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  • 3D physics engine for accurate collision handling on desktop/laptop computers (non-console)

    - by Georges Oates Larsen
    What are your suggestions for a physics engine that satisfies the following criteria? Capable of calculating collisions between multiple concave mesh-based colliders Handles many collisions going on at once (for instance one mesh being wedged between two others, which themselves may be wedged between two meshes) Does not allow for collider passthrough, even at high speeds. For instance, if I am applying force to a programmatically hinged object that makes it spin, I do not want it to pass through another rigidbody that it collides with while spinning. I have this problem using PhysX As implied before, reacts well to hinged objects, preferably has its own implementation of a hinge, but I am willing to program my own. The important part is that it has some sort of interface that guarantees accurate collision tracking even when dealing with these things Platform independent -- runs on mac as well as PC, also not tied down to specific graphics cards I think that's the best way to explain what I am looking for. Basically, I need SUPER reliable collisions. Something that can't be accomplished with a simple ray casting approach that sends a ray from the last position of the object to the current position (as this object may be potentially large and colliding with small objects via rotation) Bonus points for also including an OPEN SOURCE engine.

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  • Function calls to calls in windows api

    - by Apeee
    I am a beginner, and learning C, I find it hard to grasp the whole programming concept. so hopefully this would help to clear up some things along the way. When programming in windows, which is my aim for the time being, it is really hard for me to understand how windows communicate with the programs that run on it. A question i have been pondering about is how when you incorporate a function call which is in another memory location on the disk or memory(not a function you yourself wrote and is included in the compilation), especially the windows API, does the compiler know where the function location is so when the program is run it can call that function? For example, a very simple program that displays a window which reads hello world. You would have to call windows API functions to achieve such features as creating the window, its size, colors and so on... So basically what I am struggling to grasp is how the programs I write communicate with the platform, framework they are run on(generally windows for Windows API). Apart from clarification on this one above, i would love a resource that explains this concept further. Thanks for your time!

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  • WebCenter at Oracle Day Toronto

    - by Lance Shaw
    The Oracle Day event took place in Toronto yesterday at the Hyatt Regency Hotel downtown.  Attendance was excellent and it was standing room only at the keynote sessions.   Anytime the venue has to bring in chairs to handle the overflow crowd, you know there is a lot of interest! This year, WebCenter was featured prominently as part of the Fusion Middleware session track.  What was interesting to see was just how many customers are interested in consolidating and simplifying their existing infrastructure.  So many companies are still struggling with information silos such as file shares, SharePoint Sites and a myriad of departmental or process-centric repositories.  Naturally, these get more and more expensive to manage over time so there is a high level of interest in reducing the size, scope and cost of this infrastructure.  When companies see how they can use Fusion Middleware and related technologies to integrate with WebCenter Content, Imaging and other solutions to centralize content delivery across business applications, they quickly realize that there are significant cost savings to be had. Oracle Day Events are happening all over the world and there is likely going to be one near you.  To check out the full list and to register, visit the Event page here.  It is a great way to not only hear about WebCenter and how it can be used to your advantage, but also a great way to learn about the broader set of related products in the Fusion Middleware portfolio that are available to extend and enhance the power of your particular business solutions. If you cannot make it, or missed the event in your area, be sure to visit our new WebCenter Content page with a variety of informative assets all in one simple location.  It's a new page designed to provide you with easy access to customer stories, videos, whitepapers, webcasts and more.  We hope you find it valuable!

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  • Retexturing a model via API on the web

    - by AndyMcKenna
    I'm looking at creating a site where a user could see our product and configure the options or look of it and see an image that represents that. The way I'm doing it now is if you have Piece A selected and then you choose Texture X, I have an image on the filesystem that is A with X applied to it. I just swap out my default image with that specific one. One product has 8 areas, with 10-70 pieces per area, and about 200 textures for each piece. Programming the site was pretty simple but we are getting bogged down in rendering all these pieces/textures and entering them into the system. What I would love to do is build a model and have some way to apply the textures via API and render it to the browser. I would even settle for exporting a flat image and pulling that into the browser. Is that possible with something like SolidWorks, 3DSMax, or something else? If the rendering is too time intensive it would still help to batch create all my images and use them the way I am currently.

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  • Recursion in F#

    - by MarkPearl
    Things are slowly coming together – I was able to look at a bit of F# code and intuitively know what it was going to do (yay)… So today I saw a blog post by Bob Palmer on Fibonacci numbers in F# which inspired me to look at bit into recursion. First the C# example… class Program { public static void CountDown(int n) { switch (n) { case 0: Console.WriteLine("End of Count"); break; default: Console.WriteLine(n); CountDown(n-1); break; } } static void Main(string[] args) { CountDown(10); Console.ReadLine(); } }   In F#, the equivalent would look something like this… open System let rec CountDown n = match n with | 0 -> Console.WriteLine("End of Count"); | n -> Console.WriteLine(n); CountDown (n-1); CountDown 10 Console.ReadLine()   Pretty simple stuff. With F# you when making recursive calls you need to explicitly declare that the function is recursive with the “rec” keyword. Otherwise the code is pretty easy to read and self explanatory.

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  • LibGdx, Texture an Object

    - by Gigi10012
    I want to set texture to an Object, this is my playerobject class: private boolean up; private float speed; private float fallacceleration = 20; private float acceleration = 15; private float maxSpeed = 300; SpriteBatch batch; public Player() { x = MyGdxGame.WIDTH - 9*MyGdxGame.WIDTH/10; y = MyGdxGame.HEIGHT - 3 * MyGdxGame.HEIGHT/10; shapex = new float[4]; shapey = new float[4]; radians = 2*MathUtils.PI; batch = new SpriteBatch(); } private void setShape() { //Simple Arrow Shape ...... } public void update(float dt) { setShape(); } public void draw(ShapeRenderer sr) { sr.setColor(0F, 0F, 0F, 1F); sr.begin(ShapeType.Line); //Drawing Shape .............. sr.end(); } What I have to do to add texture to that object? (I'm using LibGdx)

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  • What should I "forget" when going to Javascript?

    - by ElGringoGrande
    I went from C=64 Basic and assembler to FORTRAN and C to C++ and Java. Professionally I started in Visual Basic for applications then to Visual Basic 4, 5, 6. After that VB.NET AND C# with some Java here and there. I have played with Ruby and Python and found both fun. During each step I never felt like I had to forget what I had learned before. I always felt like I was just learning better and/or slightly different ways of doing things but the difference was not major. The difference was like the difference between American, Australian and British English. (Maybe assembler was Latin and FORTRAN was Spanish.) But now I am using JavaScript to do real, actual work. (Before used it as a "Scripting" language pure a simple.) And I just feel like I have to forget some things to become proficient in it. It feels like some old Egyptian language. What should I forget? Is it just that code organization is different (no real classes so no one class one file)? Or is it something more basic?

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  • I receive the error 'grub-install /dev/sda failed' while attempting to install Ubuntu as the computer's only OS.

    - by Liath
    I am attempting to install Ubuntu on a box which was previously running Windows 7. I have also experienced the dreaded "Unable to install GRUB" error. I am not attempting to dual boot. I have previously run a Windows boot disk and removed all existing partitions. If I run the Ubuntu 12.04 install CD and click install after the config screens, I get the error Executing 'grub-install /dev/sda' failed. This is a fatal error. (It is the same error as this question: Unable to install GRUB) All the questions I've read while looking for a solution are related to dual boot. I'm not interested in dual boot, I'm after a clean out the box Ubuntu install. How can I achieve this? (For my sanity, please use very simple instructions when responding. I don't claim to have any talent either for linux or as a sysadmin) Additional details copied from comments dated: 2012-05-29 ~15:19Z After booting from the CD, clicking Try Ubuntu, and then sudo fdisk /dev/sda I get fdisk: unable to seek on /dev/sda: Invalid argument sudo fdisk /dev/sdb gives Device contains neither a valid DOS partiion table, nor Sun, SGI or OSF disklabel. Building a new DOS disklabel with disk identifier 0x15228d1d. Changes will remain in memory only until you decide to write them. After that of course, the previous content won't be recoverable. Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite). Command (m for help): I should add the Live CD desktop is graphically bad. I've got missing parts of programs and the terminal occasionally reflects to the bottom of the screen. But I can't imagine this is related.

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  • What is the simplest way to render video into memory (for drawing to a texture) in .NET?

    - by sebf
    In my project I would like to be able to play back video on surfaces in the world. I intend to do this by having the video frames rendered to a block of memory, then use this to update a texture each frame. Everything is in place - except for the part that actually gets the video. I have looked on Google and found that the video library world is very expansive (and geared towards video processing), and am having trouble finding a suitable one. FFMpeg is very comprehensive, but is an entire suite and would take a good amount of work to integrate. So far the most promising library I've found is the one based on the VLC player libraries - by virtue of it using the same resources as VLC Player it is known to be very capable; it also renders to blocks of memory, but the API (at least of the one on Codeplex) is more of a port of the C++ API rather than a managed wrapper. The 'solution' can be any wrapper/API/library, but with characteristics that make it suitable for use in a rendering engine, namely: Renders the video frame data to memory, so it can be picked up and passed to a texture on the GPU easily. Super simple - all that is needed is a way to load, jump and render a frame programatically - ideally it would use the systems codecs and not require an assortment of plugins. Permissive license (LGPL or more free-er) .NET bindings at least; all the better if it is natively managed Can anyone suggest a lightweight, (.NET) library, that can take a video file, and spit out some frames into a byte[]?

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  • Being stupid to get better productivity?

    - by loki2302
    I've spent a lot of time reading different books about "good design", "design patterns", etc. I'm a big fan of the SOLID approach and every time I need to write a simple piece of code, I think about the future. So, if implementing a new feature or a bug fix requires just adding three lines of code like this: if(xxx) { doSomething(); } It doesn't mean I'll do it this way. If I feel like this piece of code is likely to become larger in the nearest future, I'll think of adding abstractions, moving this functionality somewhere else and so on. The goal I'm pursuing is keeping average complexity the same as it was before my changes. I believe, that from the code standpoint, it's quite a good idea - my code is never long enough, and it's quite easy to understand the meanings for different entities, like classes, methods, and relations between classes and objects. The problem is, it takes too much time, and I often feel like it would be better if I just implemented that feature "as is". It's just about "three lines of code" vs. "new interface + two classes to implement that interface". From a product standpoint (when we're talking about the result), the things I do are quite senseless. I know that if we're going to work on the next version, having good code is really great. But on the other side, the time you've spent to make your code "good" may have been spent for implementing a couple of useful features. I often feel very unsatisfied with my results - good code that only can do A is worse than bad code that can do A, B, C, and D. Are there any books, articles, blogs, or your ideas that may help with developing one's "being stupid" approach?

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  • Hexagonal Tiles

    - by PATRY
    i'm doing a tactical game (X-Com / Fallout style) for fun. I've decided to use an hexagonal map, but i'm having a graphic problem. My current map display is HUD-like, with only the border of the map cells displayed, without any texture. it's simple and allow for display of different types of informations by varying the color of the border. For exemple the "danger view mode" displays the borders with a color going from green (no damage possible) to red (prob of damage 90%). Now, It's a bit hard to différenciate the kind of tile the player is on. I could put a plain color (green is grass, pale blue is water...), but this is going to limit the possibilities. Thus, i would like to display a texture on my tiles. Since the map are generated, i can not use a picture for the whole map with the HUD over. So, my question is : does any one knows how i could generate the sealess hexagonal textures (algo or plugin), or if there is a site with some hexagonal tiles ?

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  • Unable to debug an encodded javascript?

    - by miles away
    I’m having some problems debugging an encoded javacscript. This script I’m referring to given in this link over here. The encoding here is simple and it works by shifting the unicodes values to whatever Codekey was use during encoding. The code that does the decoding is given here in plain English below:- <script language="javascript"> function dF(s){ var s1=unescape(s.substr(0,s.length-1)); var t=''; for(i=0;i<s1.length;i++)t+=String.fromCharCode(s1.charCodeAt(i)-s.substr(s.length-1,1)); document.write(unescape(t)); } </script> I’m interested in knowing or understanding the values (e.g s1,t). Like for example when the value of i=0 what values would the following attributes / method would hold s1.charCodeAt(i) and s.substr(s.length-1,1) The reason I’m doing this is to understand as to how a CodeKey function really works. I don’t see anything in the code above which tells it to decode on the basis of codekey value. The only thing I can point in the encoding text is the last character which is set to 1 , 2 ,3 or 4 depending upon the codekey selected during encoding process. One can verify using the link I have given above. However, to debug, I’m using firebug addon with the script running as localhost on my wamp server. I’m able to put a breakpoint on the js using firebug but I’m unable to retrieve any of the user defined parameters or functions I mentioned above. I want to know under this context what would be best way to debug this encoded js.

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  • Entity framework separating entities for product and customer specific implementation

    - by Codecat
    I am designing an application with intention into making it a product line. I would like to extend the functionality across all layers and first struggle is with domain models. For example, core functionality would have entity named Invoice with few standard fields and then customer requirements will add some new fields to it, but I don't want to add to core Invoice class. For every customer I could use customer specific DbContext and injected correct context with dependency injection. Also every customer will get they own deployment public class Product.Domain.Invoice { public int InvoiceId { get; set; } // Other fields } How to approach this problem? Solution 1 does not work since Entity Framework does not allow same simple name classes. public class CustomerA.Domain.Invoice : Product.Domain.Invoice { public User ReviewedBy { get; set; } public DateTime? ReviewedOn { get; set; } } Solution 2 Create separate table and link it to core domain table. Reusing services and controllers could be harder. public class CustomerA.Domain.CustomerAInvoice { public Product.Domain.Invoice Invoice { get; set; } public User ReviewedBy { get; set; } public DateTime? ReviewedOn { get; set; } }

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  • Understanding IDAT chunk of PNG file format

    - by DRapp
    From the sample image below, I have a border in yellow just for display purposes only. The actual .png file is a simple black/white image 3 pixels by 3 pixels. I was originally thinking to try as a 2x2, but that would not help trying to interpret low/hi vs hi/low drawing stream. At least this way, I would have two black, one white from the top, or one white, two black from the bottom.. So I read the chunks of data, get to the IDAT chunk, decode that (zlib) and come up with 12 bytes as follows 00 20 00 40 00 80 So, my question, how does the above get broken down into the 3x3 black and white sample... Also, it is saved in palette format and properly recognizes the bit depth of 1 and color palette of 2... color pallet[0] is RGBA all zeros. Palette1 has RGBA of 255, 255, 255, 0 I'll eventually get into the multiple other depth formats later, just wanted to start with what would expect to be the easiest. Part II. Any guidance on handling the other depth formats would help if anything special to be considered especially regarding alpha channel (which I am already looking for in the palette) that might trip me up.

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  • How can I improve the "smoothness" of a 2D side-scrolling iPhone game?

    - by MrDatabase
    I'm working on a relatively simple 2D side-scrolling iPhone game. The controls are tilt-based. I use OpenGL ES 1.1 for the graphics. The game state is updated at a rate of 30 Hz... And the drawing is updated at a rate of 30 fps (via NSTimer). The smoothness of the drawing is ok... But not quite as smooth as a game like iFighter. What can I do to improve the smoothness of the game? Here are the potential issues I've briefly considered: I'm varying the opacity of up to 15 "small" (20x20 pixels) textures at a time... Apparently varying the opacity in this manner can degrade drawing performance I'm rendering at only 30 fps (via NSTimer)... Perhaps 2D games like iFighter are rendered at a higher frame rate? Perhaps the game state could be updated at a faster rate? Note the acceleration vales are updated at 100 Hz... So I could potentially update part of the game state at 100 hz All of my textures are PNG24... Perhaps PNG8 would help (due to smaller size etc)

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  • How to pass one float as four unsigned chars to shader by glVertexPointAttrib?

    - by Kog
    For each vertex I use two floats as position and four unsigned bytes as color. I want to store all of them in one table, so I tried casting those four unsigned bytes to one float, but I am unable to do that correctly... All in all, my tests came to one point: GLfloat vertices[] = { 1.0f, 0.5f, 0, 1.0f, 0, 0 }; glEnableVertexAttribArray(0); glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), vertices); // VER1 - draws red triangle // unsigned char colors[] = { 0xff, 0, 0, 0xff, 0xff, 0, 0, 0xff, 0xff, 0, 0, // 0xff }; // glEnableVertexAttribArray(1); // glVertexAttribPointer(1, 4, GL_UNSIGNED_BYTE, GL_TRUE, 4 * sizeof(GLubyte), // colors); // VER2 - draws greenish triangle (not "pure" green) // float f = 255 << 24 | 255; //Hex:0xff0000ff // float colors2[] = { f, f, f }; // glEnableVertexAttribArray(1); // glVertexAttribPointer(1, 4, GL_UNSIGNED_BYTE, GL_TRUE, 4 * sizeof(GLubyte), // colors2); // VER3 - draws red triangle int i = 255 << 24 | 255; //Hex:0xff0000ff int colors3[] = { i, i, i }; glEnableVertexAttribArray(1); glVertexAttribPointer(1, 4, GL_UNSIGNED_BYTE, GL_TRUE, 4 * sizeof(GLubyte), colors3); glDrawArrays(GL_TRIANGLES, 0, 3); Above code is used to draw one simple red triangle. My question is - why do versions 1 and 3 work correctly, while version 2 draws some greenish triangle? Hex values are one I read by marking variable during debug. They are equal for version 2 and 3 - so what causes the difference?

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  • Views : ViewControllers, many to one, or one to one?

    - by conor
    I have developed an Android application where, typically, each view (layout.xml) displayed on the screen has it's own corresponding fragment (for the purpose of this question I may refer to this as a ViewController). These views and Fragments/ViewControllers are appropriately named to reflect what they display. So this has the effect of allowing the programmer to easily pinpoint the files associated with what they see on any given screen. The above refers to the one to one part of my question. Please note that with the above there are a few exceptions where very similar is displayed on two views so the ViewController is used for two views. (Using a simple switch (type) to determine what layout.xml file to load) On the flip side. I am currently working on the iOS version of the same app, which I didn't develop. It seems that they are adopting more of a one-to-many (ViewController:View) approach. There appears to be one ViewController that handles the display logic for many different types of views. In the ViewController are an assortment of boolean flags and arrays of data (to be displayed) that are used to determine what view to load and how to display it. This seems very cumbersome to me and coupled with no comments/ambiguous variable names I am finding it very difficult to implement changes into the project. What do you guys think of the two approaches? Which one would you prefer? I'm really considering putting in some extra time at work to refactor the iOS into a more 1:1 oriented approach. My reasoning for 1:1 over M:1 is that of modularity and legibility. After all, don't some people measure the quality of code based on how easy it is for another developer to pick up the reigns or how easy it is to pull a piece of code and use it somewhere else?

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  • Strategy for hosting 700+ domains names, each with a static HTML site

    - by jonschlinkert
    I have a portfolio of more than 700 domain names, and ideally I'd like to put up a single-page HTML/CSS/JavaScript webpage for each domain. Is there a system/strategy/workflow that will allow me to: Automate the deployment of new websites, quickly and easily without having to manually initiate each new website in an admin panel. For instance, I've seen dropbox-based solutions that claim to make it simple to setup new websites on your dropbox account, but you still have to set each one up in an admin interface first. It would be so much easier to have a folder naming convention that allowed the user to easily clone/copy/duplicate sites inside their Dropbox App folder (https://www.dropbox.com/developers/blog/23) to create new ones. Sounds interesting, however... It's easy to manage CNAMEs on the registrar-side, but is there a way to quickly associate CNAMEs with new websites (on the hosting side), maybe using the method offered by gh-pages-style (https://help.github.com/articles/setting-up-a-custom-domain-with-pages)? With GitHub's gh-pages, all you have to do is drop a file called CNAME into your repo, with the domain name you want associated with the repo inside the file. gh-pages isn't a good solution for what I'm doing though unfortunately. I'm also a front-end developer, specializing in rapid web development and "front-end build systems", so I building and maintaining static assets for hundreds of sites is no problem. It's the hosting-side that I really struggle with. Any suggestions?

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  • How can I properly create /dev/dvd?

    - by chazomaticus
    Certain programs look for /dev/dvd by default to find DVDs. When I first boot my computer without a DVD inserted, /dev/dvd exists and points to the correct place (/dev/sr0). However, when I insert a DVD, /dev/dvd disappears. I'd like it to stick around so I don't have to navigate to /dev/sr0 in programs that are looking for DVDs. How do I ensure that the /dev/dvd symlink exists and points to the right place? It looks like I can add something to /etc/udev/rules.d/70-persistent-cd.rules. This site gives a couple of examples, but the 70-persistent-cd.rules file says "add the ENV{GENERATED}=1 flag to your own rules", which isn't part of the examples. The man 7 udev page is impenetrable to me, and I'm not convinced the linked page gives 100% of the information I need. So, what can I do on a modern, Ubuntu 12.04 (or later) system to make /dev/dvd always exist and point to the right device? EDIT: Is it as simple as adding ENV{GENERATED}=1 to the rules in the linked page, something like this: SUBSYSTEM=="block", KERNEL=="sr0", SYMLINK+="dvd", GROUP="cdrom", ENV{GENERATED}=1 Is that the right information for modern Ubuntu? What is ENV{GENERATED} doing there, when it wasn't generated, but hand-written?

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  • What is a Coding Dojo?

    - by huwyss
    Recently i found out that there is a thing called "coding dojo". The point behind it is that software developers want to have a space to learn new stuff like processes, methods, coding details, languages, and whatnot in an environment without stress. Just for fun. No competition. No results required. No deadlines.Some days ago I joined the Zurich coding dojo. We were three programmers with different backgrounds.We gave ourselves the task to develop a method that takes an input value and returns its prime factors. We did pair programming and every few minutes we switched positions. We used test driven development. The chosen programming language was Ruby.I haven't really done TDD before. It was pretty interesting to see the algorithm develop following the testcases.We started with the first test input=1 then developed the most simple productive program that passed this very first test. Then we added the next test input=2 and implemented the productive code. We kept adding tests and made sure all tests are passed until we had the general solution.When we improved the performance of our code we saw the value of the tests we wrote before. Of course our first performance improvement broke several tests.It was a very interesting experience to see how other developers think and how they work. I will participate at the dojo again and can warmly recommend it to anyone. There are  coding dojos all over the world.Have fun!

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  • Is Wordpress more appropriate than Magento/Opencart for site like this?

    - by Alex
    The premise of the site is that a user pays a small fee to advertise an item that they want to sell. Therefore the user is responsible for adding the "products", not the administrator. The product upload will create a product page for that item. This is a rather common framework that I'm sure you're familiar with. My initial thought was that it would be best suited using Magento - mainly because it needs to accept payments - and the products will grow to form a catalog of categorized products. However - there is no concept of a shopping cart. A buyer does not buy the item online, or go to a checkout. They simply look at the product, and contact the seller if they like it. The buyer and seller then take it from there. For this reason, I then begin to suspect that Magento is perhaps too overkill, or just simply not the right CMS if there is on checkout procedure (other than the uploader making a payment) So then I begin to think Wordpress....Hmmm Feature requirements: User's can add content via a form process User's can be directed to a payment gateway For each product listing - a series of photographs shall be displayed, in thumbnail form Zoom capabilities/rotate on the images would be a welcome feature In short - e-commerce CMS, or something more simple?

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  • TXPAUSE : polite waiting for hardware transactional memory

    - by Dave
    Classic locks are an appropriate tool to prevent potentially conflicting operations A and B, invoked by different threads, from running at the same time. In a sense the locks cause either A to run before B or vice-versa. Similarly, we can replace the locks with hardware transactional memory, or use transactional lock elision to leverage potential disjoint access parallelism between A and B. But often we want A to wait until B has run. In a Pthreads environment we'd usually use locks in conjunction with condition variables to implement our "wait until" constraint. MONITOR-MWAIT is another way to wait for a memory location to change, but it only allows us to track one cache line and it's only available on x86. There's no similar "wait until" construct for hardware transactions. At the instruction-set level a simple way to express "wait until" in transactions would be to add a new TXPAUSE instruction that could be used within an active hardware transaction. TXPAUSE would politely stall the invoking thread, possibly surrendering or yielding compute resources, while at the same time continuing to track the transaction's address-set. Once a transaction has executed TXPAUSE it can only abort. Ideally that'd happen when some other thread modifies a variable that's in the transaction's read-set or write-set. And since we're aborting all writes would be discarded. In a sense this gives us multi-location MWAIT but with much more flexibility. We could also augment the TXPAUSE with a cycle-count bound to cap the time spent stalled. I should note that we can already enter a tight spin loop in a transaction to wait for updates to address-set to cause an abort. Assuming that the implementation monitors the address-set via cache-coherence probes, by waiting in this fashion we actually communicate via the probes, and not via memory values. That is the updating thread signals the waiter via probes instead of by traditional memory values. But TXPAUSE gives us a polite way to spin.

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  • Generic rule parser for RPG board game rules - how to do it?

    - by burzum
    I want to build a generic rule parser for pen and paper style RPG systems. A rule can involve usually 1 to N entities 1 to N roles of a dice and calculating values based on multiple attributes of an entity. For example: Player has STR 18, his currently equipped weapon gives him a bonus of +1 STR but a malus of DEX -1. He attacks a monster entity and the game logic now is required to run a set of rules or actions: Player rolls the dice, if he gets for example 8 or more (base attack value he needs to pass is one of his base attributes!) his attack is successfully. The monster then rolls the dice to calculate if the attack goes through it's armor. If yes the damage is taken if not the attack was blocked. Besides simple math rules can also have constraints like applying only to a certain class of user (warrior vs wizzard for example) or any other attribute. So this is not just limited to mathematical operations. If you're familiar with RPG systems like Dungeon and Dragons you'll know what I'm up to. My issue is now that I have no clue how to exactly build this the best possible way. I want people to be able to set up any kind of rule and later simply do an action like selecting a player and a monster and run an action (set of rules like an attack). I'm asking less for help with the database side of things but more about how to come up with a structure and a parser for it to keep my rules flexible. The language of choice for this is php by the way.

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  • Some hint to program a webservice "by subscription"

    - by Eagle
    I have some web sites programmed, I know to do it with python and PHP basically. Normally they are simple web sites, but now I want to provide REST web services but only for allowed users (allowed by me). I saw that a lot of services uses the "KEY" and "SECRET_KEY" concepts, which seems to be what I need (if I understand it right). My suppositions are: If I only do a GET service to retrieve, e.g., all my clients, without anymore, anyone can retrieve my clients without limitations. I will need some KEY generator to provide keys for my allowed users, so they can use my webservices. Only with a KEY is not enough: someone can steal a KEY and supplant my user (and this is the reason because exists a SECRET_KEY, right?). If all this is right, how can I make/use a system like that in my web services? Some open source example? Or maybe there are another easy solutions I'm not considering? My objective is to allow some users to use my web services.

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  • How do I use an API?

    - by GRardB
    Background I have no idea how to use an API. I know that all APIs are different, but I've been doing research and I don't fully understand the documentation that comes along with them. There's a programming competition at my university in a month and a half that I want to compete in (revolved around APIs) but nobody on my team has ever used one. We're computer science majors, so we have experience programming, but we've just never been exposed to an API. I tried looking at Twitter's documentation, but I'm lost. Would anyone be able to give me some tips on how to get started? Maybe a very easy API with examples, or explaining essential things about common elements of different APIs? I don't need a full-blown tutorial on Stack Overflow; I just need to be pointed in the right direction. Update The programming languages that I'm most fluent in are C (simple text editor usually) and Java (Eclipse). In an attempt to be more specific with my question: I understand that APIs (and yes, external libraries are what I was referring to) are simply sets of functions. Question I guess what I'm trying to ask is how I would go about accessing those functions. Do I need to download specific files and include them in my programs, or do they need to be accessed remotely, etc.?

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