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  • Raycasting "fisheye effect" question

    - by mattboy
    Continuing my exploration of raycasting, I am very confused about how the correction of the fisheye effect works. Looking at the screenshot below from the tutorial at permadi.com, the way I understand the cause of the fisheye effect is that the rays that are cast are distances from the player, rather than the distances perpendicular to the screen (or camera plane) which is what really needs to be displayed. The distance perpendicular to the screen then, in my world, should simply be the distance of Y coordinates (Py - Dy) assuming that the player is facing straight upwards. Continuing the tutorial, this is exactly how it seems to be according to the below screenshot. From my point of view, the "distorted distance" below is the same as the distance PD calculated above, and what's labelled the "correct distance" below should be the same as Py - Dy. Yet, this clearly isn't the case according to the tutorial. My question is, WHY is this not the same? How could it not be? What am I understanding and visualizing wrong here?

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  • SQL SERVER – Signal Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

    - by pinaldave
    In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Signal Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Signal Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Signal Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the Signalwait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the Signal wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the Signal wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • Feb 2nd Links: Visual Studio, ASP.NET, ASP.NET MVC, JQuery, Windows Phone

    - by ScottGu
    Here is the latest in my link-listing series.  Also check out my Best of 2010 Summary for links to 100+ other posts I’ve done in the last year. [I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] Community News MVCConf Conference Next Wednesday: Attend the free, online ASP.NET MVC Conference being organized by the community next Wednesday.  Here is a list of some of the talks you can watch live. Visual Studio HTML5 and CSS3 in VS 2010 SP1: Good post from the Visual Studio web tools team that talks about the new support coming in VS 2010 SP1 for HTML5 and CSS3. Database Deployment with the VS 2010 Package/Publish Database Tool: Rachel Appel has a nice post that covers how to enable database deployment using the built-in VS 2010 web deployment support.  Also check out her ASP.NET web deployment post from last month. VsVim Update Released: Jared posts about the latest update of his VsVim extension for Visual Studio 2010.  This free extension enables VIM based key-bindings within VS. ASP.NET How to Add Mobile Pages to your ASP.NET Web Forms / MVC Apps: Great whitepaper by Steve Sanderson that covers how to mobile-enable your ASP.NET and ASP.NET MVC based applications. New Entity Framework Tutorials for ASP.NET Developers: The ASP.NET and EF teams have put together a bunch of nice tutorials on using the Entity Framework data library with ASP.NET Web Forms. Using ASP.NET Dynamic Data with EF Code First (via NuGet): Nice post from David Ebbo that talks about how to use the new EF Code First Library with ASP.NET Dynamic Data. Common Performance Issues with ASP.NET Web Sites: Good post with lots of performance tuning suggestions (mostly deployment settings) for ASP.NET apps. ASP.NET MVC Razor View Converter: Free, automated tool from Terlik that can convert existing .aspx view templates to Razor view templates. ASP.NET MVC 3 Internationalization: Nadeem has a great post that talks about a variety of techniques you can use to enable Globalization and Localization within your ASP.NET MVC 3 applications. ASP.NET MVC 3 Tutorials by David Hayden: Great set of tutorials and posts by David Hayden on some of the new ASP.NET MVC 3 features. EF Fixed Concurrency Mode and MVC: Chris Sells has a nice post that talks about how to handle concurrency with updates done with EF using ASP.NET MVC. ASP.NET and jQuery jQuery Performance Tips and Tricks: A free 30 minute video that covers some great tips and tricks to keep in mind when using jQuery. jQuery 1.5’s AJAX rewrite and ASP.NET services - All is well: Nice post by Dave Ward that talks about using the new jQuery 1.5 to call ASP.NET ASMX Services. Good news according to Dave is that all is well :-) jQuery UI Modal Dialogs for ASP.NET MVC: Nice post by Rob Regan that talks about a few approaches you can use to implement dialogs with jQuery UI and ASP.NET MVC.  Windows Phone 7 Free PDF eBook on Building Windows Phone 7 Applications with Silverlight: Free book that walksthrough how to use Silverlight and Visual Studio to build Windows Phone 7 applications. Hope this helps, Scott

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  • SQL SERVER – Single Wait Time Introduction with Simple Example – Wait Type – Day 2 of 28

    - by pinaldave
    In this post, let’s delve a bit more in depth regarding wait stats. The very first question: when do the wait stats occur? Here is the simple answer. When SQL Server is executing any task, and if for any reason it has to wait for resources to execute the task, this wait is recorded by SQL Server with the reason for the delay. Later on we can analyze these wait stats to understand the reason the task was delayed and maybe we can eliminate the wait for SQL Server. It is not always possible to remove the wait type 100%, but there are few suggestions that can help. Before we continue learning about wait types and wait stats, we need to understand three important milestones of the query life-cycle. Running - a query which is being executed on a CPU is called a running query. This query is responsible for CPU time. Runnable – a query which is ready to execute and waiting for its turn to run is called a runnable query. This query is responsible for Single Wait time. (In other words, the query is ready to run but CPU is servicing another query). Suspended – a query which is waiting due to any reason (to know the reason, we are learning wait stats) to be converted to runnable is suspended query. This query is responsible for wait time. (In other words, this is the time we are trying to reduce). In simple words, query execution time is a summation of the query Executing CPU Time (Running) + Query Wait Time (Suspended) + Query Single Wait Time (Runnable). Again, it may be possible a query goes to all these stats multiple times. Let us try to understand the whole thing with a simple analogy of a taxi and a passenger. Two friends, Tom and Danny, go to the mall together. When they leave the mall, they decide to take a taxi. Tom and Danny both stand in the line waiting for their turn to get into the taxi. This is the Signal Wait Time as they are ready to get into the taxi but the taxis are currently serving other customer and they have to wait for their turn. In other word they are in a runnable state. Now when it is their turn to get into the taxi, the taxi driver informs them he does not take credit cards and only cash is accepted. Neither Tom nor Danny have enough cash, they both cannot get into the vehicle. Tom waits outside in the queue and Danny goes to ATM to fetch the cash. During this time the taxi cannot wait, they have to let other passengers get into the taxi. As Tom and Danny both are outside in the queue, this is the Query Wait Time and they are in the suspended state. They cannot do anything till they get the cash. Once Danny gets the cash, they are both standing in the line again, creating one more Single Wait Time. This time when their turn comes they can pay the taxi driver in cash and reach their destination. The time taken for the taxi to get from the mall to the destination is running time (CPU time) and the taxi is running. I hope this analogy is bit clear with the wait stats. You can check the single wait stats using following query of Glenn Berry. -- Signal Waits for instance SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%signal (cpu) waits], CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [%resource waits] FROM sys.dm_os_wait_stats OPTION (RECOMPILE); Higher the single wait stats are not good for the system. Very high value indicates CPU pressure. In my experience, when systems are running smooth and without any glitch the single wait stat is lower than 20%. Again, this number can be debated (and it is from my experience and is not documented anywhere). In other words, lower is better and higher is not good for the system. In future articles we will discuss in detail the various wait types and wait stats and their resolution. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • SQL SERVER – Puzzle – Challenge – Error While Converting Money to Decimal

    - by pinaldave
    Earlier I wrote SQL SERVER – Challenge – Puzzle – Usage of FAST Hint and I did receive some good comments. Here is another question to tease your mind. Run following script and you will see that it will thrown an error. DECLARE @mymoney MONEY; SET @mymoney = 12345.67; SELECT CAST(@mymoney AS DECIMAL(5,2)) MoneyInt; GO The datatype of money is also visually look similar to the decimal, why it would throw following error: Msg 8115, Level 16, State 8, Line 3 Arithmetic overflow error converting money to data type numeric. Please leave a comment with explanation and I will post a your answer on this blog with due credit. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Error Messages, SQL Puzzle, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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  • SWFObject and IE6 causing hair-pulling agony

    - by Piet
    I recently used SWFObject to display a flash header on a website. I chose SWFObject because: Instead of displaying an annoying ‘Install flash now’ message, it claims to be able to show alternate content. In this case: the original header image. It claims to be compatible with more or less every browser out there. Implementation went fine, until someone tested it on IE6 and got the following error: Internet explorer cannot open the Internet site http://www….. Operation aborted Which basically means that the site just can’t be visited with IE6 (still used a lot in business environments), it even seems as if there’s something wrong with your internet connection. Now, since about 10% of visitors to this site are still using IE6 (why does everyone still use Internet Explorer ???? Do YOU know that these days most people do NOT use Internet Explorer anymore ?) Now after some googling, I found the suggestion to defer loading of the SWFObject.js as follows: <script type="text/javascript" defer=”defer” src=”http://ajax.googleapis.com/ajax/libs/swfobject/2.2/swfobject.js” </script> <script type=”text/javascript” defer=”defer” swfobject.registerObject(”myId”, “9″, “”); </script> What this does according to W3C: When set, this boolean attribute provides a hint to the user agent that the script is not going to generate any document content (e.g., no “document.write” in javascript) and thus, the user agent can continue parsing and rendering. I don’t know exactly why, but: HURRAY! It works now!!! Only… IE6 and IE7 (didn’t try IE8) now gave the following error: Line: 19 Char: 1 Error: ’swfobject’ is undefined Code: 0 URL: http://www… But the flash was still running fine. Still, such an error isn’t clean, especially since almost half of the site’s visitors are using one of these Internet Explorer versions. Now, wanting a quick fix I decided to do the following: <script type="text/javascript" defer="defer" if (typeof(swfobject) != "undefined") swfobject.registerObject("myId", "9", ""); </script> I admit this is a bit of a weird ‘fix’. You’d suspect the flash to stop working on IE6/IE7, which it doesn’t. Not planning on diving into it’s inner bowels, I regard this a ‘mission accomplished’ until someone somewhere posts a better solution (for which I setup some Google alerts). Do you have a better solution? What would be the impact on the webdev economy (or your life) if all browsers were compatible? Addendum Because the above turned out not to work with the new Firefox 3.5.3 (strangely, was OK with 3.5.2 when I tested it) I decided to cut the crap and use the ‘Dynamic Publishing’ way. Ok, so it won’t work for people who have javascript disabled, but who on earth would have flash installed AND javascript disabled? To avoid the IE6 error with the ‘Dynamic Publishing’ way, I call swfobject.embedSWF right after the div that will be replaced with the flash content. Calling swfobject.embedSWF in the <head> would otherwise give me the above error in IE6 again.

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  • SQLBits - Unicode Porn

    - by Most Valuable Yak (Rob Volk)
    We've just finished up a fantastic event at SQLBits X in London!  If you've never been to SQLBits and you can make it to the UK, I highly recommend it.  If you didn't attend, here's what you missed. Meanwhile, for those who attended the Lightning Talk sessions and were disappointed that I ran out of time, here's the last part that you would have seen: /*    How to Lose Friends and Irritate People...With Unicode!     Rob Volk     SQLBits X - London - March 31, 2012 */ -- some sexy SQL DECLARE @oohbaby TABLE(i INT NOT NULL UNIQUE, uni_char AS NCHAR(i), hex AS CAST(i AS BINARY(2))) INSERT @oohbaby VALUES(664),(1022),(1023),(1120),(1150),(8857),(11609),(42420),(42427) -- change results font to larger size, some only work in grid font SELECT * FROM @oohbaby SELECT NCHAR(1022) + NCHAR(1023) AS Page3Girl It's probably better that you run this yourself, in the privacy of your own home/office, you know *wink* *wink* *nudge* *nudge* *say no more*

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  • July, the 31 Days of SQL Server DMO’s – Day 22 (sys.dm_db_index_physical_stats)

    - by Tamarick Hill
    The sys.dm_db_index_physical_stats Dynamic Management Function is used to return information about the fragmentation levels, page counts, depth, number of levels, record counts, etc. about the indexes on your database instance. One row is returned for each level in a given index, which we will discuss more later. The function takes a total of 5 input parameters which are (1) database_id, (2) object_id, (3) index_id, (4) partition_number, and (5) the mode of the scan level that you would like to run. Let’s use this function with our AdventureWorks2012 database to better illustrate the information it provides. SELECT * FROM sys.dm_db_index_physical_stats(db_id('AdventureWorks2012'), NULL, NULL, NULL, NULL) As you can see from the result set, there is a lot of beneficial information returned from this DMF. The first couple of columns in the result set (database_id, object_id, index_id, partition_number, index_type_desc, alloc_unit_type_desc) are either self-explanatory or have been explained in our previous blog sessions so I will not go into detail about these at this time. The next column in the result set is the index_depth which represents how deep the index goes. For example, If we have a large index that contains 1 root page, 3 intermediate levels, and 1 leaf level, our index depth would be 5. The next column is the index_level which refers to what level (of the depth) a particular row is referring to. Next is probably one of the most beneficial columns in this result set, which is the avg_fragmentation_in_percent. This column shows you how fragmented a particular level of an index may be. Many people use this column within their index maintenance jobs to dynamically determine whether they should do REORG’s or full REBUILD’s of a given index. The fragment count represents the number of fragments in a leaf level while the avg_fragment_size_in_pages represents the number of pages in a fragment. The page_count column tells you how many pages are in a particular index level. From my result set above, you see the the remaining columns all have NULL values. This is because I did not specify a ‘mode’ in my query and as a result it used the ‘LIMITED’ mode by default. The LIMITED mode is meant to be lightweight so it does collect information for every column in the result set. I will re-run my query again using the ‘DETAILED’ mode and you will see we now have results for these rows. SELECT * FROM sys.dm_db_index_physical_stats(db_id('AdventureWorks2012'), NULL, NULL, NULL, ‘DETAILED’)   From the remaining columns, you see we get even more detailed information such as how many records are in a particular index level (record_count). We have a column for ghost_record_count which represents the number of records that have been marked for deletion, but have not physically been removed by the background ghost cleanup process. We later see information on the MIN, MAX, and AVG record size in bytes. The forwarded_record_count column refers to records that have been updated and now no longer fit within the row on the page anymore and thus have to be moved. A forwarded record is left in the original location with a pointer to the new location. The last column in the result set is the compressed_page_count column which tells you how many pages in your index have been compressed. This is a very powerful DMF that returns good information about the current indexes in your system. However, based on the mode you select, it could be a very resource intensive function so be careful with how you use it. For more information on this Dynamic Management Function, please see the below Books Online link: http://msdn.microsoft.com/en-us/library/ms188917.aspx Follow me on Twitter @PrimeTimeDBA

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  • Ray picking - get direction from pitch and yaw

    - by Isaac Waller
    I am attempting to cast a ray from the center of the screen and check for collisions with objects. When rendering, I use these calls to set up the camera: GL11.glRotated(mPitch, 1, 0, 0); GL11.glRotated(mYaw, 0, 1, 0); GL11.glTranslated(mPositionX, mPositionY, mPositionZ); I am having trouble creating the ray, however. This is the code I have so far: ray.origin = new Vector(mPositionX, mPositionY, mPositionZ); ray.direction = new Vector(?, ?, ?); My question is: what should I put in the question mark spots? I.e. how can I create the ray direction from the pitch and roll? Any help would be much appreciated!

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  • GNOME panel crash

    - by josh
    when trying to log in using gnome-classic on ubuntu 11.10 gnome-panel crashes. I can still see the desktop and i can open applications via terminal but when i try to run gnome-panel using "gnome-panel" or "gnome-panel --replace" it crashes with this error: (gnome-panel:9694): Gtk-CRITICAL **: gtk_style_context_get: assertion `priv->widget_path != NULL' failed (gnome-panel:9694): Gtk-CRITICAL **: gtk_style_context_get: assertion `priv->widget_path != NULL' failed (gnome-panel:9694): GLib-GObject-WARNING **: invalid uninstantiatable type `(null)' in cast to `PanelWidget' gnome-panel: /build/buildd/cairo-1.10.2/src/cairo-pattern.c:764: cairo_pattern_reference: Assertion `((*&(&pattern->ref_count)->ref_count) > 0)' failed. Aborted

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  • Oracle ‘In Touch’ PartnerCast – Be prepared for a year of growth!

    - by Claudia Caramelli-Oracle
    Dear partner, you are warmly welcomed to join your host David Callaghan, Senior Vice President Alliances & Channels - Oracle EMEA, for the latest headlines from the Oracle Partner Network. With a strong focus on direct partner benefit, 'In Touch' is your chance to stay up to date, share best practices and pose those burning questions to Oracle that you would like answered. In this next cast, David’s studio guests and his regional reporters will be looking at the priorities for EMEA partners and how best to grow with Oracle as we move into the new financial year. So please click here and register now!This partnercast will be held on Jul 01, 2014 from10:30am to 11:15am GMT.  Don't miss this opportunity and follow the conversation on Twitter searching for #OracleInTouch hashtag.

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  • Odd MVC 4 Beta Razor Designer Issue

    - by Rick Strahl
    This post is a small cry for help along with an explanation of a problem that is hard to describe on twitter or even a connect bug and written in hopes somebody has seen this before and any ideas on what might cause this. Lots of helpful people had comments on Twitter for me, but they all assumed that the code doesn't run, which is not the case - it's a designer issue. A few days ago I started getting some odd problems in my MVC 4 designer for an app I've been working on for the past 2 weeks. Basically the MVC 4 Razor designer keeps popping me errors, about the call signature to various Html Helper methods being incorrect. It also complains about the ViewBag object and not supporting dynamic requesting to load assemblies into the project. Here's what the designer errors look like: You can see the red error underlines under the ViewBag and an Html Helper I plopped in at the top to demonstrate the behavior. Basically any HtmlHelper I'm accessing is showing the same errors. Note that the code *runs just fine* - it's just the designer that is complaining with Errors. What's odd about this is that *I think* this started only a few days ago and nothing consequential that I can think of has happened to the project or overall installations. These errors aren't critical since the code runs but pretty annoying especially if you're building and have .csHtml files open in Visual Studio mixing these fake errors with real compiler errors. What I've checked Looking at the errors it indeed looks like certain references are missing. I can't make sense of the Html Helpers error, but certainly the ViewBag dynamic error looks like System.Core or Microsoft.CSharp assemblies are missing. Rest assured they are there and the code DOES run just fine at runtime. This is a designer issue only. I went ahead and checked the namespaces that MVC has access to in Razor which lives in the Views folder's web.config file: /Views/web.config For good measure I added <system.web.webPages.razor> <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, <split for layout> Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" /> <pages pageBaseType="System.Web.Mvc.WebViewPage"> <namespaces> <add namespace="System.Web.Mvc" /> <add namespace="System.Web.Mvc.Ajax" /> <add namespace="System.Web.Mvc.Html" /> <add namespace="System.Web.Routing" /> <add namespace="System.Linq" /> <add namespace="System.Linq.Expressions" /> <add namespace="ClassifiedsBusiness" /> <add namespace="ClassifiedsWeb"/> <add namespace="Westwind.Utilities" /> <add namespace="Westwind.Web" /> <add namespace="Westwind.Web.Mvc" /> </namespaces> </pages> </system.web.webPages.razor> For good measure I added System.Linq and System.Linq.Expression on which some of the Html.xxxxFor() methods rely, but no luck. So, has anybody seen this before? Any ideas on what might be causing these issues only at design time rather, when the final compiled code runs just fine?© Rick Strahl, West Wind Technologies, 2005-2012Posted in Razor  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • 3D Ray Casting / Picking

    - by Chris
    Hi, I am not sure if I should post this link, but I feel this falls into game development just as much as it does math. I have a ray cast's far and near values and I am trying to calculate the end point of the ray so that I can either draw a line to show the ray, or render an object at the end of 3d mouse position. Here is my post on the stack overflow math site, if there is a problem with me doing this just close the thread. Thank you. http://math.stackexchange.com/questions/15918/help-with-matrix-mathematica

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  • Adventures in MVVM &ndash; ViewModel Location and Creation

    - by Brian Genisio's House Of Bilz
    More Adventures in MVVM In this post, I am going to explore how I prefer to attach ViewModels to my Views.  I have published the code to my ViewModelSupport project on CodePlex in case you'd like to see how it works along with some examples.  Some History My approach to View-First ViewModel creation has evolved over time.  I have constructed ViewModels in code-behind.  I have instantiated ViewModels in the resources sectoin of the view. I have used Prism to resolve ViewModels via Dependency Injection. I have created attached properties that use Dependency Injection containers underneath.  Of all these approaches, I continue to find issues either in composability, blendability or maintainability.  Laurent Bugnion came up with a pretty good approach in MVVM Light Toolkit with his ViewModelLocator, but as John Papa points out, it has maintenance issues.  John paired up with Glen Block to make the ViewModelLocator more generic by using MEF to compose ViewModels.  It is a great approach, but I don’t like baking in specific resolution technologies into the ViewModelSupport project. I bring these people up, not to name drop, but to give them credit for the place I finally landed in my journey to resolve ViewModels.  I have come up with my own version of the ViewModelLocator that is both generic and container agnostic.  The solution is blendable, configurable and simple to use.  Use any resolution mechanism you want: MEF, Unity, Ninject, Activator.Create, Lookup Tables, new, whatever. How to use the locator 1. Create a class to contain your resolution configuration: public class YourViewModelResolver: IViewModelResolver { private YourFavoriteContainer container = new YourFavoriteContainer(); public YourViewModelResolver() { // Configure your container } public object Resolve(string viewModelName) { return container.Resolve(viewModelName); } } Examples of doing this are on CodePlex for MEF, Unity and Activator.CreateInstance. 2. Create your ViewModelLocator with your custom resolver in App.xaml: <VMS:ViewModelLocator x:Key="ViewModelLocator"> <VMS:ViewModelLocator.Resolver> <local:YourViewModelResolver /> </VMS:ViewModelLocator.Resolver> </VMS:ViewModelLocator> 3. Hook up your data context whenever you want a ViewModel (WPF): <Border DataContext="{Binding YourViewModelName, Source={StaticResource ViewModelLocator}}"> This example uses dynamic properties on the ViewModelLocator and passes the name to your resolver to figure out how to compose it. 4. What about Silverlight? Good question.  You can't bind to dynamic properties in Silverlight 4 (crossing my fingers for Silverlight 5), but you CAN use string indexing: <Border DataContext="{Binding [YourViewModelName], Source={StaticResource ViewModelLocator}}"> But, as John Papa points out in his article, there is a silly bug in Silverlight 4 (as of this writing) that will call into the indexer 6 times when it binds.  While this is little more than a nuisance when getting most properties, it can be much more of an issue when you are resolving ViewModels six times.  If this gets in your way, the solution (as pointed out by John), is to use an IndexConverter (instantiated in App.xaml and also included in the project): <Border DataContext="{Binding Source={StaticResource ViewModelLocator}, Converter={StaticResource IndexConverter}, ConverterParameter=YourViewModelName}"> It is a bit uglier than the WPF version (this method will also work in WPF if you prefer), but it is still not all that bad.  Conclusion This approach works really well (I suppose I am a bit biased).  It allows for composability from any mechanisim you choose.  It is blendable (consider serving up different objects in Design Mode if you wish... or different constructors… whatever makes sense to you).  It works in Cider.  It is configurable.  It is flexible.  It is the best way I have found to manage View-First ViewModel hookups.  Thanks to the guys mentioned in this article for getting me to something I love using.  Enjoy.

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  • ASP.NET Podcast Show #149 - MonoDroid Development on the Apple Macintosh OSX

    - by Wallym
    Given that I have a cast on my arm, I installed the MonoDroid Development Framework for Apple Macs today.  I walked through it and found that things are pretty much the same as with the MonoDroid plugin for Visual Studio 2010.  This post shows the video displaying this.  This video is based on MonoDroid Preview 11.1. Subscribe to everything. Subscribe to WMV. Subscribe to M4V for iPhone/iPad. Subscribe to MP3. Download WMV. Download M4V. Download MP4. Download MP3.

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  • Raycasting tutorial / vector math question

    - by mattboy
    I'm checking out this nice raycasting tutorial at http://lodev.org/cgtutor/raycasting.html and have a probably very simple math question. In the DDA algorithm I'm having trouble understanding the calcuation of the deltaDistX and deltaDistY variables, which are the distances that the ray has to travel from 1 x-side to the next x-side, or from 1 y-side to the next y-side, in the square grid that makes up the world map (see below screenshot). In the tutorial they are calculated as follows, but without much explanation: //length of ray from one x or y-side to next x or y-side double deltaDistX = sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX)); double deltaDistY = sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY)); rayDirY and rayDirX are the direction of a ray that has been cast. How do you get these formulas? It looks like pythagorean theorem is part of it, but somehow there's division involved here. Can anyone clue me in as to what mathematical knowledge I'm missing here, or "prove" the formula by showing how it's derived?

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  • Question about casting a class in Java with generics

    - by Florian F
    In Java 6 Class<? extends ArrayList<?>> a = ArrayList.class; gives and error, but Class<? extends ArrayList<?>> b = (Class<? extends ArrayList<?>>)ArrayList.class; gives a warning. Why is (a) an error? What is it, that Java needs to do in the assignment, if not the cast shown in (b)? And why isn't ArrayList compatible with ArrayList? I know one is "raw" and the other is "generic", but what is it you can do with an ArrayList and not with an ArrayList, or the other way around?

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  • Obsolete Computer Parts as Art [DIY]

    - by Jason Fitzpatrick
    If you’re like most geeks, you’ve got a box of aging computer equipment you just haven’t got around to hauling to your city’s haz-mat drop off site. This simple tutorial turns cast off circuit boards into wall art. While the author of the tutorial opted to use motherboards, you could easily use smaller frames/mats and use old expansion boards too. The process involves inexpensive IKEA frames with mats, popping the I/O ports off the boards to make them thinner, and drilling small mount holes in the backer board to mount the boards in place. Hit up the link below for more details. Motherboard Art [via IKEAHackers] How to Use an Xbox 360 Controller On Your Windows PC Download the Official How-To Geek Trivia App for Windows 8 How to Banish Duplicate Photos with VisiPic

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  • Proactive Support Sessions at OUG London and OUG Ireland

    - by THE
    .conf td { width: 350px; border: 1px solid black; background-color: #ffcccc; } table { border: 1px solid black; } tr { border: 0px solid black; } td { border: 1px solid black; padding: 5px; } Oracle Proactive Support Technology is proud to announce that two members of its team will be speaking at the UK and Ireland User Group Conferences this year. Maurice and Greg plan to run the following sessions (may be subject to change): Maurice Bauhahn OUG Ireland BI & EPM and Technology Joint SIG Meeting 20 November 2012 BI&EPM SIG event in Ireland (09:00-17:00) and OUG London EPM & Hyperion Conference 2012 Tuesday 23rd to Wednesday 24th Oct 2012 Profit from Oracle Diagnostic Tools Embedded in EPM Oracle bundles in many of its software suites valuable toolsets to collect logs and settings, slice/dice error messages, track performance, and trace activities across services. Become familiar with several enterprise-level diagnostic tools embedded in Enterprise Performance Management (Enterprise Manager Fusion Middleware Control, Remote Diagnostic Agent, Dynamic Monitoring Service, and Oracle Diagnostic Framework). Expedite resolution of Service Requests as you learn to upload output from these tools to My Oracle Support. Who will benefit from attending the session? Geeks will find this most beneficial, but anyone who raises Oracle technical service requests will learn valuable pointers that may speed resolution. The focus is on the EPM stack, but this session will benefit almost everyone who needs to drill deeper into Oracle software environments. What will delegates learn from the session? Delegates who participate in this session will learn: How to access and run Remote Diagnostic Agent, Enterprise Manager Fusion Middleware Control, Dynamic Monitoring Service, and Oracle Diagnostic Framework. How to exploit the strengths of each tool. How to pass the outputs to My Oracle Support. How to restrict exposure of sensitive information. OUG Ireland BI & EPM and Technology Joint SIG Meeting 20 November 2012 BI&EPM SIG event in Ireland (09:00-17:00) and OUG London EPM & Hyperion Conference 2012 Tuesday 23rd to Wednesday 24th Oct 2012 Using EPM-Specific Troubleshooting Tools EPM developers have created a number of EPM-specific tools to collect logs and configuration files, centralize configuration information, and validate a configured installation (Ziplogs, EPM Registry Editor, [Deployment Report, Registry Cleanup Utility, Reset Configuration Tool, EPMSYS Hostname Check] and Validate [EPM System Diagnostic]). Learn how to use these tools on your own or to expedite Service Request resolution. Who will benefit from attending the session? Anyone who monitors Oracle EPM environments or raises service requests will learn valuable lessons that could speed resolution of those requests. Anyone from novices to experts will benefit from this review of custom troubleshooting EPM tools. What will delegates learn from the session? Learn where to locate and start EPM troubleshooting tools created by EPM developers Learn how to collect and upload outputs of EPM troubleshooting tools. Adapt to history of changes in these tools across time and version. Learn how to make critical changes in configurations. Grzegorz Reizer OUG London EPM & Hyperion Conference 2012 Tuesday 23rd to Wednesday 24th Oct 2012 EPM 11.1.2.2: Detailed overview of new features and improvements in Financial Management products. This presentation is a detailed overview of new features and improvements introduced in Enterprise Performance Management 11.1.2.2 for Financial Management products (Hyperion Financial Managment, Hyperion Planning, Financial Close Management). The presentation will cover a number of new product features from recently introduced configurable dimensionality in HFM to new functionality enhancements in Planning. We'll close the session with an overview of upgrade options from earlier product releases.

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  • SQLPASS BoD Polls Close this Friday

    - by RickHeiges
    Research, Contemplate, Vote. In case you didn't hear, there is a campaign going on that impacts the PASS Organization and the SQL Community. If you were a PASS member before June 1, 2012, you should have received a ballot link via email. Polls close at 3pm PT on Friday, Oct 12, 2012. I am fortunate to know all 5 candidates for this year's election and count them among my friends. The problem that I have is that I only have 3 votes to cast. At this point, I have decided on 2 of my 3 votes. Since I...(read more)

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  • Interop effects by resolving and instantiating types with ArcObjects

    - by Marko Apfel
    Problem this code does not work Type t = typeof(ESRI.ArcGIS.Framework.AppRefClass); System.Object obj = Activator.CreateInstance(t); but yet this code Type t = Type.GetTypeFromCLSID(typeof(ESRI.ArcGIS.Framework.AppRefClass).GUID); System.Object obj = Activator.CreateInstance(t); Reason In the first variant the runtime tries to cast to AppRefClass . This is not possible. And in the second one, the runtime does not knows anything about AppRefClass. So it leave it as IUnknown.   (originally communicated by my co-worker Ralf)

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  • Implementing a modern web application with Web API on top of old services

    - by Gaui
    My company has many WCF services which may or may not be replaced in the near future. The old web application is written in WebForms and communicates straight with these services via SOAP and returns DataTables. Now I am designing a new modern web application in a modern style, an AngularJS client which communicates with an ASP.NET Web API via JSON. The Web API then communicates with the WCF services via SOAP. In the future I want to let the Web API handle all requests and go straight to the database, but because the business logic implemented in the WCF services is complicated it's going to take some time to rewrite and replace it. Now to the problem: I'm trying to make it easy in the near future to replace the WCF services with some other data storage, e.g. another endpoint, database or whatever. I also want to make it easy to unit test the business logic. That's why I have structured the Web API with a repository layer and a service layer. The repository layer has a straight communication with the data storage (WCF service, database, or whatever) and the service layer then uses the repository (Dependency Injection) to get the data. It doesn't care where it gets the data from. Later on I can be in control and structure the data returned from the data storage (DataTable to POCO) and be able to test the logic in the service layer with some mock repository (using Dependency Injection). Below is some code to explain where I'm going with this. But my question is, does this all make sense? Am I making this overly complicated and could this be simplified in any way possible? Does this simplicity make this too complicated to maintain? My main goal is to make it as easy as possible to switch to another data storage later on, e.g. an ORM and be able to test the logic in the service layer. And because the majority of the business logic is implemented in these WCF services (and they return DataTables), I want to be in control of the data and the structure returned to the client. Any advice is greatly appreciated. Update 20/08/14 I created a repository factory, so services would all share repositories. Now it's easy to mock a repository, add it to the factory and create a provider using that factory. Any advice is much appreciated. I want to know if I'm making things more complicated than they should be. So it looks like this: 1. Repository Factory public class RepositoryFactory { private Dictionary<Type, IServiceRepository> repositories; public RepositoryFactory() { this.repositories = new Dictionary<Type, IServiceRepository>(); } public void AddRepository<T>(IServiceRepository repo) where T : class { if (this.repositories.ContainsKey(typeof(T))) { this.repositories.Remove(typeof(T)); } this.repositories.Add(typeof(T), repo); } public dynamic GetRepository<T>() { if (this.repositories.ContainsKey(typeof(T))) { return this.repositories[typeof(T)]; } throw new RepositoryNotFoundException("No repository found for " + typeof(T).Name); } } I'm not very fond of dynamic but I don't know how to retrieve that repository otherwise. 2. Repository and service // Service repository interface // All repository interfaces extend this public interface IServiceRepository { } // Invoice repository interface // Makes it easy to mock the repository later on public interface IInvoiceServiceRepository : IServiceRepository { List<Invoice> GetInvoices(); } // Invoice repository // Connects to some data storage to retrieve invoices public class InvoiceServiceRepository : IInvoiceServiceRepository { public List<Invoice> GetInvoices() { // Get the invoices from somewhere // This could be a WCF, a database, or whatever using(InvoiceServiceClient proxy = new InvoiceServiceClient()) { return proxy.GetInvoices(); } } } // Invoice service // Service that handles talking to a real or a mock repository public class InvoiceService { // Repository factory RepositoryFactory repoFactory; // Default constructor // Default connects to the real repository public InvoiceService(RepositoryFactory repo) { repoFactory = repo; } // Service function that gets all invoices from some repository (mock or real) public List<Invoice> GetInvoices() { // Query the repository return repoFactory.GetRepository<IInvoiceServiceRepository>().GetInvoices(); } }

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  • Silverlight Cream for May 27, 2010 -- #871

    - by Dave Campbell
    In this Issue: Phil Middlemiss, Max Paulousky, Jeff Wilcox, David Anson, René Schulte, Xianzhong Zhu, Jeff Handley, John Papa, Jeremy Likness, and Marlon Grech. Shoutouts: SilverLaw has a great demo at the Expression Gallery, and we're all going to look forward to the blog post explaining it: Flexible Surface Effect SilverLaw> has another use for the above in this text morphing Effect: Morphing Text Effect Matthias Shapiro contributed a chapter for a book on Visualization and it's available as a free download: Free Chapter From Beautiful Visualization Andy Beaulieu has a demo up as almost a spoiler for a future Coding4Fun app... and how cool is this: Shuffleboard: A Windows Phone 7 Sample Game From SilverlightCream.com: Separating Content and Presentation with the ContentControl Phil Middlemiss' latest is out on SilverlightShow and is all about the ContentControl and separating layout and content ... demo project source included Search Engine Optimization (SEO) for Silverlight Applications. Part 1 Max Paulousky has part one of a long series he's starting on a demo project to explain a bunch of MEF, MVVM, and WCF RIA concepts. This first one contains the overview and also discusses SEO. There is a link to the app and material in the post if you read Russian :) Updated Silverlight Unit Test Framework bits for Windows Phone and Silverlight 3 Jeff Wilcox has available updated Unit Test bits for Silverlight 3 -- read that as WP7... read the rest of the information on his post. Easily animate orientation changes for any Windows Phone application with this handy source code David Anson has some code up that you're going to want if you're programming WP7 ... just watch the video ... you'll be downloading the code just like I did :) SilverShader – Introduction to Silverlight and WPF Pixel Shaders René Schulte has a post up at Coding4Fun about PixelShaders... how to write them and an application that uses them... this is a great long tutorial... a must read. Developing Freecell Game Using Silverlight 3 Part 2 Xianzhong Zhu has part 2 of his FreeCell game development posted ... lots of detailed descriptions and code, plus all the code of course! Async Validation with RIA Services Jeff Handley has a post up that is sort of a follow-on to a year-old post on async validation with RIA services and DataForm and how it's all much easier now in SL4. Learning Blend with .toolbox (Silverlight TV #29) John Papa and Arturo Toledo discuss .toolbox in Silverlight TV #29 -- have you made yourself an avatar yet? ... well go get on-board with this great learning tool! Silverlight Out of Browser Dynamic Modules in Offline Mode OOB isn't difficult, dynamic modules can become a bit more, but what if you're OOB... ok what if you're OOB and offline? ... Jeremy Likness has a possible solution for this with an OfflineCatalog. MEFedMVVM v1.0 Explained Marlon Grech has a great into to MEFedMVVM in this post. If you're trying to get your head around MEF and MVVM in either WPF or Silverlight, here's a good starting point. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • First time shadow mapping problems

    - by user1294203
    I have implemented basic shadow mapping for the first time in OpenGL using shaders and I'm facing some problems. Below you can see an example of my rendered scene: The process of the shadow mapping I'm following is that I render the scene to the framebuffer using a View Matrix from the light point of view and the projection and model matrices used for normal rendering. In the second pass, I send the above MVP matrix from the light point of view to the vertex shader which transforms the position to light space. The fragment shader does the perspective divide and changes the position to texture coordinates. Here is my vertex shader, #version 150 core uniform mat4 ModelViewMatrix; uniform mat3 NormalMatrix; uniform mat4 MVPMatrix; uniform mat4 lightMVP; uniform float scale; in vec3 in_Position; in vec3 in_Normal; in vec2 in_TexCoord; smooth out vec3 pass_Normal; smooth out vec3 pass_Position; smooth out vec2 TexCoord; smooth out vec4 lightspace_Position; void main(void){ pass_Normal = NormalMatrix * in_Normal; pass_Position = (ModelViewMatrix * vec4(scale * in_Position, 1.0)).xyz; lightspace_Position = lightMVP * vec4(scale * in_Position, 1.0); TexCoord = in_TexCoord; gl_Position = MVPMatrix * vec4(scale * in_Position, 1.0); } And my fragment shader, #version 150 core struct Light{ vec3 direction; }; uniform Light light; uniform sampler2D inSampler; uniform sampler2D inShadowMap; smooth in vec3 pass_Normal; smooth in vec3 pass_Position; smooth in vec2 TexCoord; smooth in vec4 lightspace_Position; out vec4 out_Color; float CalcShadowFactor(vec4 lightspace_Position){ vec3 ProjectionCoords = lightspace_Position.xyz / lightspace_Position.w; vec2 UVCoords; UVCoords.x = 0.5 * ProjectionCoords.x + 0.5; UVCoords.y = 0.5 * ProjectionCoords.y + 0.5; float Depth = texture(inShadowMap, UVCoords).x; if(Depth < (ProjectionCoords.z + 0.001)) return 0.5; else return 1.0; } void main(void){ vec3 Normal = normalize(pass_Normal); vec3 light_Direction = -normalize(light.direction); vec3 camera_Direction = normalize(-pass_Position); vec3 half_vector = normalize(camera_Direction + light_Direction); float diffuse = max(0.2, dot(Normal, light_Direction)); vec3 temp_Color = diffuse * vec3(1.0); float specular = max( 0.0, dot( Normal, half_vector) ); float shadowFactor = CalcShadowFactor(lightspace_Position); if(diffuse != 0 && shadowFactor > 0.5){ float fspecular = pow(specular, 128.0); temp_Color += fspecular; } out_Color = vec4(shadowFactor * texture(inSampler, TexCoord).xyz * temp_Color, 1.0); } One of the problems is self shadowing as you can see in the picture, the crate has its own shadow cast on itself. What I have tried is enabling polygon offset (i.e. glEnable(POLYGON_OFFSET_FILL), glPolygonOffset(GLfloat, GLfloat) ) but it didn't change much. As you see in the fragment shader, I have put a static offset value of 0.001 but I have to change the value depending on the distance of the light to get more desirable effects , which not very handy. I also tried using front face culling when I render to the framebuffer, that didn't change much too. The other problem is that pixels outside the Light's view frustum get shaded. The only object that is supposed to be able to cast shadows is the crate. I guess I should pick more appropriate projection and view matrices, but I'm not sure how to do that. What are some common practices, should I pick an orthographic projection? From googling around a bit, I understand that these issues are not that trivial. Does anyone have any easy to implement solutions to these problems. Could you give me some additional tips? Please ask me if you need more information on my code. Here is a comparison with and without shadow mapping of a close-up of the crate. The self-shadowing is more visible.

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  • A Quantity class with units

    - by Ryan Ohs
    Goals Create a class that associates a numeric quantity with a unit of measurement. Provide support for simple arithmetic and comparison operations. Implementation An immutable class (Could have been struct but I may try inheritance later) Unit is stored in an enumeration Supported operations: Addition w/ like units Subtraction w/ like units Multiplication by scalar Division by scalar Modulus by scalar Equals() >, >=, <, <=, == IComparable ToString() Implicit cast to Decimal The Source The souce can be downloaded from Github. Notes This class does not support any arithmetic that would modify the unit. This class is not suitable for manipulating currencies. Future Ideas Have a CompositeQuantity class that would allow quantities with unlike units to be combined. Similar currency class with support for allocations/distributions. Provide conversion between units. (Actually I think this would be best placed in an external service. Many situations I deal with require some sort of dynamic conversion ratio.)

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