Search Results

Search found 1066 results on 43 pages for 'collision avoidance'.

Page 37/43 | < Previous Page | 33 34 35 36 37 38 39 40 41 42 43  | Next Page >

  • Pure functional programming and game state

    - by Fu86
    Is there a common technique to handle state (in general) in a functional programming language? There are solutions in every (functional) programming language to handle global state, but I want to avoid this as far as I could. All state in a pure functional manner are function parameters. So I need to put the whole game state (a gigantic hashmap with the world, players, positions, score, assets, enemies, ...)) as a parameter to all functions which wants to manipulate the world on a given input or trigger. The function itself picks the relevant information from the gamestate blob, do something with it, manipulate the gamestate and return the gamestate. But this looks like a poor mans solution for the problem. If I put the whole gamestate into all functions, there is no benefit for me in contrast to global variables or the imperative approach. I could put just the relevant information into the functions and return the actions which will be taken for the given input. And one single function apply all the actions to the gamestate. But most functions need a lot of "relevant" information. move() need the object position, the velocity, the map for collision, position of all enemys, current health, ... So this approach does not seem to work either. So my question is how do I handle the massive amount of state in a functional programming language -- especially for game development?

    Read the article

  • 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

    Read the article

  • Managing many draw calls for dynamic objects

    - by codetiger
    We are developing a game (cross-platform) using Irrlicht. The game has many (around 200 - 500) dynamic objects flying around during the game. Most of these objects are static mesh and build from 20 - 50 unique Meshes. We created seperate scenenodes for each object and referring its mesh instance. But the output was very much unexpected. Menu screen: (150 tris - Just to show you the full speed rendering performance of 2 test computers) a) NVidia Quadro FX 3800 with 1GB: 1600 FPS DirectX and 2600 FPS on OpenGL b) Mac Mini with Geforce 9400M 256mb: 260 FPS in OpenGL Now inside the game in a test level: (160 dynamic objects counting around 10K tris): a) NVidia Quadro FX 3800 with 1GB: 45 FPS DirectX and 50 FPS on OpenGL b) Mac Mini with Geforce 9400M 256mb: 45 FPS in OpenGL Obviously we don't have the option of mesh batch rendering as most of the objects are dynamic. And the one big static terrain is already in single mesh buffer. To add more information, we use one 2048 png for texture for most of the dynamic objects. And our collision detection hardly and other calculations hardly make any impact on FPS. So we understood its the draw calls we make that eats up all FPS. Is there a way we can optimize the rendering, or are we missing something?

    Read the article

  • Seperation of drawing and logic in games

    - by BFree
    I'm a developer that's just now starting to mess around with game development. I'm a .Net guy, so I've messed with XNA and am now playing around with Cocos2d for the iPhone. My question really is more general though. Let's say I'm building a simple Pong game. I'd have a Ball class and a Paddle class. Coming from the business world development, my first instinct is to not have any drawing or input handling code in either of these classes. //pseudo code class Ball { Vector2D position; Vector2D velocity; Color color; void Move(){} } Nothing in the ball class handles input, or deals with drawing. I'd then have another class, my Game class, or my Scene.m (in Cocos2D) which would new up the Ball, and during the game loop, it would manipulate the ball as needed. The thing is though, in many tutorials for both XNA and Cocos2D, I see a pattern like this: //pseudo code class Ball : SomeUpdatableComponent { Vector2D position; Vector2D velocity; Color color; void Update(){} void Draw(){} void HandleInput(){} } My question is, is this right? Is this the pattern that people use in game development? It somehow goes against everything I'm used to, to have my Ball class do everything. Furthermore, in this second example, where my Ball knows how to move around, how would I handle collision detection with the Paddle? Would the Ball need to have knowledge of the Paddle? In my first example, the Game class would have references to both the Ball and the Paddle, and then ship both of those off to some CollisionDetection manager or something, but how do I deal with the complexity of various components, if each individual component does everything themselves? (I hope I'm making sense.....)

    Read the article

  • Quadcopters Play Catch [Video]

    - by Jason Fitzpatrick
    Working like a group of hive-minded bees, these quadcopters come off as almost playful with their ball throwing antics. Courtesy of the folks at the Swiss Federal Institute of Technology in Zurich’s Institute for Dynamic Systems and Control, we’re treated to a video of three quadcopters playing catch in the research facility’s Flying Machine Area. They explain the processes demonstrated in the video: This video shows three quadrocopters cooperatively tossing and catching a ball with the aid of an elastic net. To toss the ball, the quadrocopters accelerate rapidly outward to stretch the net tight between them and launch the ball up. Notice in the video that the quadrocopters are then pulled forcefully inward by the tension in the elastic net, and must rapidly stabilize in order to avoid a collision. Once recovered, the quadrotors cooperatively position the net below the ball in order to catch it. Because they are coupled to each other by the net, the quadrocopters experience complex forces that push the vehicles to the limits of their dynamic capabilities. To exploit the full potential of the vehicles under these circumstances requires several novel algorithms, including: HTG Explains: How Antivirus Software Works HTG Explains: Why Deleted Files Can Be Recovered and How You Can Prevent It HTG Explains: What Are the Sys Rq, Scroll Lock, and Pause/Break Keys on My Keyboard?

    Read the article

  • Help w/ iPad 1 performance for tile-based DOM Javascript game

    - by butr0s
    I've made a 2D tile-based game with DOM/Javascript. For each level, the map data is loaded and parsed, then lots of tiles ( elements) are drawn onto a larger "map" element. The map is inside of a container that hides overflow, so I can move the map element around by positioning it absolutely. Works a treat on desktop browsers, and my iPad 2. My problem is that performance is really bad on iPad 1. The performance hit is directly related to all the tile elements in my map, because when I remove or reduce the number of tiles drawn, performance improves. Optimizing my collision detection loop has no effect. My first thought was to batch groups of tiles into containers, then hide/show them based on proximity to the player, however this still causes a huge hiccup when the player moves and a new group of tiles is displayed (offscreen). Actually removing the out-of-sight elements from the DOM, then re-adding them as necessary is no faster. Anyone know of any tips that might speed up DOM performance here? My map is 1920 x 1920 pixels, so as far as I know should be within the WebKit texture limit on iOS 5/iPad. The map is being moved with CSS3 transforms, and I've picked all the other obvious low-hanging fruit.

    Read the article

  • Polygon is rotating too fast

    - by Manderin87
    I am going to be using a polygon collision detection method to test when objects collide. I am attempting to rotate a polygon to match the sprites rotation. However, the polygon is rotating too fast, much faster than the sprite is. I feel its a timing issue, but the sprite rotates like it is supposed to. Can anyone look at my code and tell me what could be causing this issue? public void rotate(float x0, float y0, double angle) { for(Point point : mPoints) { float x = (float) (x0 + (point.x - x0) * Math.cos(Utilities.toRadians(angle)) - (point.y - y0) * Math.sin(Utilities.toRadians(angle))); float y = (float) (y0 + (point.x - x0) * Math.sin(Utilities.toRadians(angle)) + (point.y - y0) * Math.cos(Utilities.toRadians(angle))); point.x = x; point.y = y; } } This algorithm works when done singly, but once I plug it into the update method the rotation is too fast. The Points used are: P1 608, 368 P2 640, 464 P3 672, 400 Origin x0 is: 640 400 The angle goes from 0 to 360 as the sprite rotates. When the codes executes the triangle looks like a star because its moving so fast. The rotation is done in the sprites update method. The rotation method just increases the sprites degree by .5 when it executes. public void update() { if(isActive()) { rotate(); mBounding.rotate(mPosition.x, mPosition.y, mDegree); } }

    Read the article

  • What's a good way to check that a player has clicked on an object in a 3D game?

    - by imja
    I'm programming a 3D game (using C++ and OpenGL), and I have a few 3D objects in the scene, we can say they are boxes for this example. I want to let the player click on those boxes to select them (ie. they might change color) with the typical restriction like if more than one box is located where the user clicked, only the one closest to the camera would get selected. What would be the best way to do this? The fact that these objects go through several transforms before getting to window coordinates is what makes this a bit tricky. One approach I thought about was that if the player clicks on the screen, I could normalize the x,y coordinates of mouse click and then transform the bounding box coordinates of the objects into clip-space so that I could compare then to the normalized mouse coordinates. I guess I could then do some sort of ray-box collision test to see if any objects lie as the path of the mouse click. I'm afraid I might be over complicating it. Any better methods out there?

    Read the article

  • Sub-systems in game engines

    - by Hillel
    So here's the problem- I'm writing my own engine library, and it works fine with stuff like menus and the actual game screen. The thing is, I can't really figure out how to integrate something like an intro or dialogue preceding certain levels into this system. Let's look at another example- say I have a game-specific engine which gets a Level object and runs it. Engine would have its own collision and physics system, all hard coded. Now, what if at some point in a level, I want the player to enter a mini-game with different rules? How do I morph the Engine class to support these sub-systems without having to deal with their code all the time (as in: if(regular game) ... else if(mini game) ...)? And what if I want an intro animation at the start of a level, and I want the player to be able to assume control of his character once the animation ends, do I implement the animation into the Engine class itself? Or maybe I need to run another class, CutScene, and when it ends, it calls Engine and starts the level? What if I want to add a dialogue system, where at the start of each level there's a short dialogue and the player can't control his character, and once it ends, he can? Would I then run the dialogue code inside the Engine code? Maybe these sub-systems should all be scripted? I don't know anything about scripting, is it necessary for this kind of situation? Any help would be appreciated.

    Read the article

  • Input prediction and server re-simultaion

    - by Lope
    I have read plenty of articles about multiplayer principles and I have basic client-server system set up. There is however one thing I am not clear on. When player enters input, it is sent to the server and steps back in time to check if what should have happened at the time of that input and it resimulates the world again. So far everything's clear. All articles took shooting as an example, because it is easy to explain and it is pretty straightforward, but I believe movement is more complicated. Imagine following situation: 2 players move towards each other. A------<------B Player A stops halfway towards the collision point, but there is lag spike so the command does not arrive on the server for a second or so. Current state of the world on the server (and on the other clients as well) at the time when input arrives is this: [1]: -------AB------- The command arrives and we go back in time and re-simulate the world, the result is this: [2]: ---AB----------- Player A sees situation [2] which is correct, but the player is suddenly teleported from the position in [1] (center) to the position in [2]. Is this how this is supposed to work? Point of the client prediction is to give lagged player feeling that everything is smooth, not to ruin experience for other players. Alternative is to discard timestamp on the player's input and handle it when it arrives on the server without going back in time. This, however, creates even more severe problems for lagged player (even if he is lagging just a bit)

    Read the article

  • Rectangular Raycasting?

    - by igrad
    If you've ever played The Swapper, you'll have a good idea of what I'm asking about. I need to check for, and isolate, areas of a rectangle that may intersect with either a circle or another rectangle. These selected areas will receive special properties, and the areas will be non-static, since the intersecting shapes themselves will also be dynamic. My first thought was to use raycasting detection, though I've only seen that in use with circles, or even ellipses. I'm curious if there's a method of using raycasting with a more rectangular approach, or if there's a totally different method already in use to accomplish this task. I would like something more exact than checking in large chunks, and since I'm using SDL2 with a logical renderer size of 1920x1080, checking if each pixel is intersecting is out of the question, as it would slow things down past a playable speed. I already have a multi-shape collision function-template in place, and I could use that, though it only checks if sides or corners are intersecting; it does not compute the overlapping area, or even find the circle's secant line, though I can't imagine it would be overly complex to implement. TL;DR: I need to find and isolate areas of a rectangle that may intersect with a circle or another rectangle without checking every single pixel on-screen.

    Read the article

  • What could cause a sudden stop in Box2D?

    - by alexanderpine
    I'm using Box2d for a game, and I have a bug that's driving me nuts. I've simplified the situation down to a square player sliding back and forth frictionlessly on top of a floor composed of a series of square tiles, driven by the left and right keys (which apply a horizontal force). Works great, sliding back and forth across the whole floor. Except... Every once in a while, the player will suddenly stick at the edge of one of the tiles as if it is hitting a (nonexistent) wall. Further pushes in the same direction it was traveling will fail, but as soon as I push backwards once in the opposite direction, I can push forwards past the sticking point again. The sticking point seems to be random, except for being on the edge of a tile. Happens while going left or right. For debugging purposes, I keep the Positions/velocity values for the previous two update ticks and print them out when this stop occurs. As an example, here you see the player moving right, decelerating slightly; pos2 should be about 8.7, but it stops dead instead. tick0: pos= 8.4636 vel= 7.1875 tick1: pos= 8.5816 vel= 7.0833 tick2: pos= 8.5816 vel= 0.0000 So, as the player is 0.8 and the tiles 1.0 wide, the player is stopping just as it is about to cross onto the next tile (8.5816 + 0.8/2 = 8.9816). In fact, I get a collision message (which I ignore except noting that it happened). It only seems to happen at x.5816 (or -x.4184) while moving right, and x.4167 (or -x.5833) while moving left I said that it's like hitting a wall, but in fact, when it hits a wall, the numbers look more like: tick0: pos0= 12.4131 vel2= 8.4375 tick1: pos1= 12.5555 vel1= 8.5417 tick2: pos2= 12.5850 vel0= 0.0000 so it moves further right on the last tick, which puts it in contact with the wall. Anyone seen anything like this. Any suggestion on how I could be causing this behavior.

    Read the article

  • Which jar has JBox2d's p5 package

    - by Brantley Blanchard
    Using eclipse, I'm trying to write a simple hello world program in processing that simply draws a rectangle on the screen then has gravity drop it as seen in this Tutorial. The problem is that when I try to import the p5 package, it's not resolving so I can't declare my Physics object. I tried two things. Download the zip, unzip it, then import the 3 jars (library, serialization, & testbed) a. import org.jbox2d.p5.*; doesn't resolve but the others do b. Physics physics; doesn't resolve Download the older standalone testbed jar then import it a. Physics physics; doesn't resolve; Here is basically where I'm starting import org.jbox2d.util.nonconvex.*; import org.jbox2d.dynamics.contacts.*; import org.jbox2d.testbed.*; import org.jbox2d.collision.*; import org.jbox2d.common.*; import org.jbox2d.dynamics.joints.*; import org.jbox2d.p5.*; import org.jbox2d.dynamics.*; import processing.core.PApplet; public class MyFirstJBox2d extends PApplet { Physics physics; public void setup() { size(640,480); frameRate(60); initScene(); } public void draw() { background(0); if (keyPressed) { //Reset everything physics.destroy(); initScene(); } } public void initScene() { physics = new Physics(this, width, height); physics.setDensity(1.0f); physics.createRect(300,200,340,300); } }

    Read the article

  • Collider2D and Rigidbody2D, how do they work?

    - by user42646
    I have been learning JavaScript and Unity for a week now. I learned how to make Cube as a Ground and another Cube as a player and I used this code to make the Player Cube move forward and backward and jumping var walkspeed: float = 5.0; var jumpheight: float = 250.0; var grounded = false; function Update() { rigidbody.freezeRotation = true; if (Input.GetKey("a")) transform.Translate(Vector3(-1, 0, 0) * Time.deltaTime * walkspeed); if (Input.GetKey("d")) transform.Translate(Vector3(1, 0, 0) * Time.deltaTime * walkspeed); if (Input.GetButton("Jump")) { Jump(); } } function OnCollisionEnter(hit: Collision) { grounded = true; } function Jump() { if (grounded == true) { rigidbody.AddForce(Vector3.up * jumpheight); grounded = false; } } I also learned how to make a character hit box. how to make a sprite and animation. pretty much the basic stuff. Couple of days ago I created simple ground in Photoshop and a simple character and imported them to Unity3D. Whenever I use my code above the character keeps falling from the scene. Like the character has nothing to stand on. After thinking about it it make sense because I really didn't make anything to make the player character understand that he should stand on something so I started reading about this issue and I realized that there is something called Collider2D and Rigidbody2D. Now I'm really stuck here I just don't know what to do. I applied the rigibody2d to my character picture and the Collider2D to the ground picture but whenever I play the project the gravity makes my character falls down. This is my question: How can I make the rigibody2d object realize that it shouldn't fall if there is a Collider2D object under it? So when I jump it's going to jump and the gravity going to bring it back to the ground.

    Read the article

  • Drawing chunks, and positioning the camera

    - by Troubleshoot
    I've seen many questions and answers regarding how to draw tiled maps but I can't really get my head around it. Many answers suggest either loading the visible part of the map, or loading and unloading chunks of the map. I've decided the best option would be to load chunks, but I'm slightly confused as to how this would be implemented. Currently I'm loading the full map to a 2D array of buffered images, then drawing it every time repaint is called. Q1: If I were to load chunks of the map, would I load the map as a whole then draw the necessary chunk(s), or load & unload the chunks as the player moves along, and if so, how? My second question regards the camera. I want the player to be in the centre of the X axis and the camera to follow it. I've thought of drawing everything in relation to the map and calculating the position of the camera in relation to the players coordinates on the map. So, to calculate the camera's X position I understand that I should use cameraX = playerX - (canvasWidth/2), but how should I calculate the Y position? I want the camera to only move up when the player reaches cameraHeight/2 but to move down when the player reaches 3/4(cameraHeight). Q2: Should I check for this in the same way I check for collision, and move the camera relative to the movement of the player until the player stops moving, or am I thinking about it in the wrong way?

    Read the article

  • What’s Your Tax Strategy? Automate the Tax Transfer Pricing Process!

    - by tobyehatch
    Does your business operate in multiple countries? Well, whether you like it or not, many local and international tax authorities inspect your tax strategy.  Legal, effective tax planning is perceived as a “moral” issue. CEOs are being asked to testify on their process of tax transfer pricing between multinational legal entities.  Marc Seewald, Senior Director of Product Management for EPM Applications specializing in all tax subjects and Product Manager for Oracle Hyperion Tax Provisioning, and Bart Stoehr, Senior Director of Product Strategy for Oracle Hyperion Profitability and Cost Management joined me for a discussion/podcast on this interesting subject.  So what exactly is “tax transfer pricing”? Marc defined it this way. “Tax transfer pricing is a profit allocation methodology required to be used by multinational corporations. Specifically, the ultimate goal of the transfer pricing is to ensure that the global multinational pays their fair share of income tax in each of their local markets. Specifically, it prevents companies from unfairly moving profit from ‘high tax’ countries to ‘low tax’ countries.” According to Marc, in today’s global economy, profitability can be significantly impacted by goods and services exchanged between the related divisions within a single multinational company.  To ensure that these cost allocations are done fairly, there are rules that govern the process. These rules ensure that intercompany allocations fairly represent the actual nature of the businesses activity- as if two divisions were unrelated - and provide a clear audit trail of how the costs have been allocated to prove that allocations fall within reasonable ranges.  What are the repercussions of improper tax transfer pricing? How important is it? Tax transfer pricing allocations can materially impact the amount of overall corporate income taxes paid by a company worldwide, in some cases by hundreds of millions of dollars!  Since so much tax revenue is at stake, revenue agencies like the IRS, and international regulatory bodies like the Organization for Economic Cooperation and Development (OECD) are pushing to reform and clarify reporting for tax transfer pricing. Most recently the OECD announced an “Action Plan for Base Erosion and Profit Shifting”. As Marc explained, the times are changing and companies need to be responsive to this issue. “It feels like every other week there is another company being accused of avoiding taxes,” said Marc. Most recently, Caterpillar was accused of avoiding billions of dollars in taxes. In the last couple of years, Apple, GE, Ikea, and Starbucks, have all been accused of tax avoidance. It’s imperative that companies like these have a clear and auditable tax transfer process that enables them to justify tax transfer pricing allocations and avoid steep penalties and bad publicity. Transparency and efficiency are what is needed when it comes to the tax transfer pricing process. Bart explained that tax transfer pricing is driving a deeper inspection of profit recognition specifically focused on the tax element of profit.  However, allocations needed to support tax profitability are nearly identical in process to allocations taking place in other parts of the finance organization. For example, the methods and processes necessary to arrive at tax profitability by legal entity are no different than those used to arrive at fully loaded profitability for a product line. In fact, there is a great opportunity for alignment across these two different functions.So it seems that tax transfer pricing should be reflected in profitability in general. Bart agreed and told us more about some of the critical sub-processes of an overall tax transfer pricing process within the Oracle solution for tax transfer pricing.  “First, there is a ton of data preparation, enrichment and pre-allocation data analysis that is managed in the Oracle Hyperion solution. This serves as the “data staging” to the next, critical sub-processes.  From here, we leverage the Oracle EPM platform’s ability to re-use dimensions and legal entity driver data and financial data with Oracle Hyperion Profitability and Cost Management (HPCM).  Within HPCM, we manage the driver data, define the legal entity to legal entity allocation rules (like cost plus), and have the option to test out multiple, simultaneous tax transfer pricing what-if scenarios.  Once processed, a tax expert can evaluate the effectiveness of any one scenario result versus another via a variance analysis configured with HPCM’s pre-packaged reporting capability known as Oracle Hyperion SmartView for Office.”   Further, Bart explained that the ability to visibly demonstrate how a cost or revenue has been allocated is really helpful and auditable.  “HPCM’s Traceability Maps are that visual representation of all allocation flows that have been executed and is the tax transfer analyst’s best friend in maintaining clear documentation for tax transfer pricing audits. Simply click and drill as you inspect the chain of allocation definitions and results. Once final, the post-allocated tax data can be compared to the GL to create invoices and journal entries for posting to your GL system of choice.  Of course, there is a framework for overall governance of the journal entries, allocation percentages, and reporting to include necessary approvals.” Lastly, Marc explained that the key value in using the Oracle Hyperion solution for tax transfer pricing is that it keeps everything in alignment in one single place. Specifically, Oracle Hyperion effectively becomes the single book of record for the GAAP, management, and the tax set of books. There are many benefits to having one source of the truth. These include EFFICIENCY, CONTROLS and TRANSPARENCY.So, what’s your tax strategy? Why not automate the tax transfer pricing process!To listen to the entire podcast, click here.To learn more about Oracle Hyperion Profitability and Cost Management (HPCM), click here.

    Read the article

  • Windows Azure Recipe: Software as a Service (SaaS)

    - by Clint Edmonson
    The cloud was tailor built for aspiring companies to create innovative internet based applications and solutions. Whether you’re a garage startup with very little capital or a Fortune 1000 company, the ability to quickly setup, deliver, and iterate on new products is key to capturing market and mind share. And if you can capture that share and go viral, having resiliency and infinite scale at your finger tips is great peace of mind. Drivers Cost avoidance Time to market Scalability Solution Here’s a sketch of how a basic Software as a Service solution might be built out: Ingredients Web Role – this hosts the core web application. Each web role will host an instance of the software and as the user base grows, additional roles can be spun up to meet demand. Access Control – this service is essential to managing user identity. It’s backed by a full blown implementation of Active Directory and allows the definition and management of users, groups, and roles. A pre-built ASP.NET membership provider is included in the training kit to leverage this capability but it’s also flexible enough to be combined with external Identity providers including Windows LiveID, Google, Yahoo!, and Facebook. The provider model provides extensibility to hook into other industry specific identity providers as well. Databases – nearly every modern SaaS application is backed by a relational database for its core operational data. If the solution is sold to organizations, there’s a good chance multi-tenancy will be needed. An emerging best practice for SaaS applications is to stand up separate SQL Azure database instances for each tenant’s proprietary data to ensure isolation from other tenants. Worker Role – this is the best place to handle autonomous background processing such as data aggregation, billing through external services, and other specialized tasks that can be performed asynchronously. Placing these tasks in a worker role frees the web roles to focus completely on user interaction and data input and provides finer grained control over the system’s scalability and throughput. Caching (optional) – as a web site traffic grows caching can be leveraged to keep frequently used read-only, user specific, and application resource data in a high-speed distributed in-memory for faster response times and ultimately higher scalability without spinning up more web and worker roles. It includes a token based security model that works alongside the Access Control service. Blobs (optional) – depending on the nature of the software, users may be creating or uploading large volumes of heterogeneous data such as documents or rich media. Blob storage provides a scalable, resilient way to store terabytes of user data. The storage facilities can also integrate with the Access Control service to ensure users’ data is delivered securely. Training & Examples These links point to online Windows Azure training labs and examples where you can learn more about the individual ingredients described above. (Note: The entire Windows Azure Training Kit can also be downloaded for offline use.) Windows Azure (16 labs) Windows Azure is an internet-scale cloud computing and services platform hosted in Microsoft data centers, which provides an operating system and a set of developer services which can be used individually or together. It gives developers the choice to build web applications; applications running on connected devices, PCs, or servers; or hybrid solutions offering the best of both worlds. New or enhanced applications can be built using existing skills with the Visual Studio development environment and the .NET Framework. With its standards-based and interoperable approach, the services platform supports multiple internet protocols, including HTTP, REST, SOAP, and plain XML SQL Azure (7 labs) Microsoft SQL Azure delivers on the Microsoft Data Platform vision of extending the SQL Server capabilities to the cloud as web-based services, enabling you to store structured, semi-structured, and unstructured data. Windows Azure Services (9 labs) As applications collaborate across organizational boundaries, ensuring secure transactions across disparate security domains is crucial but difficult to implement. Windows Azure Services provides hosted authentication and access control using powerful, secure, standards-based infrastructure. Developing Applications for the Cloud, 2nd Edition (eBook) This book demonstrates how you can create from scratch a multi-tenant, Software as a Service (SaaS) application to run in the cloud using the latest versions of the Windows Azure Platform and tools. The book is intended for any architect, developer, or information technology (IT) professional who designs, builds, or operates applications and services that run on or interact with the cloud. Fabrikam Shipping (SaaS reference application) This is a full end to end sample scenario which demonstrates how to use the Windows Azure platform for exposing an application as a service. We developed this demo just as you would: we had an existing on-premises sample, Fabrikam Shipping, and we wanted to see what it would take to transform it in a full subscription based solution. The demo you find here is the result of that investigation See my Windows Azure Resource Guide for more guidance on how to get started, including more links web portals, training kits, samples, and blogs related to Windows Azure.

    Read the article

  • Computer Networks UNISA - Chap 8 &ndash; Wireless Networking

    - by MarkPearl
    After reading this section you should be able to Explain how nodes exchange wireless signals Identify potential obstacles to successful transmission and their repercussions, such as interference and reflection Understand WLAN architecture Specify the characteristics of popular WLAN transmission methods including 802.11 a/b/g/n Install and configure wireless access points and their clients Describe wireless MAN and WAN technologies, including 802.16 and satellite communications The Wireless Spectrum All wireless signals are carried through the air by electromagnetic waves. The wireless spectrum is a continuum of the electromagnetic waves used for data and voice communication. The wireless spectrum falls between 9KHZ and 300 GHZ. Characteristics of Wireless Transmission Antennas Each type of wireless service requires an antenna specifically designed for that service. The service’s specification determine the antenna’s power output, frequency, and radiation pattern. A directional antenna issues wireless signals along a single direction. An omnidirectional antenna issues and receives wireless signals with equal strength and clarity in all directions The geographical area that an antenna or wireless system can reach is known as its range Signal Propagation LOS (line of sight) uses the least amount of energy and results in the reception of the clearest possible signal. When there is an obstacle in the way, the signal may… pass through the object or be obsrobed by the object or may be subject to reflection, diffraction or scattering. Reflection – waves encounter an object and bounces off it. Diffraction – signal splits into secondary waves when it encounters an obstruction Scattering – is the diffusion or the reflection in multiple different directions of a signal Signal Degradation Fading occurs as a signal hits various objects. Because of fading, the strength of the signal that reaches the receiver is lower than the transmitted signal strength. The further a signal moves from its source, the weaker it gets (this is called attenuation) Signals are also affected by noise – the electromagnetic interference) Interference can distort and weaken a wireless signal in the same way that noise distorts and weakens a wired signal. Frequency Ranges Older wireless devices used the 2.4 GHZ band to send and receive signals. This had 11 communication channels that are unlicensed. Newer wireless devices can also use the 5 GHZ band which has 24 unlicensed bands Narrowband, Broadband, and Spread Spectrum Signals Narrowband – a transmitter concentrates the signal energy at a single frequency or in a very small range of frequencies Broadband – uses a relatively wide band of the wireless spectrum and offers higher throughputs than narrowband technologies The use of multiple frequencies to transmit a signal is known as spread-spectrum technology. In other words a signal never stays continuously within one frequency range during its transmission. One specific implementation of spread spectrum is FHSS (frequency hoping spread spectrum). Another type is known as DSS (direct sequence spread spectrum) Fixed vs. Mobile Each type of wireless communication falls into one of two categories Fixed – the location of the transmitted and receiver do not move (results in energy saved because weaker signal strength is possible with directional antennas) Mobile – the location can change WLAN (Wireless LAN) Architecture There are two main types of arrangements Adhoc – data is sent directly between devices – good for small local devices Infrastructure mode – a wireless access point is placed centrally, that all devices connect with 802.11 WLANs The most popular wireless standards used on contemporary LANs are those developed by IEEE’s 802.11 committee. Over the years several distinct standards related to wireless networking have been released. Four of the best known standards are also referred to as Wi-Fi. They are…. 802.11b 802.11a 802.11g 802.11n These four standards share many characteristics. i.e. All 4 use half duplex signalling Follow the same access method Access Method 802.11 standards specify the use of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) to access a shared medium. Using CSMA/CA before a station begins to send data on an 802.11 network, it checks for existing wireless transmissions. If the source node detects no transmission activity on the network, it waits a brief period of time and then sends its transmission. If the source does detect activity, it waits a brief period of time before checking again. The destination node receives the transmission and, after verifying its accuracy, issues an acknowledgement (ACT) packet to the source. If the source receives the ACK it assumes the transmission was successful, – if it does not receive an ACK it assumes the transmission failed and sends it again. Association Two types of scanning… Active – station transmits a special frame, known as a prove, on all available channels within its frequency range. When an access point finds the probe frame, it issues a probe response. Passive – wireless station listens on all channels within its frequency range for a special signal, known as a beacon frame, issued from an access point – the beacon frame contains information necessary to connect to the point. Re-association occurs when a mobile user moves out of one access point’s range and into the range of another. Frames Read page 378 – 381 about frames and specific 802.11 protocols Bluetooth Networks Sony Ericson originally invented the Bluetooth technology in the early 1990s. In 1998 other manufacturers joined Ericsson in the Special Interest Group (SIG) whose aim was to refine and standardize the technology. Bluetooth was designed to be used on small networks composed of personal communications devices. It has become popular wireless technology for communicating among cellular telephones, phone headsets, etc. Wireless WANs and Internet Access Refer to pages 396 – 402 of the textbook for details.

    Read the article

  • Merging dictionaries in C#

    - by orip
    What's the best way to merge 2 or more dictionaries (Dictionary<T1,T2>) in C#? (3.0 features like LINQ are fine). I'm thinking of a method signature along the lines of: public static Dictionary<TKey,TValue> Merge<TKey,TValue>(Dictionary<TKey,TValue>[] dictionaries); or public static Dictionary<TKey,TValue> Merge<TKey,TValue>(IEnumerable<Dictionary<TKey,TValue>> dictionaries); EDIT: Got a cool solution from JaredPar and Jon Skeet, but I was thinking of something that handles duplicate keys. In case of collision, it doesn't matter which value is saved to the dict as long as it's consistent.

    Read the article

  • How to investigate if opencl is possible for an algorithm

    - by Marnix
    I have a heavy-duty algorithm in C# that takes two large Bitmaps of about 10000x5000 and performs photo and ray collision operations on a 3D model to map photos on the 3D model. I would like to know if it is possible to convert such an algorithm to OpenCL to optimize parallel operations during the algorithm. But before asking you to go into the details of the algorithm, I would like to know how I can investigate if my algorithm is convertible to OpenCL. I am not experienced in OpenCL and I would like to know if it is worth it to get into it and learn how it works. Are there things I have to look for that will definitely not work on the graphics card? (for-loops, recursion) Update: My algorithm goes something like: foreach photo split the photo in 64x64 blocks foreach block cast a ray from the camera to the 3D model foreach triangle in 3D model perform raycheck

    Read the article

  • Can zlib.crc32 or zlib.adler32 be safely used to mask primary keys in URLs?

    - by David Eyk
    In Django Design Patterns, the author recommends using zlib.crc32 to mask primary keys in URLs. After some quick testing, I noticed that crc32 produces negative integers about half the time, which seems undesirable for use in a URL. zlib.adler32 does not appear to produce negatives, but is described as "weaker" than CRC. Is this method (either CRC or Adler-32) safe for usage in a URL as an alternate to a primary key? (i.e. is it collision-safe?) Is the "weaker" Adler-32 a satisfactory alternative for this task? How the heck do you reverse this?! That is, how do you determine the original primary key from the checksum?

    Read the article

  • Short unique id in php

    - by Antti
    I want to create a unique id but uniqid() is giving something like '492607b0ee414'. What i would like is something similar to what tinyurl gives: '64k8ra'. The shorter, the better. The only requirements are that it should not have an obvious order and that it should look prettier than a seemingly random sequence of numbers. Letters are preferred over numbers and ideally it would not be mixed case. As the number of entries will not be that many (up to 10000 or so) the risk of collision isn't a huge factor. Any suggestions appreciated.

    Read the article

  • MVC ActionLink omits action when action equals default route value

    - by rjygraham
    I have the following routes defined for my application: routes.MapRoute( "Referral", // Route name "{referralCode}", // URL with parameters new { controller = "Home", action = "Index" } // Parameter defaults ); routes.MapRoute( "Default", // Route name "{controller}/{action}", // URL with parameters new { controller = "Home", action = "Index" } // Parameter defaults ); And I'm trying to create an ActionLink to go on the Index action on my AdminController: @Html.ActionLink("admin", "Index", "Admin") However, when the view is executed the ActionLink renders as (Index action value is omitted): <a href="/Admin">admin</a> Normally this would be ok, but it's causing a collision with the "Referral" route. NOTE: If I instead use ActionLink to render a different action like "Default," the ActionLink renders correctly: <a href="/Admin/Default">admin</a> The fact that the "Default" action renders correctly leads me to believe the problem has to do with the default value specified for the route. Is there anyway to force ActionLink to render the "Index" action as well?

    Read the article

  • RuntimeException: Could not start Selenium session: Internal Server Error

    - by user79685
    I am trying to detect a midair collision problem (simultaneous editin) using selenium. So I start a selenium session A with following (Super Class) selenium = new MASSelenium(serverHost, serverPort, *iexplore, browserURL); selenium.start(); selenium.open("index.cgi"); then I try starting a different selenium session B pointing to a different browser from the superclass (Sub Class): selenium2 = new MASSelenium(getServerHost(), getServerPort(), *firefox, getBrowserURL()); selenium2.start(); selenium2.open("index.cgi"); It works fine on my local machine (behaves as expected) but then when i run this same test on a remote machine (using bamboo build tool), i get this exception: java.lang.RuntimeException: Could not start Selenium session: Internal Server Error at com.thoughtworks.selenium.DefaultSelenium.start(DefaultSelenium.java:89) at gov.baba.arc.mas.selenium.tests.SimultaneousEditingConflictDetected.setUp(SimultaneousEditingConflictDetected.java:78) Caused by: com.thoughtworks.selenium.SeleniumException: Internal Server Error at com.thoughtworks.selenium.HttpCommandProcessor.throwAssertionFailureExceptionOrError(HttpCommandProcessor.java:97) at com.thoughtworks.selenium.HttpCommandProcessor.getCommandResponseAsString(HttpCommandProcessor.java:168) at com.thoughtworks.selenium.HttpCommandProcessor.executeCommandOnServlet(HttpCommandProcessor.java:104) at com.thoughtworks.selenium.HttpCommandProcessor.doCommand(HttpCommandProcessor.java:86) Any idea why this is happening?

    Read the article

  • ^M characters when using Tramp (on Windows) to connect to Ubuntu Server

    - by jamting
    I've set up Tramp on Emacs on my Windows 7 box (64 bit). For this test, this is the only thing in my emacs-config: (setq tramp-default-method "plink") Then I connect to my Ubuntu Server 9.10 running in a VM on my local network. Connection goes fine, i can use dired to browse folders and open files. Yay! However, git status shows up as: Git:master^M An when i open speedbar all folders and files ends with ^M, ie: <+ conf/^M Does anyone know how to prevent this line-ending collision from occurring?

    Read the article

< Previous Page | 33 34 35 36 37 38 39 40 41 42 43  | Next Page >