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  • Reference - What does this error mean in PHP?

    - by hakre
    On Stackoverflow you can see a lot of questions popping up about errors. Some users do not even know that error messages exists, others are asking about code that gives an error message but they do not understand the error message. If the error message is common, many questions about the same kind of error appears, but it is hard to find existing Q&A about the topic. Please add "your favorite" error message, one per answer, a short description what it means (even if it is only highlighting terms to their manual page) and a listing of existing Q&A that are of value. This will create a list. The question is a community wiki, so you are not answering for reputation but for creating a reference list for new users. It's based on error messages. Compare with the existing Reference - What does this symbol mean in PHP? question, which works pretty well. What are common errors in PHP and what are their Solutions. Index of Errors Just starting, but there are already some: Warning: Cannot modify header information - headers already sent Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in ... on line Parse error: syntax error, unexpected T_XXX in YYY on line ZZZ Fatal Error: Call to a member function ... on a non-object

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  • Trouble deciding return type of a method that returns a SortedSet

    - by devoured elysium
    I am supposed to make a class that should be a container for an interval of values (like in mathematics). I have already decided that I'll use internally a SortedSet. One of the the things I'm supposed to implement is a method that "gets an ordered set with all the elements in the interval". class Interval { private SortedSet sortedSet = new something(); ... <<method that should return an ordered set of values>> } My question resides in what should be both the method's return type and name. Several hypothesis arise: SortedSet getSortedElements(); I am internally using a SortedSet, so I should return that type. I should state that intent in the method's name. SortedSet getElements(); I am internally using a SortedSet, but there's no point in stating that in the method name(I don't see a big point in this one). Set getElements(); I should try to always return the most basic type, thus I am returning a Set. By the contract and definition of the method, people already know all the elements are in order. Set getSortedElements(); For the method return type, the same as above. About the method name, you are stating clearly what this method is going to return: a set of elements that are sorted. I'm inclined to use 4. , but the others also seem alright. Is there a clear winner? Why?

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  • What does "Select Distinct Null As xxxxx" mean?

    - by Soylent Green
    Background: I am mapping Sybase stored procedure return values to java objects using Spring. For example I map a Sybase datatype of varchar as a String type in Java, and a Sybase datatype of int as an int type in Java, etc. I have come across the following code in one of the stored procedures: SELECT DISTINCT A.Col1 AS val1, A.Col2 AS val2, NULL AS someVal, A.col3 AS val3, ... A.col9 AS val9 FROM #SomeTable A ORDER BY Col2, Col3 I have 2 related questions: What does Null mean in this scenario? I am confused as to what is happening here. I am able to determine the data type of Col1, Col2, etc. of course by looking at the table definition of Table A defined earlier in the stored procedure. Thus I know what datatype I can define in my Java object for val1, val2, etc.. But what about "someVal"? What datatype mapping am I supposed to perform for this Null value? I am fairly inexperienced in SQL. Perhaps the answer is much simpler than I realize.

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  • Twitter gem - undefined method `stringify_keys’

    - by Piet
    Have you been getting the following errors when running the Twitter gem lately ? /usr/local/lib/ruby/gems/1.8/gems/httparty-0.4.3/lib/httparty/response.rb:15:in `send': undefined method `stringify_keys' for # (NoMethodError) from /usr/local/lib/ruby/gems/1.8/gems/httparty-0.4.3/lib/httparty/response.rb:15:in `method_missing’ from /usr/local/lib/ruby/gems/1.8/gems/mash-0.0.3/lib/mash.rb:131:in `deep_update’ from /usr/local/lib/ruby/gems/1.8/gems/mash-0.0.3/lib/mash.rb:50:in `initialize’ from /usr/local/lib/ruby/gems/1.8/gems/twitter-0.6.13/lib/twitter/search.rb:101:in `new’ from /usr/local/lib/ruby/gems/1.8/gems/twitter-0.6.13/lib/twitter/search.rb:101:in `fetch’ from test.rb:26 It’s because Twitter has been sending back plain text errors that are treated as a string instead of json and can’t be properly ‘Mashed’ by the Twitter gem. Also check http://github.com/jnunemaker/twitter/issues#issue/6. Without diving into the bowels of the Twitter gem or HTTParty, you could ‘begin…rescue’ this error and try again in 5 minutes. I fixed it by overriding the offending code to return nil and checking for a nil response as follows: module Twitter class Search def fetch(force=false) if @fetch.nil? || force query = @query.dup query[:q] = query[:q].join(' ') query[:format] = 'json' #This line is the hack and whole reason we're monkey-patching at all. response = self.class.get('http://search.twitter.com/search', :query => query, :format => :json) #Our patch: response should be a Hash. If it isnt, return nil. return nil if response.class != Hash @fetch = Mash.new(response) end @fetch end end end (adapted from http://github.com/jnunemaker/twitter/issues#issue/9) If you have a better solution: speak up!

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  • Modular programming is the method of programming small task or programs

    Modular programming is the method of programming small task or sub-programs that can be arranged in multiple variations to perform desired results. This methodology is great for preventing errors due to the fact that each task executes a specific process and can be debugged individually or within a larger program when combined with other tasks or sub programs. C# is a great example of how to implement modular programming because it allows for functions, methods, classes and objects to be use to create smaller sub programs. A program can be built from smaller pieces of code which saves development time and reduces the chance of errors because it is easier to test a small class or function for a simple solutions compared to testing a full program which has layers and layers of small programs working together.Yes, it is possible to write the same program using modular and non modular programming, but it is not recommend it. When you deal with non modular programs, they tend to contain a lot of spaghetti code which can be a pain to develop and not to mention debug especially if you did not write the code. In addition, in my experience they seem to have a lot more hidden bugs which waste debugging and development time. Modular programming methodology in comparision to non-mondular should be used when ever possible due to the use of small components. These small components allow business logic to be reused and is easier to maintain. From the user’s view point, they cannot really tell if the code is modular or not with today’s computers.

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  • rake aborted! undefined local variable or method

    - by Subhransu
    In a fresh new Ubuntu machine, I have installed ruby with sudo apt-get install ruby1.8 and then installed rubygem1.8 with : sudo apt-get install rubygems and after that installed rails3.2.8 with : gem install rails The procedure was very simple. But here comes the problem. When I tried checking the version of rake with rake --trace -version I got the following error: rake aborted! undefined local variable or method `rsion' for #<Rake::Application:0xb72c731c> /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:316:in `standard_rake_options' /usr/lib/ruby/1.8/optparse.rb:1298:in `eval' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:316:in `standard_rake_options' /usr/lib/ruby/1.8/optparse.rb:1298:in `call' /usr/lib/ruby/1.8/optparse.rb:1298:in `parse_in_order' /usr/lib/ruby/1.8/optparse.rb:1254:in `catch' /usr/lib/ruby/1.8/optparse.rb:1254:in `parse_in_order' /usr/lib/ruby/1.8/optparse.rb:1248:in `order!' /usr/lib/ruby/1.8/optparse.rb:1339:in `permute!' /usr/lib/ruby/1.8/optparse.rb:1360:in `parse!' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:425:in `handle_options' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:74:in `init' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:72:in `init' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:64:in `run' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /var/lib/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run' /var/lib/gems/1.8/gems/rake-0.9.2.2/bin/rake:33 /usr/local/bin/rake:19:in `load' /usr/local/bin/rake:19 Is it the problem due to I have installed straight from ubuntu apt-get package manager ?

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  • what does AngleVectors method in quake 3 source code does

    - by kypronite
    I just downloaded quake 3 for learning purposes. I know some of some linear algebra(basic vector math ie: dot,cross product). However I can't decipher what below method does, I know what is yaw,pitch and roll. But I can't connect these with vector. Worse, I'm not sure this fall under what math 'category', so I don't really know how to google. Hence the question here. Anyone? void AngleVectors( const vec3_t angles, vec3_t forward, vec3_t right, vec3_t up) { float angle; static float sr, sp, sy, cr, cp, cy; // static to help MS compiler fp bugs angle = angles[YAW] * (M_PI*2 / 360); sy = sin(angle); cy = cos(angle); angle = angles[PITCH] * (M_PI*2 / 360); sp = sin(angle); cp = cos(angle); angle = angles[ROLL] * (M_PI*2 / 360); sr = sin(angle); cr = cos(angle); if (forward) { forward[0] = cp*cy; forward[1] = cp*sy; forward[2] = -sp; } if (right) { right[0] = (-1*sr*sp*cy+-1*cr*-sy); right[1] = (-1*sr*sp*sy+-1*cr*cy); right[2] = -1*sr*cp; } if (up) { up[0] = (cr*sp*cy+-sr*-sy); up[1] = (cr*sp*sy+-sr*cy); up[2] = cr*cp; } } ddddd

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  • TypeError: Cannot call method 'hasOwnProperty' of null, while creating a QMLscene window

    - by tomoqv
    I am trying to make a simple Ubuntu Touch web application with Qt Creator. I have set up a new project according to the tutorial and committed the files to Bazaar. I have set a url instead of the default index.htm in the qml file of the project. Using build-run loads a QML Scene window with the desired webpage, but Qt Creator yields the following output: Starting /usr/lib/i386-linux-gnu/qt5/bin/qmlscene -I /home/tomas/ubuntu-sdk/SL-planner -I /usr/bin -I /usr/lib/i386-linux-gnu/qt5/qml /home/tomas/ubuntu-sdk/SL-planner/SL-planner.qml unity::action::ActionManager::ActionManager(QObject*): Could not determine application identifier. HUD will not work properly. Provide your application identifier in $APP_ID environment variable. file:///usr/lib/i386-linux-gnu/qt5/qml/Ubuntu/Components/MainView.qml:257: TypeError: Cannot call method 'hasOwnProperty' of null My SL-planner.qml looks like this: import QtQuick 2.0 import Ubuntu.Components 0.1 import QtWebKit 3.0 /*! \brief MainView with a Flickable WebView. */ MainView { // objectName for functional testing purposes (autopilot-qt5) objectName: "mainView" // Note! applicationName needs to match the "name" field of the click manifest applicationName: "com.ubuntu.developer.tomoqv.SL-planner" /* This property enables the application to change orientation when the device is rotated. The default is false. */ automaticOrientation: true width: units.gu(100) height: units.gu(75) Flickable { id: webViewFlickable anchors.fill: parent WebView { id: webView anchors.fill: parent url: "http://mobil.sl.se" } } } What am I missing?

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  • Get entities ids from two similar collections using one method

    - by Patryk Roszczyniala
    I've got two lists: List<Integer, ZooEntity> zoos; List<Integer, List<ZooEntity>> groupOfZoos; These operations will return collections of values: Collection<ZooEntity> cz = zoos.values(); Collection<List<ZooEntity>> czList = groupOfZoos.values(); What I want to achieve is to get list of all zoo ids. List<Integer> zooIds = cz ids + czList ids; Of course I can create two methods to do what I want: public List<Integer> getIdsFromFlatList(Collection<ZooEntity> list) { List<Integer> ids = new ArrayList<Integer>(); for (ZooEntity z : list) { ids.add(z.getId()); } return ids; } public List<Integer> getIdsFromNestedList(Collection<List<ZooEntity>> list) { List<Integer> ids = new ArrayList<Integer>(); for (List<ZooEntity> zList : list) { for (ZooEntity z : zList) { ids.add(z.getId()); } } return ids; } As you can see those two methods are very similar and here is my question: Is it good to create one method (for example using generics) which will get ids from those two lists (zoos and groupOfZoos). If yes how it should look like? If no what is the best solution? BTW. This is only the example. I've got very similar problem at job and I want to do it in preety way (I can't change enities, I can change only getIds...() methods).

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  • Drawing text from update method in XNA

    - by Sigh-AniDe
    I am having a problem drawing the "Game Over!" text once the user is on the last tile. This is what I have: The Update and drawText methods are in a class named turtle: public void Update(float scalingFactor, int[,] map, SpriteBatch batch, SpriteFont font) { if (isMovable(mapX, mapY - 1, map)) { position.Y = position.Y - (int)scalingFactor; angle = 0.0f; Program.form.direction = ""; if (mapX == 17 && mapY == 1)// This is the last tile(Tested) { Program.form.BackColor = System.Drawing.Color.Red; drawText(batch, font); } } } public void drawText(SpriteBatch spritebatch, SpriteFont spriteFont) { textPosition.X = 200; // a vector2 textPosition.Y = 200; spritebatch.Begin(SpriteSortMode.BackToFront, BlendState.AlphaBlend); spritebatch.DrawString(spriteFont, "Game Over!!!", textPosition, Color.Red); spritebatch.End(); } This update is in the Game1 class: protected override void Update(GameTime gameTime) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); turtle.Update(scalingFactor, map, spriteBatch, font); base.Update(gameTime); } I have also added the font content to LoadContent: font = Content.Load<SpriteFont>("fontType"); What am I doing wrong? Why does the text not want to show on game completion? If I call the turtle.draw() in the main Draw method. The "Game Over" text stays on screen from the beggining. What am I missing? Thanks

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  • Bad archive mirror using PXE boot method

    - by user11566
    I'm trying to automatically install Ubuntu on a client PC by using the PXE BOOT method....my Objectives are below: I am following the steps given in this link installation using PXE BOOT the server will have a KICKSTART config file which contains the parameters for the OS installation and the files which are required for the OS installations. the client will have to detect this configuration along with the setup files and complete the installation without any input from the user. In my server I have installed DHCP3-server,Apache2 and TFTP to help me with the installation. I have nearly achieved my first objective, I am able to boot my client using the files stored in the server but during the installation stage it is asking me to CHOOSE A MIRROR OF UBUNTU ARCHIVE I gave the server's IP address and the path in the server where the files are located but then its giving me this error BAD ARCHIVE MIRROR So is it possible that instead of downloading all the files from the internet and storing them on my disk can I use the files which comes with the UBUNTU-CD, and how to store these files in what format (should I zip them) on the disk? secondly I am also generating the ks.cfg which I wanted to give to the client for automatic installation of the OS. So how should the configuration file be given to the installation process?

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  • Method for spawning enemies according to player score and game time

    - by Sun
    I'm making a top-down shooter and want to scale the difficulty of the game according to what the score is and how much time has Passed. Along with this, I want to spawn enemies in different patterns and increase the intervals at which these enemies are shown. I'm going for a similar effect to Geometry wars. However, I can think of a to do this other than have multiple if-else statments, e.g. : if (score > 1000) { //spawn x amount if enemies } else if (score > 10000) { //spawn x amount of enemy type 1 & 2 } else if (score > 15000) { //spawn x amount of enemy type 1 & 2 & 3 } else if (score > 25000) { //spawn x amount of enemy type 1 & 2 & 3 //create patterns with enemies } ...etc What would be a better method of spawning enemies as I have described?

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  • Object inheritance and method parameters/return types - Please check my logic

    - by user2368481
    I'm preparing for a test and doing practice questions, this one in particular I am unsure I did correctly: We are given a very simple UML diagram to demonstrate inheritance: I hope this is clear, it shows that W inherits from V and so on: |-----Y V <|----- W<|-----| |-----X<|----Z and this code: public X method1(){....} method2(new Y()); method2(method1()); method2(method3()); The questions and my answers: Q: What types of objects could method1 actually return? A: X and Z, since the method definition includes X as the return type and since Z is a kind of X is would be OK to return either. Q: What could the parameter type of method2 be? A: Since method2 in the code accepts Y, X and Z (as the return from method1), the parameter type must be either V or W, as Y,X and Z inherit from both of these. Q: What could return type of method3 be? A: Return type of method3 must be V or W as this would be consistent with answer 2.

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  • Abstract Factory Method and Polymorphism

    - by Scotty C.
    Being a PHP programmer for the last couple of years, I'm just starting to get into advanced programming styles and using polymorphic patterns. I was watching a video on polymorphism the other day, and the guy giving the lecture said that if at all possible, you should get rid of if statements in your code, and that a switch is almost always a sign that polymorphism is needed. At this point I was quite inspired and immediately went off to try out these new concepts, so I decided to make a small caching module using a factory method. Of course the very first thing I have to do is create a switch to decide what file encoding to choose. DANG! class Main { public static function methodA($parameter='') { switch ($parameter) { case 'a': $object = new \name\space\object1(); break; case 'b': $object = new \name\space\object2(); break; case 'c': $object = new \name\space\object3(); break; default: $object = new \name\space\object1(); } return (sekretInterface $object); } } At this point I'm not really sure what to do. As far as I can tell, I either have to use a different pattern and have separate methods for each object instance, or accept that a switch is necessary to "switch" between them. What do you guys think?

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  • Extracting Frustum Planes (Hartmann & Gribbs method)

    - by DAVco
    I have been grappling with the Hartmann/Gribbs method of extracting the Frustum planes for some time now, with little success. There doesn't appear to be a "definitive" topic or tutorial which combines all the necessary information, so perhaps this can be it First of all, I am attempting to do this in C# (For Playstation Mobile), using OpenGL style Column-Major matrices in a Right-Handed coordinate system but obviously the math will work in any language. My projection matrix has a Near plane at 1.0, Far plane at 1000, FOV of 45.0 and Aspect of 1.7647. I want to get my planes in World-Space, so I build my frustum from the View-Projection Matrix (that's projectionMatrix * viewMatrix). The view Matrix is the inverse of the camera's World-Transform. The problem is; regardless of what I tweak, I can't seem to get a correct frustum. I think that I may be missing something obvious. Focusing on the Near and Far planes for the moment (since they have the most obvious normals when correct), when my camera is positioned looking down the negative z-axis, I get two planes facing in the same direction, rather than opposite directions. If i strafe my camera left and right (while still looking along the z axis) the x value of the normal vector changes. Obviously, something is fundamentally wrong here; I just can't figure out what - maybe someone here can?

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  • Creating an update method in a different class

    - by Sweta Dwivedi
    I have created a class called 3D model which will animate my 3D model by changing the model position according to the values based in a .txt file through a list... Since i'm using a foreach loop to read the point values when it reaches the end of the file.. XNA throws an out of bounds exception .. (which is obvious) but if i add the same code in my Game.cs update(gameTime) method.. then i dont have this problem..Any idea how to make my 3D model update work same as the update in game.cs .. Here is the code for some idea: public void patterns(GameTime gameTime) { motion_z = new List<Point3D>(); if (pattern == 1) { f = "E:/Motion_Track-output/Output1.txt"; } if (pattern == 2) { f = "E:/Motion_Track-output/cruse.txt"; } // TODO: Add your update logic here using (StreamReader r = new StreamReader(f)) { string line; //Viewport view = graphics.GraphicsDevice.Viewport; int maxWidth = view.Width; int maxHeight = view.Height; while ((line = r.ReadLine()) != null) { string[] temp = line.Split(','); int x = (int)Math.Floor(((float.Parse(temp[0]) * 0.5f) + 0.5f) * maxWidth); int y = (int)Math.Floor(((float.Parse(temp[1]) * -0.5f) + 0.5f) * maxHeight); int z = (int)Math.Floor(((float.Parse(temp[2]) / 4 * 20000))); motion_z.Add(new Point3D(x, y, z)); } modelPosition.X = (float)(motion_z[i].X); modelPosition.Y = (float)(motion_z[i].Y); modelPosition.Z = (float)(motion_z[i].Z); i++; } //Console.WriteLine("modelposX:" + modelPosition.X + "," + "motionzX:" + motion_z[i].X); }

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  • 15 Puzzle Shuffle Method Issues

    - by Codemiester
    I am making a 15 puzzle game in C# that allows the user to enter a custom row and column value up to a maximum of a 10 x 10 puzzle. Because of this I am having problems with the shuffle method. I want to make it so the puzzle is always solvable. By first creating a winning puzzle then shuffling the empty space. The problem is it is too inefficient to call every click event each time. I need a way to invoke the click event of a button adjacent to the empty space but not diagonal. I also use an invisible static button for the empty spot. The PuzzlePiece class inherits from Button. I am not too sure how to do this. I would appreciate any help. Thanks here is what I have: private void shuffleBoard() { //5 is just for test purposes for (int i = 0; i < 5; i++) { foreach (Control item in this.Controls) { if (item is PuzzlePiece) { ((PuzzlePiece)item).PerformClick(); } } } } void PuzzlePiece_Click(object sender, EventArgs e) { PuzzlePiece piece = (PuzzlePiece)sender; if (piece.Right == puzzleForm.emptyPiece.Left && piece.Top == puzzleForm.emptyPiece.Top) { movePiece(piece); } else if (piece.Left == puzzleForm.emptyPiece.Right && piece.Top == puzzleForm.emptyPiece.Top) { movePiece(piece); } else if (piece.Top == puzzleForm.emptyPiece.Bottom && piece.Left == puzzleForm.emptyPiece.Left) { movePiece(piece); } else if (piece.Bottom == puzzleForm.emptyPiece.Top && piece.Left == puzzleForm.emptyPiece.Left) { movePiece(piece); } }

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  • OpenWeb(String) method

    - by ybbest
    I guess this is a SharePoint beginner problem ,however it took me a while to figure out what the problem is and I will blog it to help me to remember. Basically I wrote the following code to grab some list item from my SharePoint subsite http://win-oirj50igics/RestAPI,however I got the error stating that : “<nativehr>0×80070002</nativehr><nativestack></nativestack>There is no Web named / http://win-oirj50igics/RestAPI”. The problem is that OpenWeb(String) method returns the web site that is located at the specified server-relative or site-relative URL. It is the relative URL , so after I changed http://win-oirj50igics/RestAPI to RestAPI, everything works fine. using (SPSite site = new SPSite(http://win-oirj50igics/)) { SPWeb web = site.OpenWeb("http://win-oirj50igics/RestAPI"); SPQuery query = new SPQuery(); query.Query = camlDocument.InnerXml; SPListItemCollection items = web.Lists["Songs"].GetItems(query); IEnumerable<Song> sortedItems = from item in items.OfType<SPListItem>() orderby item.Title select new Song {SongName = item.Title, SongID = item.ID}; songs.AddRange(sortedItems); }

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  • Failing Screen Resize Method

    - by StrongJoshua
    So I want my game to draw to a specific "optimal" size and then be stretched to fit screens that are a different size. I'm using LibGDX and figured that I could just draw everything to a FrameBuffer and then resize that buffer to the appropriate size when drawing it to the actual display. However, my method does not work, it just results in a black screen with the top right quarter of the screen white.Intermediary is the FBO, interMatrix is a Matrix4 object, and camera is an OrthographicCamera. @Override public void render() { // update actors currentStage.act(); //render to intermediary buffer batch.setProjectionMatrix(interMatrix); intermediary.begin(); batch.begin(); currentStage.draw(); batch.flush(); intermediary.end(); //resize to actual width and height Sprite s = new Sprite(intermediary.getColorBufferTexture()); s.flip(true, false); batch.setProjectionMatrix(camera.combined); batch.draw(s.getTexture(), 0, 0, width, height); batch.end(); } These are the constructors for the above mentioned objects (GAME_WIDTH and HEIGHT are the "optimal" settings, width and height are the actual sizes, which are the same when running on desktop). intermediary = new FrameBuffer(Format.RGBA8888, GAME_WIDTH, GAME_HEIGHT, false); interMatrix = new Matrix4(); camera = new OrthographicCamera(width, height); interMatrix.setToOrtho2D(0, 0, GAME_WIDTH, GAME_HEIGHT); Is there a better way of doing this or can is this a viable option and how do I fix what I have?

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  • Point in Polygon, Ray Method: ending infinite line

    - by user2878528
    Having a bit of trouble with point in polygon collision detection using the ray method i.e. http://en.wikipedia.org/wiki/Point_in_polygon My problem is I need to give an end to the infinite line created. As with this infinite line I always get an even number of intersections and hence an invalid result. i.e. ignore or intersection to the right of the point being checked what I have what I want My current code based of Mecki awesome response for (int side = 0; side < vertices.Length; side++) { // Test if current side intersects with ray. // create infinite line // See: http://en.wikipedia.org/wiki/Linear_equation a = end_point.Y - start_point.Y; b = start_point.X - end_point.X; c = end_point.X * start_point.Y - start_point.X * end_point.Y; //insert points of vector d2 = a * vertices[side].Position.X + b * vertices[side].Position.Y + c; if (side - 1 < 0) d1 = a * vertices[vertices.Length - 1].Position.X + b * vertices[vertices.Length - 1].Position.Y + c; else d1 = a * vertices[side-1].Position.X + b * vertices[side-1].Position.Y + c; // If points have opposite sides, intersections++; if (d1 > 0 && d2 < 0 ) intersections++; if (d1 < 0 && d2 > 0 ) intersections++; } //if intersections odd inside = true if ((intersections % 2) == 1) inside = true; else inside = false;

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  • XNA - Inconsistent accessibility: parameter type is less accessible than method

    - by DijkeMark
    I have a level class in which I make a new turret. I give the turret the level class as parameter. So far so good. Then in the Update function of the Turret I call a function Shoot(), which has that level parameter it got at the moment I created it. But from that moment it gives the following error: Inconsistent accessibility: parameter type 'Space_Game.Level' is less accessible than method 'Space_Game.GameObject.Shoot(Space_Game.Level, string)' All I know it has something to do with not thr right protection level or something like that. The level class: public Level(Game game, Viewport viewport) { _game = game; _viewport = viewport; _turret = new Turret(_game, "blue", this); _turret.SetPosition((_viewport.Width / 2).ToString(), (_viewport.Height / 2).ToString()); } The Turret Class: public Turret(Game game, String team, Level level) :base(game) { _team = team; _level = level; switch (_team) { case "blue": _texture = LoadResources._blue_turret.Texture; _rows = LoadResources._blue_turret.Rows; _columns = LoadResources._blue_turret.Columns; _maxFrameCounter = 10; break; default: break; } _frameCounter = 0; _currentFrame = 0; _currentFrameMultiplier = 1; } public override void Update() { base.Update(); SetRotation(); Shoot(_level, "turret"); } The Shoot Function (Which is in GameObject class. The Turret Class inherited the GameObject Class. (Am I saying that right?)): protected void Shoot(Level level, String type) { MouseState mouse = Mouse.GetState(); if (mouse.LeftButton == ButtonState.Pressed) { switch (_team) { case "blue": switch (type) { case "turret": TurretBullet _turretBullet = new TurretBullet(_game, _team); level.AddProjectile(_turretBullet); break; default: break; } break; default: break; } } } Thanks in Advance, Mark Dijkema

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  • Best Practice: What can be the hashCode() method implementation if custom field used in equals() method are null?

    - by goodspeed
    What is the best practice to return a value for hashCode() method if custom field used in equals are null ? I have a situation, where equals() override is implemented using custom fields. Usually it it is better to override hashCode() also using that custom fields used in equals(). But if all the custom fields used in equals() are null, then what would be the best implementation for hashCode()? Example: class Person { private String firstName; private String lastName; public String getFirstName() { return firstName; } public String getLastName() { return lastName; } @Override public boolean equals(Object object) { boolean result = false; if (object == null || object.getClass() != getClass()) { result = false; } else { Person person = (Person) object; if (this.firstName == person.getFirstName() && this.lastName == tiger.getLastName()) { result = true; } } return result; } @Override public int hashCode() { int hash = 3; if(this.firstName == null || this.lastName == null) { // <b>What is the best practice here, </b> // <b>is return super.hashCode() better ?</b> } hash = 7 * hash + this.firstName.hashCode(); hash = 7 * hash + this.lastName.hashCode(); return hash; } } is it required to check for null in hashCode() ? If yes, what should be returned if custom values are null ?

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  • LibGDX onTouch() method kill on touch

    - by johnny-b
    How can I add this on my application. i want to use the onTouch() method from the implementation of the InputProcessor to kill the enemies on screen. how do i do that? do i have to do anything to the enemy class? please help Thank you M @Override public boolean touchDown(int screenX, int screenY, int pointer, int button) { return false; } here is my enemy class public class Bullet extends Sprite { private Vector2 velocity; private float lifetime; public Bullet(float x, float y) { velocity = new Vector2(0, 0); } public void update(float delta) { float targetX = GameWorld.getBall().getX(); float targetY = GameWorld.getBall().getY(); float dx = targetX - getX(); float dy = targetY - getY(); float distToTarget = (float) Math.sqrt(dx * dx + dy * dy); velocity.x += dx * delta; velocity.y += dy * delta; } } i am rendering all graphics in a GameRender class and a gameworld class if you need more info please let me know Thank you

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  • Use constructor or setter method?

    - by user633600
    I am working on a UI code where I have an Action class, something like this - public class MyAction extends Action { public MyAction() { setText("My Action Text"); setToolTip("My Action Tool tip"); setImage("Some Image"); } } When this Action class was created it was pretty much assumed that the Action class wont be customizable (in a sense- its text, tooltip or image will be not be changed anywhere in the code). Of late, now we are in need of changing the action text at some location in code. So I suggested my co-worker to remove the hardcoded action text from the constructor and accept it as an argument, so that everybody is forced to pass the action text. Something like this code below - public class MyAction extends Action { public MyAction(String actionText) { setText(actionText); setTooltip("My Action tool tip); setImage("My Image"); } } He however thinks that since setText() method belongs to base class. It can be flexibly used to pass the action text wherever action instance is created. That way, there is no need to change the existing MyAction class. So his code would look something like this. MyAction action = new MyAction(); //this creates action instance with the hardcoded text action.setText("User required new action text"); //overwrite the exisitng text. I am not sure if that is a correct way to deal with problem. I think in above mentioned case user is anyway going to change the text, so why not force him while constructing the action. The only benefit I see with the original code is that user can create Action class without much thinking about setting text.

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  • Creating a Predicate Builder extension method

    - by Rippo
    I have a Kendo UI Grid that I am currently allowing filtering on multiple columns. I am wondering if there is a an alternative approach removing the outer switch statement? Basically I want to able to create an extension method so I can filter on a IQueryable<T> and I want to drop the outer case statement so I don't have to switch column names. private static IQueryable<Contact> FilterContactList(FilterDescriptor filter, IQueryable<Contact> contactList) { switch (filter.Member) { case "Name": switch (filter.Operator) { case FilterOperator.StartsWith: contactList = contactList.Where(w => w.Firstname.StartsWith(filter.Value.ToString()) || w.Lastname.StartsWith(filter.Value.ToString()) || (w.Firstname + " " + w.Lastname).StartsWith(filter.Value.ToString())); break; case FilterOperator.Contains: contactList = contactList.Where(w => w.Firstname.Contains(filter.Value.ToString()) || w.Lastname.Contains(filter.Value.ToString()) || (w.Firstname + " " + w.Lastname).Contains( filter.Value.ToString())); break; case FilterOperator.IsEqualTo: contactList = contactList.Where(w => w.Firstname == filter.Value.ToString() || w.Lastname == filter.Value.ToString() || (w.Firstname + " " + w.Lastname) == filter.Value.ToString()); break; } break; case "Company": switch (filter.Operator) { case FilterOperator.StartsWith: contactList = contactList.Where(w => w.Company.StartsWith(filter.Value.ToString())); break; case FilterOperator.Contains: contactList = contactList.Where(w => w.Company.Contains(filter.Value.ToString())); break; case FilterOperator.IsEqualTo: contactList = contactList.Where(w => w.Company == filter.Value.ToString()); break; } break; } return contactList; } Some additional information, I am using NHibernate Linq. Also another problem is that the "Name" column on my grid is actually "Firstname" + " " + "LastName" on my contact entity. We can also assume that all filterable columns will be strings.

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