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• TDD: Write a separate test for object initialization or relying on other tests exercising it

  - by DXM

  This seems to be the common pattern that's emerging in some of the tests I've worked on lately. We have a class, and quite often this is legacy code whose design can't be easily altered, which has a bunch of member variables. There's some kind of "Initialize" or "Load" function which would put an object into a valid state. Only after it is initialized/loaded, are the members in the proper state so that other methods can be exercised. So when we start writing tests, first test is "TestLoad" and all we put in there is exercising initialization logic. Then we might add one (or few) TestLoadFailureXXX tests and those are definitely valuable. Then we start writing tests to verify other behaviors but all of them require the object to be loaded. So they all start by running exactly the same code as "TestLoad". So my question: Is TestLoad even necessary? Do you take it and let other tests simply exercise the loading? Or leave it so things are more explicit? I know that each unit test function should have no (or as little as possible) overlap with other test functions, but it seems like in cases of loading, this is unavoidable. And whether we like it or not, if something in the loading code breaks, we will end up with a whole test suite of failures. Is there another approach that I might be missing here? Thank you for the responses. It definitely makes sense that you want to see "InitializationTest" and if that fails you know where to start looking. In case it matters, this question is mostly about C++ and we use CppUnit framework. And now, thanks to sleske, I'll be constantly wishing that CppUnit supported test dependencies. Might have to hack something in one of these days :)

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• Collision planes confusion

  - by Jeffrey

  I'm following this tutorial by thecplusplusguy and in the linked video he explain that for example for the world basement and walls we need to create the actual rendered (shown to the player) walls and then duplicate them, place them in the same coordinates as the rendered walls and call them collision (by defining their material to collision). Then it defines in the Object loader function that those objects with material == collision are collision planes and should not be rendered but just used to check collision. Now I'm pretty confused. Why would we add this kind of complexity to a problem that can easily be solved by a simple loadObject(string plane_object, bool check_collision);: Creating only the walls object (by loading .obj file in plane_object) Define them also as collision planes whenever the check_collision is set to true In this case we have lowered the complexity of his method and make it more flexible and faster to develop (faster because we don't always have to make a copy for each plane and flexible because we don't hardcode the Object loader). The only case in which this method could not work is when we need hidden collision planes, and for that we could modify the loadObject() function like this: loadObject(string plane_object, bool check_collision = true, bool hide_object = false); Creating only the walls object (by loading .obj file in plane_object) Define them also as collision planes whenever the check_collision is set to true And add the ability to actually show the object or hide it based on hide_object. The final question is: am I right? What would the possible problem encountered with my solution versus his?

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• Antenna Aligner part 2: Finding the right direction

  - by Chris George

  Last time I managed to get "my first app(tm)" built, published and running on my iPhone. This was really cool, a piece of my code running on my very own device. Ok, so I'm easily pleased! The next challenge was actually trying to determine what it was I wanted this app to do, and how to do it. Reverting back to good old paper and pen, I started sketching out designs for the app. I knew I wanted it to get a list of transmitters, then clicking on a transmitter would display a compass type view, with an arrow pointing the right way. I figured there would not be much point in continuing until I know I could do the graphical part of the project, i.e. the rotating compass, so armed with that reasoning (plus the fact I just wanted to get on and code!), I once again dived into visual studio. Using my friend (google) I found some example code for getting the compass data from the phone using the PhoneGap framework. // onSuccess: Get the current heading // function onSuccess(heading) {    alert('Heading: ' + heading); } navigator.compass.getCurrentHeading(onSuccess, onError); Using the ripple mobile emulator this showed that it was successfully getting the compass heading. But it didn't work when uploaded to my phone. It turns out that the examples I had been looking at were for PhoneGap 1.0, and Nomad uses PhoneGap 1.4.1. In 1.4.1, getCurrentHeading provides a compass object to onSuccess, not just a numeric value, so the code now looks like // onSuccess: Get the current magnetic heading // function onSuccess(heading) {    alert('Heading: ' + heading.magneticHeading); }; navigator.compass.getCurrentHeading(onSuccess, onError); So the lesson learnt from this... read the documentation for the version you are actually using! This does, however, lead to compatibility problems with ripple as it only supports 1.0 which is a real pain. I hope that the ripple system is updated sometime soon.

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• What technical test should I give to a job candidate

  - by Romain Braun

  I'm not sure if this is the right stackexhange website, but : I have three candidates coming in tomorrow. One has 15 years of experience in PHP, and the two others have about 1 year of experience in PHP/ frontend development. For the last ones I was thinking about a test where they would have to develop a web app allowing users to manage other users, as in : Display a list of users, display a single user, modify an user, and add extended properties to an user. This way it would feature html, css, js, ajax, php and SQL. Do you think this would be a good test? What test should I give to the first one? He needs something much more difficult, I guess. I'm also listening, if you have any advice/ideas about what makes a good developer, and what I should pay attention to in the guys' codes. I was also considering thinking outside of the box, more algorithm-related, and asked him to make the fastest function to tell if a number is a prime number, because there are a lot of optimizations you can apply to such a function. They have one day to do it.

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• How bad is it to have two methods with the same name but different signatures in two classes?

  - by Super User

  I have a design problem related to a public interface, the names of methods, and the understanding of my API and code. I have two classes like this: class A: ... function collision(self): .... ... class B: .... function _collision(self, another_object, l, r, t, b): .... The first class has one public method named collision, and the second has one private method called _collision. The two methods differs in argument type and number. As an example let's say that _collision checks if the object is colliding with another object with certain conditions l, r, t, b (collide on the left side, right side, etc) and returns true or false. The public collision method, on the other hand, resolves all the collisions of the object with other objects. The two methods have the same name because I think it's better to avoid overloading the design with different names for methods that do almost the same thing, but in distinct contexts and classes. Is this clear enough to the reader or I should change the method's name?

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• Remove enemy when bullet hits enemy

  - by jordi12100

  For my education I have to make a basic game in HTML5 canvas. The game is a shooter game. When you can move left - right and space is shoot. When I shoot the bullets will move up. The enemy moves down. When the bullet hits the enemy the enemy has to dissapear and it will gain +1 score. But the enemy will dissapear after it comes up the screen. Demo: http://jordikroon.nl/test.html space = shoot + enemy shows up This is my code: for (i=0;i<enemyX.length;i++) { if(enemyX[i] > canvas.height) { enemyY.splice(i,1); enemyX.splice(i,1); } else { enemyY[i] += 5; moveEnemy(enemyX[i],enemyY[i]); } } for (i=0;i<bulletX.length;i++) { if(bulletY[i] < 0) { bulletY.splice(i,1); bulletX.splice(i,1); } else { bulletY[i] -= 5; moveBullet(bulletX[i],bulletY[i]); for (ib=0;ib<enemyX.length;ib++) { if(bulletX[i] + 50 < enemyX[ib] || enemyX[ib] + 50 < bulletX[i] || bulletY[i] + 50 < enemyY[ib] || enemyY[ib] + 50 < bulletY[i]) { ++score; enemyY.splice(i,1); enemyX.splice(i,1); } } } } Objects: function moveBullet(posX,posY) { //console.log(posY); ctx.arc(posX, (posY-150), 10, 0 , 2 * Math.PI, false); } function moveEnemy(posX,posY) { ctx.rect(posX, posY, 50, 50); ctx.fillStyle = '#ffffff'; ctx.fill(); }

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• Investigating Strategies For Functional Decomposition

  - by Liam McLennan

  Introducing Functional Decomposition Before I begin I must apologise. I think I am using the term ‘functional decomposition’ loosely, and probably incorrectly. For the purpose of this article I use functional decomposition to mean the recursive splitting of a large problem into increasingly smaller ones, so that the one large problem may be solved by solving a set of smaller problems. The justification for functional decomposition is that the decomposed problem is more easily solved. As software developers we recognise that the smaller pieces are more easily tested, since they do less and are more cohesive. Functional decomposition is important to all scientific pursuits. Once we understand natural selection we can start to look for humanities ancestral species, once we understand the big bang we can trace our expanding universe back to its origin. Isaac Newton acknowledged the compositional nature of his scientific achievements: If I have seen further than others, it is by standing upon the shoulders of giants   The Two Strategies For Functional Decomposition of Computer Programs Private Methods When I was working on my undergraduate degree I was taught to functionally decompose problems by using private methods. Consider the problem of painting a house. The obvious solution is to solve the problem as a single unit: public void PaintAHouse() { // all the things required to paint a house ... } We decompose the problem by breaking it into parts: public void PaintAHouse() { PaintUndercoat(); PaintTopcoat(); } private void PaintUndercoat() { // everything required to paint the undercoat } private void PaintTopcoat() { // everything required to paint the topcoat } The problem can be recursively decomposed until a sufficiently granular level of detail is reached: public void PaintAHouse() { PaintUndercoat(); PaintTopcoat(); } private void PaintUndercoat() { prepareSurface(); fetchUndercoat(); paintUndercoat(); } private void PaintTopcoat() { fetchPaint(); paintTopcoat(); } According to Wikipedia, at least one computer programmer has referred to this process as “the art of subroutining”. The practical issues that I have encountered when using private methods for decomposition are: To preserve the top level API all of the steps must be private. This means that they can’t easily be tested. The private methods often have little cohesion except that they form part of the same solution. Decomposing to Classes The alternative is to decompose large problems into multiple classes, effectively using a class instead of each private method. The API delegates to related classes, so the API is not polluted by the sub-steps of the problem, and the steps can be easily tested because they are each in their own highly cohesive class. Additionally, I think that this technique facilitates better adherence to the Single Responsibility Principle, since each class can be decomposed until it has precisely one responsibility. Revisiting my previous example using class composition: public class HousePainter { private undercoatPainter = new UndercoatPainter(); private topcoatPainter = new TopcoatPainter(); public void PaintAHouse() { undercoatPainter.Paint(); topcoatPainter.Paint(); } } Summary When decomposing a problem there is more than one way to represent the sub-problems. Using private methods keeps the logic in one place and prevents a proliferation of classes (thereby following the four rules of simple design) but the class decomposition is more easily testable and more compatible with the Single Responsibility Principle.

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• Parsing mathematical experssions with two values that have parenthesis and minus signs

  - by user45921

  I'm trying to parse equations like these which only has two values or the square root of a certain value from a text file: 100+100 -100-100 -(100)+(-100) sqrt(100) by the minues signs, parenthesis and the operator symbol in the middle and the square root, and I have no idea how to start off... I've got the file part done and the simple calculation parts except that I couldnt get my program to solve the equations in the above. #include <stdio.h> #include <string.h> #include <stdlib.h> #include <math.h> main(){ FILE *fp; char buff[255], sym,sym2,del1,del2,del3,del4; double num1, num2; int ret; fp = fopen("input.txt","r"); while(fgets(buff,sizeof(buff),fp)!=NULL){ char *tok = buff; sscanf(tok,"%lf%c%lf",&num1,&sym,&num2); switch(sym){ case '+': printf("%lf\n", num1+num2); break; case '-': printf("%lf\n", num1-num2); break; case '*': printf("%lf\n", num1*num2); break; case '/': printf("%lf\n", num1/num2); break; default: printf("The input value is not correct\n"); break; } } fclose(fp); } that is what have I written for the other basic operations without parenthesis and the minus sign for the second value and it works great for the simple ones. I'm using a switch method to calculate the add, sub, mul and divide but I'm not sure how to properly use the sscanf function (if I am not using it properly) or if there is another way using a function like strtok to properly parse the parenthesis and the minus signs. Any kind help?

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• JRuby and JVM Languages at JavaOne!

  - by Yolande Poirier

  "My goal with my talks at JavaOne is to teach what is happening at the JVM level and below so people understand better where we are going" explains Charles Nutter, Jruby project lead. In this interview, Charles shared the JRuby features he presented at the JVM Language Summit. They include foreign function interface (FFI), IO layer, character transcoding, regular expressions, compilers, coroutines, and more.  At JavaOne, he will be presenting:  Going Native: Bringing FFI to the JVM The Java Native Runtime (JNR) is a high-speed foreign function interface (FFI) for calling native code from Java without ever writing a line of C. Based on the success of JNR, JDK Enhancement Proposal (JEP) 191 will bring FFI to OpenJDK as an internal API.  The Emerging Languages Bowl: The Big League Challenge In this panel discussion, these emerging languages are portrayed by their respective champions, who explain how they may help your everyday life as a Java developer. Script Bowl 2014: The Battle Rages On In this contest, languages that run on the JVM, represented by their respective language experts, battle for most popular language status by showing off their new features. Audience members will also vote on a language that should not return in 2015. Returning from 2013 are language gurus representing Clojure, Groovy, JRuby, and Scala.

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• How bad it's have two methods with the same name but differents signatures in two classes?

  - by Super User

  I have a design problem relationated with the public interface, the names of methods and the understanding of my API and my code. I have two classes like this: class A: ... function collision(self): .... ... class B: .... function _collision(self, another_object, l, r, t, b): .... The first class have one public method named collision and the second have one private method called _collision. The two methods differs in arguments type and number. In the API _m method is private. For the example let's say that the _collision method checks if the object is colliding with another_ object with certain conditions l, r, t, b (for example, collide the left side, the right side, etc) and returns true or false according to the case. The collision method, on the other hand, resolves all the collisions of the object with other objects. The two methods have the same name because I think is better avoid overload the design with different names for methods who do almost the same think, but in distinct contexts and classes. This is clear enough to the reader or I should change the method's name?

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• Facebook Like javascript related to Time Spent Downloading a page Increase in GWT?

  - by donaldthe

  Hi, I installed the Facebook Like button Javascript version on my website on December 15th. Take a look at this report from Google Webmaster Central. Crawl stats Googlebot activity in the last 90 days The crawl stats are from Googlebot which as far as I know doesn't execute Javascript. Could the Facebook Like Javascript code, "The XFBML version" be related to large spike in Time spent downloading a page? (By the way the huge spike in November was caused by a mistake where every image request was getting a 301.) I'm not sure what caused the spike to go down by half somewhere in December. It may have been related to a faulty setting in web.config. I'm at a loss as to what I can do about this or even how to tell if this is my problem or Googlebots crawl problem. Here is the Facebook code I am using to create the like button. It is right after the opening body tag <div id="fb-root"></div> <script> window.fbAsyncInit = function() { FB.init({appId: 'xxxxx', status: true, cookie: true, xfbml: true}); }; (function() { var e = document.createElement('script'); e.async = true; e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js'; document.getElementById('fb-root').appendChild(e); }()); ` and this creates the like box: <fb:like show_faces="false"></fb:like> If the Javascript can't be the problem any ideas on where to start looking would be appreciated.

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• Simple Interactive Search with jQuery and ASP.Net MVC

  - by Doug Lampe

  Google now has a feature where the search updates as you type in the search box.  You can implement the same feature in your MVC site with a little jQuery and MVC Ajax.  Here's how: Create a javascript global variable to hold the previous value of your search box. Use setTimeout to check to see if the search box has changed after some interval.  (Note: Don't use setInterval since we don't want to have to turn the timer off while Ajax is processing.) Submit the form if the value is changed. Set the update target to display your results. Set the on success callback to "start" the timer again.  This, along with step 2 above will make sure that you don't sent multipe requests until the initial request has finished processing. Here is the code: <script type="text/javascript"> var searchValue = $('#Search').val(); $(function () {     setTimeout(checkSearchChanged, 0.1); }); function checkSearchChanged() {     var currentValue = $('#Search').val();     if ((currentValue) && currentValue != searchValue && currentValue != '') {         searchValue = $('#Search').val();         $('#submit').click();     }     else {         setTimeout(checkSearchChanged, 0.1);     } } </script> <h2>Search</h2> <% using (Ajax.BeginForm("SearchResults", new AjaxOptions { UpdateTargetId = "searchResults", OnSuccess = "checkSearchChanged" })) { %>     Search: <%   = Html.TextBox("Search", null, new { @class = "wide" })%><input id="submit" type="submit" value="Search" /> <% } %> <div id="searchResults"></div> That's it!

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• Languages with a clear distinction between subroutines that are purely functional, mutating, state-changing, etc?

  - by CPX

  Lately I've become more and more frustrated that in most modern programming languages I've worked with (C/C++, C#, F#, Ruby, Python, JS and more) there is very little, if any, language support for determining what a subroutine will actually do. Consider the following simple pseudo-code: var x = DoSomethingWith(y); How do I determine what the call to DoSomethingWith(y) will actually do? Will it mutate y, or will it return a copy of y? Does it depend on global or local state, or is it only dependent on y? Will it change the global or local state? How does closure affect the outcome of the call? In all languages I've encountered, almost none of these questions can be answered by merely looking at the signature of the subroutine, and there is almost never any compile-time or run-time support either. Usually, the only way is to put your trust in the author of the API, and hope that the documentation and/or naming conventions reveal what the subroutine will actually do. My question is this: Does there exist any languages today that make symbolic distinctions between these types of scenarios, and places compile-time constraints on what code you can actually write? (There is of course some support for this in most modern languages, such as different levels of scope and closure, the separation between static and instance code, lambda functions, et cetera. But too often these seem to come into conflict with each other. For instance, a lambda function will usually either be purely functional, and simply return a value based on input parameters, or mutate the input parameters in some way. But it is usually possible to access static variables from a lambda function, which in turn can give you access to instance variables, and then it all breaks apart.)

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• When writing tests for a Wordpress plugin, should i run them inside wordpress or in a normal browser?

  - by Nicola Peluchetti

  I have started using BDD for a wordpress plugin i'm working on and i'm rewriting the js codebase to do tests. I've encountered a few problems but i'm going steady now, i was wondering if i had the right approach, because i'm writing test that should pass in a normal browser environment and not inside wordpress. I choose to do this because i want my plugin to be totally indipendent from the wordpress environment, i'm using requirejs in a way that i don't expose any globals and i'm loading my version of jQuery that doesn't override the one that ships with Wordpress. In this way my plugin would work the same on every wordpress version and my code would not break if they cheange the jQuery version or someone use my plugin on an old wordpress version. I wonder if this is the right approach or if i should always test inside the environment i'm working in. Since wordpress implies some globals i had to write some function purely for testing purpose, like "get_ajax_url": function() { if( typeof window.ajaxurl === "undefined" ) { return "http://localhost/wordpress/wp-admin/admin-ajax.php"; } else { return window.ajaxurl; } }, but apart from that i got everything working right. What do you think?

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• When module calling gets ugly

  - by Pete

  Has this ever happened to you? You've got a suite of well designed, single-responsibility modules, covered by unit tests. In any higher-level function you code, you are (95% of the code) simply taking output from one module and passing it as input to the next. Then, you notice this higher-level function has turned into a 100+ line script with multiple responsibilities. Here is the problem. It is difficult (impossible) to test that script. At least, it seems so. Do you agree? In my current project, all of the bugs came from this script. Further detail: each script represents a unique solution, or algorithm, formed by using different modules in different ways. Question: how can you remedy this situation? Knee-jerk answer: break the script up into single-responsibility modules. Comment on knee-jerk answer: it already is! Best answer I can come up with so far: create higher-level connector objects which "wire" modules together in particular ways (take output from one module, feed it as input to another module). Thus if our script was: FooInput fooIn = new FooInput(1, 2); FooOutput fooOutput = fooModule(fooIn); Double runtimevalue = getsomething(fooOutput.whatever); BarInput barIn = new BarInput( runtimevalue, fooOutput.someOtherValue); BarOutput barOut = barModule(BarIn); It would become with a connector: FooBarConnectionAlgo fooBarConnector = new fooBarConnector(fooModule, barModule); FooInput fooIn = new FooInput(1, 2); BarOutput barOut = fooBarConnector(fooIn); So the advantage is, besides hiding some code and making things clearer, we can test FooBarConnectionAlgo. I'm sure this situation comes up a lot. What do you do?

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• How to handle key in PhP array if the key contains japanese characters [migrated]

  - by Jim Thio

  I have this array: [ID] => ????????-???????????__35.79_139.72 [Email] => [InBuildingAddress] => [Price] => [Street] => [Title] => ???????? ??????????? [Website] => [Zip] => [Rating Star] => 0 [Rating Weight] => 0 [Latitude] => 35.7865334803033 [Longitude] => 139.716800710514 [Building] => [City] => Unknown_Japan [OpeningHour] => [TimeStamp] => 0000-00-00 00:00:00 [CountViews] => 0 Then I do something like this: $output[$info['ID']]=$info; //mess up here $tes=$info['ID']['Title']; Well guess what it messes up. Basically even though the content of an array in PhP can be Japanese. Is this true? What's wrong. The error I got is: Debug Warning: /sdfdsfdf/api/test2.php line 36 - Cannot find element ????????-???????????__35.79_139.72 in variable Debug Warning: /sdfdsfdf/api/test2.php line 36 - main() [function.main]: It is not safe to rely on the system's timezone settings. You are required to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Asia/Krasnoyarsk' for '7.0/no DST' instead So many question mark Why is this happening. What's really going on inside PhP? Where can I learn more of such things. Most importantly, what would be the best way to handle this situation. Should I tell PhP to internally always use UTF-8? Does PhP array inherenty cannot use non ascii id?

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• Google analytics set up with wrong domain

  - by Tom

  I have recently embedded Google Analytics into a site using the default embed code. <script> (function (i, s, o, g, r, a, m) { i['GoogleAnalyticsObject'] = r; i[r] = i[r] || function () { (i[r].q = i[r].q || []).push(arguments) }, i[r].l = 1 * new Date(); a = s.createElement(o), m = s.getElementsByTagName(o)[0]; a.async = 1; a.src = g; m.parentNode.insertBefore(a, m) })(window, document, 'script', '//www.google-analytics.com/analytics.js', 'ga'); ga('create', 'UA-XXXXXXXX-1', 'MYDOMAIN.COM'); ga('send', 'pageview'); </script> However I had MYDOMAIN.COM set to an incorrect domain. The views for the site seem very low, however, I can see myself there as a visitor in the real time scanner. What effect would setting the domain incorrectly have had? How does Google use this parameter?

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• Can Mailchimp APIs be used to send templated transaction email triggered by actions on my website?

  - by HenryW

  I am currently playing around with Mailchimp's APIs, but the documentation to me is not very clear. Here is what I actually want: Have the templates I created on Mailchimp, be visible on my own server. Assign each template I made to a specific action (logged in,subscribed, created order, or new password). This is functionality that I already tested with Mandrill, but the template exists on mandrill's account. If option 1 is not possible, can I still make my own template in my own environment, and send that template out over Mailchimp or Mandrill? Should I use Mailchimps services for this or send the email directly from my own server? Curent used function: function tep_mandrill_mail($to_name, $to_email_address, $email_subject, $email_text, $from_email_name, $from_email_address) { if (SEND_EMAILS != 'true') return false; $uri = 'https://mandrillapp.com/api/1.0/messages/send-template.json'; $postString = '{ "key": "xxxxxxxxxxx", "template_name": "sometemplatename", "template_content": [ { "name": "header", "content": "*|HEADERSTUFF|*" }, { "name": "main", "content": "*|CONTENTSTUFF|*" }, { "name": "footer", "content": "*|FOOTERSTUFF|*" } ], "message": { "subject": "'.$email_subject.'", "from_email": "'.$from_email_adress.'", "from_name": "'.$from_email_name.'", "to": [ { "email": "'.$to_email_address.'", "name": "'.$to_name.'" } ], "important": false, "track_opens": true, "merge": true, "merge_vars": [ { "rcpt": "'.$to_email_address.'", "vars": [ { "name": "HEADERSTUFF", "content": "'.$email_subject.'" }, { "name": "CONTENTSTUFF", "content": "'.$email_text.'" }, { "name": "FOOTERSTUFF", "content": "paulvale-foot" } ] } ], "tags": [ "password_forgotten" ] }, "async": false, "ip_pool": "Main Pool" }'; $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $uri); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true ); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true ); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_POSTFIELDS, $postString); curl_exec($ch); }

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• Handling Types for Real and Complex Matrices in a BLAS Wrapper

  - by mga

  I come from a C background and I'm now learning OOP with C++. As an exercise (so please don't just say "this already exists"), I want to implement a wrapper for BLAS that will let the user write matrix algebra in an intuitive way (e.g. similar to MATLAB) e.g.: A = B*C*D.Inverse() + E.Transpose(); My problem is how to go about dealing with real (R) and complex (C) matrices, because of C++'s "curse" of letting you do the same thing in N different ways. I do have a clear idea of what it should look like to the user: s/he should be able to define the two separately, but operations would return a type depending on the types of the operands (R*R = R, C*C = C, R*C = C*R = C). Additionally R can be cast into C and vice versa (just by setting the imaginary parts to 0). I have considered the following options: As a real number is a special case of a complex number, inherit CMatrix from RMatrix. I quickly dismissed this as the two would have to return different types for the same getter function. Inherit RMatrix and CMatrix from Matrix. However, I can't really think of any common code that would go into Matrix (because of the different return types). Templates. Declare Matrix<T> and declare the getter function as T Get(int i, int j), and operator functions as Matrix *(Matrix RHS). Then specialize Matrix<double> and Matrix<complex>, and overload the functions. Then I couldn't really see what I would gain with templates, so why not just define RMatrix and CMatrix separately from each other, and then overload functions as necessary? Although this last option makes sense to me, there's an annoying voice inside my head saying this is not elegant, because the two are clearly related. Perhaps I'm missing an appropriate design pattern? So I guess what I'm looking for is either absolution for doing this, or advice on how to do better.

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• Moving characters on a grid [on hold]

  - by madmax1

  i am developing my first game with C++. My game uses a grid of rectangles. I have a class Board which manages the grid as a whole, initializes the terrain, places/removes characters, etc. It has a 2D vector of a class Field, which handles the Structure of the field, contained Objects, Characters, etc. Field again contains a vector of class Character, which are positioned on the field. Now i want to implement the functionality to move a character on the board, however dont know which is best practice to do so. Should i implement a moveCharacter(character, offset) function in Board, make it search for the character and move it? Or should i implement a function move(offset) in Character? This sure would be nicest, however makes characters necessary to know the board they are on, or the field which in turn knows the board. On the one hand i feel like i should avoid inclusion between classes as much as possible e.g. to increase portability of classes for different projects, on the other hand i think the character.move() functionality is most comfortable for further development. Im pretty new to "bigger" C++ projects and these kind of design questions pop up more and more often lately and i have troubles deciding. Thanks a lot for any advice!

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• GLES2.0 3D Android game performance and multi threading the update?

  - by Ofer

  I have profiled my mixed Java\C++ Android game and I got the following result: https://dl.dropbox.com/u/8025882/PompiDev/AndroidProfile.png As you can see, the pink think is a C++ functions that updates the game. It does things like updating the logic but it mostly it generates a "request list" for rendering. The thing is, I generate DrawLists on C++ and then send them to Java to process and draw using GLES2.0. Since then I was able to improve update from 9ms down to about 7ms, but I would like to ask if I would benefit from multi threading the update? As I understand from that diagram is that the function that takes the most time is the one you see it's color on the timeline. So the pink area is taken mostly by update. The other area has MainOpenGL.Handle as it's main contributor(whch is my java function), but since it's not drawn to the top of the diagram I can conclude other things are happening at the same time that use the CPU? Or even GPU stuff that isn't shown in this diagram. I am not sure how the GPU works on this. Does it calculate stuff in parallel to the CPU? Or is it part of the CPU usage as in SoC? I am not sure. Anyway, in case GPU things DO happen in parallel to CPU, then I would guess that if I do this C++ Update in parallel to the thread that makes the OpenGL calls, I might make use of "dead CPU time" due to GPU stalling or maybe have the GPU calls getting processed earlier because it won't have to wait for Update to finish? How do you suggest to improve performance based on that? Thanks.

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• How to properly multi thread an RPG

  - by Nagrom_17

  I am working on an RPG type game in Java and I would like to know a few things relating to threading, What is the best way to implement a "wait for this then do this" without hanging the whole thread? Like waiting for a player to move to a location then pick up an item? or to wait one second then attack? Currently I am spawning new threads every time I need to wait for something, but that doesn't feel like the best solution. Any help is appreciated. EDIT: Clarification and an example of how I currently do things. User clicks on an item The function walkToAndPickUp(item) is called which is basically this: Make a new thread so we don't freeze the thread handling input while the player moves. Tell player to move to the item While the player is not at the item(The player moves through an update() function called in a different thread, I don't know how else to do it without freezing threads) Repeat until the player is at the item If the player is at the item then call delete item from map and add to inventory.

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• Unable to debug an encodded javascript?

  - by miles away

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

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• How do I draw a dotted or dashed line?

  - by Gagege

  I'm trying to draw a dashed or dotted line by placing individual segments(dashes) along a path and then separating them. The only algorithm I could come up with for this gave me a dash length that was variable based on the angle of the line. Like this: private function createDashedLine(fromX:Float, fromY:Float, toX:Float, toY:Float):Sprite { var line = new Sprite(); var currentX = fromX; var currentY = fromY; var addX = (toX - fromX) * 0.0075; var addY = (toY - fromY) * 0.0075; line.graphics.lineStyle(1, 0xFFFFFF); var count = 0; // while line is not complete while (!lineAtDestination(fromX, fromY, toX, toY, currentX, currentY)) { /// move line draw cursor to beginning of next dash line.graphics.moveTo(currentX, currentY); // if dash is even if (count % 2 == 0) { // draw the dash line.graphics.lineTo(currentX + addX, currentY + addY); } // add next dash's length to current cursor position currentX += addX; currentY += addY; count++; } return line; } This just happens to be written in Haxe, but the solution should be language neutral. What I would like is for the dash length to be the same no matter what angle the line is. As is, it's just adding 75 thousandths of the line length to the x and y, so if the line is and a 45 degree angle you get pretty much a solid line. If the line is at something shallow like 85 degrees then you get a nice looking dashed line. So, the dash length is variable, and I don't want that. How would I make a function that I can pass a "dash length" into and get that length of dash, no matter what the angle is? If you need to completely disregard my code, be my guest. I'm sure there's a better solution.

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• correct way to implement auth/acl in mvc

  - by WiseStrawberry

  I am looking into making a correctly laid out MVC auth/acl system. I think I want the authentication of a user (and the session handling) to be seperate from the ACL system. (I don't know why but this seems a good idea from the things I've read) What does mvc have to do with this question you ask? Because I wish for the application to be well integrated with my acl. An example of a controller (CodeIgniter) <?php class forums extends MX_Controller { $allowed = array('users', 'admin'); $need_login = true; function __construct() { //example of checking if logged in. if($this->auth->logged_in() && $this->auth->is_admin()) { echo "you're logged in!"; } } public function add_topic() { if($this->auth->allowed('add_topic') { //some add topic things. } else { echo 'not allowed to add topic'; } } } ?> My thoughts $this->auth would be autoloaded in the system. I would like to check the $allowed array against the user currently (not) logged in and react accordingly. Is this a good way of doing things? I haven't seen much literature on mvc integration and auth. I want to make things as easy as possible.

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