2500); autohide = setTimeout(function(){$("#bn-bar").animate({top: "-30"}, "fast","linear", function(){});},10000); }) </script> Basically I am trying to load a the message when user enters my website and I will be inserting it via Google Tag Manager. Below is a page where I found the code: Creative Tag Manager – Ads, Promotions, and Visitor Messaging -Lunametrics

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  • Programming logic to group a users activities like facebook. E.g. Chris is now friends with A, B and C

    - by Chris Dowdeswell
    So I am trying to develop an activity feed for my site, Basically If I UNION a bunch of activities into a feed I would end up with something like the following. Chris is now friends with Mark Chris is now friends with Dave What I want though is a neater way of grouping these similar posts so the feed doesn't give information overload... E.g. Chris is now friends with Mark, Dave and 4 Others Any ideas on how I can approach this logically? I am using Classic ASP on SQL server. Here is the UNION statement I have so far... SELECT U.UserID As UserID, L.UN As UN,Left(U.UID,13) As ProfilePic,U.Fname + ' ' + U.Sname As FullName, 'said ' + WP.Post AS Activity, WP.Ctime FROM Users AS U LEFT JOIN Logins L ON L.userID = U.UserID LEFT OUTER JOIN WallPosts AS WP ON WP.userID = U.userID WHERE WP.Ctime IS NOT NULL UNION SELECT U.UserID As UserID, L.UN As UN,Left(U.UID,13) As ProfilePic,U.Fname + ' ' + U.Sname As FullName, 'commented ' + C.Comment AS Activity, C.Ctime FROM Users AS U LEFT JOIN Logins L ON L.userID = U.UserID LEFT OUTER JOIN Comments AS C ON C.UserID = U.userID WHERE C.Ctime IS NOT NULL UNION SELECT U.UserID As UserID, L.UN As UN,Left(U.UID,13) As ProfilePic, U.Fname + ' ' + U.Sname As FullName, 'connected with <a href="/profile.asp?un='+(SELECT Logins.un FROM Logins WHERE Logins.userID = Cn.ToUserID)+'">' + (SELECT Users.Fname + ' ' + Users.Sname FROM Users WHERE userID = Cn.ToUserID) + '</a>' AS Activity, Cn.Ctime FROM Users AS U LEFT JOIN Logins L ON L.userID = U.UserID LEFT OUTER JOIN Connections AS Cn ON Cn.UserID = U.userID WHERE CN.Ctime IS NOT NULL

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  • The correct way to Fire-and-Forget an asynchronous delegate

    - by Programming Hero
    Consider me rusty on the subject of asynchronous delegates. If I want to call a method asynchronously, in a fire-and-forget style, is this an appropriate way to do it? Action action = DoSomething; action.BeginInvoke(action.EndInvoke, null); The DoSomething() method catches all exceptions and deals with them internally. Is the call to EndInvoke appropriate? Required? Is there a clearer way to achieve the same behaviour?

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  • Map NHibernate entity to multiple tables based on parent

    - by Programming Hero
    I'm creating a domain model where entities often (but not always) have a member of type ActionLog. ActionLog is a simple class which allows for an audit trail of actions being performed on an instance. Each action is recorded as an ActionLogEntry instance. ActionLog is implemented (approximately) as follows: public class ActionLog { public IEnumerable<ActionLogEntry> Entries { get { return EntriesCollection; } } protected ICollection<ActionLogEntry> EntriesCollection { get; set; } public void AddAction(string action) { // Append to entries collection. } } What I would like is to re-use this class amongst my entities and have the entries map to different tables based on which class they are logged against. For example: public class Customer { public ActionLog Actions { get; protected set; } } public class Order { public ActionLog Actions { get; protected set; } } This design is suitable for me in the application, however I can't see a clear way to map this scenario to a database with NHibernate. I typically use Fluent NHibernate for my configuration, but I'm happy to accept answers in more general HBM xml.

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  • WCF Message Debugging on Custom Binding

    - by Programming Hero
    I've created a custom binding in WCF for a custom MessageEncoder to allow messages to be written as XML using a wider range of encodings than WCF supports out of the box. The encoder appears to be working and I am able to send and receive messages, but I want to verify that the XML message being written is exactly as required by the service I am trying to consume. I've turned on message logging for WCF using the diagnostic trace listeners to output the messages sent and received over the wire to a log file. Unfortunately, for calls using my encoder, the message is displayed as ... stream ... EDIT: I don't think it's anything to do with my custom encoding. I have experimented with my custom binding a little, switching to using the built-in text encoding and http transport. I still don't get a message body logged in the message trace. Is there anything that needs to be specified within a custom binding to enable message logging?

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  • sharing build artifacts between jobs in hudson

    - by programming panda
    Hi I'm trying to set up our build process in hudson. Job 1 will be a super fast (hopefully) continuous integration build job that will be built frequently. Job 2, will be responsible for running a comprehensive test suite, at a regular interval or triggered manually. Job 3 will be responsible for running analysis tools across the codebase (much like Job 2). I tried using the "Advanced Projects Options use custom workspace" feature so that code compiled in Job 1 can be used in Job 2 and 3. However, it seems that all build artifacts remain inside that Job 1 workspace. I'm I doing this right? Is there a better way of doing this? I guess I'm looking for something similar to a build pipeline setup...so that things can be shared and the appropriate jobs can be executed in stages. (I also considered using 'batch tasks'...but it seems like those can't be scheduled? only triggered manually?) Any suggestions are welcomed. Thanks!

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  • WCF Message Debugging on WebHttpBehavior

    - by Programming Hero
    I've created a custom binding in WCF for a custom MessageEncoder to allow messages to be written as XML using a wider range of encodings than WCF supports out of the box. The encoder appears to be working and I am able to send and receive messages, but I want to verify that the XML message being written is exactly as required by the service I am trying to consume. I've turned on message logging for WCF using the diagnostic trace listeners to output the messages sent and received over the wire to a log file. Unfortunately, for calls using my encoder, the message is displayed as ... stream ... EDIT: I don't think it's anything to do with my custom encoding. I have experimented with my custom binding a little, switching to using the built-in text encoding and http transport. I still don't get a message body logged in the message trace. EDIT2: Having done further investigation, the issue looks to be related not to the custom binding, but the custom behaviour. I'm apply the <webHttp/> behaviour. Once this is specified (along with manual addressing), the tracing behaviour shows up. Is this a known issue with WebHttpBehavior? Am I still barking up the wrong tree?

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  • High level vs. low level programming. Do I really have to choose?

    - by EpsilonVector
    Every once in a while I'm asked in interviews which I like the best- low level or high level. It seems to me that the implicit message is that they are both a specialty and they want to know which direction I'm heading. The trouble is, I seem to like both. Low level is extremely challenging and often requires a great deal of esoteric knowledge. High level is where all the sexy things happen: applications that people use directly, results that can be easily demonstrated (showed off) in a way that is accessible to everybody, and you get to work with really advanced tools and interact with new technologies. I would really love to do both, even if it means alternating between them (I doubt there are jobs that will let me do both simultaneously), but I'm guessing that the industry rewards specialists more than generalists. Will it really be problematic career wise if I never choose one over the other? Is it practical to alternate between the two in the sense that if I were to leave a job doing one of them, I should experience no "friction" trying to get a job doing the other (assuming I'm reasonably in the loop)? Are there career opportunities where you get to do both? Do I really have to choose one over the other?

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  • I've been hired on as a entry-level game developer at a company and have little/no experience in API programming, what should I expect?

    - by Mr. Geneth
    So, I've been hired on as an entry level game developer with little/no experience working with any API other than Win32. This will be an overall learning experience for me as a person and I have gone over this multiple times with the boss and he has no problem with my inexperience. He says that if I'm not worth it now, I will be later. This gives me confidence, but I still feel that I should know a lot more before tackling this position. I would be stupid to pass it up. This is one of my favorite places to come for advice and help and have tried to just accept this, but it just keeps bothering that I can't go in knowing how to at least do the basics. I want to give the company its money's worth. Ya know? My questions are: What should I expect from the other programmers in this project (In terms of patience with me and working together, and being taught)? Is this normal? Any other advice on this sort of thing would be wonderful. I just want to feel comfortable with it.

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  • Storing website hierarchy in Sql Server 2008

    - by Mika Kolari
    I want to store website page hierarchy in a table. What I would like to achieve is efficiently 1) resolve (last valid) item by path (e.g. "/blogs/programming/tags/asp.net,sql-server", "/blogs/programming/hello-world" ) 2) get ancestor items for breadcrump 3) edit an item without updating the whole tree of children, grand children etc. Because of the 3rd point I thought the table could be like ITEM id type slug title parentId 1 area blogs Blogs 2 blog programming Programming blog 1 3 tagsearch tags 2 4 post hello-world Hello World! 2 Could I use Sql Server's hierarchyid type somehow (especially point 1, "/blogs/programming/tags" is the last valid item)? Tree depth would usually be around 3-4. What would be the best way to achieve all this?

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  • Iphone memory leak with malloc

    - by Icky
    Hello. I have memory leak, found by instruments and it is supposed to be in this line of code: indices = malloc( sizeof(indices[0]) * totalQuads * 6); This is actually a code snippet from a tutorial, something which i think is leak-free so to say. Now I reckon, the error is somewhere else, but I do not know, where. These are the last trackbacks: 5 ColorRun -[EAGLView initWithCoder:] /Users/thomaskopinski/programming/colorrun_3.26/Classes/EAGLView.m:98 4 ColorRun -[EAGLView initGame] /Users/thomaskopinski/programming/colorrun_3.26/Classes/EAGLView.m:201 3 ColorRun -[SpriteSheet initWithImageNamed:spriteWidth:spriteHeight:spacing:imageScale:] /Users/thomaskopinski/programming/colorrun_3.26/SpriteSheet.m:68 2 ColorRun -[Image initWithImage:scale:] /Users/thomaskopinski/programming/colorrun_3.26/Image.m:122 1 ColorRun -[Image initImpl] /Users/thomaskopinski/programming/colorrun_3.26/Image.m:158 0 libSystem.B.dylib malloc Does anyone know how to approach this?

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  • Routing redirection decision

    - by programming late night
    I have really no idea why I'm asking this as this a really completely irrelevant question for which I should have figured out an answer within milliseconds, yet I'm doing it. So in my project I have a Router class which splits up the request and selects the right page to be loaded. Fine so far. Now I have a page displayed when the user requests a page that doesn't exist, you know, 404. So theoretically, if the user entered mydomain.com/404 (I use mod_rewrite with a requests collector via index.php?req=*) the 404 error would be shown to him, but in fact there was no error - the 404 page would be displayed as a perfectly normal page. So if someone would try out requesting the 404 page via /404, he would be shown the page but he can't tell if the 404 page he requested doesn't exist and he is actually getting a, you guessed it, 404 error or if he actually found some flaw in the system that makes him able to see an error page when there is no error. I don't know how dumb this whole thing here is but I'm sure some of you have in fact ran into this problem already. Short version: If the user enters mydomain.com/404 the 404 page is shown even though there is no 404 error. I know this is a completely irrelevant question, please don't tell me, but I just spontaneously wanted to hear your thoughts on it. Strange eh? Should I redirect direct access to my 404-page to the home page? Should I do nothing? Should I just go to bed and stop asking irrelevant stuff?

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  • In China. Want to set up my own private proxy. Already have website/webhosting. Help please! n00b with respect to coding/programming, go easy on me [closed]

    - by user1725461
    I am in China and have used freegate in the past -- http://en.wikipedia.org/wiki/Freegate Recently I've been having too many problems with that and some other web-based proxies I usually use. I have a website that is hosted in the US which I can access from China. Is there an easy way for me to setup my own secure private proxy? I'm sick of all my internet problems and looking for a new workable solution. Thank you! PS: and I really hope this is the right place for such a question...

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  • What is the benefits and drawbacks of using header files?

    - by vodkhang
    I had some experience on programming languages like Java, C#, Scala as well as some lower level programming language like C, C++, Objective - C. My observation is that low level languages separate out header files and implementation files while other higher level programming language never separate it out. They use some identifiers like public, private, protected to do the jobs of header files. I saw one benefit of using header file (in some book like Code Complete), they talk about that using header files, people can never look at our implementation file and it helps with encapsulation. A drawback is that it creates too many files for me. Sometimes, it looks like verbose. It is just my thought and I don't know if there are any other benefits and drawbacks that people ever see and work with header file This question may not relate directly to programming but I think that if I can understand better about programming to interface, design software.

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  • LINQ to SQL - database relationships won't update after submit

    - by Quantic Programming
    I have a Database with the tables Users and Uploads. The important columns are: Users -> UserID Uploads -> UploadID, UserID The primary key in the relationship is Users -> UserID and the foreign key is Uploads -> UserID. In LINQ to SQL, I do the following operations: Retrieve files var upload = new Upload(); upload.UserID = user.UserID; upload.UploadID = XXX; db.Uploads.InsertOnSubmit(upload) db.SubmitChanges(); If I do that and rerun the application (and the db object is re-built, of course) - if do something like this: foreach(var upload in user.Uploads) I get all the uploads with that user's ID. (like added in the previous example) The problem is, that my application, after adding an upload an submitting changes, doesn't update the user.Uploads collection. i.e - I don't get the newly added uploads. The user object is stored in the Session object. At first, I though that the LINQ to SQL Framework doesn't update the reference of the object, therefore I should simply "reset" the user object from a new SQL request. I mean this: Session["user"] = db.Users.Where(u => u.UserID == user.UserID).SingleOrDefault(); (Where user is the previous user) But it didn't help. Please note: After rerunning the application, user.Uploads does have the new upload! Did anyone experience this type of problem, or is it normal behavior? I am a newbie to this framework. I would gladly take any advice. Thank you!

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  • GPGPU

    WhatGPU obviously stands for Graphics Processing Unit (the silicon powering the display you are using to read this blog post). The extra GP in front of that stands for General Purpose computing.So, altogether GPGPU refers to computing we can perform on GPU for purposes beyond just drawing on the screen. In effect, we can use a GPGPU a bit like we already use a CPU: to perform some calculation (that doesn’t have to have any visual element to it). The attraction is that a GPGPU can be orders of magnitude faster than a CPU.WhyWhen I was at the SuperComputing conference in Portland last November, GPGPUs were all the rage. A quick online search reveals many articles introducing the GPGPU topic. I'll just share 3 here: pcper (ignoring all pages except the first, it is a good consumer perspective), gizmodo (nice take using mostly layman terms) and vizworld (answering the question on "what's the big deal").The GPGPU programming paradigm (from a high level) is simple: in your CPU program you define functions (aka kernels) that take some input, can perform the costly operation and return the output. The kernels are the things that execute on the GPGPU leveraging its power (and hence execute faster than what they could on the CPU) while the host CPU program waits for the results or asynchronously performs other tasks.However, GPGPUs have different characteristics to CPUs which means they are suitable only for certain classes of problem (i.e. data parallel algorithms) and not for others (e.g. algorithms with branching or recursion or other complex flow control). You also pay a high cost for transferring the input data from the CPU to the GPU (and vice versa the results back to the CPU), so the computation itself has to be long enough to justify the overhead transfer costs. If your problem space fits the criteria then you probably want to check out this technology.HowSo where can you get a graphics card to start playing with all this? At the time of writing, the two main vendors ATI (owned by AMD) and NVIDIA are the obvious players in this industry. You can read about GPGPU on this AMD page and also on this NVIDIA page. NVIDIA's website also has a free chapter on the topic from the "GPU Gems" book: A Toolkit for Computation on GPUs.If you followed the links above, then you've already come across some of the choices of programming models that are available today. Essentially, AMD is offering their ATI Stream technology accessible via a language they call Brook+; NVIDIA offers their CUDA platform which is accessible from CUDA C. Choosing either of those locks you into the GPU vendor and hence your code cannot run on systems with cards from the other vendor (e.g. imagine if your CPU code would run on Intel chips but not AMD chips). Having said that, both vendors plan to support a new emerging standard called OpenCL, which theoretically means your kernels can execute on any GPU that supports it. To learn more about all of these there is a website: gpgpu.org. The caveat about that site is that (currently) it completely ignores the Microsoft approach, which I touch on next.On Windows, there is already a cross-GPU-vendor way of programming GPUs and that is the DirectX API. Specifically, on Windows Vista and Windows 7, the DirectX 11 API offers a dedicated subset of the API for GPGPU programming: DirectCompute. You use this API on the CPU side, to set up and execute the kernels that run on the GPU. The kernels are written in a language called HLSL (High Level Shader Language). You can use DirectCompute with HLSL to write a "compute shader", which is the term DirectX uses for what I've been referring to in this post as a "kernel". For a comprehensive collection of links about this (including tutorials, videos and samples) please see my blog post: DirectCompute.Note that there are many efforts to build even higher level languages on top of DirectX that aim to expose GPGPU programming to a wider audience by making it as easy as today's mainstream programming models. I'll mention here just two of those efforts: Accelerator from MSR and Brahma by Ananth. Comments about this post welcome at the original blog.

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  • Ambient occlusion shader just shows models as all white

    - by dvds414
    Okay so I have this shader for ambient occlusion. It loads to world correctly, but it just shows all the models as being white. I do not know why. I am just running the shader while the model is rendering, is that correct? or do I need to make a render target or something? If so then how? I'm using C++. Here is my shader: float sampleRadius; float distanceScale; float4x4 xProjection; float4x4 xView; float4x4 xWorld; float3 cornerFustrum; struct VS_OUTPUT { float4 pos : POSITION; float2 TexCoord : TEXCOORD0; float3 viewDirection : TEXCOORD1; }; VS_OUTPUT VertexShaderFunction( float4 Position : POSITION, float2 TexCoord : TEXCOORD0) { VS_OUTPUT Out = (VS_OUTPUT)0; float4 WorldPosition = mul(Position, xWorld); float4 ViewPosition = mul(WorldPosition, xView); Out.pos = mul(ViewPosition, xProjection); Position.xy = sign(Position.xy); Out.TexCoord = (float2(Position.x, -Position.y) + float2( 1.0f, 1.0f ) ) * 0.5f; float3 corner = float3(-cornerFustrum.x * Position.x, cornerFustrum.y * Position.y, cornerFustrum.z); Out.viewDirection = corner; return Out; } texture depthTexture; texture randomTexture; sampler2D depthSampler = sampler_state { Texture = <depthTexture>; ADDRESSU = CLAMP; ADDRESSV = CLAMP; MAGFILTER = LINEAR; MINFILTER = LINEAR; }; sampler2D RandNormal = sampler_state { Texture = <randomTexture>; ADDRESSU = WRAP; ADDRESSV = WRAP; MAGFILTER = LINEAR; MINFILTER = LINEAR; }; float4 PixelShaderFunction(VS_OUTPUT IN) : COLOR0 { float4 samples[16] = { float4(0.355512, -0.709318, -0.102371, 0.0 ), float4(0.534186, 0.71511, -0.115167, 0.0 ), float4(-0.87866, 0.157139, -0.115167, 0.0 ), float4(0.140679, -0.475516, -0.0639818, 0.0 ), float4(-0.0796121, 0.158842, -0.677075, 0.0 ), float4(-0.0759516, -0.101676, -0.483625, 0.0 ), float4(0.12493, -0.0223423, -0.483625, 0.0 ), float4(-0.0720074, 0.243395, -0.967251, 0.0 ), float4(-0.207641, 0.414286, 0.187755, 0.0 ), float4(-0.277332, -0.371262, 0.187755, 0.0 ), float4(0.63864, -0.114214, 0.262857, 0.0 ), float4(-0.184051, 0.622119, 0.262857, 0.0 ), float4(0.110007, -0.219486, 0.435574, 0.0 ), float4(0.235085, 0.314707, 0.696918, 0.0 ), float4(-0.290012, 0.0518654, 0.522688, 0.0 ), float4(0.0975089, -0.329594, 0.609803, 0.0 ) }; IN.TexCoord.x += 1.0/1600.0; IN.TexCoord.y += 1.0/1200.0; normalize (IN.viewDirection); float depth = tex2D(depthSampler, IN.TexCoord).a; float3 se = depth * IN.viewDirection; float3 randNormal = tex2D( RandNormal, IN.TexCoord * 200.0 ).rgb; float3 normal = tex2D(depthSampler, IN.TexCoord).rgb; float finalColor = 0.0f; for (int i = 0; i < 16; i++) { float3 ray = reflect(samples[i].xyz,randNormal) * sampleRadius; //if (dot(ray, normal) < 0) // ray += normal * sampleRadius; float4 sample = float4(se + ray, 1.0f); float4 ss = mul(sample, xProjection); float2 sampleTexCoord = 0.5f * ss.xy/ss.w + float2(0.5f, 0.5f); sampleTexCoord.x += 1.0/1600.0; sampleTexCoord.y += 1.0/1200.0; float sampleDepth = tex2D(depthSampler, sampleTexCoord).a; if (sampleDepth == 1.0) { finalColor ++; } else { float occlusion = distanceScale* max(sampleDepth - depth, 0.0f); finalColor += 1.0f / (1.0f + occlusion * occlusion * 0.1); } } return float4(finalColor/16, finalColor/16, finalColor/16, 1.0f); } technique SSAO { pass P0 { VertexShader = compile vs_3_0 VertexShaderFunction(); PixelShader = compile ps_3_0 PixelShaderFunction(); } }

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  • XNA 4.0 - Normal mapping shader - strange texture artifacts

    - by Taylor
    I recently started using custom shader. Shader can do diffuse and specular lighting and normal mapping. But normal mapping is causing really ugly artifacts (some sort of pixeling noise) for textures in greater distance. It looks like this: Image link This is HLSL code: // Matrix float4x4 World : World; float4x4 View : View; float4x4 Projection : Projection; //Textury texture2D ColorMap; sampler2D ColorMapSampler = sampler_state { Texture = <ColorMap>; MinFilter = Anisotropic; MagFilter = Linear; MipFilter = Linear; MaxAnisotropy = 16; }; texture2D NormalMap; sampler2D NormalMapSampler = sampler_state { Texture = <NormalMap>; MinFilter = Anisotropic; MagFilter = Linear; MipFilter = Linear; MaxAnisotropy = 16; }; // Light float4 AmbientColor : Color; float AmbientIntensity; float3 DiffuseDirection : LightPosition; float4 DiffuseColor : Color; float DiffuseIntensity; float4 SpecularColor : Color; float3 CameraPosition : CameraPosition; float Shininess; // The input for the VertexShader struct VertexShaderInput { float4 Position : POSITION0; float2 TexCoord : TEXCOORD0; float3 Normal : NORMAL0; float3 Binormal : BINORMAL0; float3 Tangent : TANGENT0; }; // The output from the vertex shader, used for later processing struct VertexShaderOutput { float4 Position : POSITION0; float2 TexCoord : TEXCOORD0; float3 View : TEXCOORD1; float3x3 WorldToTangentSpace : TEXCOORD2; }; // The VertexShader. VertexShaderOutput VertexShaderFunction(VertexShaderInput input, float3 Normal : NORMAL) { VertexShaderOutput output; float4 worldPosition = mul(input.Position, World); float4 viewPosition = mul(worldPosition, View); output.Position = mul(viewPosition, Projection); output.TexCoord = input.TexCoord; output.WorldToTangentSpace[0] = mul(normalize(input.Tangent), World); output.WorldToTangentSpace[1] = mul(normalize(input.Binormal), World); output.WorldToTangentSpace[2] = mul(normalize(input.Normal), World); output.View = normalize(float4(CameraPosition,1.0) - worldPosition); return output; } // The Pixel Shader float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0 { float4 color = tex2D(ColorMapSampler, input.TexCoord); float3 normalMap = 2.0 *(tex2D(NormalMapSampler, input.TexCoord)) - 1.0; normalMap = normalize(mul(normalMap, input.WorldToTangentSpace)); float4 normal = float4(normalMap,1.0); float4 diffuse = saturate(dot(-DiffuseDirection,normal)); float4 reflect = normalize(2*diffuse*normal-float4(DiffuseDirection,1.0)); float4 specular = pow(saturate(dot(reflect,input.View)), Shininess); return color * AmbientColor * AmbientIntensity + color * DiffuseIntensity * DiffuseColor * diffuse + color * SpecularColor * specular; } // Techniques technique Lighting { pass Pass1 { VertexShader = compile vs_2_0 VertexShaderFunction(); PixelShader = compile ps_2_0 PixelShaderFunction(); } } Any advice? Thanks!

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  • Why is my RAID /dev/md1 showing up as /dev/md126? Is mdadm.conf being ignored?

    - by mmorris
    I created a RAID with: sudo mdadm --create --verbose /dev/md1 --level=mirror --raid-devices=2 /dev/sdb1 /dev/sdc1 sudo mdadm --create --verbose /dev/md2 --level=mirror --raid-devices=2 /dev/sdb2 /dev/sdc2 sudo mdadm --detail --scan returns: ARRAY /dev/md1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e ARRAY /dev/md2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb Which I appended it to /etc/mdadm/mdadm.conf, see below: # mdadm.conf # # Please refer to mdadm.conf(5) for information about this file. # # by default (built-in), scan all partitions (/proc/partitions) and all # containers for MD superblocks. alternatively, specify devices to scan, using # wildcards if desired. #DEVICE partitions containers # auto-create devices with Debian standard permissions CREATE owner=root group=disk mode=0660 auto=yes # automatically tag new arrays as belonging to the local system HOMEHOST <system> # instruct the monitoring daemon where to send mail alerts MAILADDR root # definitions of existing MD arrays # This file was auto-generated on Mon, 29 Oct 2012 16:06:12 -0500 # by mkconf $Id$ ARRAY /dev/md1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e ARRAY /dev/md2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb cat /proc/mdstat returns: Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md2 : active raid1 sdb2[0] sdc2[1] 208629632 blocks super 1.2 [2/2] [UU] md1 : active raid1 sdb1[0] sdc1[1] 767868736 blocks super 1.2 [2/2] [UU] unused devices: <none> ls -la /dev | grep md returns: brw-rw---- 1 root disk 9, 1 Oct 30 11:06 md1 brw-rw---- 1 root disk 9, 2 Oct 30 11:06 md2 So I think all is good and I reboot. After the reboot, /dev/md1 is now /dev/md126 and /dev/md2 is now /dev/md127????? sudo mdadm --detail --scan returns: ARRAY /dev/md/ion:1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e ARRAY /dev/md/ion:2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb cat /proc/mdstat returns: Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md126 : active raid1 sdc2[1] sdb2[0] 208629632 blocks super 1.2 [2/2] [UU] md127 : active (auto-read-only) raid1 sdb1[0] sdc1[1] 767868736 blocks super 1.2 [2/2] [UU] unused devices: <none> ls -la /dev | grep md returns: drwxr-xr-x 2 root root 80 Oct 30 11:18 md brw-rw---- 1 root disk 9, 126 Oct 30 11:18 md126 brw-rw---- 1 root disk 9, 127 Oct 30 11:18 md127 All is not lost, I: sudo mdadm --stop /dev/md126 sudo mdadm --stop /dev/md127 sudo mdadm --assemble --verbose /dev/md1 /dev/sdb1 /dev/sdc1 sudo mdadm --assemble --verbose /dev/md2 /dev/sdb2 /dev/sdc2 and verify everything: sudo mdadm --detail --scan returns: ARRAY /dev/md1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e ARRAY /dev/md2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb cat /proc/mdstat returns: Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md2 : active raid1 sdb2[0] sdc2[1] 208629632 blocks super 1.2 [2/2] [UU] md1 : active raid1 sdb1[0] sdc1[1] 767868736 blocks super 1.2 [2/2] [UU] unused devices: <none> ls -la /dev | grep md returns: brw-rw---- 1 root disk 9, 1 Oct 30 11:26 md1 brw-rw---- 1 root disk 9, 2 Oct 30 11:26 md2 So once again, I think all is good and I reboot. Again, after the reboot, /dev/md1 is /dev/md126 and /dev/md2 is /dev/md127????? sudo mdadm --detail --scan returns: ARRAY /dev/md/ion:1 metadata=1.2 name=ion:1 UUID=aa1f85b0:a2391657:cfd38029:772c560e ARRAY /dev/md/ion:2 metadata=1.2 name=ion:2 UUID=528e5385:e61eaa4c:1db2dba7:44b556fb cat /proc/mdstat returns: Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md126 : active raid1 sdc2[1] sdb2[0] 208629632 blocks super 1.2 [2/2] [UU] md127 : active (auto-read-only) raid1 sdb1[0] sdc1[1] 767868736 blocks super 1.2 [2/2] [UU] unused devices: <none> ls -la /dev | grep md returns: drwxr-xr-x 2 root root 80 Oct 30 11:42 md brw-rw---- 1 root disk 9, 126 Oct 30 11:42 md126 brw-rw---- 1 root disk 9, 127 Oct 30 11:42 md127 What am I missing here?

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