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  • DevDays ‘00 The Netherlands day #2

    - by erwin21
    Day 2 of DevDays 2010 and again 5 interesting sessions at the World Forum in The Hague. The first session of the today in the big world forum theater was from Scott Hanselman, he gives a lap around .NET 4.0. In his way of presenting he talked about all kind of new features of .NET 4.0 like MEF, threading, parallel processing, changes and additions to the CLR and DLR, WPF and all new language features of .NET 4.0. After a small break it was ready for session 2 from Scott Allen about Tips, Tricks and Optimizations of LINQ. He talked about lazy and deferred executions, the difference between IQueryable and IEnumerable and the two flavors of LINQ syntax. The lunch was again very good prepared and delicious, but after that it was time for session 3 Web Vulnerabilities and Exploits from Alex Thissen. This was no normal session but more like a workshop, we decided what kind of subjects we discussed, the subjects where OWASP, XSS and other injections, validation, encoding. He gave some handy tips and tricks how to prevent such attacks. Session 4 was about the new features of C# 4.0 from Alex van Beek. He talked about Optional- en Named Parameters, Generic Co- en Contra Variance, Dynamic keyword and COM Interop features. He showed how to use them but also when not to use them. The last session of today and also the last session of DevDays 2010 was about WCF Best Practices from Gerben van Loon. He talked about 7 best practices that you must know when you are going to use WCF. With some quick demos he showed the problem and the solution for some common issues. It where two interesting days and next year i sure will be attending again.

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  • Freeing disk space on Ubuntu to use in Windows

    - by Alex
    I have 250Gb drive on a laptop, which has Windows 7 on a 122Gb ntfs partition (which has a "boot" flag on it) and Ubuntu 12.04.1 on a 110Gb extended partition, of which the root ext4 partition is 108Gb and the swap is 1.74Gb. You can see everything in the screenshot below. My question is: I want to diminish the size of the linux root partition and then use that space to increase the windows partition. How do I do that? Also, is it possible to increase the size of the swap partition and not do any damage? If so, how? I'm using GParted, and i'd say i'm pretty confident with it. Screenshot of my partitions

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  • 2D Procedural Terrain with box2d Assets

    - by Alex
    I'm making a game that invloves a tire moving through terrain that is generated randomly over 1000 points. The terrain is always a downwards incline like so: The actual box2d terrain extends one screen width behind and infront of the circular character. I'm now at a stage where I need to add gameplay elements to the terrain such as chasms or physical objects (like the demo polygon in the picture) and am not sure of the best way to structure the procedural generation of the terrain and objects. I currently have a very simple for loop like so: for(int i = 0; i < kMaxHillPoints; i++) { hillKeyPoints[i] = CGPointMake(terrainX, terrainY); if(i%50 == 0) { i += [self generateCasmAtIndex:i]; } terrainX += winsize.width/20; terrainY -= random() % ((int) winsize.height/20); } With the generateCasmAtIndex function add points to the hillKeyPoints array and incrementing the for loop by the required amount. If I want to generate box2d objects as well for specific terrain elements, I'll also have to keep track of the current position of the player and have some sort of array of box2d objects that need to be created at certain locations. I am not sure of an efficient way to accomplish this procedural generation of terrain elements with accompanying box2d objects. My thoughts are: 1) Have many functions for each terrain element (chasm, jump etc.) which add elements to be drawn to an array that is check on each game step - similar to what I've shown above. 2) Create an array of terrain element objects that string together and are looped over to create the terrain and generate the box2d objects. Each object would hold an array of points to be drawn and and array of accompanying box2d objects. Any help on this is much appreciated as I cannot see a 'clean' solution.

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  • Why did Apple remove Python support in Mavericks, aka Mac OS X 10.9?

    - by alex gray
    Apple has removed Python support (at least on the Developer level) in 10.9. Python IS still on the machine in /System/Library/Frameworks/Python.framework... but trying to link to Python using the 10.9 SDK fails. /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/System/Library/Frameworks does not have Python. I'm not a Pythonista, but find it interesting that Apple has made this change. I don't understand why this is done and I'm a bit annoyed that I have to remove Python from my compilation units in order to compile with 10.9 SDK. Is this a statement by Apple, along the lines of "People aren't using Python very much anymore so we're going to phase out support"? Or was something else driving the change?

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  • Libraries for eclipse with CCSv5 from Texas Instruments

    - by Alex
    My system is Ubuntu 11.10 64bit and i have to run a 32bit version of eclipse to use the TI plugins for CCSv5 but it doesn't work. I tried to run eclipse in a 62bit java environment but it doesn't even start. Now I got "java version "1.6.0_30"" from Sun in 32bit and now eclipse starts but can't use the TI plug ins and I get the following errors in bash: /usr/lib/gtk-2.0/2.10.0/menuproxies/libappmenu.so: falsche ELF-Klasse: ELFCLASS64 /usr/lib/gio/modules/libgvfsdbus.so: falsche ELF-Klasse: ELFCLASS64 Failed to load module: /usr/lib/gio/modules/libgvfsdbus.so and this in a popup-window when Itry to use the plugin: The selected wizard could not be started. Plug-in com.ti.ccstudio.project.ui was unable to load class com.ti.ccstudio.project.ui.internal.wizards.importexport.temp.ExternalProjectImportWizard. An error occurred while automatically activating bundle com.ti.ccstudio.project.ui (352). T tested the libraries with file: /usr/lib/gio/modules/libgvfsdbus.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, stripped /usr/lib/gtk-2.0/2.10.0/menuproxies/libappmenu.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, stripped The ia32-libs are installed.

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  • Exporting SWF With Transparent Background For Scaleform/UDK

    - by Alex Shepard
    After looking all over in the UDN and forums I have yet to find a solution for this: I am currently using Flash CS3 and Actionscript 2.0 to build my scaleform menus and I can use them in the UDK. For various reasons I can't use the handy plugin Autodesk supplies to enable this export so I publish my flash documents to swf the old fassioned way and manually use the gfxexport.exe tool to get my .gfx file. I can then import into the UDK the normal way. My problem is that the flash movies that I import will not alpha blend even if the material is set to blend in the alpha channel of the target render texture. My project images are set up to export properly. My classpath for Actionscript 2.0 is set to the correct location. My HTML publish settings have window mode set to Transparent Windowless. Is it possible to export without the scaleform flash extension and still get the desired effects and if so how might I do so? Am I merely missing something from my project setup?

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  • Optimized Integration between Oracle Data Integrator and Oracle GoldenGate

    - by Alex Kotopoulis
    The Journalizing Knowledge Module for Oracle GoldenGate's CDC mechanism has just been released as part of the ODI 10.1.3.6_02 patch, and a very useful post from Mark Rittman gives detailed instructions about how to set it up in a sample environment. This integration combines the best of two worlds, the non-invasive, highly performant data replication from Oracle GoldenGate with the innovative and scalable EL-T concept from ODI to perform complex loads into real-time data warehouses. Please also check out the new datasheet about this integration.

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  • Would using AJAX only "Add to Cart" buttons be wise?

    - by Alex Erwin
    I want to AJAX enable all of my Add To Cart buttons because search engine bots are indexing these and not paying attention to my robots file or site map. I just don't want to loose potential customers. I have seen a number of top sites using heavily JavaScript support content, including Amazon, is it OK to follow the trend? The rest of my site progressively degrades, but I would really like to implement this because of the benefits to the customer (instant satisfaction), my infrastructure (constant page rebuilds), and allowing me to use SEO tools to optimize without the tool picking up thousands of "Add to Cart" widgets in my catalog. Thanks

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  • Unable to set my own icon for launcher item in 12.04

    - by Alex K
    I use the Faenza icon collection in Ubuntu 12.04 Unity with no issues. I decided to change my Gimp launcher icon, so I made my own (gimp-ak.png) and added it, and its appropriately sized derivatives, to the Faenza icon folders: /usr/share/icons/Faenza/apps/16/gimp-ak.png /usr/share/icons/Faenza/apps/22/gimp-ak.png /usr/share/icons/Faenza/apps/24/gimp-ak.png /usr/share/icons/Faenza/apps/32/gimp-ak.png /usr/share/icons/Faenza/apps/48/gimp-ak.png /usr/share/icons/Faenza/apps/64/gimp-ak.png /usr/share/icons/Faenza/apps/96/gimp-ak.png /usr/share/icons/Faenza/apps/scalable/gimp-ak.svg I then updated the Icon field in /usr/share/applications/gimp.desktop from "gimp" to "gimp-ak": [Desktop Entry] Version=1.0 Type=Application Name=GIMP Image Editor GenericName=Image Editor Comment=Create images and edit photographs Exec=gimp-2.6 %U TryExec=gimp-2.6 Icon=gimp-ak Terminal=false Categories=Graphics;2DGraphics;RasterGraphics;GTK; X-GNOME-Bugzilla-Bugzilla=GNOME X-GNOME-Bugzilla-Product=GIMP X-GNOME-Bugzilla-Component=General X-GNOME-Bugzilla-Version=2.6.12 X-GNOME-Bugzilla-OtherBinaries=gimp-2.6 StartupNotify=true MimeType=application/postscript;application/pdf;image/bmp;image/g3fax;image/gif;image/x-$ X-Ubuntu-Gettext-Domain=gimp20 After logging off (and even restarting), my custom icon does not show up - Gimp has the default gear icon: Setting the Icon field in gimp.desktop to any other icon in the Faenza collection works fine. What do I need to do to get my custom icon to show up properly?

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  • What do you call an obfuscator that isn't an obfuscator?

    - by Alex.Davies
    SmartAssembly, formerly {smartassembly}, version 5 is now available as an Early Access Build. You can get it here: http://www.red-gate.com/MessageBoard/viewforum.php?f=116 We're having second thoughts about the name change though. It isn't that we like the curly brackets, far from it. The trouble is that the first rule of product naming is to name a product by what it does. SmartAssembly may make an assembly smarter, but that's not something people really google for. The trouble is, I can't think of a better name for it. That's because SmartAssembly really does two completely separate things: Obfuscates Sets up your assembly for the awesome exception reports which get sent to you whenever your application crashes. You may have been (un?)lucky enough to see one in reflector if you use it. This is what those exception reports look like when they arrive back with the developer: Look at all those local variables! If you ask me, this is much cooler than the obfuscation. So obviously we don't want to call it just "Red Gate Obfuscator" or something, because it doesn't do justice to the exception reporting. What would you call it?

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  • Steam freezes at login screen

    - by Snail284069
    I have just installed Steam on Xubuntu, and after it finished installing it went to the login screen, but the screen is frozen, and I cannot press the buttons. When running Steam though the terminal it says: alex@Craptop:~$ steam Running Steam on ubuntu 14.04 32-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Gtk-Message: Failed to load module "overlay-scrollbar" Gtk-Message: Failed to load module "unity-gtk-module" Installing breakpad exception handler for appid(steam)/version(1400690891_client) [0522/174755:WARNING:proxy_service.cc(958)] PAC support disabled because there is no system implementation Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) [HTTP Remote Control] HTTP server listening on port 35849. Installing breakpad exception handler for appid(steam)/version(1400690891_client) Installing breakpad exception handler for appid(steam)/version(1400690891_client) Process 2764 created /alex-ValveIPCSharedObjects5 Installing breakpad exception handler for appid(steam)/version(1400690891_client) Generating new string page texture 12: 48x256, total string texture memory is 49.15 KB Generating new string page texture 13: 256x256, total string texture memory is 311.30 KB Generating new string page texture 14: 128x256, total string texture memory is 442.37 KB Generating new string page texture 15: 384x256, total string texture memory is 835.58 KB and then the terminal gets stuck too, letting me type into it but not doing anything. I tried reinstalling and restarting the computer, but it still keeps happening.

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  • Design pattern for procedural terrain assets

    - by Alex
    I'm developing a procedural terrain class at the moment and am stuck on the correct design pattern. The terrain is 2D and is constructed from a series of (x,y) points. I currently have a method that just randomly adds points to an array of points to generate a random spread of points. However I need a more elaborate system for generating the terrain. The terrain will be built form a series of re-accuring terrain structures eg. a pit, jump, hill etc. Each structure will have some randomness assigned to it, each height of hill will be random, pit size will be random etc. Each terrain structure will have: A property detailing the number of points making up that structure A method for generating the points (not absolutely necessary) My current thinking is to have a class for each terrain structure, create a fixed amount of terrain elements ahead of the player, loop over these and add the corresponding points to the game. What is the best way to create these procedural terrain structures when they are ultimately just a set of functions for generating terrain elements? Is a class for each terrain element excessive? I'm developing the game for iphone so any objective-c related answers would be welcome.

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  • Why not to use StackTrace to find what method called you

    - by Alex.Davies
    Our obfuscator, SmartAssembly, does some pretty crazy reflection. It's an obfuscator, it's sort of its job to do things in the most awkward way possible. But sometimes, you can go too far. One such time is this little gem from the strings encoding feature: StackTrace stackTrace = new StackTrace(); StackFrame frame = stackTrace.GetFrame(1); Type ownerType = frame.GetMethod().DeclaringType; It's designed to find the type where the calling method is defined. A user found that strings encoding occasionally broke on x64 systems. Very strange. After some debugging (thank god for Reflector Pro, it would be impossible to debug processed assemblies without it) I found that the ownerType I got back was wrong. The reason is that the x64 JIT does tail call optimisation. This saves space on the stack, and speeds things up, by throwing away a method's stack frame if the last thing that it calls is the only thing returned. When this happens, the call to StackTrace faithfully tells you that the calling method is the one that called the one we really wanted. So using StackTrace isn't safe for anything other than debugging, and it will make your code fail in unpredictable ways. Don't use it!

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  • Refactoring an immediate drawing function into VBO, access violation error

    - by Alex
    I have a MD2 model loader, I am trying to substitute its immediate drawing function with a Vertex Buffer Object one.... I am getting a really annoying access violation reading error and I can't figure out why, but mostly I'd like an opinion as to whether this looks correct (never used VBOs before). This is the original function (that compiles ok) which calculates the keyframe and draws at the same time: glBegin(GL_TRIANGLES); for(int i = 0; i < numTriangles; i++) { MD2Triangle* triangle = triangles + i; for(int j = 0; j < 3; j++) { MD2Vertex* v1 = frame1->vertices + triangle->vertices[j]; MD2Vertex* v2 = frame2->vertices + triangle->vertices[j]; Vec3f pos = v1->pos * (1 - frac) + v2->pos * frac; Vec3f normal = v1->normal * (1 - frac) + v2->normal * frac; if (normal[0] == 0 && normal[1] == 0 && normal[2] == 0) { normal = Vec3f(0, 0, 1); } glNormal3f(normal[0], normal[1], normal[2]); MD2TexCoord* texCoord = texCoords + triangle->texCoords[j]; glTexCoord2f(texCoord->texCoordX, texCoord->texCoordY); glVertex3f(pos[0], pos[1], pos[2]); } } glEnd(); What I'd like to do is to calculate all positions before hand, store them in a Vertex array and then draw them. This is what I am trying to replace it with (in the exact same part of the program) int vCount = 0; for(int i = 0; i < numTriangles; i++) { MD2Triangle* triangle = triangles + i; for(int j = 0; j < 3; j++) { MD2Vertex* v1 = frame1->vertices + triangle->vertices[j]; MD2Vertex* v2 = frame2->vertices + triangle->vertices[j]; Vec3f pos = v1->pos * (1 - frac) + v2->pos * frac; Vec3f normal = v1->normal * (1 - frac) + v2->normal * frac; if (normal[0] == 0 && normal[1] == 0 && normal[2] == 0) { normal = Vec3f(0, 0, 1); } indices[vCount] = normal[0]; vCount++; indices[vCount] = normal[1]; vCount++; indices[vCount] = normal[2]; vCount++; MD2TexCoord* texCoord = texCoords + triangle->texCoords[j]; indices[vCount] = texCoord->texCoordX; vCount++; indices[vCount] = texCoord->texCoordY; vCount++; indices[vCount] = pos[0]; vCount++; indices[vCount] = pos[1]; vCount++; indices[vCount] = pos[2]; vCount++; } } totalVertices = vCount; glEnableClientState(GL_NORMAL_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glEnableClientState(GL_VERTEX_ARRAY); glNormalPointer(GL_FLOAT, 0, indices); glTexCoordPointer(2, GL_FLOAT, sizeof(float)*3, indices); glVertexPointer(3, GL_FLOAT, sizeof(float)*5, indices); glDrawElements(GL_TRIANGLES, totalVertices, GL_UNSIGNED_BYTE, indices); glDisableClientState(GL_VERTEX_ARRAY); // disable vertex arrays glEnableClientState(GL_TEXTURE_COORD_ARRAY); glDisableClientState(GL_NORMAL_ARRAY); First of all, does it look right? Second, I get access violation error "Unhandled exception at 0x01455626 in Graphics_template_1.exe: 0xC0000005: Access violation reading location 0xed5243c0" pointing at line 7 Vec3f pos = v1->pos * (1 - frac) + v2->pos * frac; where the two Vs seems to have no value in the debugger.... Till this point the function behaves in exactly the same way as the one above, I don't understand why this happens? Thanks for any help you may be able to provide!

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  • Why lock statements don't scale

    - by Alex.Davies
    We are going to have to stop using lock statements one day. Just like we had to stop using goto statements. The problem is similar, they're pretty easy to follow in small programs, but code with locks isn't composable. That means that small pieces of program that work in isolation can't necessarily be put together and work together. Of course actors scale fine :) Why lock statements don't scale as software gets bigger Deadlocks. You have a program with lots of threads picking up lots of locks. You already know that if two of your threads both try to pick up a lock that the other already has, they will deadlock. Your program will come to a grinding halt, and there will be fire and brimstone. "Easy!" you say, "Just make sure all the threads pick up the locks in the same order." Yes, that works. But you've broken composability. Now, to add a new lock to your code, you have to consider all the other locks already in your code and check that they are taken in the right order. Algorithm buffs will have noticed this approach means it takes quadratic time to write a program. That's bad. Why lock statements don't scale as hardware gets bigger Memory bus contention There's another headache, one that most programmers don't usually need to think about, but is going to bite us in a big way in a few years. Locking needs exclusive use of the entire system's memory bus while taking out the lock. That's not too bad for a single or dual-core system, but already for quad-core systems it's a pretty large overhead. Have a look at this blog about the .NET 4 ThreadPool for some numbers and a weird analogy (see the author's comment). Not too bad yet, but I'm scared my 1000 core machine of the future is going to go slower than my machine today! I don't know the answer to this problem yet. Maybe some kind of per-core work queue system with hierarchical work stealing. Definitely hardware support. But what I do know is that using locks specifically prevents any solution to this. We should be abstracting our code away from the details of locks as soon as possible, so we can swap in whatever solution arrives when it does. NAct uses locks at the moment. But my advice is that you code using actors (which do scale well as software gets bigger). And when there's a better way of implementing actors that'll scale well as hardware gets bigger, only NAct needs to work out how to use it, and your program will go fast on it's own.

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  • problem with Webmaster Google Sitemap

    - by Alex
    I have a wp mu 3.6.1 with domain mapping (0.5.4.3) with w3tc (0.9.3) and Google XML Sitemaps (4.0 BETA). I have 4 different sitemaps. sub-1.com/sitemap.xml sub-2.com/sitemap.xml sub-3.com/sitemap.xml sub-4.com/sitemap.xml on google webmaster i got 59 errors & 14 warnings. Sitemap errorsErrors: We encountered an error while trying to access your Sitemap. Please ensure your Sitemap follows our guidelines and can be accessed at the location you provided and then resubmit. General HTTP error: 404 not found Sitemap: sub-2.com/sitemap-pt-post-2011-02.xml etc (but when i click on my sitemap links they work fine) Sitemap errorsWarnings: URLs not accessible When we tested a sample of the URLs from your Sitemap, we found that some URLs were not accessible to Googlebot due to an HTTP status error. All accessible URLs will still be submitted. Sitemap: sub-2.com/sitemap-misc.xml HTTP Error: 404 URL: /sitemap.html (but when i click on my sitemap links they work fine) Sitemap errorsIndex errors URLs not accessible When we tested a sample of the URLs from your Sitemap, we found that some URLs were not accessible to Googlebot due to an HTTP status error. All accessible URLs will still be submitted. HTTP Error: 404 URL: /sitemap-pt-post-2010-09.xml (but when i click on my sitemap links they work fine) Web pages 3,276 Submitted 3,247 Indexed what do I have to put on network adminperformance(w3tc)page cachecache preloadSitemap URL: ? i have add "/sitemap.xml" my robots.txt: http://pastebin.com/3K2U0mQa my .htaccess: http://pastebin.com/efJJ6zwy How can I make it work right?

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  • How are events in games handled?

    - by Alex
    In may games that I have played, I have seen events being triggered, such as when you walk into a certain land area while holding a specific object, it will trigger a special creature to spawn. I was wondering, how do games deal with events such as this? Not in a specific game, but in general among games. The first thought I had was that each place has a hard-coded set of events that it will call when something happens there. However, that would be too inefficient to maintain, as when something new is added, that would require modification of every part of the game that would potentially cause the event to be called. Next up, I had the idea of maybe how GUI programming works. In all of the GUI programming I've done, you create a component and a callback function, or a listener. Then, when the user interacts when the button, the callback function is called, allowing you to do something with it. So, I was thinking that in terms of a game, when a land area gets loaded the game loops over a list of all events, creating instances of them and calling public methods to bind them to the current scene. The events themselves then handle what scene it is, and if it is a scene that pertains to the event, will call the public method of the scene to bind the event to an action. Then, when the action takes place, the scene would call all events that are bound to that action. However, I'm sure that's not how games would operate either, as that would require a lot of creating of events all the time. So how to video games handle events, are either of those methods correct, or is it something completely different?

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  • XNA Deferred Shading, Replace BasicEffect

    - by Alex
    I have implemented deferred shading in my XNA 4.0 project, meaning that I need all objects to start out with the same shader "RenderGBuffer.fx". How can I use a custom Content Processor to: Not load any textures by default (I want to manually do this) Use "RenderGBuffer.fx" as the default shader instead of BasicEffect Below is the progress so far public class DeferredModelProcessor : ModelProcessor { EffectMaterialContent deferredShader; public DeferredModelProcessor() { } protected override MaterialContent ConvertMaterial(MaterialContent material, ContentProcessorContext context) { deferredShader = new EffectMaterialContent(); deferredShader.Effect = new ExternalReference<EffectContent>("DeferredShading/RenderGBuffer.fx"); return context.Convert<MaterialContent, MaterialContent>(deferredShader, typeof(MaterialProcessor).Name); } }

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  • In MATLAB, how can 'preallocating' cell arrays improve performance?

    - by Alex McMurray
    I was reading this article on MathWorks about improving MATLAB performance and you will notice that one of the first suggestions is to preallocate arrays, which makes sense. But it also says that preallocating Cell arrays (that is arrays which may contain different, unknown datatypes) will improve performance. But how will doing so improve performance because the datatypes are unknown so it doesn't know how much contiguous memory it will require even if it knows the shape of the cell array, and therefore it can't preallocate the memory surely? So how does this result in any improvement in performance? I apologise if this question is better suited for StackOverflow than Programmers but it isn't asking about a specific problem so I thought it fit better here, please let me know if I am mistaken though. Any explanation would be greatly appreciated :)

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  • Constraint-based expert systems design and development [on hold]

    - by Alex B.
    I would appreciate some recommendations & resources on design and development of expert systems, in particular, knowledge-based & constraint-based (not recommendation) systems. Ideally, your answers should consider the perspective (context) of using a SaaS business model and open source rules engine. How would you advise to address performance, scalability and other architectural criteria? Any other considerations on undertaking such project will be appreciated. Thanks much in advance!

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  • Two Wifi Icons in Panel [Solved]

    - by Alex
    I have the exact problem in 13.10 as this user Two Wifi indicators in panel. Here are some screenshots: Here are some screenshots from another user: http://ubuntuforums.org/showthread.php?t=2183020&p=12825563 ifconfig and iwconfig outputs $ ifconfig lo Link encap:Local Loopback inet addr:XXXXXX Mask:XXXXXXX inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:2243 errors:0 dropped:0 overruns:0 frame:0 TX packets:2243 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:209889 (209.8 KB) TX bytes:209889 (209.8 KB) wlan0 Link encap:Ethernet HWaddr XXXXXXXXX inet addr:XXXXXX Bcast:XXXXXXXX Mask:XXXXXXX inet6 addr: XXXXXXX Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:5925 errors:0 dropped:0 overruns:0 frame:0 TX packets:3361 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2951818 (2.9 MB) TX bytes:630579 (630.5 KB) $ iwconfig lo no wireless extensions. wlan0 IEEE 802.11abgn ESSID:"XXXXX" Mode:Managed Frequency:2.437 GHz Access Point: XXXXXXXX Bit Rate=72.2 Mb/s Tx-Power=15 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:on Link Quality=49/70 Signal level=-61 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:153 Invalid misc:472 Missed beacon:0

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  • Automated Error Reporting in .NET Reflector - harnessing the most powerful test rig in existence

    - by Alex.Davies
    I know a testing system that will find more bugs than all the unit testing, integration testing, and QA you could possibly do. And the chances are you're not using it. It's called your users. It's a cliché that you should test so that you find your bugs rather than your users. Of course you should. But it's also a cliché that no software is ever shipped bug-free. Lost cause? No, opportunity! I think .NET Reflector 6 is pretty stable. In fact I know exactly how stable it is, because some (surprisingly high) proportion of its users tell me every time it crashes: If they press "Send Error Report", I get: And then I fix it. As a rough guess, while a standard stack trace is enough to fix a problem 30% of the time, having all those local variables in the stack trace means I can fix it about 80% of the time. How does this all happen? Did it take ages to code this swish system? Nope, it was one checkbox in SmartAssembly. It adds some clever code to your assembly to capture local variables every time an exception is thrown, and to ask your user to report it to you, with a variety of other useful information. Of course not all bugs show up as exceptions. But if you get used to knowing that SmartAssembly will tell you when an exception happens, you begin to change your coding style. Now, as long as an exception gets thrown in any situation you don't expect, you'll fix it if it ever happens. You'll start throwing exceptions liberally, and stop having to think about whether tiny edge cases are possible, as long as they throw an exception if they happen.

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  • C# async and actors

    - by Alex.Davies
    If you read my last post about async, you might be wondering what drove me to write such odd code in the first place. The short answer is that .NET Demon is written using NAct Actors. Actors are an old idea, which I believe deserve a renaissance under C# 5. The idea is to isolate each stateful object so that only one thread has access to its state at any point in time. That much should be familiar, it's equivalent to traditional lock-based synchronization. The different part is that actors pass "messages" to each other rather than calling a method and waiting for it to return. By doing that, each thread can only ever be holding one lock. This completely eliminates deadlocks, my least favourite concurrency problem. Most people who use actors take this quite literally, and there are plenty of frameworks which help you to create message classes and loops which can receive the messages, inspect what type of message they are, and process them accordingly. But I write C# for a reason. Do I really have to choose between using actors and everything I love about object orientation in C#? Type safety Interfaces Inheritance Generics As it turns out, no. You don't need to choose between messages and method calls. A method call makes a perfectly good message, as long as you don't wait for it to return. This is where asynchonous methods come in. I have used NAct for a while to wrap my objects in a proxy layer. As long as I followed the rule that methods must always return void, NAct queued up the call for later, and immediately released my thread. When I needed to get information out of other actors, I could use EventHandlers and callbacks (continuation passing style, for any CS geeks reading), and NAct would call me back in my isolated thread without blocking the actor that raised the event. Using callbacks looks horrible though. To remind you: m_BuildControl.FilterEnabledForBuilding(    projects,    enabledProjects = m_OutOfDateProjectFinder.FilterNeedsBuilding(        enabledProjects,             newDirtyProjects =             {                 ....... Which is why I'm really happy that NAct now supports async methods. Now, methods are allowed to return Task rather than just void. I can await those methods, and C# 5 will turn the rest of my method into a continuation for me. NAct will run the other method in the other actor's context, but will make sure that when my method resumes, we're back in my context. Neither actor was ever blocked waiting for the other one. Apart from when they were actually busy doing something, they were responsive to concurrent messages from other sources. To be fair, you could use async methods with lock statements to achieve exactly the same thing, but it's ugly. Here's a realistic example of an object that has a queue of data that gets passed to another object to be processed: class QueueProcessor {    private readonly ItemProcessor m_ItemProcessor = ...     private readonly object m_Sync = new object();    private Queue<object> m_DataQueue = ...    private List<object> m_Results = ...     public async Task ProcessOne() {         object data = null;         lock (m_Sync)         {             data = m_DataQueue.Dequeue();         }         var processedData = await m_ItemProcessor.ProcessData(data); lock (m_Sync)         {             m_Results.Add(processedData);         }     } } We needed to write two lock blocks, one to get the data to process, one to store the result. The worrying part is how easily we could have forgotten one of the locks. Compare that to the version using NAct: class QueueProcessorActor : IActor { private readonly ItemProcessor m_ItemProcessor = ... private Queue<object> m_DataQueue = ... private List<object> m_Results = ... public async Task ProcessOne()     {         // We are an actor, it's always thread-safe to access our private fields         var data = m_DataQueue.Dequeue();         var processedData = await m_ItemProcessor.ProcessData(data);         m_Results.Add(processedData);     } } You don't have to explicitly lock anywhere, NAct ensures that your code will only ever run on one thread, because it's an actor. Either way, async is definitely better than traditional synchronous code. Here's a diagram of what a typical synchronous implementation might do: The left side shows what is running on the thread that has the lock required to access the QueueProcessor's data. The red section is where that lock is held, but doesn't need to be. Contrast that with the async version we wrote above: Here, the lock is released in the middle. The QueueProcessor is free to do something else. Most importantly, even if the ItemProcessor sometimes calls the QueueProcessor, they can never deadlock waiting for each other. So I thoroughly recommend you use async for all code that has to wait a while for things. And if you find yourself writing lots of lock statements, think about using actors as well. Using actors and async together really takes the misery out of concurrent programming.

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  • How do I get my clipboard (copy and paste) working again?

    - by Alex Black
    I'm running Ubuntu 9.04, and out of the blue I can no longer cut and paste, I imagine if I restart my computer I'll be able to, but thats a pain, how can I fix/reset the clipboard? Type "hello" into Text Editor Highlight the text "hello" Press CTRL-C See the text become unhighlighted (is this normal?) Press CTRL-V See the word "network" get pasted in.. perhaps that was the last thing I copied when it was still working?

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  • Just updated, after reboot my computer won't start up again

    - by Alex
    I have a macbook that I use on occasion which dual boots Ubuntu and OSX (It has rEFIt installed). I turned it on for the first time in a while and it needed a bunch of updates. So I let it run, and restarted it when it asked. When it was booting up, it got stuck at a light blue screen. There was nothing on the screen to indicate that it was doing anything - I figured it just got stuck or something, so I turned it off and back on. (I suspect now it was actually working, but I had no indication that it hadn't just frozen) Now I can't access either OSX or my Ubuntu partition. When I choose ubuntu on the rEFIt menu, it shows "No bootable device -- insert book disk and press key". If I try to start up OSX is looks like it starts loading, but instead of an apple logo there's a crossed out circle icon.

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