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  • Agile Testing Days 2012 – My First Conference!

    - by Chris George
    I’d like to give you a bit of background first… so please bear with me! In 1996, whilst studying for my final year of my degree, I applied for a job as a C++ Developer at a small software house in Hertfordshire  After bodging up the technical part of the interview I didn’t get the job, but was offered a position as a QA Engineer instead. The role sounded intriguing and the pay was pretty good so in the absence of anything else I took it. Here began my career in the world of software testing! Back then, testing/QA was often an afterthought, something that was bolted on to the development process and very much a second class citizen. Test automation was rare, and tools were basic or non-existent! The internet was just starting to take off, and whilst there might have been testing communities and resources, we were certainly not exposed to any of them. After 8 years I moved to another small company, and again didn’t find myself exposed to any of the changes that were happening in the industry. It wasn’t until I joined Red Gate in 2008 that my view of testing and software development as a whole started to expand. But it took a further 4 years for my view of testing to be totally blown open, and so the story really begins… In May 2012 I was fortunate to land the role of Head of Test Engineering. Soon after, I received an email with details for the “Agile Testi However, in my new role, I decided that it was time to bite the bullet and at least go to one conference. Perhaps I could get some new ideas to supplement and support some of the ideas I already had.ng Days” conference in Potsdam, Germany. I looked over the suggested programme and some of the talks peeked my interest. For numerous reasons I’d shied away from attending conferences in the past, one of the main ones being that I didn’t see much benefit in attending loads of talks when I could just read about stuff like that on the internet. So, on the 18th November 2012, myself and three other Red Gaters boarded a plane at Heathrow bound for Potsdam, Germany to attend Agile Testing Days 2012. Tutorial Day – “Software Testing Reloaded” We chose to do the tutorials on the 19th, I chose the one titled “Software Testing Reloaded – So you wanna actually DO something? We’ve got just the workshop for you. Now with even less powerpoint!”. With such a concise and serious title I just had to see what it was about! I nervously entered the room to be greeted by tables, chairs etc all over the place, not set out and frankly in one hell of a mess! There were a few people in there playing a game with dice. Okaaaay… this is going to be a long day! Actually the dice game was an exercise in deduction and simplification… I found it very interesting and is certainly something I’ll be using at work as a training exercise! (I won’t explain the game here cause I don’t want to let the cat out of the bag…) The tutorial consisted of several games, exploring different aspects of testing. They were all practical yet required a fair amount of thin king. Matt Heusser and Pete Walen were running the tutorial, and presented it in a very relaxed and light-hearted manner. It was really my first experience of working in small teams with testers from very different backgrounds, and it was really enjoyable. Matt & Pete were very approachable and offered advice where required whilst still making you work for the answers! One of the tasks was to devise several strategies for testing some electronic dice. The premise was that a Vegas casino wanted to use the dice to appeal to the twenty-somethings interested in tech, but needed assurance that they were as reliable and random as traditional dice. This was a very interesting and challenging exercise that forced us to challenge various assumptions, determine/clarify requirements but most of all it was frustrating because the dice made a very very irritating beeping noise. Multiple that by at least 12 dice and I was dreaming about them all that night!! Some of the main takeaways that were brilliantly demonstrated through the games were not to make assumptions, challenge requirements, and have fun testing! The tutorial lasted the whole day, but to be honest the day went very quickly! My introduction into the conference experience started very well indeed, and I would talk to both Matt and Pete several times during the 4 days. Days 1,2 & 3 will be coming soon…  

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  • Myths about Coding Craftsmanship part 2

    - by tom
    Myth 3: The source of all bad code is inept developers and stupid people When you review code is this what you assume?  Shame on you.  You are probably making assumptions in your code if you are assuming so much already.  Bad code can be the result of any number of causes including but not limited to using dated techniques (like boxing when generics are available), not following standards (“look how he does the spacing between arguments!” or “did he really just name that variable ‘bln_Hello_Cats’?”), being redundant, using properties, methods, or objects in a novel way (like switching on button.Text between “Hello World” and “Hello World “ //clever use of space character… sigh), not following the SOLID principals, hacking around assumptions made in earlier iterations / hacking in features that should be worked into the overall design.  The first two issues, while annoying are pretty easy to spot and can be fixed so easily.  If your coding team is made up of experienced professionals who are passionate about staying current then these shouldn’t be happening.  If you work with a variety of skills, backgrounds, and experience then there will be some of this stuff going on.  If you have an opportunity to mentor such a developer who is receptive to constructive criticism don’t be a jerk; help them and the codebase will improve.  A little patience can improve the codebase, your work environment, and even your perspective. The novelty and redundancy I have encountered has often been the use of creativity when language knowledge was perceived as unavailable or too time consuming.  When developers learn on the job you get a lot of this.  Rather than going to MSDN developers will use what they know.  Depending on the constraints of their assignment hacking together what they know may seem quite practical.  This was not stupid though I often wonder how much time is actually “saved” by hacking.  These issues are often harder to untangle if we ever do.  They can also grow out of control as we write hack after hack to make it work and get back to some development that is satisfying. Hacking upon an existing hack is what I call “feeding the monster”.  Code monsters are anti-patterns and hacks gone wild.  The reason code monsters continue to get bigger is that they keep growing in scope, touching more and more of the application.  This is not the result of dumb developers. It is probably the result of avoiding design, not taking the time to understand the problems or anticipate or communicate the vision of the product.  If our developers don’t understand the purpose of a feature or product how do we expect potential customers to do so? Forethought and organization are often what is missing from bad code.  Developers who do not use the SOLID principals should be encouraged to learn these principals and be given guidance on how to apply them.  The time “saved” by giving hackers room to hack will be made up for and then some. Not as technical debt but as shoddy work that if not replaced will be struggled with again and again.  Bad code is not the result of dumb developers (usually) it is the result of trying to do too much without the proper resources and neglecting the right thing that needs doing with the first thoughtless thing that comes into our heads. Object oriented code is all about relationships between objects.  Coders who believe their coworkers are all fools tend to write objects that are difficult to work with, not eager to explain themselves, and perform erratically and irrationally.  If you constantly find you are surrounded by idiots you may want to ask yourself if you are being unreasonable, if you are being closed minded, of if you have chosen the right profession.  Opening your mind up to the idea that you probably work with rational, well-intentioned people will probably make you a better coder and it might even make you less grumpy.  If you are surrounded by jerks who do not engage in the exchange of ideas who do not care about their customers or the durability of the code you are building together then I suggest you find a new place to work.  Myth 4: Customers don’t care about “beautiful” code Craftsmanship is customer focused because it means that the job was done right, the product will withstand the abuse, modifications, and scrutiny of our customers.  Users can appreciate a predictable timeline for a release, a product delivered on time and on budget, a feature set that does not interfere with the task(s) it is supporting, quick turnarounds on exception messages, self healing issues, and less issues.  These are all hindered by skimping on craftsmanship.  When we write data access and when we write reusable code.   What do you think?  Does bad code come primarily from low IQ individuals?  Do customers care about beautiful code?

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  • Taking a Flying Leap

    - by Lance Shaw
    Yesterday, I went skydiving with three of my children.  It was thrilling, scary, invigorating and exciting. While there is obvious risk involved, the reward and feeling of success was well worth it. You might already be wondering what skydiving would have to with WebCenter, so let me explain. Implementing a skydiving program and becoming an instructor does not happen overnight.  It does not happen with the purchase of the needed technology. Not one of us would go out, buy a parachute, the harnesses, helmet and all the gear and be able to convince anyone that we are now ready to be a skydiving instructor. The fact is that obtaining the technology is merely a small piece of the overall process and so is the case with managing content in your company. You don't just buy the right software (Oracle WebCenter Content) and go to your boss and declare information management success. There is planning, research and effort that goes into deploying software of any kind and especially when it is as mission-critical to the success of your business as Enterprise Content Management. To become a certified skydiving instructor takes at least 3 years of commitment and often longer. In the United States, candidates must complete over 500 solo jumps of their own over a minimum of 36 months and then must complete additional rigorous training under observation.  When you consider the amount of time and effort involved, it's not unlike getting a college degree and anyone that has trusted their lives to one of these instructors will no doubt appreciate their dedication to the curriculum.  Implementing an ECM system won't take that long, but it certainly requires commitment, analysis and consideration. But guess what?  Humans are involved and that means that mistakes can happen and that rules change.  This struck me while reading an excellent post on darkreading.com by Glenn S. Phillips entitled "Mission Impossible: 4 Reasons Compliance is Impossible".  His over-arching point was that with information management and security, environments change and people are involved meaning the work is never done.  He stated that you can never claim your compliance efforts are complete because of the following reasons. People are involved.  And lets face it, some are more trustworthy than others. Change is Constant. There is always some new technology coming along that is disruptive. Consumer grade cloud file sharing and sync tools come to mind here. Compliance is interpreted, not defined.  Laws and the judges that read them are always on the move. Technology is a tool, not a complete solution. There is no magic pill. The skydiving analogy holds true here as well.  Ultimately, a single person packs your parachute.  For obvious reasons, you prefer that this person be trustworthy but there are no absolute guarantees of a 100% error-free scenario.  Weather and wind conditions are never a constant and the best-laid plans for a great day of skydiving are easily disrupted by forces outside of your control.  Rules and regulations vary by location and may be updated at any time and as I mentioned early on, even the best technology on its own will only get you started. The good news is that, like skydiving, with the right technology, the right planning, the right team and a proper understanding of the rules and regulations that govern your industry, your ECM deployment can be a great success.  Failure to plan for any of the 4 factors that Glenn outlined in his article will certainly put your deployment and maybe even your company at risk, so consider them carefully. As a final aside, for those of you who consider skydiving an incredibly dangerous and risky pastime, consider this comparative statistic.  In 2012, the U.S. Parachute Association recorded 19 fatal skydiving accidents in the U.S. out of roughly 3.1 million jumps.  That’s 0.006 fatalities per 1,000 jumps. By comparison, the U.S. National Highway Traffic Safety Administration reports that there were 34,080 deaths due to car accidents in 2012.  Based on the percentages, one could argue that it is safer to jump out of a plane than to drive to the airport where the skydiving will take place. While the way you manage, secure, classify, control, retain and dispose of company files may not carry as much risk as driving or skydiving, it certainly carries risk for the organization when not planned and deployed appropriately.  Consider all the factors involved in your organization as you make your content management plans.  For additional areas of consideration, be sure to download our free whitepaper on the topic entitled "The Top 10 Criteria for Choosing an ECM System" which is available for download here.

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  • Computer Networks UNISA - Chap 8 &ndash; Wireless Networking

    - by MarkPearl
    After reading this section you should be able to Explain how nodes exchange wireless signals Identify potential obstacles to successful transmission and their repercussions, such as interference and reflection Understand WLAN architecture Specify the characteristics of popular WLAN transmission methods including 802.11 a/b/g/n Install and configure wireless access points and their clients Describe wireless MAN and WAN technologies, including 802.16 and satellite communications The Wireless Spectrum All wireless signals are carried through the air by electromagnetic waves. The wireless spectrum is a continuum of the electromagnetic waves used for data and voice communication. The wireless spectrum falls between 9KHZ and 300 GHZ. Characteristics of Wireless Transmission Antennas Each type of wireless service requires an antenna specifically designed for that service. The service’s specification determine the antenna’s power output, frequency, and radiation pattern. A directional antenna issues wireless signals along a single direction. An omnidirectional antenna issues and receives wireless signals with equal strength and clarity in all directions The geographical area that an antenna or wireless system can reach is known as its range Signal Propagation LOS (line of sight) uses the least amount of energy and results in the reception of the clearest possible signal. When there is an obstacle in the way, the signal may… pass through the object or be obsrobed by the object or may be subject to reflection, diffraction or scattering. Reflection – waves encounter an object and bounces off it. Diffraction – signal splits into secondary waves when it encounters an obstruction Scattering – is the diffusion or the reflection in multiple different directions of a signal Signal Degradation Fading occurs as a signal hits various objects. Because of fading, the strength of the signal that reaches the receiver is lower than the transmitted signal strength. The further a signal moves from its source, the weaker it gets (this is called attenuation) Signals are also affected by noise – the electromagnetic interference) Interference can distort and weaken a wireless signal in the same way that noise distorts and weakens a wired signal. Frequency Ranges Older wireless devices used the 2.4 GHZ band to send and receive signals. This had 11 communication channels that are unlicensed. Newer wireless devices can also use the 5 GHZ band which has 24 unlicensed bands Narrowband, Broadband, and Spread Spectrum Signals Narrowband – a transmitter concentrates the signal energy at a single frequency or in a very small range of frequencies Broadband – uses a relatively wide band of the wireless spectrum and offers higher throughputs than narrowband technologies The use of multiple frequencies to transmit a signal is known as spread-spectrum technology. In other words a signal never stays continuously within one frequency range during its transmission. One specific implementation of spread spectrum is FHSS (frequency hoping spread spectrum). Another type is known as DSS (direct sequence spread spectrum) Fixed vs. Mobile Each type of wireless communication falls into one of two categories Fixed – the location of the transmitted and receiver do not move (results in energy saved because weaker signal strength is possible with directional antennas) Mobile – the location can change WLAN (Wireless LAN) Architecture There are two main types of arrangements Adhoc – data is sent directly between devices – good for small local devices Infrastructure mode – a wireless access point is placed centrally, that all devices connect with 802.11 WLANs The most popular wireless standards used on contemporary LANs are those developed by IEEE’s 802.11 committee. Over the years several distinct standards related to wireless networking have been released. Four of the best known standards are also referred to as Wi-Fi. They are…. 802.11b 802.11a 802.11g 802.11n These four standards share many characteristics. i.e. All 4 use half duplex signalling Follow the same access method Access Method 802.11 standards specify the use of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) to access a shared medium. Using CSMA/CA before a station begins to send data on an 802.11 network, it checks for existing wireless transmissions. If the source node detects no transmission activity on the network, it waits a brief period of time and then sends its transmission. If the source does detect activity, it waits a brief period of time before checking again. The destination node receives the transmission and, after verifying its accuracy, issues an acknowledgement (ACT) packet to the source. If the source receives the ACK it assumes the transmission was successful, – if it does not receive an ACK it assumes the transmission failed and sends it again. Association Two types of scanning… Active – station transmits a special frame, known as a prove, on all available channels within its frequency range. When an access point finds the probe frame, it issues a probe response. Passive – wireless station listens on all channels within its frequency range for a special signal, known as a beacon frame, issued from an access point – the beacon frame contains information necessary to connect to the point. Re-association occurs when a mobile user moves out of one access point’s range and into the range of another. Frames Read page 378 – 381 about frames and specific 802.11 protocols Bluetooth Networks Sony Ericson originally invented the Bluetooth technology in the early 1990s. In 1998 other manufacturers joined Ericsson in the Special Interest Group (SIG) whose aim was to refine and standardize the technology. Bluetooth was designed to be used on small networks composed of personal communications devices. It has become popular wireless technology for communicating among cellular telephones, phone headsets, etc. Wireless WANs and Internet Access Refer to pages 396 – 402 of the textbook for details.

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  • Most efficient way to implement delta time

    - by Starkers
    Here's one way to implement delta time: /// init /// var duration = 5000, currentTime = Date.now(); // and create cube, scene, camera ect ////// function animate() { /// determine delta /// var now = Date.now(), deltat = now - currentTime, currentTime = now, scalar = deltat / duration, angle = (Math.PI * 2) * scalar; ////// /// animate /// cube.rotation.y += angle; ////// /// update /// requestAnimationFrame(render); ////// } Could someone confirm I know how it works? Here what I think is going on: Firstly, we set duration at 5000, which how long the loop will take to complete in an ideal world. With a computer that is slow/busy, let's say the animation loop takes twice as long as it should, so 10000: When this happens, the scalar is set to 2.0: scalar = deltat / duration scalar = 10000 / 5000 scalar = 2.0 We now times all animation by twice as much: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 2.0; angle = (Math.PI * 4) // which is 2 rotations When we do this, the cube rotation will appear to 'jump', but this is good because the animation remains real-time. With a computer that is going too quickly, let's say the animation loop takes half as long as it should, so 2500: When this happens, the scalar is set to 0.5: scalar = deltat / duration scalar = 2500 / 5000 scalar = 0.5 We now times all animation by a half: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 0.5; angle = (Math.PI * 1) // which is half a rotation When we do this, the cube won't jump at all, and the animation remains real time, and doesn't speed up. However, would I be right in thinking this doesn't alter how hard the computer is working? I mean it still goes through the loop as fast as it can, and it still has render the whole scene, just with different smaller angles! So this a bad way to implement delta time, right? Now let's pretend the computer is taking exactly as long as it should, so 5000: When this happens, the scalar is set to 1.0: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 1; angle = (Math.PI * 2) // which is 1 rotation When we do this, everything is timsed by 1, so nothing is changed. We'd get the same result if we weren't using delta time at all! My questions are as follows Mostly importantly, have I got the right end of the stick here? How do we know to set the duration to 5000 ? Or can it be any number? I'm a bit vague about the "computer going too quickly". Is there a way loop less often rather than reduce the animation steps? Seems like a better idea. Using this method, do all of our animations need to be timesed by the scalar? Do we have to hunt down every last one and times it? Is this the best way to implement delta time? I think not, due to the fact the computer can go nuts and all we do is divide each animation step and because we need to hunt down every step and times it by the scalar. Not a very nice DSL, as it were. So what is the best way to implement delta time? Below is one way that I do not really get but may be a better way to implement delta time. Could someone explain please? // Globals INV_MAX_FPS = 1 / 60; frameDelta = 0; clock = new THREE.Clock(); // In the animation loop (the requestAnimationFrame callback)… frameDelta += clock.getDelta(); // API: "Get the seconds passed since the last call to this method." while (frameDelta >= INV_MAX_FPS) { update(INV_MAX_FPS); // calculate physics frameDelta -= INV_MAX_FPS; } How I think this works: Firstly we set INV_MAX_FPS to 0.01666666666 How we will use this number number does not jump out at me. We then intialize a frameDelta which stores how long the last loop took to run. Come the first loop frameDelta is not greater than INV_MAX_FPS so the loop is not run (0 = 0.01666666666). So nothing happens. Now I really don't know what would cause this to happen, but let's pretend that the loop we just went through took 2 seconds to complete: We set frameDelta to 2: frameDelta += clock.getDelta(); frameDelta += 2.00 Now we run an animation thanks to update(0.01666666666). Again what is relevance of 0.01666666666?? And then we take away 0.01666666666 from the frameDelta: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 2 - 0.01666666666 frameDelta = 1.98333333334 So let's go into the second loop. Let's say it took 2(? Why not 2? Or 12? I am a bit confused): frameDelta += clock.getDelta(); frameDelta = frameDelta + clock.getDelta(); frameDelta = 1.98333333334 + 2 frameDelta = 3.98333333334 This time we enter the while loop because 3.98333333334 = 0.01666666666 We run update We take away 0.01666666666 from frameDelta again: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 3.98333333334 - 0.01666666666 frameDelta = 3.96666666668 Now let's pretend the loop is super quick and runs in just 0.1 seconds and continues to do this. (Because the computer isn't busy any more). Basically, the update function will be run, and every loop we take away 0.01666666666 from the frameDelta untill the frameDelta is less than 0.01666666666. And then nothing happens until the computer runs slowly again? Could someone shed some light please? Does the update() update the scalar or something like that and we still have to times everything by the scalar like in the first example?

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  • How do I cleanly design a central render/animation loop?

    - by mtoast
    I'm learning some graphics programming, and am in the midst of my first such project of any substance. But, I am really struggling at the moment with how to architect it cleanly. Let me explain. To display complicated graphics in my current language of choice (JavaScript -- have you heard of it?), you have to draw graphical content onto a <canvas> element. And to do animation, you must clear the <canvas> after every frame (unless you want previous graphics to remain). Thus, most canvas-related JavaScript demos I've seen have a function like this: function render() { clearCanvas(); // draw stuff here requestAnimationFrame(render); } render, as you may surmise, encapsulates the drawing of a single frame. What a single frame contains at a specific point in time, well... that is determined by the program state. So, in order for my program to do its thing, I just need to look at the state, and decide what to render. Right? Right. But that is more complicated than it seems. My program is called "Critter Clicker". In my program, you see several cute critters bouncing around the screen. Clicking on one of them agitates it, making it bounce around even more. There is also a start screen, which says "Click to start!" prior to the critters being displayed. Here are a few of the objects I'm working with in my program: StartScreenView // represents the start screen CritterTubView // represents the area in which the critters live CritterList // a collection of all the critters Critter // a single critter model CritterView // view of a single critter Nothing too egregious with this, I think. Yet, when I set out to flesh out my render function, I get stuck, because everything I write seems utterly ugly and reminiscent of a certain popular Italian dish. Here are a couple of approaches I've attempted, with my internal thought process included, and unrelated bits excluded for clarity. Approach 1: "It's conditions all the way down" // "I'll just write the program as I think it, one frame at a time." if (assetsLoaded) { if (userClickedToStart) { if (critterTubDisplayed) { if (crittersDisplayed) { forEach(crittersList, function(c) { if (c.wasClickedRecently) { c.getAgitated(); } }); } else { displayCritters(); } } else { displayCritterTub(); } } else { displayStartScreen(); } } That's a very much simplified example. Yet even with only a fraction of all the rendering conditions visible, render is already starting to get out of hand. So, I dispense with that and try another idea: Approach 2: Under the Rug // "Each view object shall be responsible for its own rendering. // "I'll pass each object the program state, and each can render itself." startScreen.render(state); critterTub.render(state); critterList.render(state); In this setup, I've essentially just pushed those crazy nested conditions to a deeper level in the code, hiding them from view. In other words, startScreen.render would check state to see if it needed actually to be drawn or not, and take the correct action. But this seems more like it only solves a code-aesthetic problem. The third and final approach I'm considering that I'll share is the idea that I could invent my own "wheel" to take care of this. I'm envisioning a function that takes a data structure that defines what should happen at any given point in the render call -- revealing the conditions and dependencies as a kind of tree. Approach 3: Mad Scientist renderTree({ phases: ['startScreen', 'critterTub', 'endCredits'], dependencies: { startScreen: ['assetsLoaded'], critterTub: ['startScreenClicked'], critterList ['critterTubDisplayed'] // etc. }, exclusions: { startScreen: ['startScreenClicked'], // etc. } }); That seems kind of cool. I'm not exactly sure how it would actually work, but I can see it being a rather nifty way to express things, especially if I flex some of JavaScript's events. In any case, I'm a little bit stumped because I don't see an obvious way to do this. If you couldn't tell, I'm coming to this from the web development world, and finding that doing animation is a bit more exotic than arranging an MVC application for handling simple requests - responses. What is the clean, established solution to this common-I-would-think problem?

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  • Keep a programming language backwards compatible vs. fixing its flaws

    - by Radu Murzea
    First, some context (stuff that most of you know anyway): Every popular programming language has a clear evolution, most of the time marked by its version: you have Java 5, 6, 7 etc., PHP 5.1, 5.2, 5.3 etc. Releasing a new version makes new APIs available, fixes bugs, adds new features, new frameworks etc. So all in all: it's good. But what about the language's (or platform's) problems? If and when there's something wrong in a language, developers either avoid it (if they can) or they learn to live with it. Now, the developers of those languages get a lot of feedback from the programmers that use them. So it kind of makes sense that, as time (and version numbers) goes by, the problems in those languages will slowly but surely go away. Well, not really. Why? Backwards compatibility, that's why. But why is this so? Read below for a more concrete situation. The best way I can explain my question is to use PHP as an example: PHP is loved thousands of people and hated by just as many thousands. All languages have flaws, but apparently PHP is special. Check out this blog post. It has a very long list of so called flaws in PHP. Now, I'm not a PHP developer (not yet), but I read through all of it and I'm sure that a big chunk of that list are indeed real issues. (Not all of it, since it's potentially subjective). Now, if I was one of the guys who actively develops PHP, I would surely want to fix those problems, one by one. However, if I do that, then code that relies on a particular behaviour of the language will break if it runs on the new version. Summing it up in 2 words: backwards compatibility. What I don't understand is: why should I keep PHP backwards compatible? If I release PHP version 8 with all those problems fixed, can't I just put a big warning on it saying: "Don't run old code on this version !"? There is a thing called deprecation. We had it for years and it works. In the context of PHP: look at how these days people actively discourage the use of the mysql_* functions (and instead recommend mysqli_* and PDO). Deprecation works. We can use it. We should use it. If it works for functions, why shouldn't it work for entire languages? Let's say I (the developer of PHP) do this: Launch a new version of PHP (let's say 8) with all of those flaws fixed New projects will start using that version, since it's much better, clearer, more secure etc. However, in order not to abandon older versions of PHP, I keep releasing updates to it, fixing security issues, bugs etc. This makes sense for reasons that I'm not listing here. It's common practice: look for example at how Oracle kept updating version 5.1.x of MySQL, even though it mostly focused on version 5.5.x. After about 3 or 4 years, I stop updating old versions of PHP and leave them to die. This is fine, since in those 3 or 4 years, most projects will have switched to PHP 8 anyway. My question is: Do all these steps make sense? Would it be so hard to do? If it can be done, then why isn't it done? Yes, the downside is that you break backwards compatibility. But isn't that a price worth paying ? As an upside, in 3 or 4 years you'll have a language that has 90 % of its problems fixed.... a language much more pleasant to work with. Its name will ensure its popularity. EDIT: OK, so I didn't expressed myself correctly when I said that in 3 or 4 years people will move to the hypothetical PHP 8. What I meant was: in 3 or 4 years, people will use PHP 8 if they start a new project.

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  • Namespaces are obsolete

    - by Bertrand Le Roy
    To those of us who have been around for a while, namespaces have been part of the landscape. One could even say that they have been defining the large-scale features of the landscape in question. However, something happened fairly recently that I think makes this venerable structure obsolete. Before I explain this development and why it’s a superior concept to namespaces, let me recapitulate what namespaces are and why they’ve been so good to us over the years… Namespaces are used for a few different things: Scope: a namespace delimits the portion of code where a name (for a class, sub-namespace, etc.) has the specified meaning. Namespaces are usually the highest-level scoping structures in a software package. Collision prevention: name collisions are a universal problem. Some systems, such as jQuery, wave it away, but the problem remains. Namespaces provide a reasonable approach to global uniqueness (and in some implementations such as XML, enforce it). In .NET, there are ways to relocate a namespace to avoid those rare collision cases. Hierarchy: programmers like neat little boxes, and especially boxes within boxes within boxes. For some reason. Regular human beings on the other hand, tend to think linearly, which is why the Windows explorer for example has tried in a few different ways to flatten the file system hierarchy for the user. 1 is clearly useful because we need to protect our code from bleeding effects from the rest of the application (and vice versa). A language with only global constructs may be what some of us started programming on, but it’s not desirable in any way today. 2 may not be always reasonably worth the trouble (jQuery is doing fine with its global plug-in namespace), but we still need it in many cases. One should note however that globally unique names are not the only possible implementation. In fact, they are a rather extreme solution. What we really care about is collision prevention within our application. What happens outside is irrelevant. 3 is, more than anything, an aesthetical choice. A common convention has been to encode the whole pedigree of the code into the namespace. Come to think about it, we never think we need to import “Microsoft.SqlServer.Management.Smo.Agent” and that would be very hard to remember. What we want to do is bring nHibernate into our app. And this is precisely what you’ll do with modern package managers and module loaders. I want to take the specific example of RequireJS, which is commonly used with Node. Here is how you import a module with RequireJS: var http = require("http"); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This is of course importing a HTTP stack module into the code. There is no noise here. Let’s break this down. Scope (1) is provided by the one scoping mechanism in JavaScript: the closure surrounding the module’s code. Whatever scoping mechanism is provided by the language would be fine here. Collision prevention (2) is very elegantly handled. Whereas relocating is an afterthought, and an exceptional measure with namespaces, it is here on the frontline. You always relocate, using an extremely familiar pattern: variable assignment. We are very much used to managing our local variable names and any possible collision will get solved very easily by picking a different name. Wait a minute, I hear some of you say. This is only taking care of collisions on the client-side, on the left of that assignment. What if I have two libraries with the name “http”? Well, You can better qualify the path to the module, which is what the require parameter really is. As for hierarchical organization, you don’t really want that, do you? RequireJS’ module pattern does elegantly cover the bases that namespaces used to cover, but it also promotes additional good practices. First, it promotes usage of self-contained, single responsibility units of code through the closure-based, stricter scoping mechanism. Namespaces are somewhat more porous, as using/import statements can be used bi-directionally, which leads us to my second point… Sane dependency graphs are easier to achieve and sustain with such a structure. With namespaces, it is easy to construct dependency cycles (that’s bad, mmkay?). With this pattern, the equivalent would be to build mega-components, which are an easier problem to spot than a decay into inter-dependent namespaces, for which you need specialized tools. I really like this pattern very much, and I would like to see more environments implement it. One could argue that dependency injection has some commonalities with this for example. What do you think? This is the half-baked result of some morning shower reflections, and I’d love to read your thoughts about it. What am I missing?

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  • Why do we use Pythagoras in game physics?

    - by Starkers
    I've recently learned that we use Pythagoras a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't travel faster than a MAXIMUM_VELOCITY constant in the horizontal plane: MAXIMUM_VELOCITY = <any number>; SQUARED_MAXIMUM_VELOCITY = MAXIMUM_VELOCITY * MAXIMUM_VELOCITY; function animate(){ var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; x_velocity = x_velocity / scalar; z_velocity = x_velocity / scalar; } } Let's try this with some numbers: An object is attempting to move 5 units in x and 5 units in z. It should only be able to move 5 units horizontally in total! MAXIMUM_VELOCITY = 5; SQUARED_MAXIMUM_VELOCITY = 5 * 5; SQUARED_MAXIMUM_VELOCITY = 25; function animate(){ var x_velocity = 5; var z_velocity = 5; var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); var squared_horizontal_velocity = 5 * 5 + 5 * 5; var squared_horizontal_velocity = 25 + 25; var squared_horizontal_velocity = 50; // if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ if( 50 <= 25 ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; scalar = 50 / 25; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Now this works well, but we can do the same thing without Pythagoras: MAXIMUM_VELOCITY = 5; function animate(){ var x_velocity = 5; var z_velocity = 5; var horizontal_velocity = x_velocity + z_velocity; var horizontal_velocity = 5 + 5; var horizontal_velocity = 10; // if( horizontal_velocity >= MAXIMUM_VELOCITY ){ if( 10 >= 5 ){ scalar = horizontal_velocity / MAXIMUM_VELOCITY; scalar = 10 / 5; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Benefits of doing it without Pythagoras: Less lines Within those lines, it's easier to read what's going on ...and it takes less time to compute, as there are less multiplications Seems to me like computers and humans get a better deal without Pythagoras! However, I'm sure I'm wrong as I've seen Pythagoras' theorem in a number of reputable places, so I'd like someone to explain me the benefit of using Pythagoras to a maths newbie. Does this have anything to do with unit vectors? To me a unit vector is when we normalize a vector and turn it into a fraction. We do this by dividing the vector by a larger constant. I'm not sure what constant it is. The total size of the graph? Anyway, because it's a fraction, I take it, a unit vector is basically a graph that can fit inside a 3D grid with the x-axis running from -1 to 1, z-axis running from -1 to 1, and the y-axis running from -1 to 1. That's literally everything I know about unit vectors... not much :P And I fail to see their usefulness. Also, we're not really creating a unit vector in the above examples. Should I be determining the scalar like this: // a mathematical work-around of my own invention. There may be a cleverer way to do this! I've also made up my own terms such as 'divisive_scalar' so don't bother googling var divisive_scalar = (squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY); var divisive_scalar = ( 50 / 25 ); var divisive_scalar = 2; var multiplicative_scalar = (divisive_scalar / (2*divisive_scalar)); var multiplicative_scalar = (2 / (2*2)); var multiplicative_scalar = (2 / 4); var multiplicative_scalar = 0.5; x_velocity = x_velocity * multiplicative_scalar x_velocity = 5 * 0.5 x_velocity = 2.5 Again, I can't see why this is better, but it's more "unit-vector-y" because the multiplicative_scalar is a unit_vector? As you can see, I use words such as "unit-vector-y" so I'm really not a maths whiz! Also aware that unit vectors might have nothing to do with Pythagoras so ignore all of this if I'm barking up the wrong tree. I'm a very visual person (3D modeller and concept artist by trade!) and I find diagrams and graphs really, really helpful so as many as humanely possible please!

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  • #OOW 2012 : IaaS, Private Cloud, Multitenant Database, and X3H2M2

    - by Eric Bezille
    The title of this post is a summary of the 4 announcements made by Larry Ellison today, during the opening session of Oracle Open World 2012... To know what's behind X3H2M2, you will have to wait a little, as I will go in order, beginning with the IaaS - Infrastructure as a Service - announcement. Oracle IaaS goes Public... and Private... Starting in 2004 with Fusion development, Oracle Cloud was launch last year to provide not only SaaS Application, based on standard development, but also the underlying PaaS, required to build the specifics, and required interconnections between applications, in and outside of the Cloud. Still, to cover the end-to-end Cloud  Services spectrum, we had to provide an Infrastructure as a Service, leveraging our Servers, Storage, OS, and Virtualization Technologies, all "Engineered Together". This Cloud Infrastructure, was already available for our customers to build rapidly their own Private Cloud either on SPARC/Solaris or x86/Linux... The second announcement made today bring that proposition a big step further : for cautious customers (like Banks, or sensible industries) who would like to benefits from the Cloud value of "as a Service", but don't want their Data out in the Cloud... We propose to them to operate the same systems, Exadata, Exalogic & SuperCluster, that are providing our Public Cloud Infrastructure, behind their firewall, in a Private Cloud model. Oracle 12c Multitenant Database This is also a major announcement made today, on what's coming with Oracle Database 12c : the ability to consolidate multiple databases with no extra additional  cost especially in terms of memory needed on the server node, which is often THE consolidation limiting factor. The principle could be compare to Solaris Zones, where, you will have a Database Container, who is "owning" the memory and Database background processes, and "Pluggable" Database in this Database Container. This particular feature is a strong compelling event to evaluate rapidly Oracle Database 12c once it will be available, as this is major step forward into true Database consolidation with Multitenancy on a shared (optimized) infrastructure. X3H2M2, enabling the new Exadata X3 in-Memory Database Here we are :  X3H2M2 stands for X3 (the new version of Exadata announced also today) Heuristic Hierarchical Mass Memory, providing the capability to keep most if not all the Data in the memory cache hierarchy. Of course, this is the major software enhancement of the new X3 Exadata machine, but as this is a software, our current customers would be able to benefit from it on their existing systems by upgrading to the new release. But that' not the only thing that we did with X3, at the same time we have upgraded everything : the CPUs, adding more cores per server node (16 vs. 12, with the arrival of Intel E5 / Sandy Bridge), the memory with 512GB memory as well per node,  and the new Flash Fire card, bringing now up to 22 TB of Flash cache. All of this 4TB of RAM + 22TB of Flash being use cleverly not only for read but also for write by the X3H2M2 algorithm... making a very big difference compare to traditional storage flash extension. But what does those extra performances brings to you on an already very efficient system: double your performances compare to the fastest storage array on the market today (including flash) and divide you storage price x10 at the same time... Something to consider closely this days... Especially that we also announced the availability of a new Exadata X3-2 8th rack : a good starting point. As you have seen a major opening for this year again with true innovation. But that was not the only thing that we saw today, as before Larry's talk, Fujitsu did introduce more in deep the up coming new SPARC processor, that they are co-developing with us. And as such Andrew Mendelsohn - Senior Vice President Database Server Technologies came on stage to explain that the next step after I/O optimization for Database with Exadata, was to accelerate the Database at execution level by bringing functions in the SPARC processor silicium. All in all, to process more and more Data... The big theme of the day... and of the Oracle User Groups Conferences that were also happening today and where I had the opportunity to attend some interesting sessions on practical use cases of Big Data one in Finances and Fraud profiling and the other one on practical deployment of Oracle Exalytics for Data Analytics. In conclusion, one picture to try to size Oracle Open World ... and you can understand why, with such a rich content... and this only the first day !

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  • Impressions and Reactions from Alliance 2012

    - by user739873
    Alliance 2012 has come to a conclusion.  What strikes me about every Alliance conference is the amazing amount of collaboration and cooperation I see across higher education in the sharing of best practices around the entire Oracle PeopleSoft software suite, not just the student information system (Oracle’s PeopleSoft Campus Solutions).  In addition to the vibrant U.S. organization, it's gratifying to see the growth in the international attendance again this year, with an EMEA HEUG organizing to complement the existing groups in the Netherlands, South Africa, and the U.K.  Their first meeting is planned for London in October, and I suspect they'll be surprised at the amount of interest and attendance. In my discussions with higher education IT and functional leadership at Alliance there were a number of instances where concern was expressed about Oracle's commitment to higher education as an industry, primarily because of a lack of perceived innovation in the applications that Oracle develops for this market. Here I think perception and reality are far apart, and I'd like to explain why I believe this to be true. First let me start with what I think drives this perception. Predominately it's in two areas. The first area is the user interface, both for students and faculty that interact with the system as "customers", and for those employees of the institution (faculty, staff, and sometimes students as well) that use the system in some kind of administrative role. Because the UI hasn't changed all that much from the PeopleSoft days, individuals perceive this as a dead product with little innovation and therefore Oracle isn't investing. The second area is around the integration of the higher education suite of applications (PeopleSoft Campus Solutions) and the rest of the Oracle software assets. Whether grown organically or acquired, there is an impressive array of middleware and other software products that could be leveraged much more significantly by the higher education applications than is currently the case today. This is also perceived as lack of investment. Let me address these two points.  First the UI.  More is being done here than ever before, and the PAG and other groups where this was discussed at Alliance 2012 were more numerous than I've seen in any past meeting. Whether it's Oracle development leveraging web services or some extremely early but very promising work leveraging the recent Endeca acquisition (see some cool examples here) there are a lot of resources aimed at this issue.  There are also some amazing prototypes being developed by our UX (user experience team) that will eventually make their way into the higher education applications realm - they had an impressive setup at Alliance.  Hopefully many of you that attended found this group. If not, the senior leader for that team Jeremy Ashley will be a significant contributor of content to our summer Industry Strategy Council meeting in Washington in June. In the area of integration with other elements of the Oracle stack, this is also an area of focus for the company and my team.  We're making this a priority especially in the areas of identity management and security, leveraging WebCenter more effectively for content, imaging, and mobility, and driving towards the ultimate objective of WebLogic Suite as our platform for SOA, links to learning management systems (SAIP), and content. There is also much work around business intelligence centering on OBI applications. But at the end of the day we get enormous value from the HEUG (higher education user group) and the various subgroups formed as a part of this community that help us align and prioritize our investments, whether it's around better integration with other Oracle products or integration with partner offerings.  It's one of the healthiest, mutually beneficial relationships between customers and an Education IT concern that exists on the globe. And I can't avoid mentioning that this kind of relationship between higher education and the corporate IT community that can truly address the problems of efficiency and effectiveness, institutional excellence (which starts with IT) and student success.  It's not (in my opinion) going to be solved through community source - cost and complexity only increase in that model and in the end higher education doesn't ultimately focus on core competencies: educating, developing, and researching.  While I agree with some of what Michael A. McRobbie wrote in his EDUCAUSE Review article (Information Technology: A View from Both Sides of the President’s Desk), I take strong issue with his assertion that the "the IT marketplace is just the opposite of long-term stability...."  Sure there has been healthy, creative destruction in the past 2-3 decades, but this has had the effect of, in the aggregate, benefiting education with greater efficiency, more innovation and increased stability as larger, more financially secure firms acquire and develop integrated solutions. Cole

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  • High Availability for IaaS, PaaS and SaaS in the Cloud

    - by BuckWoody
    Outages, natural disasters and unforeseen events have proved that even in a distributed architecture, you need to plan for High Availability (HA). In this entry I'll explain a few considerations for HA within Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). In a separate post I'll talk more about Disaster Recovery (DR), since each paradigm has a different way to handle that. Planning for HA in IaaS IaaS involves Virtual Machines - so in effect, an HA strategy here takes on many of the same characteristics as it would on-premises. The primary difference is that the vendor controls the hardware, so you need to verify what they do for things like local redundancy and so on from the hardware perspective. As far as what you can control and plan for, the primary factors fall into three areas: multiple instances, geographical dispersion and task-switching. In almost every cloud vendor I've studied, to ensure your application will be protected by any level of HA, you need to have at least two of the Instances (VM's) running. This makes sense, but you might assume that the vendor just takes care of that for you - they don't. If a single VM goes down (for whatever reason) then the access to it is lost. Depending on multiple factors, you might be able to recover the data, but you should assume that you can't. You should keep a sync to another location (perhaps the vendor's storage system in another geographic datacenter or to a local location) to ensure you can continue to serve your clients. You'll also need to host the same VM's in another geographical location. Everything from a vendor outage to a network path problem could prevent your users from reaching the system, so you need to have multiple locations to handle this. This means that you'll have to figure out how to manage state between the geo's. If the system goes down in the middle of a transaction, you need to figure out what part of the process the system was in, and then re-create or transfer that state to the second set of systems. If you didn't write the software yourself, this is non-trivial. You'll also need a manual or automatic process to detect the failure and re-route the traffic to your secondary location. You could flip a DNS entry (if your application can tolerate that) or invoke another process to alias the first system to the second, such as load-balancing and so on. There are many options, but all of them involve coding the state into the application layer. If you've simply moved a state-ful application to VM's, you may not be able to easily implement an HA solution. Planning for HA in PaaS Implementing HA in PaaS is a bit simpler, since it's built on the concept of stateless applications deployment. Once again, you need at least two copies of each element in the solution (web roles, worker roles, etc.) to remain available in a single datacenter. Also, you need to deploy the application again in a separate geo, but the advantage here is that you could work out a "shared storage" model such that state is auto-balanced across the world. In fact, you don't have to maintain a "DR" site, the alternate location can be live and serving clients, and only take on extra load if the other site is not available. In Windows Azure, you can use the Traffic Manager service top route the requests as a type of auto balancer. Even with these benefits, I recommend a second backup of storage in another geographic location. Storage is inexpensive; and that second copy can be used for not only HA but DR. Planning for HA in SaaS In Software-as-a-Service (such as Office 365, or Hadoop in Windows Azure) You have far less control over the HA solution, although you still maintain the responsibility to ensure you have it. Since each SaaS is different, check with the vendor on the solution for HA - and make sure you understand what they do and what you are responsible for. They may have no HA for that solution, or pin it to a particular geo, or perhaps they have a massive HA built in with automatic load balancing (which is often the case).   All of these options (with the exception of SaaS) involve higher costs for the design. Do not sacrifice reliability for cost - that will always cost you more in the end. Build in the redundancy and HA at the very outset of the project - if you try to tack it on later in the process the business will push back and potentially not implement HA. References: http://www.bing.com/search?q=windows+azure+High+Availability  (each type of implementation is different, so I'm routing you to a search on the topic - look for the "Patterns and Practices" results for the area in Azure you're interested in)

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  • UIView with IrrlichtScene - iOS

    - by user1459024
    i have a UIViewController in a Storyboard and want to draw a IrrlichtScene in this View Controller. My Code: WWSViewController.h #import <UIKit/UIKit.h> @interface WWSViewController : UIViewController { IBOutlet UILabel *errorLabel; } @end WWSViewController.mm #import "WWSViewController.h" #include "../../ressources/irrlicht/include/irrlicht.h" using namespace irr; using namespace core; using namespace scene; using namespace video; using namespace io; using namespace gui; @interface WWSViewController () @end @implementation WWSViewController -(void)awakeFromNib { errorLabel = [[UILabel alloc] init]; errorLabel.text = @""; IrrlichtDevice *device = createDevice( video::EDT_OGLES1, dimension2d<u32>(640, 480), 16, false, false, false, 0); /* Set the caption of the window to some nice text. Note that there is an 'L' in front of the string. The Irrlicht Engine uses wide character strings when displaying text. */ device->setWindowCaption(L"Hello World! - Irrlicht Engine Demo"); /* Get a pointer to the VideoDriver, the SceneManager and the graphical user interface environment, so that we do not always have to write device->getVideoDriver(), device->getSceneManager(), or device->getGUIEnvironment(). */ IVideoDriver* driver = device->getVideoDriver(); ISceneManager* smgr = device->getSceneManager(); IGUIEnvironment* guienv = device->getGUIEnvironment(); /* We add a hello world label to the window, using the GUI environment. The text is placed at the position (10,10) as top left corner and (260,22) as lower right corner. */ guienv->addStaticText(L"Hello World! This is the Irrlicht Software renderer!", rect<s32>(10,10,260,22), true); /* To show something interesting, we load a Quake 2 model and display it. We only have to get the Mesh from the Scene Manager with getMesh() and add a SceneNode to display the mesh with addAnimatedMeshSceneNode(). We check the return value of getMesh() to become aware of loading problems and other errors. Instead of writing the filename sydney.md2, it would also be possible to load a Maya object file (.obj), a complete Quake3 map (.bsp) or any other supported file format. By the way, that cool Quake 2 model called sydney was modelled by Brian Collins. */ IAnimatedMesh* mesh = smgr->getMesh("/Users/dbocksteger/Desktop/test/media/sydney.md2"); if (!mesh) { device->drop(); if (!errorLabel) { errorLabel = [[UILabel alloc] init]; } errorLabel.text = @"Konnte Mesh nicht laden."; return; } IAnimatedMeshSceneNode* node = smgr->addAnimatedMeshSceneNode( mesh ); /* To let the mesh look a little bit nicer, we change its material. We disable lighting because we do not have a dynamic light in here, and the mesh would be totally black otherwise. Then we set the frame loop, such that the predefined STAND animation is used. And last, we apply a texture to the mesh. Without it the mesh would be drawn using only a color. */ if (node) { node->setMaterialFlag(EMF_LIGHTING, false); node->setMD2Animation(scene::EMAT_STAND); node->setMaterialTexture( 0, driver->getTexture("/Users/dbocksteger/Desktop/test/media/sydney.bmp") ); } /* To look at the mesh, we place a camera into 3d space at the position (0, 30, -40). The camera looks from there to (0,5,0), which is approximately the place where our md2 model is. */ smgr->addCameraSceneNode(0, vector3df(0,30,-40), vector3df(0,5,0)); /* Ok, now we have set up the scene, lets draw everything: We run the device in a while() loop, until the device does not want to run any more. This would be when the user closes the window or presses ALT+F4 (or whatever keycode closes a window). */ while(device->run()) { /* Anything can be drawn between a beginScene() and an endScene() call. The beginScene() call clears the screen with a color and the depth buffer, if desired. Then we let the Scene Manager and the GUI Environment draw their content. With the endScene() call everything is presented on the screen. */ driver->beginScene(true, true, SColor(255,100,101,140)); smgr->drawAll(); guienv->drawAll(); driver->endScene(); } /* After we are done with the render loop, we have to delete the Irrlicht Device created before with createDevice(). In the Irrlicht Engine, you have to delete all objects you created with a method or function which starts with 'create'. The object is simply deleted by calling ->drop(). See the documentation at irr::IReferenceCounted::drop() for more information. */ device->drop(); } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. } - (void)viewDidUnload { [super viewDidUnload]; // Release any retained subviews of the main view. } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } @end Sadly the result is just a black View in the Simulator. :( Hope here is anyone who can explain me how i draw the scene in a UIView. Furthermore I'm getting this Error: Could not load sprite bank because the file does not exist: #DefaultFont How can i fix it ?

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  • Multiple enemy array in LibGDX

    - by johnny-b
    I am trying to make a multiple enemy array, where every 30 secods a new bullet comes from a random point. And if the bullet is clicked it should disapear and a pop like an explosion should appear. And if the bullet hits the ball then the ball pops. so the bullet should change to a different sprite or texture. same with the ball pop. But all that happens is the bullet if touched pops and nothing else happens. And if modified then the bullet keeps flashing as the update is way too much. I have added COMMENTS in the code to explain more on the issues. below is the code. if more code is needed i will provide. Thank you public class GameRenderer { private GameWorld myWorld; private OrthographicCamera cam; private ShapeRenderer shapeRenderer; private SpriteBatch batcher; // Game Objects private Ball ball; private ScrollHandler scroller; private Background background; private Bullet bullet1; private BulletPop bPop; private Array<Bullet> bullets; // This is for the delay of the bullet coming one by one every 30 seconds. /** The time of the last shot fired, we set it to the current time in nano when the object is first created */ double lastShot = TimeUtils.nanoTime(); /** Convert 30 seconds into nano seconds, so 30,000 milli = 30 seconds */ double shotFreq = TimeUtils.millisToNanos(30000); // Game Assets private TextureRegion bg, bPop; private Animation bulletAnimation, ballAnimation; private Animation ballPopAnimation; public GameRenderer(GameWorld world) { myWorld = world; cam = new OrthographicCamera(); cam.setToOrtho(true, 480, 320); batcher = new SpriteBatch(); // Attach batcher to camera batcher.setProjectionMatrix(cam.combined); shapeRenderer = new ShapeRenderer(); shapeRenderer.setProjectionMatrix(cam.combined); // This is suppose to produce 10 bullets at random places on the background. bullets = new Array<Bullet>(); Bullet bullet = null; float bulletX = 00.0f; float bulletY = 00.0f; for (int i = 0; i < 10; i++) { bulletX = MathUtils.random(-10, 10); bulletY = MathUtils.random(-10, 10); bullet = new Bullet(bulletX, bulletY); AssetLoader.bullet1.flip(true, false); AssetLoader.bullet2.flip(true, false); bullets.add(bullet); } // Call helper methods to initialize instance variables initGameObjects(); initAssets(); } private void initGameObjects() { ball = GameWorld.getBall(); bullet1 = myWorld.getBullet1(); bPop = myWorld.getBulletPop(); scroller = myWorld.getScroller(); } private void initAssets() { bg = AssetLoader.bg; ballAnimation = AssetLoader.ballAnimation; bullet1Animation = AssetLoader.bullet1Animation; ballPopAnimation = AssetLoader.ballPopAnimation; } // This is to take the bullet away when clicked or touched. public void onClick() { for (int i = 0; i < bullets.size; i++) { if (bullets.get(i).getBounds().contains(0, 0)) bullets.removeIndex(i); } } private void drawBackground() { batcher.draw(bg1, background.getX(), background.getY(), background.getWidth(), backgroundMove.getHeight()); } public void render(float runTime) { Gdx.gl.glClearColor(0, 0, 0, 1); Gdx.gl.glClear(GL30.GL_COLOR_BUFFER_BIT); batcher.begin(); // Disable transparency // This is good for performance when drawing images that do not require // transparency. batcher.disableBlending(); drawBackground(); batcher.enableBlending(); // when the bullet hits the ball, it should be disposed or taken away and a ball pop sprite/texture should be put in its place if (bullet1.collides(ball)) { // draws the bPop texture but the bullet does not go just keeps going around, and the bPop texture goes. batcher.draw(AssetLoader.bPop, 195, 273); } batcher.draw(AssetLoader.ballAnimation.getKeyFrame(runTime), ball.getX(), ball.getY(), ball.getWidth(), ball.getHeight()); // this is where i am trying to make the bullets come one by one, and if removed via the onClick() then bPop animation // should play but does not??? if(TimeUtils.nanoTime() - lastShot > shotFreq){ // Create your stuff for (int i = 0; i < bullets.size; i++) { bullets.get(i); batcher.draw(AssetLoader.bullet1Animation.getKeyFrame(runTime), bullet1.getX(), bullet1.getY(), bullet1.getOriginX(), bullet1.getOriginY(), bullet1.getWidth(), bullet1.getHeight(), 1.0f, 1.0f, bullet1.getRotation()); if (bullets.removeValue(bullet1, false)) { batcher.draw(AssetLoader.ballPopAnimation.getKeyFrame(runTime), bPop1.getX(), bPop1.getY(), bPop1.getWidth(), bPop1.getHeight()); } } /* Very important to set the last shot to now, or it will mess up and go full auto */ lastShot = TimeUtils.nanoTime(); } // End SpriteBatch batcher.end(); } } Thank you

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  • Thinking differently about BI delivery

    - by jamiet
    My day job involves implementing Business Intelligence (BI) solutions which, as I have said before, is simply about giving people the information they need to do their jobs. I’m always interested in learning about new ways of achieving that aim and that is my motivation for writing blog entries that are not concerned with SQL or SQL Server per se. Implementing BI systems usually involves hacking together a bunch third party products with some in-house “glue” and delivering information using some shiny, expensive web-based front-end tool; the list of vendors that supply such tools is big and ever-growing. No doubt these tools have their place and of late I have started to wonder whether they can be supplemented with different ways of delivering information. The problem I have with these separate web-based tools is exactly that – they are separate web-based tools. What’s the problem with that you might ask? I’ll explain! They force the information worker to go somewhere unfamiliar in order to get the information they need to do their jobs. Would it not be better if we could deliver information into the tools that those information workers are already using and not force them to go somewhere else? I look at the rise of blogging over recent years and I realise that what made them popular is that people can subscribe to RSS feeds and have information pushed to them in their tool of choice rather than them having to go and find the information for themselves in a tool that has been foisted upon them. Would it not be a good idea to adopt the principle of subscription for the benefit of delivering BI information as well? I think it would and in the rest of this blog entry I’ll outline such a scenario where the power of subscription could be used to enhance the delivery of information to information workers. Typical questions that information workers ask might be: What are my year-on-year sales figures? What was my footfall yesterday? How many widgets have I sold so far today? Each of those questions includes a time element and that shouldn’t surprise us, any BI system that I have worked on includes the dimension of time. Now, what do people use to view and organise their time-oriented information? Its not a trick question, they use a calendar and in the enterprise space more often than not that calendar is managed using Outlook. Given then that information workers are already looking at their calendar in Outlook anyway would it not make sense then to deliver information into that same calendar? Of course it would. Calendars are a great way of visualising information such as sales figures. Observe: Just in this single screenshot I have managed to convey a multitude of information. The information worker can see, at a glance, information about hourly/daily/weekly/monthly sales and, moreover, he/she is viewing that information right inside the tool that they use every day. There is no effort on the part of him/her, the information just appears hour after hour, day after day. Taking the idea further, each one of those calendar items could be a mini-dashboard in its own right. Double-clicking on an item could show a plethora of other information about that time slot such as breaking the sales down per region or year-over-year comparisons. Perhaps the title could employ a sparkline? Loads of possibilities. The point is that calendars are a completely natural way to visualise information; we should make more use of them! The real beauty of delivering information using calendars for us BI developers is that it should be so easy. In the case of Outlook we don’t need to write complicated VBA code that can go and manipulate a person’s calendar, simply publishing data in a format that Outlook can understand is sufficient and happily such formats already exist; iCalendar is the accepted format and the even more flexible xCalendar is hopefully on its way as well.   I’d like to make one last point and this one is with my SQL Server hat on. Reporting Services 2008 R2 introduced the ability to publish data as subscribable Atom feeds so it seems logical that it could also be a vehicle for delivering calendar feeds too. If you think this would be a good idea go and vote for it at Publish data as iCalendar feeds and please please please add some comments (especially if you vote it down). Work smarter, not harder! @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • What Counts for A DBA - Logic

    - by drsql
    "There are 10 kinds of people in the world. Those who will always wonder why there are only two items in my list and those who will figured it out the first time they saw this very old joke."  Those readers who will give up immediately and get frustrated with me for not explaining it to them are not likely going to be great technical professionals of any sort, much less a programmer or administrator who will be constantly dealing with the common failures that make up a DBA's day.  Many of these people will stare at this like a dog staring at a traffic signal and still have no more idea of how to decipher the riddle. Without explanation they will give up, call the joke "stupid" and, feeling quite superior, walk away indignantly to their job likely flipping patties of meat-by-product. As a data professional or any programmer who has strayed  to this very data-oriented blog, you would, if you are worth your weight in air, either have recognized immediately what was going on, or felt a bit ignorant.  Your friends are chuckling over the joke, but why is it funny? Unfortunately you left your smartphone at home on the dresser because you were up late last night programming and were running late to work (again), so you will either have to fake a laugh or figure it out.  Digging through the joke, you figure out that the word "two" is the most important part, since initially the joke mentioned 10. Hmm, why did they spell out two, but not ten? Maybe 10 could be interpreted a different way?  As a DBA, this sort of logic comes into play every day, and sometimes it doesn't involve nerdy riddles or Star Wars folklore.  When you turn on your computer and get the dreaded blue screen of death, you don't immediately cry to the help desk and sit on your thumbs and whine about not being able to work. Do that and your co-workers will question your nerd-hood; I know I certainly would. You figure out the problem, and when you have it narrowed down, you call the help desk and tell them what the problem is, usually having to explain that yes, you did in fact try to reboot before calling.  Of course, sometimes humility does come in to play when you reach the end of your abilities, but the ‘end of abilities’ is not something any of us recognize readily. It is handy to have the ability to use logic to solve uncommon problems: It becomes especially useful when you are trying to solve a data-related problem such as a query performance issue, and the way that you approach things will tell your coworkers a great deal about your abilities.  The novice is likely to immediately take the approach of  trying to add more indexes or blaming the hardware. As you become more and more experienced, it becomes increasingly obvious that performance issues are a very complex topic. A query may be slow for a myriad of reasons, from concurrency issues, a poor query plan because of a parameter value (like parameter sniffing,) poor coding standards, or just because it is a complex query that is going to be slow sometimes. Some queries that you will deal with may have twenty joins and hundreds of search criteria, and it can take a lot of thought to determine what is going on.  You can usually figure out the problem to almost any query by using basic knowledge of how joins and queries work, together with the help of such things as the query plan, profiler or monitoring tools.  It is not unlikely that it can take a full day’s work to understand some queries, breaking them down into smaller queries to find a very tiny problem. Not every time will you actually find the problem, and it is part of the process to occasionally admit that the problem is random, and everything works fine now.  Sometimes, it is necessary to realize that a problem is outside of your current knowledge, and admit temporary defeat: You can, at least, narrow down the source of the problem by looking logically at all of the possible solutions. By doing this, you can satisfy your curiosity and learn more about what the actual problem was. For example, in the joke, had you never been exposed to the concept of binary numbers, there is no way you could have known that binary - 10 = decimal - 2, but you could have logically come to the conclusion that 10 must not mean ten in the context of the joke, and at that point you are that much closer to getting the joke and at least won't feel so ignorant.

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  • Defining scope for Record Count functoid:

    - by ArunManick
    Defining scope for Record Count functoid: Problem: One of the most common scenarios in BizTalk is calculating the record count of repeating structure. BizTalk has come up with an advanced functoid called Record Count functoid which will give the record count for the repeating structure however you cannot define the scope for a Record Count functoid. Because Record Count functoid accepts exactly one parameter which can be repeating record or field element.   If somebody don’t know what “scope” means I will explain with a simple example. Consider that we have a source schema having a structure Country -> State -> City. Country will have various states and each state will have different cities. Now you want to calculate no. of cities present in each state. Here scope is defined at the parent node “State”. Traditional Record Count functoid will give the total no. of cities present in the source message and not the State level city count.   Source Schema:   Destination Schema:   Soultion #1: As the title indicates we are not going to add one more parameter to the record count functoid. Instead of that, we are going to achieve the solution with the help of Scripting functoid with Inline XSLT script. XSLT is basically the transformation language used in the mapping.     “No.OfCities” indicates the destination field name to which we are going to send the value. In count(City), “count” refers to built in XPath function used in XSLT and “City” refers to source schema record name. Here you can find the list of built-in functions available in XSLT.   The mapping will look like as follows:   The 2 Record Count functoids used in this map will give the total number of states and total number of cities as that of input message.   Soultion #2:  If someone doesn’t like XSLT code and they wish to achieve the solution using functoids alone, then here is another solution.   Use logical Existence functoid to check whether “City” exist or not Connect the output of Logical Existence functoid to the Value Mapping functoid with second parameter as constant “1”. Hence if the first parameter is TRUE it will give the output as “1”. Connect the output of Value Mapping functoid to the Cumulative Sum functoid with scope as “1”   This will calculate the City count at the state level. The mapping will look like as follows:     Let us see the sample input and the map output.   Input: <?xml version="1.0" encoding="utf-8"?> <ns0:Country xmlns:ns0="http://RecordCount.Source">   <State>     <StateName>Tamilnadu</StateName>     <City>       <CityName>Pollachi</CityName>     </City>     <City>       <CityName>Coimbatore</CityName>     </City>     <City>       <CityName>Chennai</CityName>     </City>   </State>   <State>     <StateName>Kerala</StateName>     <City>       <CityName>Palakad</CityName>     </City>   </State>   <State>     <StateName>Karnataka</StateName>     <City>       <CityName>Bangalore</CityName>     </City>     <City>       <CityName>Mangalore</CityName>     </City>   </State> </ns0:Country>     Output: <ns0:Country xmlns:ns0="http://RecordCount.Destination">           <No.OfStates>3</No.OfStates>           <No.OfCities>6</No.OfCities>           <States>                    <No.OfCities>3</No.OfCities>           </States>           <States>                    <No.OfCities>1</No.OfCities>           </States>           <States>                    <No.OfCities>2</No.OfCities>           </States> </ns0:Country>   Conclusion: This is my first post and I hope you enjoyed it.   -Arun

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  • Why do we use the Pythagorean theorem in game physics?

    - by Starkers
    I've recently learned that we use Pythagorean theorem a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't travel faster than a MAXIMUM_VELOCITY constant in the horizontal plane: MAXIMUM_VELOCITY = <any number>; SQUARED_MAXIMUM_VELOCITY = MAXIMUM_VELOCITY * MAXIMUM_VELOCITY; function animate(){ var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; x_velocity = x_velocity / scalar; z_velocity = x_velocity / scalar; } } Let's try this with some numbers: An object is attempting to move 5 units in x and 5 units in z. It should only be able to move 5 units horizontally in total! MAXIMUM_VELOCITY = 5; SQUARED_MAXIMUM_VELOCITY = 5 * 5; SQUARED_MAXIMUM_VELOCITY = 25; function animate(){ var x_velocity = 5; var z_velocity = 5; var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); var squared_horizontal_velocity = 5 * 5 + 5 * 5; var squared_horizontal_velocity = 25 + 25; var squared_horizontal_velocity = 50; // if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ if( 50 <= 25 ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; scalar = 50 / 25; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Now this works well, but we can do the same thing without Pythagoras: MAXIMUM_VELOCITY = 5; function animate(){ var x_velocity = 5; var z_velocity = 5; var horizontal_velocity = x_velocity + z_velocity; var horizontal_velocity = 5 + 5; var horizontal_velocity = 10; // if( horizontal_velocity >= MAXIMUM_VELOCITY ){ if( 10 >= 5 ){ scalar = horizontal_velocity / MAXIMUM_VELOCITY; scalar = 10 / 5; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Benefits of doing it without Pythagoras: Less lines Within those lines, it's easier to read what's going on ...and it takes less time to compute, as there are less multiplications Seems to me like computers and humans get a better deal without Pythagorean theorem! However, I'm sure I'm wrong as I've seen Pythagoras' theorem in a number of reputable places, so I'd like someone to explain me the benefit of using Pythagorean theorem to a maths newbie. Does this have anything to do with unit vectors? To me a unit vector is when we normalize a vector and turn it into a fraction. We do this by dividing the vector by a larger constant. I'm not sure what constant it is. The total size of the graph? Anyway, because it's a fraction, I take it, a unit vector is basically a graph that can fit inside a 3D grid with the x-axis running from -1 to 1, z-axis running from -1 to 1, and the y-axis running from -1 to 1. That's literally everything I know about unit vectors... not much :P And I fail to see their usefulness. Also, we're not really creating a unit vector in the above examples. Should I be determining the scalar like this: // a mathematical work-around of my own invention. There may be a cleverer way to do this! I've also made up my own terms such as 'divisive_scalar' so don't bother googling var divisive_scalar = (squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY); var divisive_scalar = ( 50 / 25 ); var divisive_scalar = 2; var multiplicative_scalar = (divisive_scalar / (2*divisive_scalar)); var multiplicative_scalar = (2 / (2*2)); var multiplicative_scalar = (2 / 4); var multiplicative_scalar = 0.5; x_velocity = x_velocity * multiplicative_scalar x_velocity = 5 * 0.5 x_velocity = 2.5 Again, I can't see why this is better, but it's more "unit-vector-y" because the multiplicative_scalar is a unit_vector? As you can see, I use words such as "unit-vector-y" so I'm really not a maths whiz! Also aware that unit vectors might have nothing to do with Pythagorean theorem so ignore all of this if I'm barking up the wrong tree. I'm a very visual person (3D modeller and concept artist by trade!) and I find diagrams and graphs really, really helpful so as many as humanely possible please!

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  • My own personal use of Oracle Linux

    - by wcoekaer
    It always is easier to explain something with examples... Many people still don't seem to understand some of the convenient things around using Oracle Linux and since I personally (surprise!) use it at home, let me give you an idea. I have quite a few servers at home and I also have 2 hosted servers with a hosted provider. The servers at home I use mostly to play with random Linux related things, or with Oracle VM or just try out various new Oracle products to learn more. I like the technology, it's like a hobby really. To be able to have a good installation experience and use an officially certified Linux distribution and not waste time trying to find the right libraries, I, of course, use Oracle Linux. Now, at least I can get a copy of Oracle Linux for free (even if I was not working for Oracle) and I can/could use that on as many servers at home (or at my company if I worked elsewhere) for testing, development and production. I just go to http://edelivery.oracle.com/linux and download the version(s) I want and off I go. Now, I also have the right (and not because I am an employee) to take those images and put them on my own server and give them to someone else, I in fact, just recently set up my own mirror on my own hosted server. I don't have to remove oracle-logos, I don't have to rebuild the ISO images, I don't have to recompile anything, I can just put the whole binary distribution on my own server without contract. Perfectly free to do so. Of course the source code of all of this is there, I have a copy of the UEK code at home, just cloned from https://oss.oracle.com/git/?p=linux-2.6-unbreakable.git. And as you can see, the entire changelog, checkins, merges from Linus's tree, complete overview of everything that got changed from kernel to kernel, from patch to patch, errata to errata. No obfuscating, no tar balls and spending time with diff, or go read bug reports to find out what changed (seems silly to me). Some of my servers are on the external network and I need to be current with security errata, but guess what, no problem, my servers are hooked up to http://public-yum.oracle.com which is open, free, and completely up to date, in a consistent, reliable way with any errata, security or bugfix. So I have nothing to worry about. Also, not because I am an employee. Anyone can. And, with this, I also can, and have, set up my own mirror site that hosts these RPMs. both binary and source rpms. Because I am free to get them and distribute them. I am quite capable of supporting my servers on my own, so I don't need to rely on the support organization so I don't need to have a support subscription :-). So I don't need to pay. Neither would you, at least not with Oracle Linux. Another cool thing. The hosted servers came (unfortunately) with Centos installed. While Centos works just fine as is, I tend to prefer to be current with my security errata(reliably) and I prefer to just maintain one yum repository instead of 2, I converted them over to Oracle Linux as well (in place) so they happily receive and use the exact same RPMs. Since Oracle Linux is exactly the same from a user/application point of view as RHEL, including files like /etc/redhat-release and no changes from .el. to .centos. I know I have nothing to worry about installing one of the RHEL applications. So, OL everywhere makes my life a lot easier and why not... Next! Since I run Oracle VM and I have -tons- of VM's on my machines, in some cases on my big WOPR box I have 15-20 VMs running. Well, no problem, OL is free and I don't have to worry about counting the number of VMs, whether it's 1, or 4, or more than 10 ... like some other alternatives started doing... and finally :) I like to try out new stuff, not 3 year old stuff. So with UEK2 as part of OL6 (and 6.3 in particular) I can play with a 3.0.x based kernel and it just installs and runs perfectly clean with OL6, so quite current stuff in an environment that I know works, no need to toy around with an unsupported pre-alpha upstream distribution with libraries and versions that are not compatible with production software (I have nothing against ubuntu or fedora or opensuse... just not what I can rely on or use for what I need, and I don't need a desktop). pretty compelling. I say... and again, it doesn't matter that I work for Oracle, if I was working elsewhere, or not at all, all of the above would still apply. Student, teacher, developer, whatever. contrast this with $349 for 2 sockets and oneguest and selfsupport per year to even just get the software bits.

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  • Fixing a collision detection bug in Slick2D

    - by Jesse Prescott
    My game has a bug with collision detection. If you go against the wall and tap forward/back sometimes the game thinks the speed you travelled at is 0 and the game doesn't know how to get you out of the wall. My collision detection works by getting the speed you hit the wall at and if it is positive it moves you back, if it is negative it moves you forward. It might help if you download it: https://rapidshare.com/files/1550046269/game.zip Sorry if I explained badly, it's hard to explain. float maxSpeed = 0.3f; float minSpeed = -0.2f; float acceleration = 0.002f; float deacceleration = 0.001f; float slowdownSpeed = 0.002f; float rotateSpeed = 0.08f; static float currentSpeed = 0; boolean up = false; boolean down = false; boolean noKey = false; static float rotate = 0; //Image effect system static String locationCarNormal; static String locationCarFront; static String locationCarBack; static String locationCarBoth; static boolean carFront = false; static boolean carBack = false; static String imageRef; boolean collision = false; public ComponentPlayerMovement(String id, String ScarNormal, String ScarFront, String ScarBack, String ScarBoth) { this.id = id; playerBody = new Rectangle(900/2-16, 700/2-16, 32, 32); locationCarNormal = ScarNormal; locationCarFront = ScarFront; locationCarBack = ScarBack; locationCarBoth = ScarBoth; imageRef = locationCarNormal; } @Override public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException { Input input = gc.getInput(); playerBody.transform(Transform.createRotateTransform(2)); float hip = currentSpeed * delta; float unstuckspeed = 0.05f * delta; if(carBack && !carFront) { imageRef = locationCarBack; ComponentImageRender.updateImage(); } else if(carFront && !carBack) { imageRef = locationCarFront; ComponentImageRender.updateImage(); } else if(carFront && carBack) { imageRef = locationCarBoth; ComponentImageRender.updateImage(); } if(input.isKeyDown(Input.KEY_RIGHT)) { rotate += rotateSpeed * delta; owner.setRotation(rotate); } if(input.isKeyDown(Input.KEY_LEFT)) { rotate -= rotateSpeed * delta; owner.setRotation(rotate); } if(input.isKeyDown(Input.KEY_UP)) { if(!collision) { up = true; noKey = false; if(currentSpeed < maxSpeed) { currentSpeed += acceleration; } MapCoordStorage.mapX += hip * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= hip * Math.cos(Math.toRadians(rotate)); } else { currentSpeed = 1; } } else if(input.isKeyDown(Input.KEY_DOWN) && !collision) { down = true; noKey = false; if(currentSpeed > minSpeed) { currentSpeed -= slowdownSpeed; } MapCoordStorage.mapX += hip * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= hip * Math.cos(Math.toRadians(rotate)); } else { noKey = true; if(currentSpeed > 0) { currentSpeed -= deacceleration; } else if(currentSpeed < 0) { currentSpeed += acceleration; } MapCoordStorage.mapX += hip * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= hip * Math.cos(Math.toRadians(rotate)); } if(entityCollisionWith()) { collision = true; if(currentSpeed > 0 || up) { up = true; currentSpeed = 0; carFront = true; MapCoordStorage.mapX += unstuckspeed * Math.sin(Math.toRadians(rotate-180)); MapCoordStorage.mapY -= unstuckspeed * Math.cos(Math.toRadians(rotate-180)); } else if(currentSpeed < 0 || down) { down = true; currentSpeed = 0; carBack = true; MapCoordStorage.mapX += unstuckspeed * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= unstuckspeed * Math.cos(Math.toRadians(rotate)); } else { currentSpeed = 0; } } else { collision = false; up = false; down = false; } if(currentSpeed >= -0.01f && currentSpeed <= 0.01f && noKey && !collision) { currentSpeed = 0; } } public static boolean entityCollisionWith() throws SlickException { for (int i = 0; i < BlockMap.entities.size(); i++) { Block entity1 = (Block) BlockMap.entities.get(i); if (playerBody.intersects(entity1.poly)) { return true; } } return false; } }

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  • In 3D camera math, calculate what Z depth is pixel unity for a given FOV

    - by badweasel
    I am working in iOS and OpenGL ES 2.0. Through trial and error I've figured out a frustum to where at a specific z depth pixels drawn are 1 to 1 with my source textures. So 1 pixel in my texture is 1 pixel on the screen. For 2d games this is good. Of course it means that I also factor in things like the size of the quad and the size of the texture. For example if my sprite is a quad 32x32 pixels. The quad size is 3.2 units wide and tall. And the texcoords are 32 / the size of the texture wide and tall. Then the frustum is: matrixFrustum(-(float)backingWidth/frustumScale,(float)backingWidth/frustumScale, -(float)backingHeight/frustumScale, (float)backingHeight/frustumScale, 40, 1000, mProjection); Where frustumScale is 800 for a retina screen. Then at a distance of 800 from camera the sprite is pixel for pixel the same as photoshop. For 3d games sometimes I still want to be able to do this. But depending on the scene I sometimes need the FOV to be different things. I'm looking for a way to figure out what Z depth will achieve this same pixel unity for a given FOV. For this my mProjection is set using: matrixPerspective(cameraFOV, near, far, (float)backingWidth / (float)backingHeight, mProjection); With testing I found that at an FOV of 45.0 a Z of 38.5 is very close to pixel unity. And at an FOV of 30.0 a Z of 59.5 is about right. But how can I calculate a value that is spot on? Here's my matrixPerspecitve code: void matrixPerspective(float angle, float near, float far, float aspect, mat4 m) { //float size = near * tanf(angle / 360.0 * M_PI); float size = near * tanf(degreesToRadians(angle) / 2.0); float left = -size, right = size, bottom = -size / aspect, top = size / aspect; // Unused values in perspective formula. m[1] = m[2] = m[3] = m[4] = 0; m[6] = m[7] = m[12] = m[13] = m[15] = 0; // Perspective formula. m[0] = 2 * near / (right - left); m[5] = 2 * near / (top - bottom); m[8] = (right + left) / (right - left); m[9] = (top + bottom) / (top - bottom); m[10] = -(far + near) / (far - near); m[11] = -1; m[14] = -(2 * far * near) / (far - near); } And my mView is set using: lookAtMatrix(cameraPos, camLookAt, camUpVector, mView); * UPDATE * I'm going to leave this here in case anyone has a different solution, can explain how they do it, or why this works. This is what I figured out. In my system I use a 10th scale unit to pixels on non-retina displays and a 20th scale on retina displays. The iPhone is 640 pixels wide on retina and 320 pixels wide on non-retina (obsolete). So if I want something to be the full screen width I divide by 20 to get the OpenGL unit width. Then divide that by 2 to get the left and right unit position. Something 32 units wide centered on the screen goes from -16 to +16. Believe it or not I have an excel spreadsheet do all this math for me and output all the vertex data for my sprite sheet. It's an arbitrary thing I made up to do .1 units = 1 non-retina pixel or 2 retina pixels. I could have made it .01 units = 2 pixels and someday I might switch to that. But for now it's the other. So the width of the screen in units is 32.0, and that means the left most pixel is at -16.0 and the right most is at 16.0. After messing a bit I figured out that if I take the [0] value of an identity modelViewProjection matrix and multiply it by 16 I get the depth required to get 1:1 pixels. I don't know why. I don't know if the 16 is related to the screen size or just a lucky guess. But I did a test where I placed a sprite at that calculated depth and varied the FOV through all the valid values and the object stays steady on screen with 1:1 pixels. So now I'm just calculating the unityDepth that way. If someone gives me a better answer I'll checkmark it.

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  • Xml failing to deserialise

    - by Carnotaurus
    I call a method to get my pages [see GetPages(String xmlFullFilePath)]. The FromXElement method is supposed to deserialise the LitePropertyData elements to strongly type LitePropertyData objects. Instead it fails on the following line: return (T)xmlSerializer.Deserialize(memoryStream); and gives the following error: <LitePropertyData xmlns=''> was not expected. What am I doing wrong? I have included the methods that I call and the xml data: public static T FromXElement<T>(this XElement xElement) { using (var memoryStream = new MemoryStream(Encoding.ASCII.GetBytes(xElement.ToString()))) { var xmlSerializer = new XmlSerializer(typeof(T)); return (T)xmlSerializer.Deserialize(memoryStream); } } public static List<LitePageData> GetPages(String xmlFullFilePath) { XDocument document = XDocument.Load(xmlFullFilePath); List<LitePageData> results = (from record in document.Descendants("row") select new LitePageData { Guid = IsValid(record, "Guid") ? record.Element("Guid").Value : null, ParentID = IsValid(record, "ParentID") ? Convert.ToInt32(record.Element("ParentID").Value) : (Int32?)null, Created = Convert.ToDateTime(record.Element("Created").Value), Changed = Convert.ToDateTime(record.Element("Changed").Value), Name = record.Element("Name").Value, ID = Convert.ToInt32(record.Element("ID").Value), LitePageTypeID = IsValid(record, "ParentID") ? Convert.ToInt32(record.Element("ParentID").Value) : (Int32?)null, Html = record.Element("Html").Value, FriendlyName = record.Element("FriendlyName").Value, Properties = record.Element("Properties") != null ? record.Element("Properties").Element("LitePropertyData").FromXElement<List<LitePropertyData>>() : new List<LitePropertyData>() }).ToList(); return results; } Here is the xml: <?xml version="1.0" encoding="utf-8"?> <root> <rows> <row> <ID>1</ID> <ImageUrl></ImageUrl> <Html>Home page</Html> <Created>01-01-2012</Created> <Changed>01-01-2012</Changed> <Name>Home page</Name> <FriendlyName>home-page</FriendlyName> </row> <row xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <Guid>edeaf468-f490-4271-bf4d-be145bc6a1fd</Guid> <ID>8</ID> <Name>Unused</Name> <ParentID>1</ParentID> <Created>2006-03-25T10:57:17</Created> <Changed>2012-07-17T12:24:30.0984747+01:00</Changed> <ChangedBy /> <LitePageTypeID xsi:nil="true" /> <Html> What is the purpose of this option? This option checks the current document for accessibility issues. It uses Bobby to provide details of whether the current web page conforms to W3C's WCAG criteria for web content accessibility. Issues with Bobby and Cynthia Bobby and Cynthia are free services that supposedly allow a user to expose web page accessibility barriers. It is something of a guide but perhaps a blunt instrument. I tested a few of the webpages that I have designed. Sure enough, my pages fall short and for good reason. I am not about to claim that Bobby and Cynthia are useless. Although it is useful and commendable tool, it project appears to be overly ambitious. Nevertheless, let me explain my issues with Bobby and Cynthia: First, certain W3C standards for designing web documents are often too strict and unworkable. For instance, in some versions W3C standards for HTML, certain tags should not include a particular attribute, whereas in others they are requisite if the document is to be ???well-formed???. The standard that a designer chooses is determined usually by the requirements specification document. This specifies which browsers and versions of those browsers that the web page is expected to correctly display. Forcing a hypertext document to conform strictly to a specific W3C standard for HTML is often no simple task. In the worst case, it cannot conform without losing some aesthetics or accessibility functionality. Second, the case of HTML documents is not an isolated case. Standards for XML, XSL, JavaScript, VBScript, are analogous. Therefore, you might imagine the problems when you begin to combine these languages and formats in an HTML document. Third, there is always more than one way to skin a cat. For example, Bobby and Cynthia may flag those IMG tags that do not contain a TITLE attribute. There might be good reason that a web developer chooses not to include the title attribute. The title attribute has a limited numbers of characters and does not support carriage returns. This is a major defect in the design of this tag. In fact, before the TITLE attribute was supported, there was the ALT attribute. Most browsers support both, yet they both perform a similar function. However, both attributes share the same deficiencies. In practice, there are instances where neither attribute would be used. Instead, for example, the developer would write some JavaScript or VBScript to circumvent these deficiencies. The concern is that Bobby and Cynthia would not notice this because it does not ???understand??? what the JavaScript does. </Html> <FriendlyName>unused</FriendlyName> <IsDeleted>false</IsDeleted> <Properties> <LitePropertyData> <Description>Image for the page</Description> <DisplayEditUI>true</DisplayEditUI> <OwnerTab>1</OwnerTab> <DisplayName>Image Url</DisplayName> <FieldOrder>1</FieldOrder> <IsRequired>false</IsRequired> <Name>ImageUrl</Name> <IsModified>false</IsModified> <ParentPageID>3</ParentPageID> <Type>String</Type> <Value xsi:type="xsd:string">smarter.jpg</Value> </LitePropertyData> <LitePropertyData> <Description>WebItemApplicationEnum</Description> <DisplayEditUI>true</DisplayEditUI> <OwnerTab>1</OwnerTab> <DisplayName>WebItemApplicationEnum</DisplayName> <FieldOrder>1</FieldOrder> <IsRequired>false</IsRequired> <Name>WebItemApplicationEnum</Name> <IsModified>false</IsModified> <ParentPageID>3</ParentPageID> <Type>Number</Type> <Value xsi:type="xsd:string">1</Value> </LitePropertyData> </Properties> <Seo> <Author>Phil Carney</Author> <Classification /> <Copyright>Carnotaurus</Copyright> <Description> What is the purpose of this option? This option checks the current document for accessibility issues. It uses Bobby to provide details of whether the current web page conforms to W3C's WCAG criteria for web content accessibility. Issues with Bobby and Cynthia Bobby and Cynthia are free services that supposedly allow a user to expose web page accessibility barriers. It is something of a guide but perhaps a blunt instrument. I tested a few of the webpages that I have designed. Sure enough, my pages fall short and for good reason. I am not about to claim that Bobby and Cynthia are useless. Although it is useful and commendable tool, it project appears to be overly ambitious. Nevertheless, let me explain my issues with Bobby and Cynthia: First, certain W3C standards for designing web documents are often too strict and unworkable. For instance, in some versions W3C standards for HTML, certain tags should not include a particular attribute, whereas in others they are requisite if the document is to be ???well-formed???. The standard that a designer chooses is determined usually by the requirements specification document. This specifies which browsers and versions of those browsers that the web page is expected to correctly display. Forcing a hypertext document to conform strictly to a specific W3C standard for HTML is often no simple task. In the worst case, it cannot conform without losing some aesthetics or accessibility functionality. Second, the case of HTML documents is not an isolated case. Standards for XML, XSL, JavaScript, VBScript, are analogous. Therefore, you might imagine the problems when you begin to combine these languages and formats in an HTML document. Third, there is always more than one way to skin a cat. For example, Bobby and Cynthia may flag those IMG tags that do not contain a TITLE attribute. There might be good reason that a web developer chooses not to include the title attribute. The title attribute has a limited numbers of characters and does not support carriage returns. This is a major defect in the design of this tag. In fact, before the TITLE attribute was supported, there was the ALT attribute. Most browsers support both, yet they both perform a similar function. However, both attributes share the same deficiencies. In practice, there are instances where neither attribute would be used. Instead, for example, the developer would write some JavaScript or VBScript to circumvent these deficiencies. The concern is that Bobby and Cynthia would not notice this because it does not ???understand??? what the JavaScript does. </Description> <Keywords>unused</Keywords> <Title>unused</Title> </Seo> </row> </rows> </root> EDIT Here are my entities: public class LitePropertyData { public virtual string Description { get; set; } public virtual bool DisplayEditUI { get; set; } public int OwnerTab { get; set; } public virtual string DisplayName { get; set; } public int FieldOrder { get; set; } public bool IsRequired { get; set; } public string Name { get; set; } public virtual bool IsModified { get; set; } public virtual int ParentPageID { get; set; } public LiteDataType Type { get; set; } public object Value { get; set; } } [Serializable] public class LitePageData { public String Guid { get; set; } public Int32 ID { get; set; } public String Name { get; set; } public Int32? ParentID { get; set; } public DateTime Created { get; set; } public String CreatedBy { get; set; } public DateTime Changed { get; set; } public String ChangedBy { get; set; } public Int32? LitePageTypeID { get; set; } public String Html { get; set; } public String FriendlyName { get; set; } public Boolean IsDeleted { get; set; } public List<LitePropertyData> Properties { get; set; } public LiteSeoPageData Seo { get; set; } /// <summary> /// Saves the specified XML full file path. /// </summary> /// <param name="xmlFullFilePath">The XML full file path.</param> public void Save(String xmlFullFilePath) { XDocument doc = XDocument.Load(xmlFullFilePath); XElement demoNode = this.ToXElement<LitePageData>(); demoNode.Name = "row"; doc.Descendants("rows").Single().Add(demoNode); doc.Save(xmlFullFilePath); } }

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  • django: failing tests from django.contrib.auth

    - by gruszczy
    When I run my django test I get following errors, that are outside of my test suite: ====================================================================== ERROR: test_known_user (django.contrib.auth.tests.remote_user.RemoteUserCustomTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 160, in test_known_user super(RemoteUserCustomTest, self).test_known_user() File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 67, in test_known_user self.assertEqual(response.context['user'].username, 'knownuser') TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_last_login (django.contrib.auth.tests.remote_user.RemoteUserCustomTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 87, in test_last_login self.assertNotEqual(default_login, response.context['user'].last_login) TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_no_remote_user (django.contrib.auth.tests.remote_user.RemoteUserCustomTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 33, in test_no_remote_user self.assert_(isinstance(response.context['user'], AnonymousUser)) TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_unknown_user (django.contrib.auth.tests.remote_user.RemoteUserCustomTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 168, in test_unknown_user super(RemoteUserCustomTest, self).test_unknown_user() File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 51, in test_unknown_user self.assertEqual(response.context['user'].username, 'newuser') TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_known_user (django.contrib.auth.tests.remote_user.RemoteUserNoCreateTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 67, in test_known_user self.assertEqual(response.context['user'].username, 'knownuser') TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_last_login (django.contrib.auth.tests.remote_user.RemoteUserNoCreateTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 87, in test_last_login self.assertNotEqual(default_login, response.context['user'].last_login) TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_no_remote_user (django.contrib.auth.tests.remote_user.RemoteUserNoCreateTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 33, in test_no_remote_user self.assert_(isinstance(response.context['user'], AnonymousUser)) TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_unknown_user (django.contrib.auth.tests.remote_user.RemoteUserNoCreateTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 118, in test_unknown_user self.assert_(isinstance(response.context['user'], AnonymousUser)) TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_known_user (django.contrib.auth.tests.remote_user.RemoteUserTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 67, in test_known_user self.assertEqual(response.context['user'].username, 'knownuser') TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_last_login (django.contrib.auth.tests.remote_user.RemoteUserTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 87, in test_last_login self.assertNotEqual(default_login, response.context['user'].last_login) TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_no_remote_user (django.contrib.auth.tests.remote_user.RemoteUserTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 33, in test_no_remote_user self.assert_(isinstance(response.context['user'], AnonymousUser)) TypeError: 'NoneType' object is unsubscriptable ====================================================================== ERROR: test_unknown_user (django.contrib.auth.tests.remote_user.RemoteUserTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/remote_user.py", line 51, in test_unknown_user self.assertEqual(response.context['user'].username, 'newuser') TypeError: 'NoneType' object is unsubscriptable ====================================================================== FAIL: test_current_site_in_context_after_login (django.contrib.auth.tests.views.LoginTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/pymodules/python2.6/django/contrib/auth/tests/views.py", line 190, in test_current_site_in_context_after_login self.assertEquals(response.status_code, 200) AssertionError: 302 != 200 Could anyone explain me, what am I doing wrong or what I should set to get those tests pass?

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  • To connect Gstreamer with Qt in order to play a gstreamer video in the Qt Widget

    - by raggio
    I tried using phonon to play the video but could not succeed. Off-late came to know through the Qt forums that even the latest version of Qt does not support phonon. Thats when i started using Gstreamer.Any suggestions as to how to connect the Gstreamer window with the Qt widget?My aim is to play a video using Gstreamer on the Qt widget.So how do i link the gstreamer window and the Qt widget? I am successful in getting the Id of the widget through winid(). Further with the help of Gregory Pakosz, I have added the below 2 lines of code in my application - QApplication::syncX(); gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(sink), widget->winId()); However am not able to link the Qt widget with the gstreamer video window. This is what my sample code would look like :- int main(int argc, char *argv[]) { printf("winid=%d\n", w.winId()); gst_init (NULL,NULL); /* create a new bin to hold the elements */ bin = gst_pipeline_new ("pipeline"); /* create a disk reader */ filesrc = gst_element_factory_make ("filesrc", "disk_source"); g_assert (filesrc); g_object_set (G_OBJECT (filesrc), "location", "PATH_TO_THE_EXECUTABLE", NULL); demux = gst_element_factory_make ("mpegtsdemux", "demuxer"); if (!demux) { g_print ("could not find plugin \"mpegtsmux\""); return -1; } vdecoder = gst_element_factory_make ("mpeg2dec", "decode"); if (!vdecoder) { g_print ("could not find plugin \"mpeg2dec\""); return -1; } videosink = gst_element_factory_make ("xvimagesink", "play_video"); g_assert (videosink); /* add objects to the main pipeline */ gst_bin_add_many (GST_BIN (bin), filesrc, demux, vdecoder, videosink, NULL); /* link the elements */ gst_element_link_many (filesrc, demux, vdecoder, videosink, NULL); gst_element_set_state(videosink, GST_STATE_READY); QApplication::syncX(); gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(videosink), w.winId()); /* start playing */ gst_element_set_state (bin, GST_STATE_PLAYING); } Could you explain more in detail about the usage of gst_x_overlay_set_xwindow_id() wrt my context? Could i get any hint as to how i can integrate gstreamer under Qt? Please help me solve this problem

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  • This page calls for XML namespace declared with prefix br but no taglibrary exists

    - by Christopher W. Allen-Poole
    I just finished the Netbeans introduction to Hibernate tutorial ( http://netbeans.org/kb/docs/web/hibernate-webapp.html#01 ) and I am getting the following error: "This page calls for XML namespace declared with prefix br but no taglibrary exists" Now, I have seen a similar question somewhere else: http://forums.sun.com/thread.jspa?threadID=5430327 but the answer is not listed there. Or, if it is, then I am clearly missing it -- line one of my index.xhtml file reads "http://www.w3.org/1999/xhtml". It also does not explain why, when I reload localhost:8080, the message disappears. Here is my index.xhtml file: <html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://java.sun.com/jsf/html" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:f="http://java.sun.com/jsf/core"> <ui:composition template="./template.xhtml"> <ui:define name="body"> <h:form> <h:commandLink action="#{filmController.previous}" value="Previous #{filmController.pageSize}" rendered="#{filmController.hasPreviousPage}"/> <h:commandLink action="#{filmController.next}" value="Next #{filmController.pageSize}" rendered="#{filmController.hasNextPage}"/> <h:dataTable value="#{filmController.filmTitles}" var="item" border="0" cellpadding="2" cellspacing="0" rowClasses="jsfcrud_odd_row,jsfcrud_even_row" rules="all" style="border:solid 1px"> <h:column> <f:facet name="header"> <h:outputText value="Title"/> </f:facet> <h:outputText value="#{item.title}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText value="Description"/> </f:facet> <h:outputText value="#{item.description}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText value=" "/> </f:facet> <h:commandLink action="#{filmController.prepareView}" value="View"/> </h:column> </h:dataTable> <br/> </h:form> </ui:define> </ui:composition> </html>

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