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PASS: Board Q&A at the Summit

- by Bill Graziano

The last two years we’ve put the Board in front of the members and taken questions. We’re going to do that again this year. It will be in Room 307/308 from 12:15 to 1:30 on Friday. Yes, this time overlaps with the Birds of a Feather Lunch and the start of afternoon sessions – but only partially. You can attend the Q&A and still get to parts of both of those. There just isn’t a great time to do this. Every time overlaps with something. We can’t do it after the last session on Friday. We can’t fit it between the last session and the evening events on Wednesday or Thursday. We had some discussion around breakfast time but I didn’t think that was realistic. This is the least bad time we could come up with. Last year we had 60-70 people attend. These are the items that were specific things that I could work on: The first question was whether to increase transparency around individual votes of Board members. We approved this at the Board meeting the following day. The only caveat was that if the Board is given confidential information as a basis for their vote then we may not be able to disclose individual votes. Putting a Director in a position where they can’t publicly defend the reason for their vote is a difficult situation. Thanks Kendal! Can we have a Board member discretionary fund? As background, I took a couple of people to lunch so we could have a quiet place to talk. I bought lunch but wasn’t able to expense it back to PASS. We just don’t have a budget item for things like this. I think we should. I would guess the entire Board would like it also. It was in an earlier version of the budget but came out as part of a cost-cutting move to balance the budget. I’d like to see it added back in but we’ll have to see. I know there were a comments about the elections. At this point we had created the Election Review Committee. I’ve already written at length about this process. Where does IT work go? PASS started to publish our internal management reports starting in December 2010. You can find them on our Governance page. These aren’t filtered at all and include a variety of information about IT projects. The most recent update had roughly a page of updates related to IT. Lots of the work was related to Summit and the Orator tool that we use to manage speaker submissions. There were numerous requests that Tina Turner not be repeated. Done. I don’t think we’ll do anything quite like that again. We had a request for a payment plan for Summit. We looked into this briefly but didn’t take any action. We didn’t think the effort was worth the small number of people that would use it. If you disagree, submit this on our Summit Feedback site and get some votes. There were lots of suggestions around the first-timers events – especially from first timers. You can find all our current activities related to first-timers at the First Timers page on the Summit web site. Plus links to 34 (!) blog posts on suggestions for first-timers. And a big THANK YOU to Confio and Red Gate for sponsoring this. I hope you get the chance to attend. These events are very helpful to me as a Board member. I like being able to look around the room as comments are being made and see the audience reaction. It helps me gauge the interest in an idea. I’d also like to direct you to the Summit Feedback site. You can submit and vote on ideas to make the Summit a better experience. As of right now we have the suggestions from last year still up. We may reset these prior to the Summit though.

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Source Control and SQL Development – Part 3

- by Ajarn Mark Caldwell

In parts one and two of this series, I have been specifically focusing on the latest version of SQL Source Control by Red Gate Software. But I have been doing source-controlled SQL development for years, long before this product was available, and well before Microsoft came out with Database Projects for Visual Studio. “So, how does that work?” you may wonder. Well, let me share some of the details of how we do it where I work… The key to this approach is that everything is done via Transact-SQL script files; either natively written T-SQL, or generated. My preference is to write all my code by hand, which forces you to become better at your SQL syntax. But if you really prefer to use the Management Studio GUI to make database changes, you can still do that, and then you use the Generate Scripts feature of the GUI to produce T-SQL scripts afterwards, and store those in your source control system. You can generate scripts for things like stored procedures and views by right-clicking on the database in the Object Explorer, and Choosing Tasks, Generate Scripts (see figure 1 to the left). You can also do that for the CREATE scripts for tables, but that does not work when you have a table that is already in production, and you need to make just a simple change, such as adding a new column or index. In this case, you can use the GUI to make the table changes, and then instead of clicking the Save button, click the Generate Change Script button (). Then, once you have saved the change script, go ahead and execute it on your development database to actually make the change. I believe that it is important to actually execute the script rather than just click the Save button because this is your first test that your change script is working and you didn’t somehow lose a portion of the change. As you can imagine, all this generating of scripts can get tedious and tempting to skip entirely, so again, I would encourage you to just get in the habit of writing your own Transact-SQL code, and then it is just a matter of remembering to save your work, just like you are in the habit of saving changes to a Word or Excel document before you exit the program. So, now that you have all of these script files, what do you do with them? Well, we organize ours into folders labeled ChangeScripts, Functions, Views, and StoredProcedures, and those folders are loaded into our source control system. ChangeScripts contains all of the table and index changes, and anything else that is basically a one-time-only execution. Of course you want to write your scripts with qualifying logic so that if a script were accidentally run more than once in a database, it would not crash nor corrupt anything; but these scripts are really intended to be run only once in a database. Once you have your initial set of scripts loaded into source control, then making changes, such as altering a stored procedure becomes a simple matter of checking out your CREATE PROCEDURE* script, editing it in SSMS, saving the change, executing the script in order to effect the change in your database, and then checking the script back in to source control. Of course, this is where the lack of integration for source control systems within SSMS becomes an irritation, because this means that in addition to SSMS, I also have my source control client application running to do the check-out and check-in. And when you have 800+ procedures like we do, that can be quite tedious to locate the procedure I want to change in source control, check it out, then locate the script file in my working folder, open it in SSMS, do the change, save it, and the go back to source control to check in. Granted, it is not nearly as burdensome as, say, losing your source code and having to rebuild it from memory, or losing the audit trail that good source control systems provide. It is worth the effort, and this is how I have been doing development for the last several years. Remember that everything that the SQL Server Management Studio does in modifying your database can also be done in plain Transact-SQL code, and this is what you are storing. And now I have shown you how you can do it all without spending any extra money. You already have source control, or can get free, open-source source control systems (almost seems like an oxymoron, doesn’t it) and of course Management Studio is free with your SQL Server database engine software. So, whether you spend the money on tools to make it easier, or not, you now have no excuse for not using source control with your SQL development. * In our current model, the scripts for stored procedures and similar database objects are written with an IF EXISTS…DROP… at the top, followed by the CREATE PROCEDURE… section, and that followed by a section that assigns permissions. This allows me to run the same script regardless of whether the procedure previously existed in the database. If the script was only an ALTER PROCEDURE, then it would fail the first time that procedure was deployed to a database, unless you wrote other code to stub it if it did not exist. There are a few different ways you could organize your scripts for deployment, each with its own trade-offs, but I think it is absolutely critical that whichever way you organize things, you ensure that the same script is run throughout the deployment cycle, and do not allow customizations to creep in between TEST and PROD. If you do, then you have broken the integrity of your deployment process because what you deployed to PROD was not exactly the same as what was tested in TEST, so you effectively have now released untested code into PROD.

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Error in my Separating Axis Theorem collision code

- by Holly

The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; int x; int y; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } public void update(int xPos, int yPos){ x = xPos; y = yPos; } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(new Vect(vertices[0].x+x, vertices[0].y+y)); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(new Vect(vertices[i].x+x, vertices[i].y+y)); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if(y > other.x && other.y > x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

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JustCode Provides Reflector Alternative

- by Joe Mayo

If you've been a loyal Reflector user, you've probably been exposed to the debacle surrounding RedGate's decision to no longer offer a free version. Since then, the race has begun for a replacement with a provider that would stand by their promises to the community. Mono has an ongoing free alternative, which has been available for a long time. However, other vendors are stepping up to the plate, with their own offerings. If Not Reflector, Then What? One of these vendors is Telerik. In their recent Q1 2011 release of JustCode, Telerik offers a decompilation utility rivaling what we've become accustomed to in Reflector. Not only does Telerik offer a usable replacement, but they've (in my opinion), produced a product that integrates more naturally with visual Studio than any other product ever has. Telerik's decompilation process is so easy that the accompanying demo in this post is blindingly short (except for the presence of verbose narrative). If you want to follow along with this demo, you'll need to have Telerik JustCode installed. If you don't have JustCode yet, you can buy it or download a trial at the Telerik Web site . A Tall Tale; Prove It! With JustCode, you can view code in the .NET Framework or any other 3rd party library (that isn't well obfuscated). This demo depends on LINQ to Twitter, which you can download from CodePlex.com and create a reference or install the package online as described in my previous post on NuGet. Regardless of the method, you'll have a project with a reference to LINQ to Twitter. Use a Console Project if you want to follow along with this demo. Note: If you've created a Console project, remember to ensure that the Target Framework is set to .NET Framework 4. The default is .NET Framework 4 Client Profile, which doesn't work with LINQ to Twitter. You can check by double-clicking the Properties folder on the project and inspecting the Target Framework setting. Next, you'll need to add some code to your program that you want to inspect. Here, I add code to instantiate a TwitterContext, which is like a LINQ to SQL DataContext, but works with Twitter: var l2tCtx = new TwitterContext(); If you're following along add the code above to the Main method, which will look similar to this: using LinqToTwitter; namespace NuGetInstall { class Program { static void Main(string[] args) { var l2tCtx = new TwitterContext(); } } } The code above doesn't really do anything, but it does give something that I can show and demonstrate how JustCode decompilation works. Once the code is in place, click on TwitterContext and press the F12 (Go to Definition) key. As expected, Visual Studio opens a metadata file with prototypes for the TwitterContext class. Here's the result: Opening a metadata file is the normal way that Visual Studio works when navigating to the definition of a type where you don't have the code. The scenario with TwitterContext happens because you don't have the source code to the file. Visual Studio has always done this and you can experiment by selecting any .NET type, i.e. a string type, and observing that Visual Studio opens a metadata file for the .NET String type. The point I'm making here is that JustCode works the way Visual Studio works and you'll see how this can make your job easier. In the previous figure, you only saw prototypes associated with the code. i.e. Notice that the default constructor is empty. Again, this is normal because Visual Studio doesn't have the ability to decompile code. However, that's the purpose of this post; showing you how JustCode fills that gap. To decompile code, right click on TwitterContext in the metadata file and select JustCode Navigate -> Decompile from the context menu. The shortcut keys are Ctrl+1. After a brief pause, accompanied by a progress window, you'll see the metadata expand into full decompiled code. Notice below how the default constructor now has code as opposed to the empty member prototype in the original metadata: And Why is This So Different? Again, the big deal is that Telerik JustCode decompilation works in harmony with the way that Visual Studio works. The navigate to functionality already exists and you can use that, along with a simple context menu option (or shortcut key) to transform prototypes into decompiled code. Telerik is filling the the Reflector/Red Gate gap by providing a supported alternative to decompiling code. Many people, including myself, used Reflector to decompile code when we were stuck with buggy libraries or insufficient documentation. Now we have an alternative that's officially supported by a company with an excellent track record for customer (developer) service, Telerik. Not only that, JustCode has several other IDE productivity tools that make the deal even sweeter. Joe

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NetBeans, JSF, and MySQL Primary Keys using AUTO_INCREMENT

- by MarkH

I recently had the opportunity to spin up a small web application using JSF and MySQL. Having developed JSF apps with Oracle Database back-ends before and possessing some small familiarity with MySQL (sans JSF), I thought this would be a cakewalk. Things did go pretty smoothly...but there was one little "gotcha" that took more time than the few seconds it really warranted. The Problem Every DBMS has its own way of automatically generating primary keys, and each has its pros and cons. For the Oracle Database, you use a sequence and point your Java classes to it using annotations that look something like this: @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="POC_ID_SEQ") @SequenceGenerator(name="POC_ID_SEQ", sequenceName="POC_ID_SEQ", allocationSize=1) Between creating the actual sequence in the database and making sure you have your annotations right (watch those typos!), it seems a bit cumbersome. But it typically "just works", without fuss. Enter MySQL. Designating an integer-based field as PRIMARY KEY and using the keyword AUTO_INCREMENT makes the same task seem much simpler. And it is, mostly. But while NetBeans cranks out a superb "first cut" for a basic JSF CRUD app, there are a couple of small things you'll need to bring to the mix in order to be able to actually (C)reate records. The (RUD) performs fine out of the gate. The Solution Omitting all design considerations and activity (!), here is the basic sequence of events I followed to create, then resolve, the JSF/MySQL "Primary Key Perfect Storm": Fire up NetBeans. Create JSF project. Create Entity Classes from Database. Create JSF Pages from Entity Classes. Test run. Try to create record and hit error. It's a simple fix, but one that was fun to find in its completeness. :-) Even though you've told it what to do for a primary key, a MySQL table requires a gentle nudge to actually generate that new key value. Two things are needed to make the magic happen. First, you need to ensure the following annotation is in place in your Java entity classes: @GeneratedValue(strategy = GenerationType.IDENTITY) All well and good, but the real key is this: in your controller class(es), you'll have a create() function that looks something like this, minus the comment line and the setId() call in bold red type: public String create() { try { // Assign 0 to ID for MySQL to properly auto_increment the primary key. current.setId(0); getFacade().create(current); JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("CategoryCreated")); return prepareCreate(); } catch (Exception e) { JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured")); return null; } } Setting the current object's primary key attribute to zero (0) prior to saving it tells MySQL to get the next available value and assign it to that record's key field. Short and simple…but not inherently obvious if you've never used that particular combination of NetBeans/JSF/MySQL before. Hope this helps! All the best, Mark

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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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Dealing with "I-am-cool-and-you-are-dumb" manager [closed]

- by Software Guy

I have been working with a software company for about 6 months now. I like the projects I work on there and I really like all the people there except for 1 guy. That guy is technically smart, and he is a co-founder of the company. He is an okay guy in person (the kind you wouldn't want to care about much) but things get tricky when he is your manager. In general I am all okay but there are times when I feel I am not being treated fairly: He doesn't give much thought to when he makes mistakes and when I do something similar, he is super critical. Recently he went as far as to say "I am not sure if I can trust you with this feature". The detais of this specific case are this: I was working on this feature, and I was already a couple of hours over my normal working hours, and then I decided to stop and continue tomorrow. We use git, and I like to commit changes locally and only push when I feel they are ready. This manager insists that I push all the changes to the central repo (in case my hard drive crashes). So I push the change, and the ticket is marked as "to be tested". Next day I come in, he sits next to me and starts complaining and says that I posted above. I really didn't know what to say, I tried to explain to him that the ticket is still being worked upon but he didn't seem to listen. He interrupts me in-between when I am coding, which I do not mind, but when I do that same, his face turns like this :| and reacts as if his work was super important and I am just wasting his time. He asks me to accumulate all questions, and then ask him altogether which is not always possible, as you need a clarification before you can continue on a feature implementation. And when I am coding, he talks on the phone with his customers next to me (when he can go to the meeting room with his laptop) and doesn't care. He made me switch to a whole new IDE (from Netbeans to a commercial IDE costing a lot of money) for a really tiny feature (which I later found out was in Netbeans as well!). I didn't make a big deal out of it as I am equally comfortable working with this new IDE, but I couldn't get the science behind his obsession. He said this feature makes sure that if any method is updated by a programmer, the IDE will turn the method name to red in places where it is used. I told him that I do not have a problem since I always search for method usage in the project and make sure its updated. IDEs even have refactoring features for exactly that, but... I recently implemented a feature for a project, and I was happy about it and considering him a senior, I asked him his comments about the implementation quality.. he thought long and hard, made a few funny faces, and when he couldn't find anything, he said "ummm, your program will crash if JS is disabled" - he was wrong, since I had made sure it would work fine with default values even if JS was disabled. I told him that and then he said "oh okay". BUT, the funny thing is, a few days back, he implemented something and I objected with "But that would not run if JS is disabled" and his response was "We don't have to care about people who disable JS" :-/ Once he asked me to investigate if there was a way to modify a CMS generated menu programmatically by extending the CMS, I did my research and told him that the only was is to inject a menu item using JavaScript / jQuery and his reaction was "ah that's ugly, and hacky, not acceptable" and two days later, I see that feature implemented in the same way as I had suggested. The point is, his reaction was not respectful at all, even if what I proposed was hacky, he should be respectful, that I know what's hacky and if I am suggesting something hacky, there must be a reason for it. There are plenty of other reasons / examples where I feel I am not being treated fairly. I want your advice as to what is it that I am doing wrong and how to deal with such a situation. The other guys in the team are actually very good people, and I do not want to leave the job either (although I could, if I want to). All I want is respect and equal treatment. I have thought about talking to this guy in a face to face meeting, but that worries me that his attitude might get worse and make things more difficult for me (since he doesn't seem to be the guy who thinks he can be wrong too). I am also considering talking to the other co-founder but I am not sure how he will take it (as both founders have been friends forever). Thanks for reading the long message, I really appreciate your help.

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UIImagePickerController, UIImage, Memory and More!

- by Itay

I've noticed that there are many questions about how to handle UIImage objects, especially in conjunction with UIImagePickerController and then displaying it in a view (usually a UIImageView). Here is a collection of common questions and their answers. Feel free to edit and add your own. I obviously learnt all this information from somewhere too. Various forum posts, StackOverflow answers and my own experimenting brought me to all these solutions. Credit goes to those who posted some sample code that I've since used and modified. I don't remember who you all are - but hats off to you! How Do I Select An Image From the User's Images or From the Camera? You use UIImagePickerController. The documentation for the class gives a decent overview of how one would use it, and can be found here. Basically, you create an instance of the class, which is a modal view controller, display it, and set yourself (or some class) to be the delegate. Then you'll get notified when a user selects some form of media (movie or image in 3.0 on the 3GS), and you can do whatever you want. My Delegate Was Called - How Do I Get The Media? The delegate method signature is the following: - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info; You should put a breakpoint in the debugger to see what's in the dictionary, but you use that to extract the media. For example: UIImage* image = [info objectForKey:UIImagePickerControllerOriginalImage]; There are other keys that work as well, all in the documentation. OK, I Got The Image, But It Doesn't Have Any Geolocation Data. What gives? Unfortunately, Apple decided that we're not worthy of this information. When they load the data into the UIImage, they strip it of all the EXIF/Geolocation data. Can I Get To The Original File Representing This Image on the Disk? Nope. For security purposes, you only get the UIImage. How Can I Look At The Underlying Pixels of the UIImage? Since the UIImage is immutable, you can't look at the direct pixels. However, you can make a copy. The code to this looks something like this: UIImage* image = ...; // An image NSData* pixelData = (NSData*) CGDataProviderCopyData(CGImageGetDataProvider(image.CGImage)); unsigned char* pixelBytes = (unsigned char *)[pixelData bytes]; // Take away the red pixel, assuming 32-bit RGBA for(int i = 0; i < [pixelData length]; i += 4) { pixelBytes[i] = 0; // red pixelBytes[i+1] = pixelBytes[i+1]; // green pixelBytes[i+2] = pixelBytes[i+2]; // blue pixelBytes[i+3] = pixelBytes[i+3]; // alpha } However, note that CGDataProviderCopyData provides you with an "immutable" reference to the data - meaning you can't change it (and you may get a BAD_ACCESS error if you do). Look at the next question if you want to see how you can modify the pixels. How Do I Modify The Pixels of the UIImage? The UIImage is immutable, meaning you can't change it. Apple posted a great article on how to get a copy of the pixels and modify them, and rather than copy and paste it here, you should just go read the article. Once you have the bitmap context as they mention in the article, you can do something similar to this to get a new UIImage with the modified pixels: CGImageRef ref = CGBitmapContextCreateImage(bitmap); UIImage* newImage = [UIImage imageWithCGImage:ref]; Do remember to release your references though, otherwise you're going to be leaking quite a bit of memory. After I Select 3 Images From The Camera, I Run Out Of Memory. Help! You have to remember that even though on disk these images take up only a few hundred kilobytes at most, that's because they're compressed as a PNG or JPG. When they are loaded into the UIImage, they become uncompressed. A quick over-the-envelope calculation would be: width x height x 4 = bytes in memory That's assuming 32-bit pixels. If you have 16-bit pixels (some JPGs are stored as RGBA-5551), then you'd replace the 4 with a 2. Now, images taken with the camera are 1600 x 1200 pixels, so let's do the math: 1600 x 1200 x 4 = 7,680,000 bytes = ~8 MB 8 MB is a lot, especially when you have a limit of around 24 MB for your application. That's why you run out of memory. OK, I Understand Why I Have No Memory. What Do I Do? There is never any reason to display images at their full resolution. The iPhone has a screen of 480 x 320 pixels, so you're just wasting space. If you find yourself in this situation, ask yourself the following question: Do I need the full resolution image? If the answer is yes, then you should save it to disk for later use. If the answer is no, then read the next part. Once you've decided what to do with the full-resolution image, then you need to create a smaller image to use for displaying. Many times you might even want several sizes for your image: a thumbnail, a full-size one for displaying, and the original full-resolution image. OK, I'm Hooked. How Do I Resize the Image? Unfortunately, there is no defined way how to resize an image. Also, it's important to note that when you resize it, you'll get a new image - you're not modifying the old one. There are a couple of methods to do the resizing. I'll present them both here, and explain the pros and cons of each. Method 1: Using UIKit + (UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize; { // Create a graphics image context UIGraphicsBeginImageContext(newSize); // Tell the old image to draw in this new context, with the desired // new size [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)]; // Get the new image from the context UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext(); // End the context UIGraphicsEndImageContext(); // Return the new image. return newImage; } This method is very simple, and works great. It will also deal with the UIImageOrientation for you, meaning that you don't have to care whether the camera was sideways when the picture was taken. However, this method is not thread safe, and since thumbnailing is a relatively expensive operation (approximately ~2.5s on a 3G for a 1600 x 1200 pixel image), this is very much an operation you may want to do in the background, on a separate thread. Method 2: Using CoreGraphics + (UIImage*)imageWithImage:(UIImage*)sourceImage scaledToSize:(CGSize)newSize; { CGFloat targetWidth = targetSize.width; CGFloat targetHeight = targetSize.height; CGImageRef imageRef = [sourceImage CGImage]; CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef); CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef); if (bitmapInfo == kCGImageAlphaNone) { bitmapInfo = kCGImageAlphaNoneSkipLast; } CGContextRef bitmap; if (sourceImage.imageOrientation == UIImageOrientationUp || sourceImage.imageOrientation == UIImageOrientationDown) { bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo); } else { bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo); } if (sourceImage.imageOrientation == UIImageOrientationLeft) { CGContextRotateCTM (bitmap, radians(90)); CGContextTranslateCTM (bitmap, 0, -targetHeight); } else if (sourceImage.imageOrientation == UIImageOrientationRight) { CGContextRotateCTM (bitmap, radians(-90)); CGContextTranslateCTM (bitmap, -targetWidth, 0); } else if (sourceImage.imageOrientation == UIImageOrientationUp) { // NOTHING } else if (sourceImage.imageOrientation == UIImageOrientationDown) { CGContextTranslateCTM (bitmap, targetWidth, targetHeight); CGContextRotateCTM (bitmap, radians(-180.)); } CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef); CGImageRef ref = CGBitmapContextCreateImage(bitmap); UIImage* newImage = [UIImage imageWithCGImage:ref]; CGContextRelease(bitmap); CGImageRelease(ref); return newImage; } The benefit of this method is that it is thread-safe, plus it takes care of all the small things (using correct color space and bitmap info, dealing with image orientation) that the UIKit version does. How Do I Resize and Maintain Aspect Ratio (like the AspectFill option)? It is very similar to the method above, and it looks like this: + (UIImage*)imageWithImage:(UIImage*)sourceImage scaledToSizeWithSameAspectRatio:(CGSize)targetSize; { CGSize imageSize = sourceImage.size; CGFloat width = imageSize.width; CGFloat height = imageSize.height; CGFloat targetWidth = targetSize.width; CGFloat targetHeight = targetSize.height; CGFloat scaleFactor = 0.0; CGFloat scaledWidth = targetWidth; CGFloat scaledHeight = targetHeight; CGPoint thumbnailPoint = CGPointMake(0.0,0.0); if (CGSizeEqualToSize(imageSize, targetSize) == NO) { CGFloat widthFactor = targetWidth / width; CGFloat heightFactor = targetHeight / height; if (widthFactor > heightFactor) { scaleFactor = widthFactor; // scale to fit height } else { scaleFactor = heightFactor; // scale to fit width } scaledWidth = width * scaleFactor; scaledHeight = height * scaleFactor; // center the image if (widthFactor > heightFactor) { thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5; } else if (widthFactor < heightFactor) { thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5; } } CGImageRef imageRef = [sourceImage CGImage]; CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef); CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef); if (bitmapInfo == kCGImageAlphaNone) { bitmapInfo = kCGImageAlphaNoneSkipLast; } CGContextRef bitmap; if (sourceImage.imageOrientation == UIImageOrientationUp || sourceImage.imageOrientation == UIImageOrientationDown) { bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo); } else { bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo); } // In the right or left cases, we need to switch scaledWidth and scaledHeight, // and also the thumbnail point if (sourceImage.imageOrientation == UIImageOrientationLeft) { thumbnailPoint = CGPointMake(thumbnailPoint.y, thumbnailPoint.x); CGFloat oldScaledWidth = scaledWidth; scaledWidth = scaledHeight; scaledHeight = oldScaledWidth; CGContextRotateCTM (bitmap, radians(90)); CGContextTranslateCTM (bitmap, 0, -targetHeight); } else if (sourceImage.imageOrientation == UIImageOrientationRight) { thumbnailPoint = CGPointMake(thumbnailPoint.y, thumbnailPoint.x); CGFloat oldScaledWidth = scaledWidth; scaledWidth = scaledHeight; scaledHeight = oldScaledWidth; CGContextRotateCTM (bitmap, radians(-90)); CGContextTranslateCTM (bitmap, -targetWidth, 0); } else if (sourceImage.imageOrientation == UIImageOrientationUp) { // NOTHING } else if (sourceImage.imageOrientation == UIImageOrientationDown) { CGContextTranslateCTM (bitmap, targetWidth, targetHeight); CGContextRotateCTM (bitmap, radians(-180.)); } CGContextDrawImage(bitmap, CGRectMake(thumbnailPoint.x, thumbnailPoint.y, scaledWidth, scaledHeight), imageRef); CGImageRef ref = CGBitmapContextCreateImage(bitmap); UIImage* newImage = [UIImage imageWithCGImage:ref]; CGContextRelease(bitmap); CGImageRelease(ref); return newImage; } The method we employ here is to create a bitmap with the desired size, but draw an image that is actually larger, thus maintaining the aspect ratio. So We've Got Our Scaled Images - How Do I Save Them To Disk? This is pretty simple. Remember that we want to save a compressed version to disk, and not the uncompressed pixels. Apple provides two functions that help us with this (documentation is here): NSData* UIImagePNGRepresentation(UIImage *image); NSData* UIImageJPEGRepresentation (UIImage *image, CGFloat compressionQuality); And if you want to use them, you'd do something like: UIImage* myThumbnail = ...; // Get some image NSData* imageData = UIImagePNGRepresentation(myThumbnail); Now we're ready to save it to disk, which is the final step (say into the documents directory): // Give a name to the file NSString* imageName = @"MyImage.png"; // Now, we have to find the documents directory so we can save it // Note that you might want to save it elsewhere, like the cache directory, // or something similar. NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString* documentsDirectory = [paths objectAtIndex:0]; // Now we get the full path to the file NSString* fullPathToFile = [documentsDirectory stringByAppendingPathComponent:imageName]; // and then we write it out [imageData writeToFile:fullPathToFile atomically:NO]; You would repeat this for every version of the image you have. How Do I Load These Images Back Into Memory? Just look at the various UIImage initialization methods, such as +imageWithContentsOfFile: in the Apple documentation.

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Using Stored Procedures in SSIS

- by dataintegration

The SSIS Data Flow components: the source task and the destination task are the easiest way to transfer data in SSIS. Some data transactions do not fit this model, they are procedural tasks modeled as stored procedures. In this article we show how you can call stored procedures available in RSSBus ADO.NET Providers from SSIS. In this article we will use the CreateJob and the CreateBatch stored procedures available in RSSBus ADO.NET Provider for Salesforce, but the same steps can be used to call a stored procedure in any of our data providers. Step 1: Open Visual Studio and create a new Integration Services Project. Step 2: Add a new Data Flow Task to the Control Flow window. Step 3: Open the Data Flow Task and add a Script Component to the data flow pane. A dialog box will pop-up allowing you to select the Script Component Type: pick the source type as we will be outputting columns from our stored procedure. Step 4: Double click the Script Component to open the editor. Step 5: In the "Inputs and Outputs" settings, enter all the columns you want to output to the data flow. Ensure the correct data type has been set for each output. You can check the data type by selecting the output and then changing the "DataType" property from the property editor. In our example, we'll add the column JobID of type String. Step 6: Select the "Script" option in the left-hand pane and click the "Edit Script" button. This will open a new Visual Studio window with some boiler plate code in it. Step 7: In the CreateOutputRows() function you can add code that executes the stored procedures included with the Salesforce Component. In this example we will be using the CreateJob and CreateBatch stored procedures. You can find a list of the available stored procedures along with their inputs and outputs in the product help. //Configure the connection string to your credentials String connectionString = "Offline=False;user=myusername;password=mypassword;access token=mytoken;"; using (SalesforceConnection conn = new SalesforceConnection(connectionString)) { //Create the command to call the stored procedure CreateJob SalesforceCommand cmd = new SalesforceCommand("CreateJob", conn); cmd.CommandType = CommandType.StoredProcedure; cmd.Parameters.Add(new SalesforceParameter("ObjectName", "Contact")); cmd.Parameters.Add(new SalesforceParameter("Action", "insert")); //Execute CreateJob //CreateBatch requires JobID as input so we store this value for later SalesforceDataReader rdr = cmd.ExecuteReader(); String JobID = ""; while (rdr.Read()) { JobID = (String)rdr["JobID"]; } //Create the command for CreateBatch, for this example we are adding two new rows SalesforceCommand batCmd = new SalesforceCommand("CreateBatch", conn); batCmd.CommandType = CommandType.StoredProcedure; batCmd.Parameters.Add(new SalesforceParameter("JobID", JobID)); batCmd.Parameters.Add(new SalesforceParameter("Aggregate", "<Contact><Row><FirstName>Bill</FirstName>" + "<LastName>White</LastName></Row><Row><FirstName>Bob</FirstName><LastName>Black</LastName></Row></Contact>")); //Execute CreateBatch SalesforceDataReader batRdr = batCmd.ExecuteReader(); } Step 7b: If you had specified output columns earlier, you can now add data into them using the UserComponent Output0Buffer. For example, we had set an output column called JobID of type String so now we can set a value for it. We will modify the DataReader that contains the output of CreateJob like so:. while (rdr.Read()) { Output0Buffer.AddRow(); JobID = (String)rdr["JobID"]; Output0Buffer.JobID = JobID; } Step 8: Note: You will need to modify the connection string to include your credentials. Also ensure that the System.Data.RSSBus.Salesforce assembly is referenced and include the following using statements to the top of the class: using System.Data; using System.Data.RSSBus.Salesforce; Step 9: Once you are done editing your script, save it, and close the window. Click OK in the Script Transformation window to go back to the main pane. Step 10: If had any outputs from the Script Component you can use them in your data flow. For example we will use a Flat File Destination. Configure the Flat File Destination to output the results to a file, and you should see the JobId in the file. Step 11: Your project should be ready to run.

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Unexpected advantage of Engineered Systems

- by user12244672

It's not surprising that Engineered Systems accelerate the debugging and resolution of customer issues. But what has surprised me is just how much faster issue resolution is with Engineered Systems such as SPARC SuperCluster. These are powerful, complex, systems used by customers wanting extreme database performance, app performance, and cost saving server consolidation. A SPARC SuperCluster consists or 2 or 4 powerful T4-4 compute nodes, 3 or 6 extreme performance Exadata Storage Cells, a ZFS Storage Appliance 7320 for general purpose storage, and ultra fast Infiniband switches. Each with its own firmware. It runs Solaris 11, Solaris 10, 11gR2, LDoms virtualization, and Zones virtualization on the T4-4 compute nodes, a modified version of Solaris 11 in the ZFS Storage Appliance, a modified and highly tuned version of Oracle Linux running Exadata software on the Storage Cells, another Linux derivative in the Infiniband switches, etc. It has an Infiniband data network between the components, a 10Gb data network to the outside world, and a 1Gb management network. And customers can run whatever middleware and apps they want on it, clustered in whatever way they want. In one word, powerful. In another, complex. The system is highly Engineered. But it's designed to run general purpose applications. That is, the physical components, configuration, cabling, virtualization technologies, switches, firmware, Operating System versions, network protocols, tunables, etc. are all preset for optimum performance and robustness. That improves the customer experience as what the customer runs leverages our technical know-how and best practices and is what we've tested intensely within Oracle. It should also make debugging easier by fixing a large number of variables which would otherwise be in play if a customer or Systems Integrator had assembled such a complex system themselves from the constituent components. For example, there's myriad network protocols which could be used with Infiniband. Myriad ways the components could be interconnected, myriad tunable settings, etc. But what has really surprised me - and I've been working in this area for 15 years now - is just how much easier and faster Engineered Systems have made debugging and issue resolution. All those error opportunities for sub-optimal cabling, unusual network protocols, sub-optimal deployment of virtualization technologies, issues with 3rd party storage, issues with 3rd party multi-pathing products, etc., are simply taken out of the equation. All those error opportunities for making an issue unique to a particular set-up, the "why aren't we seeing this on any other system ?" type questions, the doubts, just go away when we or a customer discover an issue on an Engineered System. It enables a really honed response, getting to the root cause much, much faster than would otherwise be the case. Here's a couple of examples from the last month, one found in-house by my team, one found by a customer: Example 1: We found a node eviction issue running 11gR2 with Solaris 11 SRU 12 under extreme load on what we call our ExaLego test system (mimics an Exadata / SuperCluster 11gR2 Exadata Storage Cell set-up). We quickly established that an enhancement in SRU12 enabled an 11gR2 process to query Infiniband's Subnet Manager, replacing a fallback mechanism it had used previously. Under abnormally heavy load, the query could return results which were misinterpreted resulting in node eviction. In several daily joint debugging sessions between the Solaris, Infiniband, and 11gR2 teams, the issue was fully root caused, evaluated, and a fix agreed upon. That fix went back into all Solaris releases the following Monday. From initial issue discovery to the fix being put back into all Solaris releases was just 10 days. Example 2: A customer reported sporadic performance degradation. The reasons were unclear and the information sparse. The SPARC SuperCluster Engineered Systems support teams which comprises both SPARC/Solaris and Database/Exadata experts worked to root cause the issue. A number of contributing factors were discovered, including tunable parameters. An intense collaborative investigation between the engineering teams identified the root cause to a CPU bound networking thread which was being starved of CPU cycles under extreme load. Workarounds were identified. Modifications have been put back into 11gR2 to alleviate the issue and a development project already underway within Solaris has been sped up to provide the final resolution on the Solaris side. The fixed SPARC SuperCluster configuration greatly aided issue reproduction and dramatically sped up root cause analysis, allowing the correct workarounds and fixes to be identified, prioritized, and implemented. The customer is now extremely happy with performance and robustness. Since the configuration is common to other customers, the lessons learned are being proactively rolled out to other customers and incorporated into the installation procedures for future customers. This effectively acts as a turbo-boost to performance and reliability for all SPARC SuperCluster customers. If this had occurred in a "home grown" system of this complexity, I expect it would have taken at least 6 months to get to the bottom of the issue. But because it was an Engineered System, known, understood, and qualified by both the Solaris and Database teams, we were able to collaborate closely to identify cause and effect and expedite a solution for the customer. That is a key advantage of Engineered Systems which should not be underestimated. Indeed, the initial issue mitigation on the Database side followed by final fix on the Solaris side, highlights the high degree of collaboration and excellent teamwork between the Oracle engineering teams. It's a compelling advantage of the integrated Oracle Red Stack in general and Engineered Systems in particular.

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ADF version of "Modern" dialog windows

- by Martin Deh

It is no surprise with the popularity of the i-devices (iphone, ipad), that many of the iOS UI based LnF (look and feel) would start to inspire web designers to incorporate the same LnF into their web sites. Take for example, a normal dialog popup. In the iOS world, the LnF becomes a bit more elegant by add just a simple element as a "floating" close button: In this blog post, I will describe how this can be accomplished using OOTB ADF components and CSS3 style elements. There are two ways that this can be achieved. The easiest way is to simply replace the default image, which looks like this, and adjust the af|panelWindow:close-icon-style skin selector. Using this simple technique, you can come up with this: The CSS code to produce this effect is pretty straight forward: af|panelWindow.test::close-icon-style{ background-image: url("../popClose.gif"); line-height: 10px; position: absolute; right: -10px; top: -10px; height:38px; width:38px; outline:none; } You can see from the CSS, the position of the region, which holds the image, is relocated based on the position based attributes. Also, the addition of the "outline" attribute removes the border that is visible in Chrome and IE. The second example, is based on not having an image to produce the close button. Like the previous sample, I will use the OOTB panelWindow. However, this time I will use a OOTB commandButton to replace the image. The construct of the components looks like this: The commandButton is positioned first in the hierarchy making the re-positioning easier. The commandButton will also need a style class assigned to it (i.e. closeButton), which will allow for the positioning and the over-riding of the default skin attributes of a default button. In addition, the closeIconVisible property is set to false, since the default icon is no longer needed. Once this is done, the rest is in the CSS. Here is the sample that I created that was used for an actual customer POC: The CSS code for the button: af|commandButton.closeButton, af|commandButton.closeButton af|commandButton:text-only{ line-height: 10px; position: absolute; right: -10px; top: -10px; -webkit-border-radius: 70px; -moz-border-radius: 70px; -ms-border-radius: 70px; border-radius: 70px; background-image:none; border:#828c95 1px solid; background-color:black; font-weight: bold; text-align: center; text-decoration: none; color:white; height:30px; width:30px; outline:none; } The CSS uses the border radius to create the round effect on the button (in IE 8, since border-radius is not supported, this will only work with some added code). Also, I add the box-shadow attribute to the panelWindow style class to give it a nice shadowing effect.

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Add Widget via Action in Toolbar

- by Geertjan

The question of the day comes from Vadim, who asks on the NetBeans Platform mailing list: "Looking for example showing how to add Widget to Scene, e.g. by toolbar button click." Well, the solution is very similar to this blog entry, where you see a solution provided by Jesse Glick for VisiTrend in Boston: https://blogs.oracle.com/geertjan/entry/zoom_capability Other relevant articles to read are as follows: http://netbeans.dzone.com/news/which-netbeans-platform-action http://netbeans.dzone.com/how-to-make-context-sensitive-actions Let's go through it step by step, with this result in the end, a solution involving 4 classes split (optionally, since a central feature of the NetBeans Platform is modularity) across multiple modules: The Customer object has a "name" String and the Droppable capability has a method "doDrop" which takes a Customer object: public interface Droppable { void doDrop(Customer c);} In the TopComponent, we use "TopComponent.associateLookup" to publish an instance of "Droppable", which creates a new LabelWidget and adds it to the Scene in the TopComponent. Here's the TopComponent constructor: public CustomerCanvasTopComponent() { initComponents(); setName(Bundle.CTL_CustomerCanvasTopComponent()); setToolTipText(Bundle.HINT_CustomerCanvasTopComponent()); final Scene scene = new Scene(); final LayerWidget layerWidget = new LayerWidget(scene); Droppable d = new Droppable(){ @Override public void doDrop(Customer c) { LabelWidget customerWidget = new LabelWidget(scene, c.getTitle()); customerWidget.getActions().addAction(ActionFactory.createMoveAction()); layerWidget.addChild(customerWidget); scene.validate(); } }; scene.addChild(layerWidget); jScrollPane1.setViewportView(scene.createView()); associateLookup(Lookups.singleton(d));} The Action is displayed in the toolbar and is enabled only if a Droppable is currently in the Lookup: @ActionID( category = "Tools", id = "org.customer.controler.AddCustomerAction")@ActionRegistration( iconBase = "org/customer/controler/icon.png", displayName = "#AddCustomerAction")@ActionReferences({ @ActionReference(path = "Toolbars/File", position = 300)})@NbBundle.Messages("AddCustomerAction=Add Customer")public final class AddCustomerAction implements ActionListener { private final Droppable context; public AddCustomerAction(Droppable droppable) { this.context = droppable; } @Override public void actionPerformed(ActionEvent ev) { NotifyDescriptor.InputLine inputLine = new NotifyDescriptor.InputLine("Name:", "Data Entry"); Object result = DialogDisplayer.getDefault().notify(inputLine); if (result == NotifyDescriptor.OK_OPTION) { Customer customer = new Customer(inputLine.getInputText()); context.doDrop(customer); } }} Therefore, when the Properties window, for example, is selected, the Action will be disabled. (See the Zoomable example referred to in the link above for another example of this.) As you can see above, when the Action is invoked, a Droppable must be available (otherwise the Action would not have been enabled). The Droppable is obtained in the Action and a new Customer object is passed to its "doDrop" method. The above in pictures, take note of the enablement of the toolbar button with the red dot, on the extreme left of the toolbar in the screenshots below: The above shows the JButton is only enabled if the relevant TopComponent is active and, when the Action is invoked, the user can enter a name, after which a new LabelWidget is created in the Scene. The source code of the above is here: http://java.net/projects/nb-api-samples/sources/api-samples/show/versions/7.3/misc/WidgetCreationFromAction Note: Showing this as an MVC example is slightly misleading because, depending on which model object ("Customer" and "Droppable") you're looking at, the V and the C are different. From the point of view of "Customer", the TopComponent is the View, while the Action is the Controler, since it determines when the M is displayed. However, from the point of view of "Droppable", the TopComponent is the Controler, since it determines when the Action, i.e., which is in this case the View, displays the presence of the M.

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Accelerating 2d object collision with other objects [on hold]

- by Silent Cave

Making my very first attempt at game programming with SDL/OpenGL. So I made an object Actor witch can move in all four sides with acceleration. And there are bunch of other rectangles to collide to. the image Movement and collision detection alghorythms work just fine by itself, but when combined to prevent the green rectangle from crossing black rectangles, it gives me a kind of funny resault. Let me show you the code first: from Actor.h class Actor{ public: SDL_Rect * dim; alphaColor * col; float speed; float xlGrav, xrGrav, yuGrav, ydGrav; float acceleration; bool left,right,up,down; Actor(SDL_Rect * dim,alphaColor * col, float speed, float acceleration); bool colides(const SDL_Rect & rect); bool check_for_collisions(const std::vector<SDL_Rect*> & gameObjects ); }; from actor.cpp bool Actor::colides(const SDL_Rect & rect){ if (dim->x + dim->w < rect.x) return false; if (dim->x > rect.x + rect.w) return false; if (dim->y + dim->h < rect.y) return false; if (dim->y > rect.y + rect.h) return false; return true; } movement logic from main.cpp if (actor->left){ if(actor->xlGrav < actor->speed){ actor->xlGrav += actor->speed*actor->acceleration; }else actor->xlGrav = actor->speed; actor->dim->x -= actor->xlGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x += actor->xlGrav; actor->xlGrav = 0; } } if (!actor->left){ if(actor->xlGrav - actor->speed*actor->acceleration > 0){ actor->xlGrav -= actor->speed*actor->acceleration; }else actor->xlGrav = 0; actor->dim->x -= actor->xlGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x += actor->xlGrav; actor->xlGrav = 0; } } if (actor->right){ if(actor->xrGrav < actor->speed){ actor->xrGrav += actor->speed*actor->acceleration; }else actor->xrGrav = actor->speed; actor->dim->x += actor->xrGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x -= actor->xrGrav; actor->xrGrav = 0; } } if (!actor->right){ if(actor->xrGrav - actor->speed*actor->acceleration > 0){ actor->xrGrav -= actor->speed*actor->acceleration; }else actor->xrGrav = 0; actor->dim->x += actor->xrGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x -= actor->xrGrav; actor->xrGrav = 0; } } if (actor->up){ if(actor->yuGrav < actor->speed){ actor->yuGrav += actor->speed*actor->acceleration; }else actor->yuGrav = actor->speed; actor->dim->y -= actor->yuGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y += actor->yuGrav; actor->yuGrav = 0; } } if (!actor->up){ if(actor->yuGrav - actor->speed*actor->acceleration > 0){ actor->yuGrav -= actor->speed*actor->acceleration; }else actor->yuGrav = 0; actor->dim->y -= actor->yuGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y += actor->yuGrav; actor->yuGrav = 0; } } if (actor->down){ if(actor->ydGrav < actor->speed){ actor->ydGrav += actor->speed*actor->acceleration; }else actor->ydGrav = actor->speed; actor->dim->y += actor->ydGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y -= actor->ydGrav; actor->ydGrav = 0; } } if (!actor->down){ if(actor->ydGrav - actor->speed*actor->acceleration > 0){ actor->ydGrav -= actor->speed*actor->acceleration; }else actor->ydGrav = 0; actor->dim->y += actor->ydGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y -= actor->ydGrav; actor->ydGrav = 0; } } So, if the green box approaches an obstacle from up or left, everything goes as planned - object stops, and it's acceleration drops to zero. But if it comes from bottom or right, it enters into obstacles inner space and starts strangely dance, I'd rather say move in inverted controls. What do I fail to see?

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how to label a cuboid using open gl?

- by usha

hi this is how my 3dcuboid looks ,i have attached complete code , i want to label this cuboid using different name across sides how is it possible using opengl in android...plz help me out public class MyGLRenderer implements Renderer { Context context; Cuboid rect; private float mCubeRotation; // private static float angleCube = 0; // Rotational angle in degree for cube (NEW) // private static float speedCube = -1.5f; // Rotational speed for cube (NEW) public MyGLRenderer(Context context) { rect = new Cuboid(); this.context = context; } public void onDrawFrame(GL10 gl) { // TODO Auto-generated method stub gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); gl.glLoadIdentity(); // Reset the model-view matrix gl.glTranslatef(0.2f, 0.0f, -8.0f); // Translate right and into the screen gl.glScalef(0.8f, 0.8f, 0.8f); // Scale down (NEW) gl.glRotatef(mCubeRotation, 1.0f, 1.0f, 1.0f); // gl.glRotatef(angleCube, 1.0f, 1.0f, 1.0f); // rotate about the axis (1,1,1) (NEW) rect.draw(gl); mCubeRotation -= 0.15f; //angleCube += speedCube; } public void onSurfaceChanged(GL10 gl, int width, int height) { // TODO Auto-generated method stub if (height == 0) height = 1; // To prevent divide by zero float aspect = (float)width / height; // Set the viewport (display area) to cover the entire window gl.glViewport(0, 0, width, height); // Setup perspective projection, with aspect ratio matches viewport gl.glMatrixMode(GL10.GL_PROJECTION); // Select projection matrix gl.glLoadIdentity(); // Reset projection matrix // Use perspective projection GLU.gluPerspective(gl, 45, aspect, 0.1f, 100.f); gl.glMatrixMode(GL10.GL_MODELVIEW); // Select model-view matrix gl.glLoadIdentity(); // Reset } public void onSurfaceCreated(GL10 gl, EGLConfig config) { // TODO Auto-generated method stub gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Set color's clear-value to black gl.glClearDepthf(1.0f); // Set depth's clear-value to farthest gl.glEnable(GL10.GL_DEPTH_TEST); // Enables depth-buffer for hidden surface removal gl.glDepthFunc(GL10.GL_LEQUAL); // The type of depth testing to do gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST); // nice perspective view gl.glShadeModel(GL10.GL_SMOOTH); // Enable smooth shading of color gl.glDisable(GL10.GL_DITHER); // Disable dithering for better performance }} public class Cuboid{ private FloatBuffer mVertexBuffer; private FloatBuffer mColorBuffer; private ByteBuffer mIndexBuffer; private float vertices[] = { //width,height,depth -2.5f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, -1.0f, -2.5f, 1.0f, -1.0f, -2.5f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -2.5f, 1.0f, 1.0f }; private float colors[] = { // R,G,B,A COLOR 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.5f, 0.0f, 1.0f, 1.0f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f }; private byte indices[] = { // VERTEX 0,1,2,3,4,5,6,7 REPRESENTATION FOR FACES 0, 4, 5, 0, 5, 1, 1, 5, 6, 1, 6, 2, 2, 6, 7, 2, 7, 3, 3, 7, 4, 3, 4, 0, 4, 7, 6, 4, 6, 5, 3, 0, 1, 3, 1, 2 }; public Cuboid() { ByteBuffer byteBuf = ByteBuffer.allocateDirect(vertices.length * 4); byteBuf.order(ByteOrder.nativeOrder()); mVertexBuffer = byteBuf.asFloatBuffer(); mVertexBuffer.put(vertices); mVertexBuffer.position(0); byteBuf = ByteBuffer.allocateDirect(colors.length * 4); byteBuf.order(ByteOrder.nativeOrder()); mColorBuffer = byteBuf.asFloatBuffer(); mColorBuffer.put(colors); mColorBuffer.position(0); mIndexBuffer = ByteBuffer.allocateDirect(indices.length); mIndexBuffer.put(indices); mIndexBuffer.position(0); } public void draw(GL10 gl) { gl.glFrontFace(GL10.GL_CW); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVertexBuffer); gl.glColorPointer(4, GL10.GL_FLOAT, 0, mColorBuffer); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_COLOR_ARRAY); gl.glDrawElements(GL10.GL_TRIANGLES, 36, GL10.GL_UNSIGNED_BYTE, mIndexBuffer); gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); gl.glDisableClientState(GL10.GL_COLOR_ARRAY); } } public class Draw3drect extends Activity { private GLSurfaceView glView; // Use GLSurfaceView // Call back when the activity is started, to initialize the view @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); glView = new GLSurfaceView(this); // Allocate a GLSurfaceView glView.setRenderer(new MyGLRenderer(this)); // Use a custom renderer this.setContentView(glView); // This activity sets to GLSurfaceView } // Call back when the activity is going into the background @Override protected void onPause() { super.onPause(); glView.onPause(); } // Call back after onPause() @Override protected void onResume() { super.onResume(); glView.onResume(); } }

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From Pocket to Instapaper

- by Michael Freidgeim

Some time ago I’ve described the issues that I’ve had since a new version of Read It Later, named Pocket, was introduced.I’ve waited with hope for a new upgrade, but I had a huge disappointment with the latest version 16 June 2012. It didn’t fixed any of the two major problems, that I experienced since new Pocket was introduced- 1. iPad app still didn’t show many of the saved links. 2. ability to rename articles on iPad still wasn’t restored.I’ve posted the message into their forum. They did not show my comment on their forum( I would name it censorship, not moderation), but a few days ago I’ve received an email, recommending “try logging out of the app on your iPad, and back in again.” Their suggestion helped, but I don’t understand, why it is not posted as a recommendation on their support site.So I decided to try InstAPaper on my iPad, Previously I’ve used it for Kindle. I never considered it before on iPad, because there were no free demo and I was very satisfied with RIL free and then RIL Pro. Currently InstAPaper cost $3, so the price is not an issue.I’ve checked that it has most of features that I am using(e.g. renaming, folders) and I am quite happy with it now. Actually I am using Pocket (or RIL free) for old bookmarks( I have 1000+ stored on my iPad) and for new bookmarks I am using InstAPaper.Having a solid experience with RIL/Pocket I’ve created a list of suggestions to Marco Arment to implement.1. Some pages stored in InstAPaper have removed essential sections of the text. E.g in many blogs comments are not stored in InstAPaper. Some pages lost almost all of important links (e.g. http://www.lib.rus.ec/a/32416 -sorry, in Russian). RIL/Pocket has 2 modes to store offline- Web view and Article view. Web View includes all links/images of the original page, but it’s very reliable. Article view suppose to strip unrelated information, but often corrupts the content. I prefer to use offline Web view.InstAPaper should also support offline Web view, in case if stripped view removes important part of content.2. Black full screen Saving on iPad Safari is very annoying. After user pressed a bookmark, the saving has some delay and then for a few seconds prevents from reading the text.Would be better to show as message on the top part(as in Pocket ). I am surprised, that a full screen popup was implemented recently as a desired feature. 3.There are no comments allowed on http://blog.instapaper.com/. I would prefer to post some of these notes as comments on http://blog.instapaper.com/ rather than write them in my blog and then send link to Marco.(I found recommendation how to add support of comments on tumblr at http://www.tumblr.com/help, but then realized that Marko was the lead developer ofTumblr.)4. Also there is no support forum. I understand that maintenance of the forum ican be a hassle, but stackexchange fSome time ago I’ve described the issues that I’ve had since a new version of Read It Later, named Pocket, was introduced.I’ve waited with hope for a new upgrade, but I had a huge disappointment with the latest version 16 June 2012. It didn’t fixed any of the two major problems, that I experienced since new Pocket was introduced- orums can be referred on http://www.instapaper.com/main/support page, i.e.http://webapps.stackexchange.com/search?q=Instapaper or http://apple.stackexchange.com/search?q=Instapaper 5. Tags are more convenient than folders. i.e. an ability for the same article to have more than one tag. Also creating of new folders is not supported offline, which is an annoying limitation.6. I would like to have a narrow list - additionally to existing list modes have a subject only list or subject+site list to show more list items on a screen.7. Limit of 500 offline articles sounds quite big, but my RIL list exceeded 1000, so it could be a issue in the future.8. Search button on iPad version is visible, but doesn’t work- it forces to buy Premium subscription. I think, that it’s not correct. If the button in a paid version is visible and enabled, it should provide a working functionality, e.g. search in article names only. And leave full-text search for the premium support.9..Copy URL is an important operation and deserves to be in a first level of Action menu, rather than in Share sub-menu.I’ve also have comment re post http://www.marco.org/2011/04/28/removed-instapaper-free. Marco Arment explained, why he doesn’t provide free version of Instapaper. I believe that he is loosing essential part of his customers. When I decided which of iPad application to choose, I’ve selected RIL, because I was able to play with free version, and I liked it. I didn’t have a chance to compare RIL and InstAPaper on iPad, so I’ve bought RIL pro. For a user there is no point to pay even $3 , if there are similar free product, that user can try and see, is it suitable for him/her.I’ve also played with Readability. It doesn’t have folders or tags(which is very important for me), but nicely supports full text search

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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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Nodemanager Init.d Script

- by john.graves(at)oracle.com

I’ve seen many of these floating around. This is my favourite on an Ubuntu based machine. Just throw it into the /etc/init.d directory and update the following lines: export MW_HOME=/opt/app/wls10.3.4 user='weblogic' Then run: update-rc.d nodemanager default Everything else should be ok for 10.3.4. #!/bin/sh # ### BEGIN INIT INFO # Provides: nodemanager # Required-Start: # Required-Stop: # Default-Start: 2 3 4 5 # Default-Stop: 0 1 6 # Short-Description: WebLogic Nodemanager ### END INIT INFO # nodemgr Oracle Weblogic NodeManager service # # chkconfig: 345 85 15 # description: Oracle Weblogic NodeManager service # ### BEGIN INIT INFO # Provides: nodemgr # Required-Start: $network $local_fs # Required-Stop: # Should-Start: # Should-Stop: # Default-Start: 3 4 5 # Default-Stop: 0 1 2 6 # Short-Description: Oracle Weblogic NodeManager service. # Description: Starts and stops Oracle Weblogic NodeManager. ### END INIT INFO # Source function library. . /lib/lsb/init-functions # set Weblogic environment defining CLASSPATH and LD_LIBRARY_PATH # to start/stop various components. export MW_HOME=/opt/app/wls10.3.4 # # Note: # The setWLSEnv.sh not only does a good job of setting the environment, # but also advertises the fact explicitly in the console! Silence it. # . $MW_HOME/wlserver_10.3/server/bin/setWLSEnv.sh > /dev/null # set NodeManager environment export NodeManagerHome=$WL_HOME/common/nodemanager NodeManagerLockFile=$NodeManagerHome/nodemanager.log.lck # check JAVA_HOME if [ -z ${JAVA_HOME:-} ]; then export JAVA_HOME=/opt/sun/products/java/jdk1.6.0_18 fi exec=$MW_HOME/wlserver_10.3/server/bin/startNodeManager.sh prog='nodemanager' user='weblogic' is_nodemgr_running() { local nodemgr_cnt=`ps -ef | \ grep -i 'java ' | \ grep -i ' weblogic.NodeManager ' | \ grep -v grep | \ wc -l` echo $nodemgr_cnt } get_nodemgr_pid() { nodemgr_pid=0 if [ `is_nodemgr_running` -eq 1 ]; then nodemgr_pid=`ps -ef | \ grep -i 'java ' | \ grep -i ' weblogic.NodeManager ' | \ grep -v grep | \ tr -s ' ' | \ cut -d' ' -f2` fi echo $nodemgr_pid } check_nodemgr_status () { local retval=0 local nodemgr_cnt=`is_nodemgr_running` if [ $nodemgr_cnt -eq 0 ]; then if [ -f $NodeManagerLockFile ]; then retval=2 else retval=3 fi elif [ $nodemgr_cnt -gt 1 ]; then retval=4 else retval=0 fi echo $retval } start() { ulimit -n 65535 [ -x $exec ] || exit 5 echo -n $"Starting $prog: " su $user -c "$exec &" retval=$? echo return $retval } stop() { echo -n $"Stopping $prog: " kill -s 9 `get_nodemgr_pid` &> /dev/null retval=$? echo [ $retval -eq 0 ] && rm -f $NodeManagerLockFile return $retval } restart() { stop start } reload() { restart } force_reload() { restart } rh_status() { local retval=`check_nodemgr_status` if [ $retval -eq 0 ]; then echo "$prog (pid:`get_nodemgr_pid`) is running..." elif [ $retval -eq 4 ]; then echo "Multiple instances of $prog are running..." else echo "$prog is stopped" fi return $retval } rh_status_q() { rh_status >/dev/null 2>&1 } case "$1" in start) rh_status_q && exit 0 $1 ;; stop) rh_status_q || exit 0 $1 ;; restart) $1 ;; reload) rh_status_q || exit 7 $1 ;; force-reload) force_reload ;; status) rh_status ;; condrestart|try-restart) rh_status_q || exit 0 restart ;; *) echo -n "Usage: $0 {" echo -n "start|" echo -n "stop|" echo -n "status|" echo -n "restart|" echo -n "condrestart|" echo -n "try-restart|" echo -n "reload|" echo -n "force-reload" echo "}" exit 2 esac exit $? .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; }

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JPRT: A Build & Test System

- by kto

DRAFT A while back I did a little blogging on a system called JPRT, the hardware used and a summary on my java.net weblog. This is an update on the JPRT system. JPRT ("JDK Putback Reliablity Testing", but ignore what the letters stand for, I change what they mean every day, just to annoy people :\^) is a build and test system for the JDK, or any source base that has been configured for JPRT. As I mentioned in the above blog, JPRT is a major modification to a system called PRT that the HotSpot VM development team has been using for many years, very successfully I might add. Keeping the source base always buildable and reliable is the first step in the 12 steps of dealing with your product quality... or was the 12 steps from Alcoholics Anonymous... oh well, anyway, it's the first of many steps. ;\^) Internally when we make changes to any part of the JDK, there are certain procedures we are required to perform prior to any putback or commit of the changes. The procedures often vary from team to team, depending on many factors, such as whether native code is changed, or if the change could impact other areas of the JDK. But a common requirement is a verification that the source base with the changes (and merged with the very latest source base) will build on many of not all 8 platforms, and a full 'from scratch' build, not an incremental build, which can hide full build problems. The testing needed varies, depending on what has been changed. Anyone that was worked on a project where multiple engineers or groups are submitting changes to a shared source base knows how disruptive a 'bad commit' can be on everyone. How many times have you heard: "So And So made a bunch of changes and now I can't build!". But multiply the number of platforms by 8, and make all the platforms old and antiquated OS versions with bizarre system setup requirements and you have a pretty complicated situation (see http://download.java.net/jdk6/docs/build/README-builds.html). We don't tolerate bad commits, but our enforcement is somewhat lacking, usually it's an 'after the fact' correction. Luckily the Source Code Management system we use (another antique called TeamWare) allows for a tree of repositories and 'bad commits' are usually isolated to a small team. Punishment to date has been pretty drastic, the Queen of Hearts in 'Alice in Wonderland' said 'Off With Their Heads', well trust me, you don't want to be the engineer doing a 'bad commit' to the JDK. With JPRT, hopefully this will become a thing of the past, not that we have had many 'bad commits' to the master source base, in general the teams doing the integrations know how important their jobs are and they rarely make 'bad commits'. So for these JDK integrators, maybe what JPRT does is keep them from chewing their finger nails at night. ;\^) Over the years each of the teams have accumulated sets of machines they use for building, or they use some of the shared machines available to all of us. But the hunt for build machines is just part of the job, or has been. And although the issues with consistency of the build machines hasn't been a horrible problem, often you never know if the Solaris build machine you are using has all the right patches, or if the Linux machine has the right service pack, or if the Windows machine has it's latest updates. Hopefully the JPRT system can solve this problem. When we ship the binary JDK bits, it is SO very important that the build machines are correct, and we know how difficult it is to get them setup. Sure, if you need to debug a JDK problem that only shows up on Windows XP or Solaris 9, you'll still need to hunt down a machine, but not as a regular everyday occurance. I'm a big fan of a regular nightly build and test system, constantly verifying that a source base builds and tests out. There are many examples of automated build/tests, some that trigger on any change to the source base, some that just run every night. Some provide a protection gateway to the 'golden' source base which only gets changes that the nightly process has verified are good. The JPRT (and PRT) system is meant to guard the source base before anything is sent to it, guarding all source bases from the evil developer, well maybe 'evil' isn't the right word, I haven't met many 'evil' developers, more like 'error prone' developers. ;\^) Humm, come to think about it, I may be one from time to time. :\^{ But the point is that by spreading the build up over a set of machines, and getting the turnaround down to under an hour, it becomes realistic to completely build on all platforms and test it, on every putback. We have the technology, we can build and rebuild and rebuild, and it will be better than it was before, ha ha... Anybody remember the Six Million Dollar Man? Man, I gotta get out more often.. Anyway, now the nightly build and test can become a 'fetch the latest JPRT build bits' and start extensive testing (the testing not done by JPRT, or the platforms not tested by JPRT). Is it Open Source? No, not yet. Would you like to be? Let me know. Or is it more important that you have the ability to use such a system for JDK changes? So enough blabbering on about this JPRT system, tell me what you think. And let me know if you want to hear more about it or not. Stay tuned for the next episode, same Bloody Bat time, same Bloody Bat channel. ;\^) -kto

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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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YouTube Scalability Lessons

- by Bertrand Matthelié

@font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Calibri"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }h2 { margin: 12pt 0cm 3pt; page-break-after: avoid; font-size: 14pt; font-family: "Times New Roman"; font-style: italic; }a:link, span.MsoHyperlink { color: blue; text-decoration: underline; }a:visited, span.MsoHyperlinkFollowed { color: purple; text-decoration: underline; }span.Heading2Char { font-family: Calibri; font-weight: bold; font-style: italic; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Very interesting blog post by Todd Hoff at highscalability.com presenting “7 Years of YouTube Scalability Lessons in 30 min” based on a presentation from Mike Solomon, one of the original engineers at YouTube: …. The key takeaway away of the talk for me was doing a lot with really simple tools. While many teams are moving on to more complex ecosystems, YouTube really does keep it simple. They program primarily in Python, use MySQL as their database, they’ve stuck with Apache, and even new features for such a massive site start as a very simple Python program. That doesn’t mean YouTube doesn’t do cool stuff, they do, but what makes everything work together is more a philosophy or a way of doing things than technological hocus pocus. What made YouTube into one of the world’s largest websites? Read on and see... Stats @font-face { font-family: "Arial"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } 4 billion Views a day 60 hours of video is uploaded every minute 350+ million devices are YouTube enabled Revenue double in 2010 The number of videos has gone up 9 orders of magnitude and the number of developers has only gone up two orders of magnitude. 1 million lines of Python code Stack @font-face { font-family: "Arial"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } Python - most of the lines of code for YouTube are still in Python. Everytime you watch a YouTube video you are executing a bunch of Python code. Apache - when you think you need to get rid of it, you don’t. Apache is a real rockstar technology at YouTube because they keep it simple. Every request goes through Apache. Linux - the benefit of Linux is there’s always a way to get in and see how your system is behaving. No matter how bad your app is behaving, you can take a look at it with Linux tools like strace and tcpdump. MySQL - is used a lot. When you watch a video you are getting data from MySQL. Sometime it’s used a relational database or a blob store. It’s about tuning and making choices about how you organize your data. Vitess- a new project released by YouTube, written in Go, it’s a frontend to MySQL. It does a lot of optimization on the fly, it rewrites queries and acts as a proxy. Currently it serves every YouTube database request. It’s RPC based. Zookeeper - a distributed lock server. It’s used for configuration. Really interesting piece of technology. Hard to use correctly so read the manual Wiseguy - a CGI servlet container. Spitfire - a templating system. It has an abstract syntax tree that let’s them do transformations to make things go faster. Serialization formats - no matter which one you use, they are all expensive. Measure. Don’t use pickle. Not a good choice. Found protocol buffers slow. They wrote their own BSON implementation, which is 10-15 time faster than the one you can download. ...Contiues. Read the blog Watch the video

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Cocos2d: Moving background on update: offsett issue

- by mm24

working with Objective C, iOS and Cocos2d I am developing a vertical scrolling shooter game for iPhone (retina display models with 640 width x 960 height pixel resolution). My basic algorithm works as following: I create two instances of an image that has exactly 640 width x 960 height pixel of resolution, which we will call imageA and imageB I then set the two imags with exactly 480.0f of offset from each other, as the screenSize of a CCScene is set by default to 480.0f. At each update method call I move the two images by the same value. I make sure that their offsett stays to 480.0f However when running the game I see a 1 pixel height line between the two images. This literally bugs me and would like to adjust this. What am I doing wrong? This is a zoom in on the background when the "offsett line" is visible. The white line you can see divides the two background images and is not meant to exist as both images are completely black :): If I change the yPositionOfSecondElement value to 479.0f until the first loop the two images overlap correctly, but as soon as the loop starts the two images starts having an offsett of -1.0f. Here is the initialization code: -(void) init { //... screenHeight = 480.0f; yPositionOfSecondElement= screenHeight;//I tried subtracting an offsett of -1 but eventually the image would go wrong again yPositionOfFirstElement = 0.0f; loopedBackgroundImageInstanceA = [BackgroundLoopedImage loopImageForLevel:levelName]; loopedBackgroundImageInstanceA.anchorPoint = CGPointMake(0.5f, 0.0f); loopedBackgroundImageInstanceA.position = CGPointMake(160.0f, yPositionOfFirstElement); [node addChild:loopedBackgroundImageInstanceA z:zLevelBackground]; //loopedBackgroundImageInstanceA.color= ccRED; loopedBackgroundImageInstanceB = [BackgroundLoopedImage loopImageForLevel:levelName]; loopedBackgroundImageInstanceB.anchorPoint = CGPointMake(0.5f, 0.0f); loopedBackgroundImageInstanceB.position = CGPointMake(160.0f, yPositionOfSecondElement); [node addChild:loopedBackgroundImageInstanceB z:zLevelBackground]; //.... } And here is the move code called at each update: -(void) moveBackgroundSprites:(BackgroundLoopedImage*)imageA :(BackgroundLoopedImage*)imageB :(ccTime)delta { isEligibleToMove=false; //This is done to avoid rounding errors float yStep = delta * [GameController sharedGameController].currentBackgroundSpeed; NSString* formattedNumber = [NSString stringWithFormat:@"%.02f", yStep]; yStep = atof([formattedNumber UTF8String]); //First should adjust position of images [self adjustPosition:imageA :imageB]; //The can get the actual image position CGPoint posA = imageA.position; CGPoint posB = imageB.position; //Here could verify if the checksum is equal to the required difference (should be 479.0f) if (![self verifyCheckSum:posA :posB]) { CCLOG(@"does not comply A"); } //At this stage can compute the hypotetical new position CGPoint newPosA = CGPointMake(posA.x, posA.y - yStep); CGPoint newPosB = CGPointMake(posB.x, posB.y - yStep); // Reposition stripes when they're out of bounds if (newPosA.y <= -yPositionOfSecondElement) { newPosA.y = yPositionOfSecondElement; [imageA shuffle]; if (timeElapsed>=endTime && hasReachedEndLevel==FALSE) { hasReachedEndLevel=TRUE; shouldMoveImageEnd=TRUE; } } else if (newPosB.y <= -yPositionOfSecondElement) { newPosB.y = yPositionOfSecondElement; [imageB shuffle]; if (timeElapsed>=endTime && hasReachedEndLevel==FALSE) { hasReachedEndLevel=TRUE; shouldMoveImageEnd=TRUE; } } //Here should verify that the check sum is equal to 479.0f if (![self verifyCheckSum:posA :posB]) { CCLOG(@"does not comply B"); } imageA.position = newPosA; imageB.position = newPosB; //Here could verify that the check sum is equal to 479.0f if (![self verifyCheckSum:posA :posB]) { CCLOG(@"does not comply C"); } isEligibleToMove=true; } -(BOOL) verifyCheckSum:(CGPoint)posA :(CGPoint)posB { BOOL comply = false; float sum = 0.0f; if (posA.y > posB.y) { sum = posA.y - posB.y; } else if (posB.y > posA.y){ sum = posB.y - posA.y; } else{ return false; } if (sum!=yPositionOfSecondElement) { comply= false; } else{ comply=true; } return comply; } And here is what happens on the update: if(shouldMoveImageA && shouldMoveImageB) { if (isEligibleToMove) { [self moveBackgroundSprites:loopedBackgroundImageInstanceA :loopedBackgroundImageInstanceB :delta]; } Forget about shouldMoveImageA and shouldMoveImageB, this is just for when the background reaches the end of level, this works.

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What Counts For a DBA: Fitness

- by Louis Davidson

If you know me, you can probably guess that physical exercise is not really my thing. There was a time in my past when it a larger part of my life, but even then never in the same sort of passionate way as a number of our SQL friends. For me, I find that mental exercise satisfies what I believe to be the same inner need that drives people to run farther than I like to drive on most Saturday mornings, and it is certainly just as addictive. Mental fitness shares many common traits with physical fitness, especially the need to attain it through repetitive training. I only wish that mental training burned off a bacon cheeseburger in the same manner as does jogging around a dewy park on Saturday morning. In physical training, there are at least two goals, the first of which is to be physically able to do a task. The second is to train the brain to perform the task without thinking too hard about it. No matter how long it has been since you last rode a bike, you will be almost certainly be able to hop on and start riding without thinking about the process of pedaling or balancing. If you’ve never ridden a bike, you could be a physics professor /Olympic athlete and still crash the first few times you try, even though you are as strong as an ox and your knowledge of the physics of bicycle riding makes the concept child’s play. For programming tasks, the process is very similar. As a DBA, you will come to know intuitively how to backup, optimize, and secure database systems. As a data programmer, you will work to instinctively use the clauses of Transact-SQL DML so that, when you need to group data three ways (and not four), you will know to use the GROUP BY clause with GROUPING SETS without resorting to a search engine. You have the skill. Making it naturally then requires repetition and experience is the primary requirement, not just simply learning about a topic. The hardest part of being really good at something is this difference between knowledge and skill. I have recently taken several informative training classes with Kimball University on data warehousing and ETL. Now I have a lot more knowledge about designing data warehouses than before. I have also done a good bit of data warehouse designing of late and have started to improve to some level of proficiency with the theory. Yet, for all of this head knowledge, it is still a struggle to take what I have learned and apply it to the designs I am working on. Data warehousing is still a task that is not yet deeply ingrained in my brain muscle memory. On the other hand, relational database design is something that no matter how much or how little I may get to do it, I am comfortable doing it. I have done it as a profession now for well over a decade, I teach classes on it, and I also have done (and continue to do) a lot of mental training beyond the work day. Sometimes the training is just basic education, some reading blogs and attending sessions at PASS events. My best training comes from spending time working on other people’s design issues in forums (though not nearly as much as I would like to lately). Working through other people’s problems is a great way to exercise your brain on problems with which you’re not immediately familiar. The final bit of exercise I find useful for cultivating mental fitness for a data professional is also probably the nerdiest thing that I will ever suggest you do. Akin to running in place, the idea is to work through designs in your head. I have designed more than one database system that would revolutionize grocery store operations, sales at my local Target store, the ordering process at Amazon, and ways to improve Disney World operations to get me through a line faster (some of which they are starting to implement without any of my help.) Never are the designs truly fleshed out, but enough to work through structures and processes. On “paper”, I have designed database systems to catalog things as trivial as my Lego creations, rental car companies and my audio and video collections. Once I get the database designed mentally, sometimes I will create the database, add some data (often using Red-Gate’s Data Generator), and write a few queries to see if a concept was realistic, but I will rarely fully flesh out the database since I have no desire to do any user interface programming anymore. The mental training allows me to keep in practice for when the time comes to do the work I love the most for real…even if I have been spending most of my work time lately building data warehouses. If you are really strong of mind and body, perhaps you can mix a mental run with a physical run; though don’t run off of a cliff while contemplating how you might design a database to catalog the trees on a mountain…that would be contradictory to the purpose of both types of exercise.

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Profiling Startup Of VS2012 – YourKit Profiler

- by Alois Kraus

The YourKit (v7.0.5) profiler is interesting in terms of price (79€ single place license, 409€ + 1 year support and upgrades) and feature set. You do get a performance and memory profiler in one package for which you normally need also to pay extra from the other vendors. As an interesting side note the profiler UI is written in Java because they do also sell Java profilers with the same feature set. To get all methods of a VS startup you need first to configure it to include System* in the profiled methods and you need to configure * to measure wall clock time. By default it does record only CPU times which allows you to optimize CPU hungry operations. But you will never see a Thread.Sleep(10000) in the profiler blocking the UI in this mode. It can profile as all others processes started from within the profiler but it can also profile the next or all started processes. As usual it can profile in sampling and tracing mode. But since it is a memory profiler as well it does by default also record all object allocations > 1MB. With allocation recording enabled VS2012 did crash but without allocation recording there were no problems. The CPU tab contains the time line of the application and when you click in the graph you the call stacks of all threads at this time. This is really a nice feature. When you select a time region you the CPU Usage estimation for this time window. I have seen many applications consuming 100% CPU only because they did create garbage like crazy. For this is the Garbage Collection tab interesting in conjunction with a time range. This view is like the CPU table only that the CPU graph (green) is missing. All relevant information except for GCs/s is already visible in the CPU tab. Very handy to pinpoint excessive GC or CPU bound issues. The Threads tab does show the thread names and their lifetime. This is useful to see thread interactions or which thread is hottest in terms of CPU consumption. On the CPU tab the call tree does exist in a merged and thread specific view. When you click on a method you get below a list of all called methods. There you can sort for methods with a high own time which are worth optimizing. In the Method List you can select which scope you want to see. Back Traces are the methods which did call you. Callees ist the list of methods called directly or indirectly by your method as a flat list. This is not a call stack but still very useful to see which methods were slow so you can see the “root” cause quite quickly without the need to click trough long call stacks. The last view Merged Calles is a call stacked view of the previous view. This does help a lot to understand did call each method at run time. You would get the same view with a debugger for one call invocation but here you get the full statistics (invocation count) as well. Since YourKit is also a memory profiler you can directly see which objects you have on your managed heap and which objects do hold most of your precious memory. You can in in the Object Explorer view also examine the contents of your objects (strings or whatsoever) to get a better understanding which objects where potentially allocating this stuff. YourKit is a very easy to use combined memory and performance profiler in one product. The unbeatable single license price makes it very attractive to straightly buy it. Although it is a Java UI it is very responsive and the memory consumption is considerably lower compared to dotTrace and ANTS profiler. What I do really like is to start the YourKit ui and then start the processes I want to profile as usual. There is no need to alter your own application code to be able to inject a profiler into your new started processes. For performance and memory profiling you can simply select the process you want to investigate from the list of started processes. That's the way I like to use profilers. Just get out of the way and let the application run without any special preparations. Next: Telerik JustTrace

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Data Binding to Attached Properties

- by Chris Gardner

Originally posted on: http://geekswithblogs.net/freestylecoding/archive/2013/06/14/data-binding-to-attached-properties.aspx When I was working on my C#/XAML game framework, I discovered I wanted to try to data bind my sprites to background objects. That way, I could update my objects and the draw functionality would take care of the work for me. After a little experimenting and web searching, it appeared this concept was an impossible dream. Of course, when has that ever stopped me? In my typical way, I started to massively dive down the rabbit hole. I created a sprite on a canvas, and I bound it to a background object. <Canvas Name="GameField" Background="Black"> <Image Name="PlayerStrite" Source="Assets/Ship.png" Width="50" Height="50" Canvas.Left="{Binding X}" Canvas.Top="{Binding Y}"/> </Canvas> Now, we wire the UI item to the background item. public MainPage() { this.InitializeComponent(); this.Loaded += StartGame; } void StartGame( object sender, RoutedEventArgs e ) { BindingPlayer _Player = new BindingPlayer(); _Player.X = Window.Current.Bounds.Height - PlayerSprite.Height; _Player.X = ( Window.Current.Bounds.Width - PlayerSprite.Width ) / 2.0; } Of course, now we need to actually have our background object. public class BindingPlayer : INotifyPropertyChanged { private double m_X; public double X { get { return m_X; } set { m_X = value; NotifyPropertyChanged(); } } private double m_Y; public double Y { get { return m_Y; } set { m_Y = value; NotifyPropertyChanged(); } } public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } } I fired this baby up, and my sprite was correctly positioned on the screen. Maybe the sky wasn't falling after all. Wouldn't it be great if that was the case? I created some code to allow me to move the sprite, but nothing happened. This seems odd. So, I start debugging the application and stepping through code. Everything appears to be working. Time to dig a little deeper. After much profanity was spewed, I stumbled upon a breakthrough. The code only looked like it was working. What was really happening is that there was an exception being thrown in the background thread that I never saw. Apparently, the key call was the one to PropertyChanged. If PropertyChanged is not called on the UI thread, the UI thread ignores the call. Actually, it throws an exception and the background thread silently crashes. Of course, you'll never see this unless you're looking REALLY carefully. This seemed to be a simple problem. I just need to marshal this to the UI thread. Unfortunately, this object has no knowledge of this mythical UI Thread in which we speak. So, I had to pull the UI Thread out of thin air. Let's change our PropertyChanged call to look this. public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync( Windows.UI.Core.CoreDispatcherPriority.Normal, new Windows.UI.Core.DispatchedHandler( () => { PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } ) ); } Now, we raised our notification on the UI thread. Everything is fine, people are happy, and the world moves on. You may have noticed that I didn't await my call to the dispatcher. This was intentional. If I am trying to update a slew of sprites, I don't want thread being hung while I wait my turn. Thus, I send the message and move on. It is worth nothing that this is NOT the most efficient way to do this for game programming. We'll get to that in another blog post. However, it is perfectly acceptable for a business app that is running a background task that would like to notify the UI thread of progress on a periodic basis. It is worth noting that this code was written for a Windows Store App. You can do the same thing with WP8 and WPF. The call to the marshaler changes, but it is the same idea.

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How to break out of if statement

- by TheBroodian

I'm not sure if the title is exactly an accurate representation of what I'm actually trying to ask, but that was the best I could think of. I am experiencing an issue with my character class. I have developed a system so that he can perform chain attacks, and something that was important to me was that 1)button presses during the process of an attack wouldn't interrupt the character, and 2) at the same time, button presses should be stored so that the player can smoothly queue up chain attacks in the middle of one so that gameplay doesn't feel rigid or unresponsive. This all begins when the player presses the punch button. Upon pressing the punch button, the game checks the state of the dpad at the moment of the button press, and then translates the resulting combined buttons into an int which I use as an enumerator relating to a punch method for the character. The enumerator is placed into a List so that the next time the character's Update() method is called, it will execute the next punch in the list. It only executes the next punch if my character is flagged with acceptInput as true. All attacks flag acceptInput as false, to prevent the interruption of attacks, and then at the end of an attack, acceptInput is set back to true. While accepting input, all other actions are polled for, i.e. jumping, running, etc. In runtime, if I attack, and then queue up another attack behind it (by pressing forward+punch) I can see the second attack visibly execute, which should flag acceptInput as false, yet it gets interrupted and my character will stop punching and start running if I am still holding down the dpad. Included is some code for context. This is the input region for my character. //Placed this outside the if (acceptInput) tree because I want it //to be taken into account whether we are accepting input or not. //This will queue up attacks, which will only be executed if we are accepting input. //This creates a desired effect that helps control the character in a // smoother fashion for the player. if (Input.justPressed(buttonManager.Punch)) { int dpadPressed = Input.DpadState(0); if (attackBuffer.Count() < 1) { attackBuffer.Add(CheckPunch(dpadPressed)); } else { attackBuffer.Clear(); attackBuffer.Add(CheckPunch(dpadPressed)); } } if (acceptInput) { if (attackBuffer.Count() > 0) { ExecutePunch(attackBuffer[0]); attackBuffer.RemoveAt(0); } //If D-Pad left is being held down. if (Input.DpadDirectionHeld(0, buttonManager.Left)) { flipped = false; if (onGround) { newAnimation = "run"; } velocity = new Vector2(velocity.X - acceleration, velocity.Y); if (walking == true && velocity.X <= -walkSpeed) { velocity.X = -walkSpeed; } else if (walking == false && velocity.X <= -maxSpeed) { velocity.X = -maxSpeed; } } //If D-Pad right is being held down. if (Input.DpadDirectionHeld(0, buttonManager.Right)) { flipped = true; if (onGround) { newAnimation = "run"; } velocity = new Vector2(velocity.X + acceleration, velocity.Y); if (walking == true && velocity.X >= walkSpeed) { velocity.X = walkSpeed; } else if (walking == false && velocity.X >= maxSpeed) { velocity.X = maxSpeed; } } //If jump/accept button is pressed. if (Input.justPressed(buttonManager.JumpAccept)) { if (onGround) { Jump(); } } //If toggle element next button is pressed. if (Input.justPressed(buttonManager.ToggleElementNext)) { if (elements.Count != 0) { elementInUse++; if (elementInUse >= elements.Count) { elementInUse = 0; } } } //If toggle element last button is pressed. if (Input.justPressed(buttonManager.ToggleElementLast)) { if (elements.Count != 0) { elementInUse--; if (elementInUse < 0) { elementInUse = Convert.ToSByte(elements.Count() - 1); } } } //If character is in the process of jumping. if (jumping == true) { if (Input.heldDown(buttonManager.JumpAccept)) { velocity.Y -= fallSpeed.Y; maxJumpTime -= elapsed; } if (Input.justReleased(buttonManager.JumpAccept) || maxJumpTime <= 0) { jumping = false; maxJumpTime = 0; } } //Won't execute abilities if input isn't being accepted. foreach (PlayerAbility ability in playerAbilities) { if (buffer.Matches(ability)) { if (onGround) { ability.Activate(); } if (!onGround && ability.UsableInAir) { ability.Activate(); } else if (!onGround && !ability.UsableInAir) { buffer.Clear(); } } } } When the attackBuffer calls ExecutePunch(int) method, ExecutePunch() will call one of the following methods: private void NeutralPunch1() //0 { acceptInput = false; busy = true; newAnimation = "punch1"; numberOfAttacks++; timeSinceLastAttack = 0; } private void ForwardPunch2(bool toLeft) //true == 7, false == 4 { forwardPunch2Timer = 0f; acceptInput = false; busy = true; newAnimation = "punch2begin"; numberOfAttacks++; timeSinceLastAttack = 0; if (toLeft) { velocity.X -= 800; } if (!toLeft) { velocity.X += 800; } } I assume the attack is being interrupted due to the fact that ExecutePunch() is in the same if statement as running, but I haven't been able to find a suitable way to stop this happening. Thank you ahead of time for reading this, I apologize for it having become so long winded.

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