Search Results

Search found 9771 results on 391 pages for 'equivalence classes'.

Page 287/391 | < Previous Page | 283 284 285 286 287 288 289 290 291 292 293 294  | Next Page >

• Layout of mathematical views (iOS)

  - by William Jockusch

  I am trying to figure out the right way to encapsulate graphical information about mathematical objects. It is not simple. For example, a matrix can include square brackets around its entries, or not. Some things carry down to sub-objects -- for example, a matrix might track the font size to be used by its entries. Similarly, the font color and the background color would carry down to the entries. Other things do not carry down. For example, the entries of the matrix do not need to know whether or not the matrix has those square brackets. Based on all of the above, I need to calculate sizes for everything, then frames. All of this can depend on the properties stored above. The size of a matrix depends on the sizes of its entries, and also on whether or not it has those brackets. What I am having a hard time with is not the individual ways to calculate sensible frames for this or that. It is the overall organizational structure of the whole thing. How can I keep track of it all without going crazy. One particular obstacle is worth mentioning -- for reasons I don't want to go into here, I need to calculate the sizes and frames for everything before I instantiate any actual views. So, for example, if I have a Matrix object, I need to calculate its size before I make a MatrixView. If I have an equation, I need to calculate the size of the view for the equation before I create the actual view. So I clearly need separate objects for those calculations. But I can't figure out a sensible class structure for those objects. If I put them all into a single class, I get some advantages because copying then becomes easy. But I also end up with a bloated class that contains info that is irrelevant for some objects -- such as whether or not to include those brackets around the matrix. But if I use a lot of different classes, copying properties becomes a real pain. If it matters, this is all in Objective C, for an iOS environment. Any pointers would be greatly appreciated.

  Read the article

• Why would I learn C++11, having known C and C++?

  - by Shahbaz

  I am a programmer in C and C++, although I don't stick to either language and write a mixture of the two. Sometimes having code in classes, possibly with operator overloading, or templates and the oh so great STL is obviously a better way. Sometimes use of a simple C function pointer is much much more readable and clear. So I find beauty and practicality in both languages. I don't want to get into the discussion of "If you mix them and compile with a C++ compiler, it's not a mix anymore, it's all C++" I think we all understand what I mean by mixing them. Also, I don't want to talk about C vs C++, this question is all about C++11. C++11 introduces what I think are significant changes to how C++ works, but it has introduced many special cases that change how different features behave in different circumstances, placing restrictions on multiple inheritance, adding lambda functions, etc. I know that at some point in the future, when you say C++ everyone would assume C++11. Much like when you say C nowadays, you most probably mean C99. That makes me consider learning C++11. After all, if I want to continue writing code in C++, I may at some point need to start using those features simply because my colleagues have. Take C for example. After so many years, there are still many people learning and writing code in C. Why? Because the language is good. What good means is that, it follows many of the rules to create a good programming language. So besides being powerful (which easy or hard, almost all programming languages are), C is regular and has few exceptions, if any. C++11 however, I don't think so. I'm not sure that the changes introduced in C++11 are making the language better. So the question is: Why would I learn C++11? Update: My original question in short was: "I like C++, but the new C++11 doesn't look good because of this and this and this. However, deep down something tells me I need to learn it. So, I asked this question here so that someone would help convince me to learn it." However, the zealous people here can't tolerate pointing out a flaw in their language and were not at all constructive in this manner. After the moderator edited the question, it became more like a "So, how about this new C++11?" which was not at all my question. Therefore, in a day or too I am going to delete this question if no one comes up with an actual convincing argument. P.S. If you are interested in knowing what flaws I was talking about, you can edit my question and see the previous edits.

  Read the article

• Actor and Sprite, who should own these properties?

  - by Gerardo Marset

  I'm writing sort of a 2D game engine for making the process of creating games easier. It has two classes, Actor and Sprite. Actor is used for interactive elements (the player, enemies, bullets, a menu, an invisible instance that controls score, etc) and Sprite is used for animated (or not) images with transparency (or not). The actor may have an assigned sprite that represents it on the screen, which may change during the game. E.g. in a top-down action game you may have an actor with a sprite of a little guy that changes when attacking, walking, and facing different directions, etc. Currently the actor has x and y properties (its coordinates in the screen), while the sprite has an index property (the number of the frame currently being shown by the sprite). Since the sprite doesn't know which actor it belongs to (or if it belongs to an actor at all), the actor must pass its x and y coordinates when drawing the sprite. Also, since a actors may reset its sprite each frame (and usually do), the sprite's index property must be passed from the old to the new sprite like so (pseudocode): function change_sprite(new_sprite) old_index = my.sprite.index my.sprite = new_sprite() my.sprite.index = old_index % my.sprite.frames end I always thought this was kind of cumbersome, but it never was a big problem. Now I decided to add support for more properties. Namely a property to draw the sprite rotated, a property to draw it flipped, it a property draw it stretched, etc. These should probably belong to the sprite and not the actor, but if they do, the actor would have to pass them from the old to the new sprite each time it changes... On the other hand, if they belonged to the actor, the actor would have to pass each property to the sprite when drawing it (since the sprite doesn't know which actor it belongs to, and it shouldn't, since sprites aren't just meant to be used by actors, really). Another option I thought of would be having an extra class that owns all these properties (plus index, x and y) and links an actor with a sprite, but that doesn't come without drawbacks. So, what should I do with all these properties? Thanks!

  Read the article

• Sharing on Github

  - by Alan

  Over the past couple weeks I have gotten a lot of help from StackOverflow users on a project, and rather than keep the finished product to myself I wanted to share it unencumbered by licenses, but don't want there to be so much legwork during installation that users shy away from trying it. I am about to post it to Github and choosing public domain licensing. I would like to to be super simple for users to make use of and just FTP it up and go. That being said, do I need to make sure I remove things like the JQuery file, and other GPL / MIT licensed dependencies that I didn't write but that my code depends on? I haven't removed any copyright notices from the other code and all of it open source, it would just be nice if users could download everything at once while of course not trying to represent that I am the license holder of the dependencies. Inside my files are also some snippets, do those have to be externalized with installation instructions or can it be posted as is? Here is an example, my nav.php file is 115 lines long and I have these at the top: <script type="text/javascript" src="./js/ddaccordion.js"> /*********************************************** * Accordion Content script- (c) Dynamic Drive DHTML code library (www.dynamicdrive.com) * Visit http://www.dynamicDrive.com for hundreds of DHTML scripts * This notice must stay intact for legal use ***********************************************/ </script> <link href="css/admin.css" rel="stylesheet"> <script type="text/javascript"> ddaccordion.init({ headerclass: "submenuheader", //Shared CSS class name of headers group contentclass: "submenu", //Shared CSS class name of contents group revealtype: "click", //Reveal content when user clicks or onmouseover the header? Valid value: "click", "clickgo", or "mouseover" mouseoverdelay: 200, //if revealtype="mouseover", set delay in milliseconds before header expands onMouseover collapseprev: false, //Collapse previous content (so only one open at any time)? true/false defaultexpanded: [], //index of content(s) open by default [index1, index2, etc] [] denotes no content onemustopen: false, //Specify whether at least one header should be open always (so never all headers closed) animatedefault: false, //Should contents open by default be animated into view? persiststate: true, //persist state of opened contents within browser session? toggleclass: ["", ""], //Two CSS classes to be applied to the header when it's collapsed and expanded, respectively ["class1", "class2"] togglehtml: ["suffix", "<img src='./images/plus.gif' class='statusicon' />", "<img src='./images/minus.gif' class='statusicon' />"], //Additional HTML added to the header when it's collapsed and expanded, respectively ["position", "html1", "html2"] (see docs) animatespeed: "fast", //speed of animation: integer in milliseconds (ie: 200), or keywords "fast", "normal", or "slow" oninit:function(headers, expandedindices){ //custom code to run when headers have initalized //do nothing }, onopenclose:function(header, index, state, isuseractivated){ //custom code to run whenever a header is opened or closed //do nothing } }) </script>

  Read the article

• Suggestions for Summer Intern Application Assignments

  - by orangepips

  As part of our application process we want prospective college interns to complete an assignment on their own - either programming or analytical - to give us something tangible to evaluate such as code or a flowchart. I have two ideas for these assignments, one programming and one analytical, I am interested in gathering feedback about these. Programming Assignment Generate an a month's calendar for a given date. The first row should indicate the days of the week (e.g. Sunday - Saturday). Each subsequent row should contain a week's days. The date supplied should be highlighted (e.g. bolded). I am thinking we'll probably proscribe the output format even more strictly - probably down to what the HTML source should look like including CSS classes. Thinking is this forces answerers to actually do some work if they merely copy a solution from the internet. Analytical Assignment Diagram or describe in prose a system for managing a set of traffic lights for traffic at a four way intersection. Each direction (i.e. North, South, East and West) has two lanes (i.e. right and left). The left lane is turn only and has green arrow light to indicate right of way. The system is able to detect if lanes have cars in them and change the lights accordingly. I would expect a flow chart or some prose describing a finite state machine that deals with each contingency. This would hopefully provide some indication of the applicant's ability to reason through a logic problem of sorts and articulate an approach for solving. Areas Seeking Feedback Is it unreasonable to ask this of applicants? If not, is it better to request before or after a phone screen? Are these questions too hard or easy for a collegiate audience? Any suggestions for alternate questions? Do these seem like good tools for analyzing people who would part of a software development life cycle? Programming language suggestions - I'm thinking Java, Python and/or C# (we're actually a ColdFusion shop).

  Read the article

• Image first loaded, then it isn't? (XNA)

  - by M0rgenstern

  I am very confused at the Moment. I have the following Class: (Just a part of the class): public class GUIWindow { #region Static Fields //The standard image for windows. public static IngameImage StandardBackgroundImage; #endregion } IngameImage is just one of my own classes, but actually it contains a Texture2D (and some other things). In another class I load a list of GUIButtons by deserializing a XML file. public static GUI Initializazion(string pXMLPath, ContentManager pConMan) { GUI myGUI = pConMan.Load<GUI>(pXMLPath); GUIWindow.StandardBackgroundImage = new IngameImage(pConMan.Load<Texture2D>(myGUI.WindowStandardBackgroundImagePath), Vector2.Zero, 1024, 600, 1, 0, Color.White, 1.0f, true, false, false); System.Console.WriteLine("Image loaded? " + (GUIWindow.StandardBackgroundImage.ImageStrip != null)); myGUI.Windows = pConMan.Load<List<GUIWindow>>(myGUI.GUIFormatXMLPath); System.Console.WriteLine("Windows loaded"); return myGUI; } Here this line: System.Console.WriteLine("Image loaded? " + (GUIWindow.StandardBackgroundImage.ImageStrip != null)); Prints "true". To load the GUIWindows I need an "empty" constructor, which looks like that: public GUIWindow() { Name = ""; Buttons = new List<Button>(); ImagePath = ""; System.Console.WriteLine("Image loaded? (In win) " + (GUIWindow.StandardBackgroundImage.ImageStrip != null)); //Image = new IngameImage(StandardBackgroundImage); //System.Console.WriteLine( //Image.IsActive = false; SelectedButton = null; IsActive = false; } As you can see, I commented lines out in the constructor. Because: Otherwise this would crash. Here the line System.Console.WriteLine("Image loaded? (In win) " + (GUIWindow.StandardBackgroundImage.ImageStrip != null)); Doesn't print anything, it just crashes with the following errormessage: Building content threw NullReferenceException: Object reference not set to an object instance. Why does this happen? Before the program wants to load the List, it prints "true". But in the constructor, so in the loading of the list it prints "false". Can anybody please tell me why this happens and how to fix it?

  Read the article

• Self-Executing Anonymous Function vs Prototype

  - by Robotsushi

  In Javascript there are a few clearly prominent techniques for create and manage classes/namespaces in javascript. I am curious what situations warrant using one technique vs. the other. I want to pick one and stick with it moving forward. I write enterprise code that is maintained and shared across multiple teams, and I want to know what is the best practice when writing maintainable javascript ? I tend to prefer Self-Executing Anonymous Functions however I am curious what the community vote is on these techniques. Prototype : function obj() { } obj.prototype.test = function() { alert('Hello?'); }; var obj2 = new obj(); obj2.test(); Self-Closing Anonymous Function : //Self-Executing Anonymous Function (function( skillet, $, undefined ) { //Private Property var isHot = true; //Public Property skillet.ingredient = "Bacon Strips"; //Public Method skillet.fry = function() { var oliveOil; addItem( "\t\n Butter \n\t" ); addItem( oliveOil ); console.log( "Frying " + skillet.ingredient ); }; //Private Method function addItem( item ) { if ( item !== undefined ) { console.log( "Adding " + $.trim(item) ); } } }( window.skillet = window.skillet || {}, jQuery )); //Public Properties console.log( skillet.ingredient ); //Bacon Strips //Public Methods skillet.fry(); //Adding Butter & Fraying Bacon Strips //Adding a Public Property skillet.quantity = "12"; console.log( skillet.quantity ); //12 //Adding New Functionality to the Skillet (function( skillet, $, undefined ) { //Private Property var amountOfGrease = "1 Cup"; //Public Method skillet.toString = function() { console.log( skillet.quantity + " " + skillet.ingredient + " & " + amountOfGrease + " of Grease" ); console.log( isHot ? "Hot" : "Cold" ); }; }( window.skillet = window.skillet || {}, jQuery )); //end of skillet definition try { //12 Bacon Strips & 1 Cup of Grease skillet.toString(); //Throws Exception } catch( e ) { console.log( e.message ); //isHot is not defined } I feel that I should mention that the Self-Executing Anonymous Function is the pattern used by the jQuery team. Update When I asked this question I didn't truly see the importance of what I was trying to understand. The real issue at hand is whether or not to use new to create instances of your objects or to use patterns which do not require constructors of the use of the new keyword. I added my own answer, because in my opinion we should make use of patterns which don't use the new keyword. For more information please see my answer.

  Read the article

• Alternatives to multiple inheritance for my architecture (NPCs in a Realtime Strategy game)?

  - by Brettetete

  Coding isn't that hard actually. The hard part is to write code that makes sense, is readable and understandable. So I want to get a better developer and create some solid architecture. So I want to do create an architecture for NPCs in a video-game. It is a Realtime Strategy game like Starcraft, Age of Empires, Command & Conquers, etc etc.. So I'll have different kinds of NPCs. A NPC can have one to many abilities (methods) of these: Build(), Farm() and Attack(). Examples: Worker can Build() and Farm() Warrior can Attack() Citizen can Build(), Farm() and Attack() Fisherman can Farm() and Attack() I hope everything is clear so far. So now I do have my NPC Types and their abilities. But lets come to the technical / programmatical aspect. What would be a good programmatic architecture for my different kinds of NPCs? Okay I could have a base class. Actually I think this is a good way to stick with the DRY principle. So I can have methods like WalkTo(x,y) in my base class since every NPC will be able to move. But now lets come to the real problem. Where do I implement my abilities? (remember: Build(), Farm() and Attack()) Since the abilities will consists of the same logic it would be annoying / break DRY principle to implement them for each NPC (Worker,Warrior, ..). Okay I could implement the abilities within the base class. This would require some kind of logic that verifies if a NPC can use ability X. IsBuilder, CanBuild, .. I think it is clear what I want to express. But I don't feel very well with this idea. This sounds like a bloated base class with too much functionality. I do use C# as programming language. So multiple inheritance isn't an opinion here. Means: Having extra base classes like Fisherman : Farmer, Attacker won't work.

  Read the article

• Rotate camera around player and set new forward directions

  - by Samurai Fox

  I have a 3rd person camera which can rotate around the player. When I look at the back of the player and press forward, player goes forward. Then I rotate 360 around the player and "forward direction" is tilted for 90 degrees. So every 360 turn there is 90 degrees of direction change. For example when camera is facing the right side of the player, when I press button to move forward, I want player to turn to the left and make that the "new forward". I have Player object with Camera as child object. Camera object has Camera script. Inside Camera script there are Player and Camera classes. Player object itself, has Input Controller. Also I'm making this script for joystick/ controller primarily. My camera script so far: using UnityEngine; using System.Collections; public class CameraScript : MonoBehaviour { public GameObject Target; public float RotateSpeed = 10, FollowDistance = 20, FollowHeight = 10; float RotateSpeedPerTime, DesiredRotationAngle, DesiredHeight, CurrentRotationAngle, CurrentHeight, Yaw, Pitch; Quaternion CurrentRotation; void LateUpdate() { RotateSpeedPerTime = RotateSpeed * Time.deltaTime; DesiredRotationAngle = Target.transform.eulerAngles.y; DesiredHeight = Target.transform.position.y + FollowHeight; CurrentRotationAngle = transform.eulerAngles.y; CurrentHeight = transform.position.y; CurrentRotationAngle = Mathf.LerpAngle(CurrentRotationAngle, DesiredRotationAngle, 0); CurrentHeight = Mathf.Lerp(CurrentHeight, DesiredHeight, 0); CurrentRotation = Quaternion.Euler(0, CurrentRotationAngle, 0); transform.position = Target.transform.position; transform.position -= CurrentRotation * Vector3.forward * FollowDistance; transform.position = new Vector3(transform.position.x, CurrentHeight, transform.position.z); Yaw = Input.GetAxis("Right Horizontal") * RotateSpeedPerTime; Pitch = Input.GetAxis("Right Vertical") * RotateSpeedPerTime; transform.Translate(new Vector3(Yaw, -Pitch, 0)); transform.position = new Vector3(transform.position.x, transform.position.y, transform.position.z); transform.LookAt(Target.transform); } }

  Read the article

• Best Practices for serializing/persisting String Object Dictionary entities

  - by Mark Heath

  I'm noticing a trend towards using a dictionary of string to object (or sometimes string to string), instead of strongly typed objects. For example, the new Katana project makes heavy use of IDictionary<string,object>. This approach avoids the need to continually update your entity classes/DTOs and the database tables that persist them with new properties. It also avoids the need to create new derived entity types to support new types of entity, since the Dictionary is flexible enough to store any arbitrary properties. Here's a contrived example: class StorageDevice { public int Id { get; set; } public string Name { get; set; } } class NetworkShare : StorageDevice { public string Path { get; set; } public string LoginName { get; set; } public string Password { get; set; } } class CloudStorage : StorageDevice { public string ServerUri { get; set } public string ContainerName { get; set; } public int PortNumber { get; set; } public Guid ApiKey { get; set; } } versus: class StorageDevice { public IDictionary<string, object> Properties { get; set; } } Basically I'm on the lookout for any talks, books or articles on this approach, so I can pick up on any best practices / difficulties to avoid. Here's my main questions: Does this approach have a name? (only thing I've heard used so far is "self-describing objects") What are the best practices for persisting these dictionaries into a relational database? Especially the challenges of deserializing them successfully with strongly typed languages like C#. Does it change anything if some of the objects in the dictionary are themselves lists of strongly typed entities? Should a second dictionary be used if you want to temporarily store objects that are not to be persisted/serialized across a network, or should you use some kind of namespacing on the keys to indicate this?

  Read the article

• MarteEngine Tile Collision

  - by opiop65

  I need to add collision to my tile map using MarteEngine. MarteEngine is built of of slick2D. Here's my tile generation code: Code: public void render(GameContainer gc, StateBasedGame game, Graphics g) throws SlickException { for (int x = 0; x < 16; x++) { for (int y = 0; y < 16; y++) { map[x][y] = AIR; air.draw(x * GameWorld.tilesize, y * GameWorld.tilesize); } } for (int x = 0; x < 16; x++) { for (int y = 7; y < 8; y++) { map[x][y] = GRASS; grass.draw(x * tilesize, y * tilesize); } } for (int x = 0; x < 16; x++) { for (int y = 8; y < 10; y++) { map[x][y] = DIRT; dirt.draw(x * tilesize, y * tilesize); } } for (int x = 0; x < 16; x++) { for (int y = 10; y < 16; y++) { map[x][y] = STONE; stone.draw(x * tilesize, y * tilesize); } } super.render(gc, game, g); } And one of my tile classes (they're all the same, the image names are just different): Code: package MarteEngine; import org.newdawn.slick.Image; import org.newdawn.slick.SlickException; import it.randomtower.engine.entity.Entity; public class Grass extends Entity { public static Image grass = null; public Grass(float x, float y) throws SlickException { super(x, y); grass = new Image("res/grass.png"); setHitBox(0, 0, 50, 50); addType(SOLID); } } I tried to do it like this: Code: for (int x = 0; x < 16; x++) { for (int y = 7; y < 8; y++) { map[x][y] = GRASS; Grass.grass.draw(x * tilesize, y * tilesize); } } But it gave me a NullPointerException. No idea why, everything looks initialized right? I would be very grateful for some help!

  Read the article

• Defining a service layer: the text-based adventure

  - by Stacy Vicknair

  Applications these days have more options than ever for a user interface, and it’s only going to grow. A successful product might require native applications for mobile devices, a regular web implementation, or even a gaming console. These systems often will be centralized and data driven. The solution is one that’s fairly solitary, a service layer! Simply put, take what’s shared and put it behind a physical or abstract layer that defines the boundary between the specific user interface and the shared content.   I know, I know, none of this is complicated. But some times it can be difficult to discern what belongs on which side of the line. For instance, say we’re creating a service that will provide content for both an ASP.NET MVC application and a WP7 application. Although the content served to each application is the same, there are different paradigms and patterns for displaying that data in the different environments. In ASP.NET MVC, you may create a model specific to a page that combines necessary information. In the WP7 application you might require different sets of data that you will connect via MVVM with the view. The general rule of thumb is that any shared content, business rules, or data should exist separately. Any element that is specific to the current UI implementation should be included in a separate library or with the UI implementation itself. The WP7 application doesn’t need my MVC specific model classes. My MVC application doesn’t require those INotifyPropertyChanged viewmodels that the WP7 application depends on. In both cases, there should be additional processing done above the service layer to massage the data to the application’s specific needs.   Service-ocalypse: the text based adventure What helps me the most about deciding whether or not something belongs coupled to the UI implementation or in the shared implementation is thinking of the simplest implementation you could have: a console application. You might have played a game like Peasant’s Quest: The console app is the text based adventure game version of your application. If you’re service was consumed in its simplest form, you would simply have a console based API for it that issues requests. Maybe those requests aren’t SWIM TO BOAT, but they might be CREATE USER JOHN. If I issue a request, I expect that request to be issued to the service. If the service has any exceptions or issues with my input, that business logic should be encapsulated in that service, not implemented in the UI. The service layer should be your functional application in its entirety, and anything above that layer should only assist with the display of that information.

  Read the article

• Complete Beginner to Game Programming and Unreal Engine 4, Looking For Advice [on hold]

  - by onemic

  I am currently a 2nd year programming student(Just finished my first year so I will be starting my second year in September) and have mainly learned C and C++ in my classes. In terms of what I know of C++, I know about general inheritance, polymorphism, overloading operators, iterators, a little bit about templates(only class and function templates) etc. but not of the more advanced topics like linked lists and other sequential containers(containers in general I guess), enumerations, most of the standard library(other than like strings and vectors), and probably a bunch of other stuff I dont even know about yet. I subscribed to Unreal Engine 4 as I was very intrigued by their Unreal Tournament announcement earlier this month, especially after hearing that UE4 is going completely C++. Of course my end goal in doing this programming program is to eventually go into game/graphics programming. Since it's my summer off, I thought what better way then to actually apply some of my skills to a personal project so I actually have a firmer understanding of C++ past what my professors tell me. My questions are this: What would be the best way to start off making a small personal game in UE4 as a project for the summer? What should I be aiming for, especially for someone that is still learning C++? Should I focus on making a simple 2D game rather than a 3D one to get started? Seeing the Flappy Chicken showcase intrigued me because before I thought the UE engine was pretty much pigeonholed into being for FPS games What should my expectations be going into UE4 and a game engine for the first time?(UE4 will be my first foray into making a game) What can I expect to gain from making things in UE4, in terms of making games and in terms of further fleshing out my knowledge of C++? Would you recommend I start off 100% using C++ for scripting or using the visual blueprints? Since I'm not a designer, how would I be able to add objects and designs to my game? For someone at my level is retaining the UE4 subscription worth it or is it better to cancel and resub when I learn enough about UE4 and C++? Lastly is there anything to be gained in terms of knowledge/insight through me looking at the source code for UE4? I opened it in VS2013, but noticed that most of the files were C# files and not cpp's. Thanks in advance for taking the time to answer.

  Read the article

• Designing Snake AI

  - by Ronald

  I'm new to this gamedev stackechange but have used the math and cs sites before. So, I'm in a competition to create AI for a snake that will compete with 3 other snakes in 5 minute rounds where the rules are much like the traditional Nokia snake game except that there are 4 snakes, the board is 50x50 and there are a number of small obstacles on the field. Like the Nokia game, your snake grows when you get to the fruit and if you crash into yourself, another snake or the wall you die. The game runs with a 50ms delay between moves and the server sends the new game state every 50ms which the code must analyze and what not and output the next move. The winner is the snake who had the longest length at any point in the game. Tie breakers are decided by kills. So far what I have done is implemented an A* graph search from each snake to determine if my snake is the closest to the apple and if it is, it goes for the apple. Otherwise, I made a neat little algorithm to determine the emptiest area of the board, which my snake goes for, to anticipate the next apple. Other than this I have some small survivability checks to ensure my snake isn't walking into a trap that it can't get out and if it does get stuck, I have something to give it a better chance of getting out. ... Anyway, I've tested my snake on a test server and it does quite well. Generally, my strategy of only going for the apple when its a sure thing and finding space when its not makes it grow faster than any other snakes (some snakes do a similar thing but often just go to the middle or a corner) sometimes it wins these trial games but is more often than not beaten by the same snake who seems to have the edge on survivability(my snake grows quicker but then dies somehow and this other snake just plods slowly along and wins on consistency. So I was wondering about any ideas anyone has to try and improve my snake. Or maybe ideas at a new approach to take. My functions and classes are good so changes that might seem drastic shouldn't be too bad. I encourage all ideas. Any thoughts ??

  Read the article

• Is return-type-(only)-polymorphism in Haskell a good thing?

  - by dainichi

  One thing that I've never quite come to terms with in Haskell is how you can have polymorphic constants and functions whose return type cannot be determined by their input type, like class Foo a where foo::Int -> a Some of the reasons that I do not like this: Referential transparency: "In Haskell, given the same input, a function will always return the same output", but is that really true? read "3" return 3 when used in an Int context, but throws an error when used in a, say, (Int,Int) context. Yes, you can argue that read is also taking a type parameter, but the implicitness of the type parameter makes it lose some of its beauty in my opinion. Monomorphism restriction: One of the most annoying things about Haskell. Correct me if I'm wrong, but the whole reason for the MR is that computation that looks shared might not be because the type parameter is implicit. Type defaulting: Again one of the most annoying things about Haskell. Happens e.g. if you pass the result of functions polymorphic in their output to functions polymorphic in their input. Again, correct me if I'm wrong, but this would not be necessary without functions whose return type cannot be determined by their input type (and polymorphic constants). So my question is (running the risk of being stamped as a "discussion quesion"): Would it be possible to create a Haskell-like language where the type checker disallows these kinds of definitions? If so, what would be the benefits/disadvantages of that restriction? I can see some immediate problems: If, say, 2 only had the type Integer, 2/3 wouldn't type check anymore with the current definition of /. But in this case, I think type classes with functional dependencies could come to the rescue (yes, I know that this is an extension). Furthermore, I think it is a lot more intuitive to have functions that can take different input types, than to have functions that are restricted in their input types, but we just pass polymorphic values to them. The typing of values like [] and Nothing seems to me like a tougher nut to crack. I haven't thought of a good way to handle them. I doubt I am the first person to have had thoughts like these. Does anybody have links to good discussions about this Haskell design decision and the pros/cons of it?

  Read the article

• More elegant way to avoid hard coding the format of a a CSV file?

  - by dsollen

  I know this is trivial issue, but I just feel this can be more elegant. So I need to write/read data files for my program, lets say they are CSV for now. I can implement the format as I see fit, but I may have need to change that format later. The simply thing to do is something like out.write(For.getValue()+","+bar.getMinValue()+","+fi.toString()); This is easy to write, but obviously is guilty of hard coding and the general 'magic number' issue. The format is hard-coded, requires parsing of the code to figure out the file format, and changing the format requires changing multiple methods. I could instead have my constants specifying the location that I want each variable to be saved in the CSV file to remove some of the 'magic numbers'; then save/load into the an array at the location specified by the constants: int FOO_LOCATION=0; int BAR_MIN_VAL_LOCATION=1; int FI_LOCATION=2 int NUM_ARGUMENTS=3; String[] outputArguments=new String[NUM_ARGUMENTS]; outputArguments[FOO_LOCATION] = foo.getValue(); outputArgumetns[BAR_MIN_VAL_LOCATION] = bar.getMinValue(); outptArguments[FI_LOCATOIN==fi.toString(); writeAsCSV(outputArguments); But this is...extremely verbose and still a bit ugly. It makes it easy to see the format of existing CSV and to swap the location of variables within the file easily. However, if I decide to add an extra value to the csv I need to not only add a new constant, but also modify the read and write methods to add the logic that actually saves/reads the argument from the array; I still have to hunt down every method using these variables and change them by hand! If I use Java enums I can clean this up slightly, but the real issue is still present. Short of some sort of functional programming (and java's inner classes are too ugly to be considered functional) I still have no obvious way of clearly expressing what variable is associated with each constant short of writing (and maintaining) it in the read/write methods. For instance I still need to write somewhere that the FOO_LOCATION specifies the location of foo.getValue(). It seems as if there should be a prettier, easier to maintain, manner for approaching this? Incidentally, I'm working in java at the moment, however, I am interested conceptually about the design approach regardless of language. Some library in java that does all the work for me is definitely welcome (though it may prove more hassle to get permission to add it to the codebase then to just write something by hand quickly), but what I'm really asking is more about how to write elegant code if you had to do this by hand.

  Read the article

• SharePoint 2010 HierarchicalConfig Caching Problem

  - by Damon

  We've started using the Application Foundations for SharePoint 2010 in some of our projects at work, and I came across a nasty issue with the hierarchical configuration settings.  I have some settings that I am storing at the Farm level, and as I was testing my code it seemed like the settings were not being saved - at least that is what it appeared was the case at first.  However, I happened to reset IIS and the settings suddenly appeared.  Immediately, I figured that it must be a caching issue and dug into the code base.  I found that there was a 10 second caching mechanism in the SPFarmPropertyBag and the SPWebAppPropertyBag classes.  So I ran another test where I waited 10 seconds to make sure that enough time had passed to force the caching mechanism to reset the data.  After 10 minutes the cache had still not cleared.  After digging a bit further, I found a double lock check that looked a bit off in the GetSettingsStore() method of the SPFarmPropertyBag class: if (_settingStore == null || (DateTime.Now.Subtract(lastLoad).TotalSeconds) > cacheInterval)) { //Need to exist so don't deadlock. rrLock.EnterWriteLock(); try { //make sure first another thread didn't already load... if (_settingStore == null) { _settingStore = WebAppSettingStore.Load(this.webApplication); lastLoad = DateTime.Now; } } finally { rrLock.ExitWriteLock(); } } What ends up happening here is the outer check determines if the _settingStore is null or the cache has expired, but the inner check is just checking if the _settingStore is null (which is never the case after the first time it's been loaded).  Ergo, the cached settings are never reset.  The fix is really easy, just add the cache checking back into the inner if statement. //make sure first another thread didn't already load... if (_settingStore == null || (DateTime.Now.Subtract(lastLoad).TotalSeconds) > cacheInterval) { _settingStore = WebAppSettingStore.Load(this.webApplication); lastLoad = DateTime.Now; } And then it starts working just fine. as long as you wait at least 10 seconds for the cache to clear.

  Read the article

• Could I be going crazy with Event Handlers? Am I going the "wrong way" with my design?

  - by sensae

  I guess I've decided that I really like event handlers. I may be suffering a bit from analysis paralysis, but I'm concerned about making my design unwieldy or running into some other unforeseen consequence to my design decisions. My game engine currently does basic sprite-based rendering with a panning overhead camera. My design looks a bit like this: SceneHandler Contains a list of classes that implement the SceneListener interface (currently only Sprites). Calls render() once per tick, and sends onCameraUpdate(); messages to SceneListeners. InputHandler Polls the input once per tick, and sends a simple "onKeyPressed" message to InputListeners. I have a Camera InputListener which holds a SceneHandler instance and triggers updateCamera(); events based on what the input is. AgentHandler Calls default actions on any Agents (AI) once per tick, and will check a stack for any new events that are registered, dispatching them to specific Agents as needed. So I have basic sprite objects that can move around a scene and use rudimentary steering behaviors to travel. I've gotten onto collision detection, and this is where I'm not sure the direction my design is going is good. Is it a good practice to have many, small event handlers? I imagine going the way I am that I'd have to implement some kind of CollisionHandler. Would I be better off with a more consolidated EntityHandler which handles AI, collision updates, and other entity interactions in one class? Or will I be fine just implementing many different event handling subsystems which pass messages to each other based on what kind of event it is? Should I write an EntityHandler which is simply responsible for coordinating all these sub event handlers? I realize in some cases, such as my InputHandler and SceneHandler, those are very specific types of events. A large portion of my game code won't care about input, and a large portion won't care about updates that happen purely in the rendering of the scene. Thus I feel my isolation of those systems is justified. However, I'm asking this question specifically approaching game logic type events.

  Read the article

• PHP - Internal APIs/Libraries - What makes sense?

  - by Mark Locker

  I've been having a discussion lately with some colleagues about the best way to approach a new project, and thought it'd be interesting to get some external thoughts thrown into the mix. Basically, we're redeveloping a fairly large site (written in PHP) and have differing opinions on how the platform should be setup. Requirements: The platform will need to support multiple internal websites, as well as external (non-PHP) projects which at the moment consist of a mobile app and a toolbar. We have no plans/need in the foreseeable future to open up an API externally (for use in products other than our own). My opinion: We should have a library of well documented native model classes which can be shared between projects. These models will represent everything in our database and can take advantage of object orientated features such as inheritance, traits, magic methods, etc. etc. As well as employing ORM. We can then add an API layer on top of these models which can basically accept requests and route them to the appropriate methods, translating the response so that it can be used platform independently. This routing for each method can be setup as and when it's required. Their opinion: We should have a single HTTP API which is used by all projects (internal PHP ones or otherwise). My thoughts: To me, there are a number of issues with using the sole HTTP API approach: It will be very expensive performance wise. One page request will result in several additional http requests (which although local, are still ones that Apache will need to handle). You'll lose all of the best features PHP has for OO development. From simple inheritance, to employing the likes of ORM which can save you writing a lot of code. For internal projects, the actual process makes me cringe. To get a users name, for example, a request would go out of our box, over the LAN, back in, then run through a script which calls a method, JSON encodes the output and feeds that back. That would then need to be JSON decoded, and be presented as an array ready to use. Working with arrays, as appose to objects, makes me sad in a modern PHP framework. Their thoughts (and my responses): Having one method of doing thing keeps things simple. - You'd only do things differently if you were using a different language anyway. It will become robust. - Seeing as the API will run off the library of models, I think my option would be just as robust. What do you think? I'd be really interested to hear the thoughts of others on this, especially as opinions on both sides are not founded on any past experience.

  Read the article

• Collaborative work (small team) - Best practices

  - by LEM01

  I'm currently working in a very small team of programmers (2-3) and I'm looking for advices/best practices on how to organise our work. We're all working on the same application using PHP. Today we're kind of all working on our way. Today situation: List item that have to be worked on by each dev 1/week. What has to be done is defined at a high functional level (ex: Build the search engine for this product..) Commit / merge our individual branches (git) every week before the next meeting No real dev rules, no code review No test written (aouutch) Problems faced: Code quality issue: discovering someone else code is sometime tough (inline, variable+function+class names, spaces, comments..) Changes in already existing classes (impact on someone else work) Responsibility of each dev unclear: after getting someone else code and discover something messy, should I make the change? Should he make the change? How to plan those things,... What I'm looking for: Basically I'm looking into structuring the way we develop things in order to avoid frustration and improve overall quality. How to define coding standards (naming convention, code rules...)? Do you you any validation script to make sure code is valid before committing? Do you think that defining an architect role in the team is needed? Someone that would actually define what has to be developed during the next phase. By defining interfaces or class descriptions that have to be written. (Does it make sense in such a small team?) Today we're losing time into understanding what others did or tried to do, we're also losing time in discussion like "you should have done it that way! Why is this class doing that and not that..? Shouldn't we have a embedded class rather that this set of data...". I'm looking into a work process, maybe with more defined responsibilities and process in order to improve our performance. If you have experience, advices, best practices or anything to share that we could benefit from it will be much appreciated! Thanks a lot for your time!

  Read the article

• What is a useful pattern to maintaining an object state in a one to many relationship?

  - by ahenderson

  I am looking for a design for my application, here are the players(classes) involved. struct Transform { // Uses a matrix to transform the position. // Also acts acts as the state of a Dialog. Position transform(Position p); //other methods. }; struct Dialog { // There are multiple dialog for the user to transform the output. Transform& t; void ChangeTranformation(){t.rotate(360);} } struct Algorithm { //gives us a position based on an implementation. For example this can return points on a circle or line. Transform& t; Position m_p; Dialog& d; Position GetCurrentPosition(){ return t.transform(m_p);} //other methods. } Properties I need: Each algorithms has one dialog and each dialog can have many algorithms associated with it. When the user selects an algorithm a dialog associated with that algorithm is displayed. If the user selects a different algorithm then re-selects back the state is restored in the dialog. Basically I want a good design pattern to maintain the state of the dialog given that many algorithms use it and they can be switched back and forth. Does anyone have any suggestions? Here is a use case: Dialog1 has a single edit box to control the radius. Algorithm1 generates points on a unit circle. Algorithm2 is the same as Algorithm1. The user has selected Algorithm1 and entered 2 into the edit box. This will generate points on a circle of radius 2. The user then selects Algorithm2 and enters 10 into the edit box of Dialog1. This will generate points on a circle of radius 10. Finally Algorithm1 is selected again. The edit box of Dialog1 should show 2 and points on a circle of radius 2 should be generated.

  Read the article

• Entity Framework 5, separating business logic from model - Repository?

  - by bnice7

  I am working on my first public-facing web application and I’m using MVC 4 for the presentation layer and EF 5 for the DAL. The database structure is locked, and there are moderate differences between how the user inputs data and how the database itself gets populated. I have done a ton of reading on the repository pattern (which I have never used) but most of my research is pushing me away from using it since it supposedly creates an unnecessary level of abstraction for the latest versions of EF since repositories and unit-of-work are already built-in. My initial approach is to simply create a separate set of classes for my business objects in the BLL that can act as an intermediary between my Controllers and the DAL. Here’s an example class: public class MyBuilding { public int Id { get; private set; } public string Name { get; set; } public string Notes { get; set; } private readonly Entities _context = new Entities(); // Is this thread safe? private static readonly int UserId = WebSecurity.GetCurrentUser().UserId; public IEnumerable<MyBuilding> GetList() { IEnumerable<MyBuilding> buildingList = from p in _context.BuildingInfo where p.Building.UserProfile.UserId == UserId select new MyBuilding {Id = p.BuildingId, Name = p.BuildingName, Notes = p.Building.Notes}; return buildingList; } public void Create() { var b = new Building {UserId = UserId, Notes = this.Notes}; _context.Building.Add(b); _context.SaveChanges(); // Set the building ID this.Id = b.BuildingId; // Seed 1-to-1 tables with reference the new building _context.BuildingInfo.Add(new BuildingInfo {Building = b}); _context.GeneralInfo.Add(new GeneralInfo {Building = b}); _context.LocationInfo.Add(new LocationInfo {Building = b}); _context.SaveChanges(); } public static MyBuilding Find(int id) { using (var context = new Entities()) // Is this OK to do in a static method? { var b = context.Building.FirstOrDefault(p => p.BuildingId == id && p.UserId == UserId); if (b == null) throw new Exception("Error: Building not found or user does not have access."); return new MyBuilding {Id = b.BuildingId, Name = b.BuildingInfo.BuildingName, Notes = b.Notes}; } } } My primary concern: Is the way I am instantiating my DbContext as a private property thread-safe, and is it safe to have a static method that instantiates a separate DbContext? Or am I approaching this all wrong? I am not opposed to learning up on the repository pattern if I am taking the total wrong approach here.

  Read the article

• Android Array Lag?

  - by Mike

  I am making a platform game for Android. It is sort of a tile based game. I added bullets and enemies with AI and a bunch of tile types. I created a simple map with no Enemies. Everything was running well and smooth until I shot a bunch of bullets randomly everywhere. A couple of hundreds of bullets later, the FPS lowered. I made a test to find out if the bullets were the problem so I made another simple map with just a tile to stand on and left it for a while. Minutes later, I played around with it a bit to check if the FPS changed and it didnt. I reloaded the same map and shot a lot of bullets. Minutes later, the FPS was visibly lower even after the number of bullets were zero. Points to note: Programmed FPS is 30 Tested on a Samsung Galaxy Y and Samsung Galaxy W Any tile, enemy, bullet that is off screen is not drawn to prevent lag Bullets collide with Tiles (if they dont collide with in 450 frames, they are removed from the array) I used List bullets = new ListArray(); I used bullets.add(new Bullet(x, y, params...)); I used for(...){ if(...){ bullets.remove(i); } } Code for bullet: private void drawBullets(Canvas canvas) { for (int i = 0; i < bullets.size(); i++) { Bullet b = bullets.get(i); b.update(canvas); //updates physics if (b.t > blm) { //if the bullet is past its expiry bullets.remove(i); i--; } else { if (svx((b.x)) > 0 && svx(b.x) < width && svy((b.y)) > 0 && svy(b.y) < height) { // if bullet is not off screen b.draw(canvas); // draw the bullet } } } } I tried searching for solutions and references but I have no luck. I'm guessing that the lag has something to do with the Array and the Bullets or Classes that I've loaded? I'm not sure! Someone please help! Thanks in advance! :)

  Read the article

• Iscroll Wrapper doesnt get a height

  - by MCSell

  I got the following code: <div data-role="content" height="100%" data-iscroll> <div class="homebutton_zeile"> <a id="picture_home" href="#pictrues"> <div class="homebutton_all"> <div class="homebutton_name">Picture</div> <div class="homebutton_picture"> <img src="images/picture.png" alt="image" style="position: relative;"> </div> </div> </a> </div> </div> </div> My Classes of CSS .homebutton_zeile{ width: 100%; height: 30%; } .homebutton_all{ width: 30%; height: 90%; float:left; margin-left: 2%; margin-top:15px; } .homebutton_picture{ position: relative; width: 100%; height: 85%; float: left; background-color: #AAC7BD; border: 1px solid black; border-radius: 15px; box-shadow:8px 8px 8px #666; } .homebutton_name{ text-align:center; position: relative; top:-10px; width: 100%; height: 15%; margin-left: auto; text-decoration:none; color:black; } I am Using: iscroll.js jquery 1.8.2 jquery mobile 1.2.0 jqery mobile iscrollview. And if its needed to know jstorage.js and fastclick.js But the div above is not getting a height at the wrapper of iscroll. There is also a login before and this page will be shown automatically after the login after a $.mobile.changePage("#home"); function. I tried to do it as first page before the function of changePage and it gave me the same effect. If i put a   for example after the <div data-role="content" height="100%" data-iscroll>&nbps; The Wrapper get a height of 15px for the &nbps; but not for the images inside.

  Read the article

• Copying Properties between 2 Different Types&hellip;

  - by Shawn Cicoria

  I’m not sure where I had seen some of this base code, but this comes up time & time again on projects. Here’s a little method that copies all the R/W properties (public) between 2 distinct class definitions: It’s called as follows: private static void Test1() { MyClass obj1 = new MyClass() { Prop1 = "one", Prop2 = "two", Prop3 = 100 }; MyOtherClass obj2 = null; obj2 = CopyClass(obj1); Console.WriteLine(obj1); Console.WriteLine(obj2); } namespace Space1 { public class MyClass { public string Prop1 { get; set; } public string Prop2 { get; set; } public int Prop3 { get; set; } public override string ToString() { var rv = string.Format("MyClass: {0} Prop2: {1} Prop3 {2}", Prop1, Prop2, Prop3); return rv; } } } namespace Space2 { public class MyOtherClass { public string Prop1 { get; set; } public string Prop2 { get; set; } public int Prop3 { get; set; } public override string ToString() { var rv = string.Format("MyOtherClass: {0} Prop2: {1} Prop3 {2}", Prop1, Prop2, Prop3); return rv; } } Source of the method: /// /// Provides a Copy of Public fields between 2 distinct classes /// /// Source class name /// Target class name /// Instance of type Source /// An instance of type Target copying all public properties matching name from the Source. public static T CopyClass(S source) where T : new() { T target = default(T); BindingFlags flags = BindingFlags.Public | BindingFlags.Instance; if (source == null) { return (T)target; } if (target == null) target = new T(); PropertyInfo[] objProperties = target.GetType().GetProperties(flags); foreach (PropertyInfo pi in objProperties) { string name = pi.Name; PropertyInfo sourceProp = source.GetType().GetProperty(name, flags); if (sourceProp == null) { throw new ApplicationException(string.Format("CopyClass - object type {0} & {1} mismatch in property:{2}", source.GetType(), target.GetType(), name)); } if (pi.CanWrite && sourceProp.CanRead) { object sourceValue = sourceProp.GetValue(source, null); pi.SetValue(target, sourceValue, null); } else { throw new ApplicationException(string.Format("CopyClass - can't read/write a property object types {0} & {1} property:{2}", source.GetType(), target.GetType(), name)); } } return target; }

  Read the article

< Previous Page | 283 284 285 286 287 288 289 290 291 292 293 294  | Next Page >