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• Dim (NEARLY blank) laptop screen, secondary screen works - why?

  - by LIttle Ancient Forest Kami

  My laptop screen is (almost) black while my secondary screen is fine. I believe it to be backlight / brightness related. Problem description it starts when I start the laptop system loads and works fine, just screen has problems I can see the screen though very faintly / dimly - it's hard to see anything which ain't very white e.g. starting screen has big Thinkpad logo in white, large font - I can see it, though very dimly second screen works very well Official backligtht debugging: using acpi setting as prescribed there for Thinkpads didn't help I can see an entry in /sys/class/backlight/ and it changes when I press hotkeys for brightness (current backlight power for instance goes up or down) acpi-off didn't helpm neither did acpi_backlight=vendor Hardware data Laptop is Thinkpad Edge with glossy screen. 4 processors, 2 cores, exemplary CPU data from cat /proc/cpuinfo reports Genuine Intel i5 (M 480 @ 2.67GHz). OS is Ubuntu Lucid, 10.04 LTS, 64-bit, with Linux generic kernel (2.6.32-44) and GNOME 2.32.2 (though I doubt there lies the problem). $ lspci | grep VGA 01:00.0 VGA compatible controller: ATI Technologies Inc M92 [Mobility Radeon HD 4500 Series] $ lshw -C display *-display description: VGA compatible controller product: M92 [Mobility Radeon HD 4500 Series] vendor: ATI Technologies Inc physical id: 0 bus info: pci@0000:01:00.0 version: 00 width: 32 bits clock: 33MHz capabilities: pm pciexpress msi bus_master cap_list rom configuration: driver=radeon latency=0 resources: irq:33 memory:c0000000-dfffffff(prefetchable) ioport:2000(size=256) memory:f0300000-f030ffff memory:f0320000-f033ffff(prefetchable) Driver I was NOT running any proprietary drivers, just checked with "Hardware drivers". There is one for ATI that is suggested there, though I didn't need it so far. UPDATE: changing the driver to proprietary one (ATI/AMD FGLRX) didn't help. Tried and failed Resetting / running on power or battery / charging / getting rid of static electricity / warming up *doesn't help* This is NOT a blank-screen problem, at least it isn't following official Ubuntu black-screen diagnostics - I can see my screen, though barely. What I will try next: - check last updates I've made - IIRC I am running on nomodeset already, but will verify this Any ideas how to proceed best? What is most probable cause?

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• Oracle Partner Days and Oracle Days are coming to an EMEA city near you!

  - by Javier Puerta

  Oracle Partner Days A new round of Oracle Partner Days is coming to a large number of European cities. These events are exclusive for Oracle partners and will deliver to you real Business return on your OPN membership.You will hear the business opportunities coming from the adoption of the entire Oracle stack, the latest products value propositions and related sales strategy and be able to connect directly with Oracle executives and find new business opportunities with other partners in your region.The EMEA Oracle Partner Days are Local/Regional live events targeting the key contacts in sales and consultancy delivering Oracle strategy, engaging around the several perspectives of the Oracle portfolio, executive keynotes and deep dive Business content-related breakout sessions. The first city will be Frankfurt, on Oct. 29. Check the full list to find an Oracle Partner Day in a city near you. Oracle Days Oracle Days will be hosted after Oracle OpenWorld across EMEA, along October and November. By attending an Oracle Day, customers and partners can: Learn about how to leverage the power of the Oracle stack, by hearing customer case studies about successful business transformation, and by following cross-stack solution tracks within the agenda Discuss key issues for business and IT executives in cloud, big data, social, and mobile solutions, and network with peers who are facing the same challenges Meet Oracle experts and watch live demos of new products Get the latest news from Oracle OpenWorld. See full calendar and cities here

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• A few questions about how JavaScript works

  - by KayoticSully

  I originally posted on Stack Overflow and was told I might get some better answers here. I have been looking deeply into JavaScript lately to fully understand the language and have a few nagging questions that I can not seem to find answers to (Specifically dealing with Object Oriented programming. I know JavaScript is meant to be used in an OOP manner I just want to understand it for the sake of completeness). Assuming the following code: function TestObject() { this.fA = function() { // do stuff } this.fB = testB; function testB() { // do stuff } } TestObject.prototype = { fC : function { // do stuff } } What is the difference between functions fA and fB? Do they behave exactly the same in scope and potential ability? Is it just convention or is one way technically better or proper? If there is only ever going to be one instance of an object at any given time, would adding a function to the prototype such as fC even be worthwhile? Is there any benefit to doing so? Is the prototype only really useful when dealing with many instances of an object or inheritance? And what is technically the "proper" way to add methods to the prototype the way I have above or calling TestObject.prototype.functionName = function(){} every time? I am looking to keep my JavaScript code as clean and readable as possible but am also very interested in what the proper conventions for Objects are in the language. I come from a Java and PHP background and am trying to not make any assumptions about how JavaScript works since I know it is very different being prototype based. Also are there any definitive JavaScript style guides or documentation about how JavaScript operates at a low level? Thanks!

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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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• Design in "mixed" languages: object oriented design or functional programming?

  - by dema80

  In the past few years, the languages I like to use are becoming more and more "functional". I now use languages that are a sort of "hybrid": C#, F#, Scala. I like to design my application using classes that correspond to the domain objects, and use functional features where this makes coding easier, more coincise and safer (especially when operating on collections or when passing functions). However the two worlds "clash" when coming to design patterns. The specific example I faced recently is the Observer pattern. I want a producer to notify some other code (the "consumers/observers", say a DB storage, a logger, and so on) when an item is created or changed. I initially did it "functionally" like this: producer.foo(item => { updateItemInDb(item); insertLog(item) }) // calls the function passed as argument as an item is processed But I'm now wondering if I should use a more "OO" approach: interface IItemObserver { onNotify(Item) } class DBObserver : IItemObserver ... class LogObserver: IItemObserver ... producer.addObserver(new DBObserver) producer.addObserver(new LogObserver) producer.foo() //calls observer in a loop Which are the pro and con of the two approach? I once heard a FP guru say that design patterns are there only because of the limitations of the language, and that's why there are so few in functional languages. Maybe this could be an example of it? EDIT: In my particular scenario I don't need it, but.. how would you implement removal and addition of "observers" in the functional way? (I.e. how would you implement all the functionalities in the pattern?) Just passing a new function, for example?

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• Is there a schematic overview of Ubuntu's architecture?

  - by joebuntu

  Hi there, as enthusiastic, advanced Linux learner, I'd love to get an overview about Linux' architecure/structure in general. You know, like "the big picture". I'm thinking of a large schematic graphic showing what is what, who is who, what system (e.g. X) comprises which subsystems (GDM/Gnome/Compiz) on the way from a to z, from boot to interactive desktop, including the most important background services (auth, network, cron, ...). Maybe a bit like this: http://www.flickr.com/photos/pgc/140859386/ but way more detailed. There's bootchart, which produces very comprehensive charts, but they again are too detailed and difficult to get the "big picture" from. Is there such a thing? Possibly not for the whole System, but maybe for single subsystems? I had trouble searching for this, because using search terms like "scheme" or "architecture" pointed to the wrong direction (a tool called "scheme" or CAD software for linux). I appreciate any links. If there's interest in those schematic overviews and links, maybe someone could turn this post into a wiki post? Cheers, joebuntu

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• Anemic Domain Model, Business Logic and DataMapper (PHP)

  - by sunwukung

  I've implemented a rudimentary ORM layer based on DataMapper (I don't want to use a full blown ORM like Propel/Doctrine - for anything beyond simple fetch/save ops I prefer to access the data directly layer using a SQL abstraction layer). Following the DataMapper pattern, I've endeavoured to keep all persistence operations in the Mapper - including the location of related entities. My Entities have access to their Mapper, although I try not to call Mapper logic from the Entity interface (although this would be simple enough). The result is: // get a mapper and produce an entity $ProductMapper = $di->get('product_mapper'); $Product = $ProductMapper->find('[email protected]','email'); //.. mutaute some values.. save $ProductMapper->save($Product) // uses __get to trigger relation acquisition $Manufacturer = $Product->manufacturer; I've read some articles regarding the concept of an Anemic Domain model, i.e. a Model that does not contain any "business logic". When demonstrating the sort of business logic ideally suited to a Domain Model, however, acquiring related data items is a common example. Therefore I wanted to ask this question: Is persistence logic appropriate in Domain Model objects?

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• Why not commit unresolved changes?

  - by Explosion Pills

  In a traditional VCS, I can understand why you would not commit unresolved files because you could break the build. However, I don't understand why you shouldn't commit unresolved files in a DVCS (some of them will actually prevent you from committing the files). Instead, I think that your repository should be locked from pushing and pulling, but not committing. Being able to commit during the merging process has several advantages (as I see it): The actual merge changes are in history. If the merge was very large, you could make periodic commits. If you made a mistake, it would be much easier to roll back (without having to redo the entire merge). The files could remain flagged as unresolved until they were marked as resolved. This would prevent pushing/pulling. You could also potentially have a set of changesets act as the merge instead of just a single one. This would allow you to still use tools such as git rerere. So why is committing with unresolved files frowned upon/prevented? Is there any reason other than tradition?

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• Using ConcurrentQueue for thread-safe Performance Bookkeeping.

  - by Strenium

  Just a small tidbit that's sprung up today. I had to book-keep and emit diagnostics for the average thread performance in a highly-threaded code over a period of last X number of calls and no more. Need of the day: a thread-safe, self-managing stats container. Since .NET 4.0 introduced new thread-safe 'Collections.Concurrent' objects and I've been using them frequently - the one in particular seemed like a good fit for storing each threads' performance data - ConcurrentQueue. But I wanted to store only the most recent X# of calls and since the ConcurrentQueue currently does not support size constraint I had to come up with my own generic version which attempts to restrict usage to numeric types only: unfortunately there is no IArithmetic-like interface which constrains to only numeric types – so the constraints here here aren't as elegant as they could be. (Note the use of the Average() method, of course you can use others as well as make your own).   FIFO FixedSizedConcurrentQueue using System;using System.Collections.Concurrent;using System.Linq; namespace xxxxx.Data.Infrastructure{    [Serializable]    public class FixedSizedConcurrentQueue<T> where T : struct, IConvertible, IComparable<T>    {        private FixedSizedConcurrentQueue() { }         public FixedSizedConcurrentQueue(ConcurrentQueue<T> queue)        {            _queue = queue;        }         ConcurrentQueue<T> _queue = new ConcurrentQueue<T>();         public int Size { get { return _queue.Count; } }        public double Average { get { return _queue.Average(arg => Convert.ToInt32(arg)); } }         public int Limit { get; set; }        public void Enqueue(T obj)        {            _queue.Enqueue(obj);            lock (this)            {                T @out;                while (_queue.Count > Limit) _queue.TryDequeue(out @out);            }        }    } }   The usage case is straight-forward, in this case I’m using a FIFO queue of maximum size of 200 to store doubles to which I simply Enqueue() the calculated rates: Usage var RateQueue = new FixedSizedConcurrentQueue<double>(new ConcurrentQueue<double>()) { Limit = 200 }; /* greater size == longer history */   That’s about it. Happy coding!

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• How can I design my classes to include calendar events stored in a database?

  - by Gianluca78

  I'm developing a web calendar in php (using Symfony2) inspired by iCal for a project of mine. At this moment, I have two classes: a class "Calendar" and a class "CalendarCell". Here you are the two classes properties and method declarations. class Calendar { private $month; private $monthName; private $year; private $calendarCellList = array(); private $translator; public function __construct($month, $year, $translator) {} public function getCalendarCellList() {} public function getMonth() {} public function getMonthName() {} public function getNextMonth() {} public function getNextYear() {} public function getPreviousMonth() {} public function getPreviousYear() {} public function getYear() {} private function calculateDaysPreviousMonth() {} private function calculateNumericDayOfTheFirstDayOfTheWeek() {} private function isCurrentDay(\DateTime $dateTime) {} private function isDifferentMonth(\DateTime $dateTime) {} } class CalendarCell { private $day; private $month; private $dayNameAbbreviation; private $numericDayOfTheWeek; private $isCurrentDay; private $isDifferentMonth; private $translator; public function __construct(array $parameters) {} public function getDay() {} public function getMonth() {} public function getDayNameAbbreviation() {} public function isCurrentDay() {} public function isDifferentMonth() {} } Each calendar day can includes many calendar events (such as appointments or schedules) stored in a database. My question is: which is the best way to manage these calendar events in my classes? I think to add a eventList property in CalendarCell and populate it with an array of CalendarEvent objects fetched by the database. This kind of solution doesn't allow other coders to reuse the classes without db (because I should inject at least a repository services also) just to create and visualize a calendar... so maybe it could be better to extend CalendarCell (for instance in CalendarCellEvent) and add the database features? I feel like I'm missing some crucial design pattern! Any suggestion will be very appreciated!

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• CSOM (Client Side Object Model) - What's new with SharePoint 2013

  - by KunaalKapoor

  SharePoint CSOMThe Client-Side Object Model or CSOM came out with SharePoint 2010. CSOM is accessible through client.svc but all client.svc calls must go through supported WFC entry points (supported entry points are .NET, Silverlight and JavaScript). So a developer would need to use client side proxy objects exposed by either a .NET assembly or a JavaScript library. Changes with SharePoint 2013REST Capabilities - Direct access to client.svcNew APIs - App ModelREST CapabilitiesOne of the most important changes to the CSOM with SharePoint 2013 is that the web service entry point of client.svc has been extended to allow direct access  via REST-Based web service calls. This is a really critical change since its going to make the SharePoint platform accessible to any other platform, opening the horizons of integration and collaboration with other REST based platforms and devices. OData (a really popular standard data access API for HTTP-based clients) is supported similar to 2010 but will be a more important aspect of SharePoint 2013 development.New API'sCSOM for SharePoint 2013 has been buffed up with several new APIs for not only SharePoint server functionality but also an API for Windows Phone applications. For a SharePoint 2010 farm most of the new APIs mentioned below are available only via server side APIs:SearchTaxonomyPublishingWorkflowUser ProfilesE-DiscoveryAnalyticsBusiness DataIRMFeedsSharePoint 2013 remote APIs being accessible through both CSOM and REST is very important to the new app model where developers can no longer run code in a SharePoint environment nor can they access the server-side APIs. So CSOM plays the savior here.Also, you can now substitute the alias '_api' in order to reference '_vti_bin/client.svc'.

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• Is now the right time to move to .NET 4?

  - by bconlon

  The reason I pose this question is that I'm looking at WPF development and so using the latest version seems sensible. However, this means rolling out the .NET 4 runtime to PCs on old versions of the framework. Windows XP is still the number one O/S (estimated 40%+ market share). To run .NET 4 on XP requires Service Pack 3, and although it is good practice to move to the latest service packs, often large companies are slow to keep up due to the extensive testing involved. In fact, .NET 4 is not installed as standard with any Windows O/S as yet - Windows 7 and 2008 Server R2 have 3.5 installed. This is not quite as big an issue as it was for .NET 3.5 as .NET 4 is significantly smaller as it doesn't include the older runtimes - .NET 3.5 SP1 included .NET 3 and .NET 2 and was 250MB, although this was reduced by doing a web install. The size is also reduced a bit if you target the .NET 4 Client Profile, which should be OK for many WPF applications, and I think this may be rolled out as part of Windows service packs soon. But still, if your application is only 4-5 MB and you need 40-50 MB of Framework it is worth consideration before jumping in and using the new shiny features. #

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• Scene transitions

  - by Mars

  It's my first time working with actual scenes/states, aka DrawableGameComponents, which work separate from one another. I'm now wondering what's the best way to make transitions between them, and how to affect them from other scenes. Lets say I wanted to "push" one screen to the right, with another one coming in at the same time. Naturally I'd have to keep drawing both, until the transition is complete. And I'd have to adjust the coordinates I'm drawing at while doing it. Is there a way around specifically handling this special case in every single scene? Or of I wanted to fade one into the other. Basically the question stays the same, how would you do that without having to handle it in every single scene? While writing this I'm realizing it will be the same thing for all kinds of transitions. Maybe a central Draw method in the manager could be a solution, where parameters and effects are applied when necessary. But this wouldn't work if objects that are drawn have their own method, and aren't drawn within the scene, or if an effect has to be applied to the whole scene. That means, maybe scenes have to be drawn to their own rendertarget? That way one call to the base class after the normal drawing could be enough, to apply the effects, while drawing it to the main render target. But I once heard there are problems when switching from target to target, back and forth. So is that even a viable option? As you can see, I have some basic ideas how it might work... but nothing specific. I'd like to learn what's the common way to achieve such things, a general way to apply all kinds of transitions.

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• Is there a common programming term for the problems of adding features to an already-featureful program?

  - by Jeremy Friesner

  I'm looking for a commonly used programming term to describe a software-engineering phenomenon, which (for lack of a better way to describe it) I'll illustrate first with a couple of examples-by-analogy: Scenario 1: We want to build/extend a subway system on the outskirts of a small town in Wyoming. There are the usual subway-problems to solve, of course (hiring the right construction company, choosing the best route, buying the subway cars), but other than that it's pretty straightforward to implement the system because there aren't a huge number of constraints to satisfy. Scenario 2: Same as above, except now we need to build/extend the subway system in downtown Los Angeles. Here we face all of the problems we did in case (1), but also additional problems -- most of the applicable space is already in use, and has a vocal constituency which will protest loudly if we inconvenience them by repurposing, redesigning, or otherwise modifying the infrastructure that they rely on. Because of this, extensions to the system happen either very slowly and expensively, or they don't happen at all. I sometimes see a similar pattern with software development -- adding a new feature to a small/simple program is straightforward, but as the program grows, adding further new features becomes more and more difficult, if only because it is difficult to integrate the new feature without adversely affecting any of the large number of existing use-cases or user-constituencies. (even with a robust, adaptable program design, you run into the problem of the user interface becoming so elaborate that the program becomes difficult to learn or use) Is there a term for this phenomenon?

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• Is there a (family of) monotonically non-decreasing noise function(s)?

  - by Joe Wreschnig

  I'd like a function to animate an object moving from point A to point B over time, such that it reaches B at some fixed time, but its position at any time is randomly perturbed in a continuous fashion, but never goes backwards. The objects move along straight lines, so I only need one dimension. Mathematically, that means I'm looking for some continuous f(x), x ? [0,1], such that: f(0) = 0 f(1) = 1 x < y ? f(x) = f(y) At "most" points f(x + d) - f(x) bears no obvious relation to d. (The function is not uniformly increasing or otherwise predictable; I think that's also equivalent to saying no degree of derivative is a constant.) Ideally, I would actually like some way to have a family of these functions, providing some seed state. I'd need at least 4 bits of seed (16 possible functions), for my current use, but since that's not much feel free to provide even more. To avoid various issues with accumulation errors, I'd prefer the function not require any kind of internal state. That is, I want it to be a real function, not a programming "function".

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• Install Windows7 on drive with Ubuntu 12.04 already on. Is my plan good?

  - by John F

  I have Ubuntu 12.04 working fine, but need W7 occasionally. I just wanted to check that my plan for installing would work? Any help appreciated. Current partitions are: Partition....@ File System @ Mount Point @ Size.....@ Used.....@ Flags /dev/sda1....@ ext4........@ /ext4a......@ 37 GiB...@ 776 MiB..@ boot /dev/sda2....@ extended....@.............@ 122 GiB..@ -........@ ./dev/sda5...@ ext4........@ / ..........@ 37 GiB...@ 6 GiB....@ .unallocated @ unallocated @.............@ 7 GiB....@ - ...... @ ./dev/sda6 ..@ ext4........@ /home.......@ 77 GiB...@ 32 GiB...@ .unallocated @ unallocated @.............@ 65 GiB...@ - .......@ /dev/sda3...@ linux-swap..@.............@ 7 GiB....@ - .......@ My plan is to: - boot to ubuntu from USB ISO - change sda1 to NTFS - install W7 to sda1 - use the "Master Boot Record repair" utility to configure dual boot so I can see my original ubuntu installation as well as W7. Have I missed something? I'm concerned as to what the 776MB is that will be overwritten by the change to NTFS. It seems large for just the MBR? Would also appreciate it if anyone can explain what sda5 and 6 are being used for? Is sda5 Ubuntu and sda6 my data? Thanks in advance.

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• Prevent collisions between mobs/npcs/units piloted by computer AI : How to avoid mobile obstacles?

  - by Arthur Wulf White

  Lets says we have character a starting at point A and character b starting at point B. character a is headed to point B and character b is headed to point A. There are several simple ways to find the path(I will be using Dijkstra). The question is, how do I take preventative action in the code to stop the two from colliding with one another? case2: Characters a and b start from the same point in different times. Character b starts later and is the faster of the two. How do I make character b walk around character a without going through it? case3:Lets say we have m such characters in each side and there is sufficient room to pass through without the characters overlapping with one another. How do I stop the two groups of characters from "walking on top of one another" and allow them pass around one another in a natural organic way. A correct answer would be any algorithm, that given the path to the destination and a list of mobile objects that block the path, finds an alternative path or stops without stopping all units when there is sufficient room to traverse.

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• Over-scan Issues when using HDTV through VGA

  - by RPG Master

  Right now all we can do is set the TV to 1280x768 instead of its native resolution of 1360x768. Setting it to its native resolution gives you a screen with a large portion of the left side of the screen cut off. We've tried everything with the TV so now we're turning to the innards of Ubuntu in hopes of fixing this. The computer is using an NVIDIA GeForce GT240. This is its current xorg.conf: # nvidia-settings: X configuration file generated by nvidia-settings # nvidia-settings: version 1.0 (buildd@palmer) Fri Apr 9 10:35:18 UTC 2010 Section "ServerLayout" Identifier "Layout0" Screen 0 "Screen0" 0 0 InputDevice "Keyboard0" "CoreKeyboard" InputDevice "Mouse0" "CorePointer" Option "Xinerama" "0" EndSection Section "Files" EndSection Section "InputDevice" # generated from default Identifier "Mouse0" Driver "mouse" Option "Protocol" "auto" Option "Device" "/dev/psaux" Option "Emulate3Buttons" "no" Option "ZAxisMapping" "4 5" EndSection Section "InputDevice" # generated from default Identifier "Keyboard0" Driver "kbd" EndSection Section "Monitor" # HorizSync source: builtin, VertRefresh source: builtin # HorizSync 28.0 - 55.0 # VertRefresh 43.0 - 72.0 Identifier "Monitor0" VendorName "Unknown" ModelName "CRT-0" HorizSync 28.0 - 55.0 VertRefresh 43.0 - 72.0 Option "DPMS" EndSection Section "Device" Identifier "Device0" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce 6600" EndSection Section "Screen" # Removed Option "metamodes" "1360x768 +0+0; 800x600 +0+0" Identifier "Screen0" Device "Device0" Monitor "Monitor0" DefaultDepth 24 Option "TwinView" "0" Option "TwinViewXineramaInfoOrder" "CRT-0" Option "metamodes" "1360x768 +0+0" SubSection "Display" Depth 24 EndSubSection EndSection

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• Using a random string to authenticate HMAC?

  - by mrwooster

  I am designing a simple webservice and want to use HMAC for authentication to the service. For the purpose of this question we have: a web service at example.com a secret key shared between a user and the server [K] a consumer ID which is known to the user and the server (but is not necessarily secret) [D] a message which we wish to send to the server [M] The standard HMAC implementation would involve using the secret key [K] and the message [M] to create the hash [H], but I am running into issues with this. The message [M] can be quite long and tends to be read from a file. I have found its very difficult to produce a correct hash consistently across multiple operating systems and programming languages because of hidden characters which make it into various file formats. This is of course bad implementation on the client side (100%), but I would like this webservice to be easily accessible and not have trouble with different file formats. I was thinking of an alternative, which would allow the use a short (5-10 char) random string [R] rather than the message for autentication, e.g. H = HMAC(K,R) The user then passes the random string to the server and the server checks the HMAC server side (using random string + shared secret). As far as I can see, this produces the following issues: There is no message integrity - this is ok message integrity is not important for this service A user could re-use the hash with a different message - I can see 2 ways around this Combine the random string with a timestamp so the hash is only valid for a set period of time Only allow each random string to be used once Since the client is in control of the random string, it is easier to look for collisions I should point out that the principle reason for authentication is to implement rate limiting on the API service. There is zero need for message integrity, and its not a big deal if someone can forge a single request (but it is if they can forge a very large number very quickly). I know that the correct answer is to make sure the message [M] is the same on all platforms/languages before hashing it. But, taking that out of the equation, is the above proposal an acceptable 2nd best?

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• Can T520+Bumblebee run an external monitor via DisplayPort?

  - by Fen

  Using 64-bit Ubuntu 11.10 and integrated (Intel) graphics, I can run the 1600x900 laptop display plus a 1600x1200 external monitor connected to the VGA adapter. But my external monitor is 1920x1200 so I have black stripes on each side. I believe the resolution is limited like this as the maximum resolution available from the Intel GPU is 2560x1600 = 4,096,000 pixels and I'm asking for a 3520x1200 = 4,224,000 display (with 1200x300 lost above the laptop screen). At 3200x1200 = 3,840,000 pixels, the Intel GPU seems happy. Under Windows, the same limit exists when using the VGA adapter, but if I turn Optimus on then I can connect the external monitor to the DisplayPort and get its full resolution and an extended desktop. I've seen that Bumblebee can run apps on the DisplayPort using the 'optirun' command. My question is: can Bumblebee run the DisplayPort in concert with the Intel card running the laptop screen creating a large virtual desktop (as on Windows)? If so, are there any pointers to how to do this? I tried once, failed, and dropped back to Integrated Graphics (and black stripes) as I could find no reports of this configuration working.

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• How to Create a Grid for a 2D Game?

  - by SoulBeaver

  So I'm currently writing the engine for my videogame. I've almost integrated Tiled (I think) so I should have a map-creator here soon. My question is, how do I actually make the grid? I'm really confused here. If I create a large map with, say, 20x20 grids the size of 32x32 (screen size 640x640), then what do I do with it? Let's say I have the code for creating a window, and then place a player sprite that I can move with input, that's fine. If I use one map that's as big as the screen, then every pixel on the map is also a pixel on the game screen. The mapping is exact. Now what happens if I have a 2000x2000 map, for example? My character would have to keep moving and move the map around (or rather the camera focused on the player moves). Then I can no longer say that the screen maps exactly to the pixel position of the map. I tried making a Grid class that maps out the screen area to 32x32 tiles, but I'm not sure if that makes any sense. Once the map moves each tile would have to update its information, or something. I'm just really confused here. How do I actually make the tiles and a grid and map them to the data I get from tiled, or that I make myself? Are there any good examples of source code that I could look at?

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• Dynamic quadrees

  - by paul424

  recently I come out writing Quadtree for creatures culling in Opendungeons game. Thing is those are moving points and bounding hierarchy will quickly get lost if the quadtree is not rebuild very often. I have several variants, first is to upgrade the leaf position , every time creature move is requested. ( note if I would need collision detection anyway, so this might be necessery anyway). Second would be making leafs enough large , that the creature would sure stay inside it's bounding box ( due to its speed limit). The partition of a plane in quadtree is always fixed ( modulo the hierarchical unions of some parts) . For creatures close to the center of the plane , there would be no way of keeping it but inside one big leaf, besides this brokes the invariant that each point can be put into any small area as desired. So on the second thought could I use several quadrees ? Each would have its "coordinate axis XY" somwhere shifted ? Before I start playing with this maybe some other space diving structure would suit me better, unfortunetly wiki does not compare it's execution time : http://en.wikipedia.org/wiki/Grid_%28spatial_index%29#See_also

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• Learn More About the PO Approvals Analyzer

  - by LuciaC

  You may think that the PO Approvals Analyzer for Release 12 is only for diagnosing problems when you have a single Purchase Order or Requisition stuck in process, but it offers valuable information to keep your Procurement environment healthy.  Consider this:     The analyzer will list all Procurement critical patches that have not been applied.     It will provide Procurement invalid objects with error messages and provides solutions.     Validations of setup and database conditions for example max extents and space issues. Also the analyzer can be run on all Purchasing documents starting from a date you enter.  This multiple document check provides validations on:     Data corruption issues.     Workflow errors with generic messages i.e. document manager errors.     Documents with workflows in error that cannot be progressed via the application. And, unlike other diagnostics, the analyzer provides known solutions to the problems indicated! So access the Analyzer today and run it on your instance!  Access it now via Doc ID 1525670.1.

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• Must all AI states be able to react to any event?

  - by Prog

  FSMs implemented with the State design pattern are a common way to design AI agents. I am familiar with the State design pattern and know how to implement it. How is this used in games to design AI agents? Consider a simplified class Monster, representing an AI agent: class Monster { State state; // other fields omitted public void update(){ // called every game-loop cycle state.execute(this); } public void setState(State state){ this.state = state; } // irrelevant stuff omitted } There are several State subclasses implementing execute() differently. So far, classic State pattern. AI agents are subject to environmental effects and other objects communicating with them. For example, an AI agent might tell another AI agent to attack (i.e. agent.attack()). Or a fireball might tell an AI agent to fall down. This means that the agent must have methods such as attack() and fallDown(), or commonly some message receiving mechanism to understand such messages. With an FSM, the current State of the agent should be the one taking care of such method calls - i.e. the agent delegates to the current state upon every event. Is this correct? If correct, how is this done? Are all states obligated by their superclass to implement methods such as attack(), fallDown() etc., so the agent can always delegate to them on almost every event? Or is it done in some other way?

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• Are specific types still necessary?

  - by MKO

  One thing that occurred to me the other day, are specific types still necessary or a legacy that is holding us back. What I mean is: do we really need short, int, long, bigint etc etc. I understand the reasoning, variables/objects are kept in memory, memory needs to be allocated and therefore we need to know how big a variable can be. But really, shouldn't a modern programming language be able to handle "adaptive types", ie, if something is only ever allocated in the shortint range it uses fewer bytes, and if something is suddenly allocated a very big number the memory is allocated accordinly for that particular instance. Float, real and double's are a bit trickier since the type depends on what precision you need. Strings should however be able to take upp less memory in many instances (in .Net) where mostly ascii is used buth strings always take up double the memory because of unicode encoding. One argument for specific types might be that it's part of the specification, ie for example a variable should not be able to be bigger than a certain value so we set it to shortint. But why not have type constraints instead? It would be much more flexible and powerful to be able to set permissible ranges and values on variables (and properties). I realize the immense problem in revamping the type architecture since it's so tightly integrated with underlying hardware and things like serialization might become tricky indeed. But from a programming perspective it should be great no?

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