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  • Should I use procedural animation?

    - by user712092
    I have started to make a fantasy 3d fps swordplay game and I want to add animations. I don't want to animate everything by hand because it would take a lot of time, so I decided to use procedural animation. I would certainly use IK (starting with simple reaching an object with hand ...). I also assume procedural generation of animations will make less animations to do by hand (I can blend animations ...). I want also to have a planner for animation which would simplify complex animations; those which can be split to a sequence - run and then jump, jump and then roll - or which are separable - legs running and torso swinging with sword -. I want for example a character to chop a head of a big troll. If troll crouches character would just chop his head off, if it is standing he would climb on a troll. I know that I would have to describe the state ("troll is low", "troll is high", "chop troll head" ..) which would imply what regions animation will be in (if there is a gap between them character would jump), which would imply what places character can have some of legs and hands or would choose an predefined animation. My main goal is simplicity of coding, but I want my game to be looking cool also. Is it worthy to use procedural animation or does it make more troubles that it solves? (there can be lot of twiddling ...) I am using Blender Game Engine (therefore Python for scripting, and Bullet Physics).

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  • XNA - Finding boundaries in isometric tilemap

    - by Yheeky
    I have an issue with my 2D isometric engine. I'm using my own 2D camera class which works with matrices and need to find the tilemaps boundaries so the user always sees the map. Currently my map size is 100x100 (with 128x128 tiles) so the calculation (e.g. for the right boundary) is: var maxX = (TileMap.MapWidth + 1) * (TileMap.TileWidth / 2) - ViewSize.X; var maxX = (100 + 1) * (128 / 2) - 1360; // = 5104 pixels. This works fine while having scale factor of 1.0f but not for any other zoom factor. When I zoom out to 0.9f the right border should be at approx. 4954. I´m using the following code for transformation but I always get a wrong value: var maxXVector = new Vector2(maxX, 0); var maxXTransformed = Vector2.Transform(maxXVector, tempTransform).X; The result is 4593. Does anyone of you have an idea what I´m during wrong? Thanks for your help! Yheeky

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  • Calculating collision force with AfterCollision/NormalImpulse is unreliable when IgnoreCCD = false?

    - by Michael
    I'm using Farseer Physics Engine 3.3.1 in a very simple XNA 4 test game. (Note: I'm also tagging this Box2D, because Farseer is a direct port of Box2D and I will happily accept Box2D answers that solve this problem.) In this game, I'm creating two bodies. The first body is created using BodyFactory.CreateCircle and BodyType.Dynamic. This body can be moved around using the keyboard (which sets Body.LinearVelocity). The second body is created using BodyFactory.CreateRectangle and BodyType.Static. This body is static and never moves. Then I'm using this code to calculate the force of collision when the two bodies collide: staticBody.FixtureList[0].AfterCollision += new AfterCollisionEventHandler(AfterCollision); protected void AfterCollision(Fixture fixtureA, Fixture fixtureB, Contact contact) { float maxImpulse = 0f; for (int i = 0; i < contact.Manifold.PointCount; i++) maxImpulse = Math.Max(maxImpulse, contact.Manifold.Points[i].NormalImpulse); // maxImpulse should contain the force of the collision } This code works great if both of these bodies are set to IgnoreCCD=true. I can calculate the force of collision between them 100% reliably. Perfect. But here's the problem: If I set the bodies to IgnoreCCD=false, that code becomes wildly unpredictable. AfterCollision is called reliably, but for some reason the NormalImpulse is 0 about 75% of the time, so only about one in four collisions is registered. Worse still, the NormalImpulse seems to be zero for completely random reasons. The dynamic body can collide with the static body 10 times in a row in virtually exactly the same way, and only 2 or 3 of the hits will register with a NormalImpulse greater than zero. Setting IgnoreCCD=true on both bodies instantly solves the problem, but then I lose continuous physics detection. Why is this happening and how can I fix it? Here's a link to a simple XNA 4 solution that demonstrates this problem in action: http://www.mediafire.com/?a1w242q9sna54j4

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  • Looking for 2D Cross platform suggestions based on requirements specified

    - by MannyG
    I am an intermediate developer with minor experience on enterprise mobile applications for iphone, android and blackberry looking to build my first ever mobile game. I did a google search for some game dev forums and this popped up so I thought I would try posting here as I lack luck elsewhere. If you have ever heard of the game for the iphone and android platform entitled avatar fight then you will have an idea of the graphic capabilities I require. Basically the battles which are automated one sprite attacking another doing cool animations but all in 2d. My buddy and I have two motivations, one is to jump into mobile Dev as my experience is limited as is his so we would like some trending knowledge (html5 would be nice to learn) . The other is to make some money on the side, don't expect much but polishing the game and putting our all will hopefully reward us a bit. We have looked into corona engine, however a lot of people are saying it is limited in the graphics department, we are open to learning new languages like lua, c++, python etc. Others we have looked at include phonegap, rhomobile, unity, and the list goes on. I really have no idea what the pros and cons of these are but for a basic battle sequence and some mini games we want to chose the right one. Some more things that we will be doing include things like card games, side scrolling flying object based games, maybe fishing stuff. We want to start small with these minigames and work our way up to the idea we would like to implement in the future. We only want to work in 2D. So with these requirements please help me chose a platform to work on (cross platform is what we are ideally leaning towards). Please feel free to throw in some pieces of advice you may have for newbie game developers like myself too. Thank you for reading!

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  • What's a good Game development platform for a platformer game with these characteristics?

    - by Joe
    Yes, I know, the best way to make an indie game is to learn to code. I've got some scripting experience, but I want to do worldbuilding with already-existing tools (and communities surrounding those tools), and I've been really impressed with games like An Untitled Story that were made with pre-packaged toolsets at their core, like Game Maker. :) So I'm planning to make my game using either Game Maker or something like it. The basic parameters of my planned game: -2D platformer. -Physics/speed akin to Sonic the Hedgehog. -Large, non-linear world, flowing as seamlessly as possible -- think Super Metroid, but without the forced screen transitions. The first two points have me leaning toward Game Maker -- Plenty of 2D platformers have been made with it, and there are serviceable, openly available Sonic-the-Hedgehog-style physics engines for it that could be adapted to my needs with minimal muss and fuss. But the third makes me antsy -- from what limited information I hear, Game Maker has problems with large levels/boards/screens/whateveryoucallthem, thus necessitating transitions between screens. I want to avoid that if at all possible -- it would, I believe, fundamentally alter the flow of the game. I understand that generally speaking, the more you have loaded into memory the more things are going to chug (especially for a one-size-fits-all game development platform that isn't a model of efficient coding), but I'm hoping there are systems that can un-load objects that are sufficiently far offscreen and thus better produce seamlessness. Any thoughts, people? :) The sooner I can get a basic pre-fab physics engine and world-building program up and running, the sooner I can start prototyping areas and generally tooling around. Should I be looking at Game Maker, or elsewhere? (My current plan is to more-or-less build the game prototype-style, then worry about art and sound at the very end once the damn thing is playable.)

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  • Split a 2D scene in layers or have a z coordinate

    - by Bane
    I am in the process of writing a 2D game engine, and a dilemma emerged. Let me explain the situation... I have a Scene class, to which various objects can be added (Drawable, ParticleEmitter, Light2D, etc), and as this is a 2D scene, things will obviously be drawn over each other. My first thought was that I could have basic add and remove methods, but I soon realized that then there would be no way for the programmer to control the order in which things were drawn. So I can up with two options, each with its pros and cons. A) Would be to split the scene in layers. By that I mean instead of having the scene be a container of objects, have it be a container of layers, which are in turn the containers of objects. B) Would require to have some kind of z-coordinate, and then have the scene sorted so objects with lower z get drawn first. Option A is pretty solid, but the problem is with the lights. In what layer do I add it? Does it work cross-layer? On all bottom layers? And I still need the Z coordinate to calculate the shadow! Option B would require me to change all my code from having Vector2D positions, to some kind of class that inherits from Vector2D and adds a z coordinate to it (I don't want it to be a Vector3D because I still need all the same methods the 2D kind has, just with .z clamped on). Am I missing something? Is there an alternative to these methods? I'm working in Javascript, if that makes a difference.

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  • Efficiency concerning thread granularity

    - by MaelmDev
    Lately, I've been thinking of ways to use multithreading to improve the speed of different parts of a game engine. What confuses me is the appropriate granularity of threads, especially when dealing with single-instruction-multiple-data (SIMD) tasks. Let's use line-of-sight detection as an example. Each AI actor must be able to detect objects of interest around them and mark them. There are three basic ways to go about this with multithreading: Don't use threading at all. Create a thread for each actor. Create a thread for each actor-object combination. Option 1 is obviously going to be the least efficient method. However, choosing between the next two options is more difficult. Only using one thread per actor is still running through every object in series instead of in parallel. However, are CPU's able to create and join threads in the granularity posed in Option 3 efficiently? It seems like that many calls to the OS could be really slow, and varying enormously between different hardware.

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  • How to mange big amount users at server side?

    - by Rami
    I built a social android application in which users can see other users around them by gps location. at the beginning thing went well as i had low number of users, But now that I have increasing number of users (about 1500 +100 every day) I revealed a major problem in my design. In my Google App Engine servlet I have static HashMap that holding all the users profiles objects, currenty 1500 and this number will increase as more users register. Why I'm doing it Every user that requesting for the users around him compares his gps with other users and check if they are in his 10km radius, this happens every 5 min on average. That is why I can't get the users from db every time because GAE read/write operation quota will tare me apart. The problem with this desgin is As the number of users increased the Hashmap turns to null every 4-6 hours, I thing that this time is getting shorten but I'm not sure. I'm fixing this by reloading the users from the db every time I detect that it became null, But this causes DOS to my users for 30 sec, So I'm looking for better solution. I'm guessing that it happens because the size of the hashmap, Am I right? I have been advised to use spatial database, but that mean that I can't work with GAE any more and that mean that I need to build my big server all over again and lose my existing DB. Is there something I can do with the existing tools? Thanks.

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  • Leveraging Code Across Platforms in Ever Bigger Games

    - by ashes999
    Summary: The same way that I continually build complex engines and libraries within a single platform and technology to allow me to build increasingly bigger and better games, how to continue this when development crosses into different platforms? If I switch platforms, how do I leverage past code and experiences? Games are hard to build. Big games are even harder to build. I've decided that to be able to make big games, I need to start building smaller games, and building up an asset base of code, assets (graphics, sounds), tools, and most importantly, game engines, so that I can eventually get there. One game at a time. Let me give an analogy. To build an MMO 3D RPG, I would approach this by building and releasing small games with increasingly more features. This could entail, for example: A simple 2D game A tile-based game A game with RPG elements (items, equipment, monsters, battle) A full-fledged RPG A 3D RPG The problem now is if I have to change platforms or tools, I don't know how to leverage past code-bases (and experience) to start with a mature product. Right now, I'm writing Silverlight (FlatRedBall) games. Let's say I stick with this for ten years, and then suddenly decide to write a PS6 game, which is in a different programming language entirely. Granted, I have ten years of game-development experience (and correspondingly ten years of professional software development experience from my day job) to back me up. But I would still like some way to transplant that 2D RPG engine into the new programming language, or else leverage it somehow. Is this even possible? What are my options?

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  • How to manage many mobile device users at server side?

    - by Rami
    I built a social Android application in which users can see other users around them by GPS location. At the beginning thing went well as I had low number of users, but now that I have increasing number of users (about 1500 +100 every day) it has revealed a major problem in my design. In my Google App Engine servlet I have static HashMap that holds all the users profiles objects, currently 1500 and this number will increase as more users register. Why I'm doing it? Every user that requests for the users around him compares his GPS with other users and checks if they are in his 10km radius. This happens every five minutes on average. Consequently, I can't get the users from db every time because GAE read/write operation quota will tear me apart. The problem with this design is? As the number of users increases, the Hashmap turns to null every 4-6 hours, I think that this time is getting shorter, but I'm not sure. I'm fixing this by reloading the users from the db every time I detect that it becomes null, but this causes DOS to my users for 30 sec, so I'm looking for better solution. I'm guessing that it happens because the size of the hashmap. Am I right? I have been advised to use a spatial database, but that means that I can't work with GAE any more and it means that I need to build my big server all over again and lose my existing DB. Is there something I can do with the existing tools? Thanks.

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  • Java: How to Make a Player Class in a Tile-Based RPG

    - by A.K.
    So I've been following a JavaHub tutorial that basically uses a pixel engine similar to MiniCraft. I've attempted to make a Player Class as such, and I'm basically making a mock Pokemon game for learning's sake: package pokemon.entity; import java.awt.Rectangle; import pokemon.gfx.Screen; import pokemon.levelgen.Tile; import pokemon.entity.SpritesManage;; public class Player { int x, y; int vx, vy; public Rectangle AshRec; public Sprite AshSprite; Screen screen; Sprite[][] AshSheet; public Player() { AshSprite = SpritesManage.AshSheet[1][0]; AshRec = new Rectangle(0, 0, 16, 16); x = 0; y = 0; vx = 1; vy = 1; screen.renderSprite(0, 0, AshSprite); } public void update() { move(); checkCollision(); } private void checkCollision() { } private void move() { AshRec.x += vx; AshRec.y += vy; } public void render(Screen screen, int x, int y) { screen.renderSprite(x, y, AshSprite); } } I guess what I really want to do is have the Player centered in the screen and have the sprite drawn based on an Input Handler. I'm just stumped as to how to sync these together.

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  • Matrices: Arrays or separate member variables?

    - by bjz
    I'm teaching myself 3D maths and in the process building my own rudimentary engine (of sorts). I was wondering what would be the best way to structure my matrix class. There are a few options: Separate member variables: struct Mat4 { float m11, m12, m13, m14, m21, m22, m23, m24, m31, m32, m33, m34, m41, m42, m43, m44; // methods } A multi-dimensional array: struct Mat4 { float[4][4] m; // methods } An array of vectors struct Mat4 { Vec4[4] m; // methods } I'm guessing there would be positives and negatives to each. From 3D Math Primer for Graphics and Game Development, 2nd Edition p.155: Matrices use 1-based indices, so the first row and column are numbered 1. For example, a12 (read “a one two,” not “a twelve”) is the element in the first row, second column. Notice that this is different from programming languages such as C++ and Java, which use 0-based array indices. A matrix does not have a column 0 or row 0. This difference in indexing can cause some confusion if matrices are stored using an actual array data type. For this reason, it’s common for classes that store small, fixed size matrices of the type used for geometric purposes to give each element its own named member variable, such as float a11, instead of using the language’s native array support with something like float elem[3][3]. So that's one vote for method one. Is this really the accepted way to do things? It seems rather unwieldy if the only benefit would be sticking with the conventional math notation.

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  • Problems loading Hilva tutorials

    - by Beska
    I'm a newcomer to XNA, and I'm evaluating some libraries. The Hilva Graphics Engine looks interesting, and I'm trying to run their tutorials. However, all of them give me errors. For example, if I download the ParallaxMappingSample demo, and try to build it, I get Error 1 Error loading pipeline assembly "C:\Users\Me\Desktop\ParallaxMappingSample\Hilva.Content.dll". ParallaxMappingSample I get similar errors for all of the samples. Unfortunately, this error isn't very enlightening. I can see the Hilva.Content.dll in the appropriate directory. I tried removing and readding the reference from the content project, but I get the same error. I'm not sure it's relevant, but I'm on Windows 7, I'm using Microsoft Visual Studio 2010, and XNA 4.0. Is there an easy (or difficult) solution? EDIT: If you happen to try this, even if you don't have a solution, let me know about it in a comment. Whether it works for you, or if you get the same problem...either result would be something that might let me know if it's just a problem with the tutorial, or if it's on my end.

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  • Making efficeint voxel engines using "chunks"

    - by Wardy
    Concept I'm currently looking in to how voxel engines work with a view to possibly making one myself. I see a lot of stuff like this ... https://sites.google.com/site/letsmakeavoxelengine/home/chunks ... which talks about how to go about reducing the draw calls. What I can't seem to understand is how it actually saves draw call counts on the basis of the logic being something like this ... Without chunks foreach voxel in myvoxels DrawIfVisible() With Chunks foreach chunk in mychunks DrawIfVisible() which then does ... foreach voxel in myvoxels DrawIfVisible() So surely you saved nothing ?!?! You still make a draw call for each visible voxel do you not? A visible voxel needs a draw call in either scenario. The only real saving I can see is that the logic that evaluates a chunk will be able to determine if a large number of voxels are visible or not effectively saving a bit of "is this chunk visible" cpu time. But it's the draw calls that interest me ... The fewer of those, the faster the application. EDIT: In case it makes any difference I will probably be using XNA (DX not OpenGL) for my engine so don't consider my choice of example in the link above my choice of technology. But this question is such that I doubt it would matter.

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  • Farseer Physics Samples and Krypton how to reference game

    - by Krell
    I'm sure this is totally simple and yes I am new at this. I am trying to set up Krypton inside farseer. 1. create a new Krypton engine in my sub screen aka AdvancedDemo1 : PhysicsGameScreen, IDemoScreen Via this.krypton = new KryptonEngine(this, "KryptonEffect"); The problem is the KryptonEngine(this wants reference to Game game, I cant seem to reference it from FarseerPhysicsGame : Game So how would I do that? or 2. I can put it directly in FarsserPhysicsGame but again I cant seem to figure out how to reference FarseerPhysicsGame in AdvancedDemo1. or 3. I can put it inside the public FarseerPhysicsGame() and do Componenets.Add(krypton) [which works] HOWEVER I cant figure out how to reference the compoenet once it is added. You should be able to stop reading here , but for more detail I simply took the Farseer XNA Samples went into FarseerPhysicsGame.cs and deleted all the screens and menus except AdvancedDemo1 so there is one option and I just click that to load into the advancedDemo1 and thats where I want to put the lights from krypton. Thanks. Edit: Figured out 1 solution though I am still curious about others. Solution 1 I was able to use ScreenManager.Game(not sure why it was there but Ill try to figure it out later)

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  • On Developing Web Services with Global State

    - by user74418
    I'm new to web programming. I'm more experienced and comfortable with client-side code. Recently, I've been dabbling in web programming through Python's Google App Engine. I ran into some difficulty while trying to write some simple apps for the purposes of learning, mainly involving how to maintain some kind of consistent universally-accessible state for the application. I tried to write a simple queueing management system, the kind you would expect to be used in a small clinic, or at a cafeteria. Typically, this is done with hardware. You take a number from a ticketing machine, and when your number is displayed or called you approach the counter for service. Alternatively, you could be given a small pager, which will beep or vibrate when it is your turn to receive service. The former is somewhat better in that you have an idea of how many people are still ahead of you in the queue. In this situation, the global state is the last number in queue, which needs to be updated whenever a request is made to the server. I'm not sure how to best to store and maintain this value in a GAE context. The solution I thought of was to keep the value in the Datastore, attempt to query it during a ticket request, update the value, and then re-store it with put. My problem is that I haven't figured out how to lock the resource so that other requests do not check the value while it is in the middle of being updated. I am concerned that I may end up ticket requests that have the same queue number. Also, the whole solution feels awkward to me. I was wondering if there was a more natural way to accomplish this without having to go through the Datastore. Can anyone with more experience in this domain provide some advice on how to approach the design of the above application?

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  • this is my Receiving Email code,but can't Receiving Email .. (google-app-engine)

    - by zjm1126
    import logging, email from google.appengine.ext import webapp from google.appengine.ext.webapp.mail_handlers import InboundMailHandler from google.appengine.ext.webapp.util import run_wsgi_app class LogSenderHandler(InboundMailHandler): def receive(self, message): _subject = message.subject _sender=message.sender bodies = message.bodies('text/plain') allBodies = "" #for body in bodies: # allBodies = allBodies + "\n---------------------------\n" + body[1].decode() #m= mail.EmailMessage(sender="[email protected] ",subject="reply to "+_subject) #m.to = _sender #m.body =allBodies #m.send() message = mail.EmailMessage(sender="[email protected]", subject="Your account has been approved") message.to = _sender message.body = """ Dear Albert: Your example.com account has been approved. You can now visit http://www.example.com/ and sign in using your Google Account to access new features. Please let us know if you have any questions. The example.com Team """ message.send() application = webapp.WSGIApplication([LogSenderHandler.mapping()], debug=True) app.yaml: application: zjm1126 version: 1-2 runtime: python api_version: 1 inbound_services: - mail handlers: - url: /media static_dir: media - url: /_ah/mail/.+ script: handle_incoming_email.py login: admin - url: / script: a.py - url: /sign script: a.py - url: .* script: django_bootstrap.py i use my email:[email protected] send some words to [email protected] but i can't get a Receiving Email, why ??? thanks and this is the log:

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  • Using memcache to store obj's in google app engine.

    - by fredrik
    Hi, I'm trying to use memcache to cache data retrevied from the datastore. Storing stings works fine. But can't one store an object? I get an error "TypeError: 'str' object is not callable" when trying to store with this: pageData = PageType(page) memcache.add(memcacheid, pageData, 60) I've read in the documentation that it requires "The value type can be any value supported by the Python pickle module for serializing values." But don't really understand what that is. Or how to convert pageData to it. Any ideas? ..fredrik

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  • how to dispose a incoming email and then send some words back using googe-app-engine..

    - by zjm1126
    from google.appengine.api import mail i read the doc: mail.send_mail(sender="[email protected]", to="Albert Johnson <[email protected]>", subject="Your account has been approved", body=""" Dear Albert: Your example.com account has been approved. You can now visit http://www.example.com/ and sign in using your Google Account to access new features. Please let us know if you have any questions. The example.com Team """) and i know hwo to send a email using gae ,but how to check a email incoming, and then do something thanks

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  • How to roll back a google app engine transaction via web interface?

    - by LoudNPossiblyRight
    I tried to update my app on google appengine by my wireless dropped during the process. When i tried again i got an error "Another transaction by user ajakimov is already in progress for this app and major version." I know i can rollback the update using appcfg.py but i was wondering if it's possible to do this via some sort of a web interfiace (i tried the dashboard i couldn't find anything) ? Thanks.

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  • How do you Access an Authenticated Google App Engine Service with Ruby?

    - by viatropos
    I am trying to do this same thing here but with Ruby: Access Authenticated GAE Client with Python. Any ideas how to retrieve authenticated content from GAE with Ruby? I am using the Ruby GData Gem to access everything in Google Docs and such and it's making life very easy, but now I'd like to access things on GAE that require admin access, programmatically, and it doesn't support that. Here's what I'm getting (using DocList, not sure what to use yet): c = GData::Client::DocList.new c.clientlogin(username, password, nil, nil, nil, "HOSTED") c => #<GData::Client::DocList:0x201bad8 @clientlogin_service="writely", @version="2", @auth_handler=#<GData::Auth::ClientLogin:0x200803c @account_type="HOSTED", @token="long-hash", @auth_url="https://www.google.com/accounts/ClientLogin", @service="writely">, @source="AnonymousApp", @headers={"Authorization"=>"GoogleLogin auth=long-hash", "User-Agent"=>"GoogleDataRubyUtil-AnonymousApp", "GData-Version"=>"2", "Content-Type"=>"application/atom+xml"}, @authsub_scope="http://docs.google.com/feeds/", @http_service=GData::HTTP::DefaultService> url = "http://my-cdn.appspot.com/files/restricted-file.html" c.get(url) => #<GData::HTTP::Response:0x20004b8 @status_code=302, @body="", @headers={"connection"=>"close", "date"=>"Sun, 11 Apr 2010 00:30:20 GMT", "content-type"=>"text/html", "server"=>"Google Frontend", "content-length"=>"0", "location"=>"https://www.google.com/accounts/ServiceLogin service=ah&continue=http://my-cdn.appspot.com/_ah/login%3Fcontinue%3D http://my-cdn.appspot.com/files/restricted-file.html& ltmpl=gm&ahname=My+CDN&sig=a-signature"}> Any tips? That other SO question pointed to doing something with the redirect... Not sure how to handle that. Just looking for a point in the right direction from the ruby experts. Thanks.

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  • Google App Engine - Memcache - Java version of Python's client.add?

    - by Spines
    The python interface to the memcache has an add method: add(key, value, time=0, min_compress_len=0, namespace=None) Sets a key's value, if and only if the item is not already in memcache. ... The return value is True if added, False on error. So with this you can add an item if it doesn't exist, and see if it previously existed by the return value. The java memcache api equivalent for this doesn't let you know if there was a previous value or not: put(key, value, expiration, MemcacheService.SetPolicy.ADD_ONLY_IF_NOT_PRESENT); MemcacheService.SetPolicy.ADD_ONLY_IF_NOT_PRESENT: add the value if no value with the key, do nothing if the key exists Is there a way to know if a previous value existed or not with the java api? I can't just check with the contains method beforehand, because in between the call to contains and the call to put, another JVM instance could modify the memcache.

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  • How is parsing phase in a compiler different from a rule engine ?

    - by abhinav
    Hi, I have a rough understanding of how the compilers work (I mean languages, grammars, lexical analysis, parsing etc). The rule engines have various rules and associated action, just like you have rules in the grammars and you can associate actions with them in parser-generator tools like ANTLR. So I am a bit confused on how to differentiate between these two. Could anyone give a clearer, more formal explanation for the differences ? Thanks, Abhinav.

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