Search Results

Search found 1576 results on 64 pages for 'separating axis theorem'.

Page 29/64 | < Previous Page | 25 26 27 28 29 30 31 32 33 34 35 36  | Next Page >

• Silverlight Cream for March 06, 2011 -- #1054

  - by Dave Campbell

  In this Back from the Summit Issue, I am overloaded with posts to choose from. Submittals go first, but I'll eventually catch up... hopefully by MIX :) : Ollie Riches(-2-), Colin Eberhardt, John Papa, Jeremy Likness, Martin Krüger, Joost van Schaik, Karl Shifflett, Michael Crump, Georgi Stoyanov, Yochay Kiriaty, Page Brooks, and Deborah Kurata. Above the Fold: Silverlight: "ClassifiedCabinet: A Quick Start" Georgi Stoyanov WP7: "Easy access to WMAppManifest.xml App properties like version and title" Joost van Schaik Multiple: "Flashcards.Show Version 2 for the Desktop, Browser, and Windows Phone" Yochay Kiriaty Shoutouts: Mohamed Mosallem delivered an online session at the Second Riyadh Online Community Summit: Silverlight 4.0 with SharePoint 2010 John-Daniel Trask posted about a release of a new set of tools released for WP7 development... there's a free trial, so definitely worth a look: Mindscape Phone Elements released! From SilverlightCream.com: WP7Contrib: Trickling data to a bound collection Ollie Riches submitted a couple links... first up is this on a way they found to decrease the load on a data template in WP7 to get under the 90 mb limit and then added their solution to the WP7Contrib lib. WP7Contrib: Why we use SilverlightSerializer instead of DataContractSerializer Ollie Riches' next submittal compares the performance of the SilverlightSerializer & DataContractSerializer on the WP7 platform. MVVM Charting – Binding Multiple Series to a Visiblox Chart Colin Eberhardt sent me this post where he describes binding multiple series to a chart with no code-behind... great long multi-phase tutorial all with source. Silverlight TV 64: Dive into 64bit Support, App Model and Security John Papa has Nick Kramer of the Silverlight team up for his latest Silverlight TV episode, discussing some cool new Silverlight stuff: 64-bit support, multiple windows, etc. Building a Windows Phone 7 Application with UltraLight.mvvm Jeremy Likness has a pre-summit tutorial up on his UltraLight.mvvm project, and how he would use it to build a WP7 app... great to meet you, Jeremy! How to: Storyboard only start with the conspicuousness of the application in the browser window Martin Krüger continues his Storyboard startup solutions with this one about what to do if the Silverlight app is small or simply an island on an html page. Easy access to WMAppManifest.xml App properties like version and title Joost van Schaik posted about the WP7 manifest file and how you can get access to that information at runtime... why you ask? How about version number or title? Be sure to read the helpful hints in the last paragraph too! Mole 2010 Released Karl Shifflett, Josh Smith, and others have released the latest version of Mole... well worth the money in my opinion, if only it worked for Silverlight! (not their fault) Changing the Default Windows Phone 7 Deployment Target In Visual Studio 2010 Michael Crump points out an annoyance with the 2011 WP7 tools update... VS2010 defaults to the device rather than the emulator... and he shows us how to get it pointed back to the emulator! ClassifiedCabinet: A Quick Start Georgi Stoyanov posted a QuickStart to a 'ClassifiedCabinet' control posted on CodePlex... check out the demo first, you'll want to read the article after that. He builds a simple project from scratch using the control. Flashcards.Show Version 2 for the Desktop, Browser, and Windows Phone Yochay Kiriaty has a post up about FlashCards.Show version 2 that he worked on with Arik Poznanski and has it now running on the desktop, browser, and WP7, plus you get the source... I've been wanting to write just such an app for WP7, so hey... this saves me some time! A Simple Focus Manager for Jounce Applications Page Brooks has a post up about Jeremy Likness' Jounce... how to set focus to a particular control when a view loads. Silverlight Charting: Formatting the Axis Deborah Kurata is continuing her charting series with this one on setting axis font color and putting the text at an angle... really dresses up the chart! Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

  Read the article

• F1 Pit Pragmatics

  - by mikef

  "I hate computers. No, really, I hate them. I love the communications they facilitate, I love the conveniences they provide to my life. but I actually hate the computers themselves." - Scott Merrill, 'I hate computers: confessions of a Sysadmin' If Scott's goal was to polarize opinion and trigger raging arguments over the 'real reasons why computers suck', then he certainly succeeded. Impassioned vitriol sits side-by-side with rational debate. Yet Scott's fundamental point is absolutely on the money - Computers are a means to an end. The IT industry is finally starting to put weight behind the notion that good User Experience is an absolutely crucial goal, a cause championed by the likes of Microsoft's Bill Buxton, and which Apple's increasingly ubiquitous touch screen interface exemplifies. However, that doesn't change the fact that, occasionally, you just have to man up and deal with complex systems. In fact, sometimes you just need to sacrifice everything else in the name of performance. You'll find a perfect example of this Faustian bargain in Trevor Clarke's fascinating look into the (diabolical) IT infrastructure of modern F1 racing - high performance, high availability. high everything. To paraphrase, each car has up to 100 sensors, transmitting around 30Gb of data over the course of a race (70% in real-time). This data is then processed by no less than 3 servers (per car) so that the engineers in the pit have access to telemetry, strategy information, timing feeds, a connection back to the operations room in the team's home base - the list goes on. All of this while the servers are exposed "to carbon dust, oil, vibration, rain, heat, [and] variable power". Now, this is admittedly an extreme context where there's no real choice but to use complex systems where ease-of-use is, at best, a secondary concern. The flip-side is seen in small-scale personal computing such as that seen in Apple's iDevices, which are incredibly intuitive but limited in their scope. In terms of what kinds of systems they prefer to use, I suspect that most SysAdmins find themselves somewhere along this axis of Power vs. Usability, and which end of this axis you resonate with also hints at where you think the IT industry should focus its energy. Do you see yourself in the F1 pit, making split-second decisions, wrestling with information flows and reticent hardware to bend them to your will? If so, I imagine you feel that computers are subtle tools which need to be tuned and honed, using the advanced knowledge possessed only by responsible SysAdmins (If you have an iPhone, I suspect it's jail-broken). If the machines throw enigmatic errors, it's the price of flexibility and raw power. Alternatively, would you prefer to have your role more accessible, with users empowered by knowledge, spreading the load of managing IT environments? In that case, then you want hardware and software to have User Experience as their primary focus, and are of the "means to an end" school of thought (you're probably also fed up with users not listening to you when you try and help). At its heart, the dichotomy is between raw power (which might be difficult to use) and ease-of-use (which might have some limitations, but you can be up and running immediately). Of course, the ultimate goal is a fusion of flexibility, power and usability all in one system. It's achievable in specific software environments, and Red Gate considers it a target worth aiming for, but in other cases it's a goal right up there with cold fusion. I think it'll be a long time before we see it become ubiquitous. In the meantime, are you Power-Hungry or a Champion of Usability? Cheers, Michael Francis Simple Talk SysAdmin Editor

  Read the article

• Camera frustum calculation coming out wrong

  - by Telanor

  I'm trying to calculate a view/projection/bounding frustum for the 6 directions of a point light and I'm having trouble with the views pointing along the Y axis. Our game uses a right-handed, Y-up system. For the other 4 directions I create the LookAt matrix using (0, 1, 0) as the up vector. Obviously that doesn't work when looking along the Y axis so for those I use an up vector of (-1, 0, 0) for -Y and (1, 0, 0) for +Y. The view matrix seems to come out correctly (and the projection matrix always stays the same), but the bounding frustum is definitely wrong. Can anyone see what I'm doing wrong? This is the code I'm using: camera.Projection = Matrix.PerspectiveFovRH((float)Math.PI / 2, ShadowMapSize / (float)ShadowMapSize, 1, 5); for(var i = 0; i < 6; i++) { var renderTargetView = shadowMap.GetRenderTargetView((TextureCubeFace)i); var up = DetermineLightUp((TextureCubeFace) i); var forward = DirectionToVector((TextureCubeFace) i); camera.View = Matrix.LookAtRH(this.Position, this.Position + forward, up); camera.BoundingFrustum = new BoundingFrustum(camera.View * camera.Projection); } private static Vector3 DirectionToVector(TextureCubeFace direction) { switch (direction) { case TextureCubeFace.NegativeX: return -Vector3.UnitX; case TextureCubeFace.NegativeY: return -Vector3.UnitY; case TextureCubeFace.NegativeZ: return -Vector3.UnitZ; case TextureCubeFace.PositiveX: return Vector3.UnitX; case TextureCubeFace.PositiveY: return Vector3.UnitY; case TextureCubeFace.PositiveZ: return Vector3.UnitZ; default: throw new ArgumentOutOfRangeException("direction"); } } private static Vector3 DetermineLightUp(TextureCubeFace direction) { switch (direction) { case TextureCubeFace.NegativeY: return -Vector3.UnitX; case TextureCubeFace.PositiveY: return Vector3.UnitX; default: return Vector3.UnitY; } } Edit: Here's what the values are coming out to for the PositiveX and PositiveY directions: Constants: Position = {X:0 Y:360 Z:0} camera.Projection = [M11:0.9999999 M12:0 M13:0 M14:0] [M21:0 M22:0.9999999 M23:0 M24:0] [M31:0 M32:0 M33:-1.25 M34:-1] [M41:0 M42:0 M43:-1.25 M44:0] PositiveX: up = {X:0 Y:1 Z:0} target = {X:1 Y:360 Z:0} camera.View = [M11:0 M12:0 M13:-1 M14:0] [M21:0 M22:1 M23:0 M24:0] [M31:1 M32:0 M33:0 M34:0] [M41:0 M42:-360 M43:0 M44:1] camera.BoundingFrustum: Matrix = [M11:0 M12:0 M13:1.25 M14:1] [M21:0 M22:0.9999999 M23:0 M24:0] [M31:0.9999999 M32:0 M33:0 M34:0] [M41:0 M42:-360 M43:-1.25 M44:0] Top = {A:0.7071068 B:-0.7071068 C:0 D:254.5584} Bottom = {A:0.7071068 B:0.7071068 C:0 D:-254.5584} Left = {A:0.7071068 B:0 C:0.7071068 D:0} Right = {A:0.7071068 B:0 C:-0.7071068 D:0} Near = {A:1 B:0 C:0 D:-1} Far = {A:-1 B:0 C:0 D:5} PositiveY: up = {X:0 Y:0 Z:-1} target = {X:0 Y:361 Z:0} camera.View = [M11:-1 M12:0 M13:0 M14:0] [M21:0 M22:0 M23:-1 M24:0] [M31:0 M32:-1 M33:0 M34:0] [M41:0 M42:0 M43:360 M44:1] camera.BoundingFrustum: Matrix = [M11:-0.9999999 M12:0 M13:0 M14:0] [M21:0 M22:0 M23:1.25 M24:1] [M31:0 M32:-0.9999999 M33:0 M34:0] [M41:0 M42:0 M43:-451.25 M44:-360] Top = {A:0 B:0.7071068 C:0.7071068 D:-254.5585} Bottom = {A:0 B:0.7071068 C:-0.7071068 D:-254.5585} Left = {A:-0.7071068 B:0.7071068 C:0 D:-254.5585} Right = {A:0.7071068 B:0.7071068 C:0 D:-254.5585} Near = {A:0 B:1 C:0 D:-361} Far = {A:0 B:-1 C:0 D:365} When I use the resulting BoundingFrustum to cull regions outside of it, this is the result: Pass PositiveX: Drew 3 regions Pass NegativeX: Drew 6 regions Pass PositiveY: Drew 400 regions Pass NegativeY: Drew 36 regions Pass PositiveZ: Drew 3 regions Pass NegativeZ: Drew 6 regions There are only 400 regions to draw and the light is in the center of them. As you can see, the PositiveY direction is drawing every single region. With the near/far planes of the perspective matrix set as small as they are, there's no way a single frustum could contain every single region.

  Read the article

• Finding the normals of an oriented bounding box?

  - by Milo

  Here is my problem. I'm working on the physics for my 2D game. All objects are oriented bounding boxes (OBB) based on the separate axis theorem. In order to do collision resolution, I need to be able to get an object out out of the object it is penetrating. To do this I need to find the normal of the face(s) that the other OBB is touching. Example: The small red OBB is a car lets say, and the big OBB is a static building. I need to determine the unit vector that is the normal of the building edge(s) the car is penetrating to get the car out of there. Here are my questions: How do I determine which edges the car is penetrating. I know how to determine the normal of an edge, but how do I know if I need (-dy, dx) or (dy, -dx)? In the case I'm demonstrating the car is penetrating 2 edges, which edge(s) do I use to get it out? Answers or help with any or all of these is greatly appreciated. Thank you

  Read the article

• problem with frustum AABB culling in DirectX

  - by Matthew Poole

  Hi, I am currently working on a project with a few friends, and I am trying to get frustum culling working. Every single tutorial or article I go to shows that my math is correct and that this should be working. I thought maybe posting here, somebody would catch something I could not. Thank you. Here are the important code snippets /create the projection matrix void CD3DCamera::SetLens(float fov, float aspect, float nearZ, float farZ) { D3DXMatrixPerspectiveFovLH(&projMat, D3DXToRadian(fov), aspect, nearZ, farZ); } //build the view matrix after changes have been made to camera void CD3DCamera::BuildView() { //keep axes orthoganal D3DXVec3Normalize(&look, &look); //up D3DXVec3Cross(&up, &look, &right); D3DXVec3Normalize(&up, &up); //right D3DXVec3Cross(&right, &up, &look); D3DXVec3Normalize(&right, &right); //fill view matrix float x = -D3DXVec3Dot(&position, &right); float y = -D3DXVec3Dot(&position, &up); float z = -D3DXVec3Dot(&position, &look); viewMat(0,0) = right.x; viewMat(1,0) = right.y; viewMat(2,0) = right.z; viewMat(3,0) = x; viewMat(0,1) = up.x; viewMat(1,1) = up.y; viewMat(2,1) = up.z; viewMat(3,1) = y; viewMat(0,2) = look.x; viewMat(1,2) = look.y; viewMat(2,2) = look.z; viewMat(3,2) = z; viewMat(0,3) = 0.0f; viewMat(1,3) = 0.0f; viewMat(2,3) = 0.0f; viewMat(3,3) = 1.0f; } void CD3DCamera::BuildFrustum() { D3DXMATRIX VP; D3DXMatrixMultiply(&VP, &viewMat, &projMat); D3DXVECTOR4 col0(VP(0,0), VP(1,0), VP(2,0), VP(3,0)); D3DXVECTOR4 col1(VP(0,1), VP(1,1), VP(2,1), VP(3,1)); D3DXVECTOR4 col2(VP(0,2), VP(1,2), VP(2,2), VP(3,2)); D3DXVECTOR4 col3(VP(0,3), VP(1,3), VP(2,3), VP(3,3)); // Planes face inward frustum[0] = (D3DXPLANE)(col2); // near frustum[1] = (D3DXPLANE)(col3 - col2); // far frustum[2] = (D3DXPLANE)(col3 + col0); // left frustum[3] = (D3DXPLANE)(col3 - col0); // right frustum[4] = (D3DXPLANE)(col3 - col1); // top frustum[5] = (D3DXPLANE)(col3 + col1); // bottom // Normalize the frustum for( int i = 0; i < 6; ++i ) D3DXPlaneNormalize( &frustum[i], &frustum[i] ); } bool FrustumCheck(D3DXVECTOR3 max, D3DXVECTOR3 min, const D3DXPLANE* frustum) { // Test assumes frustum planes face inward. D3DXVECTOR3 P; D3DXVECTOR3 Q; bool ret = false; for(int i = 0; i < 6; ++i) { // For each coordinate axis x, y, z... for(int j = 0; j < 3; ++j) { // Make PQ point in the same direction as the plane normal on this axis. if( frustum[i][j] > 0.0f ) { P[j] = min[j]; Q[j] = max[j]; } else { P[j] = max[j]; Q[j] = min[j]; } } if(D3DXPlaneDotCoord(&frustum[i], &Q) < 0.0f ) ret = false; } return true; }

  Read the article

• Best depth sorting method for a Top Down 2D game using a 3D physics engine

  - by Alic44

  I've spent many days googling this and still have issues with my game engine I'd like to ask about, which I haven't seen addressed before. I think the problem is that my game is an unusual combination of a completely 2D graphical approach using XNA's SpriteBatch, and a completely 3D engine (the amazing BEPU physics engine) with rotation mostly disabled. In essence, my question is similar to this one (the part about "faux 3D"), but the difference is that in my game, the player as well as every other creature is represented by 3D objects, and they can all jump, pick up other objects, and throw them around. What this means is that sorting by one value, such as a Z position (how far north/south a character is on the screen) won't work, because as soon as a smaller creature jumps on top of a larger creature, or a box, and walks backwards, the moment its z value is less than that other creature, it will appear to be behind the object it is actually standing on. I actually originally solved this problem by splitting every object in the game into physics boxes which MUST have a Y height equal to their Z depth. I then based the depth sorting value on the object's y position (how high it is off the ground) PLUS its z position (how far north or south it is on the screen). The problem with this approach is that it requires all moving objects in the game to be split graphically into chunks which match up with a physical box which has its y dimension equal to its z dimension. Which is stupid. So, I got inspired last night to rewrite with a fresh approach. My new method is a little more complex, but I think a little more sane: every object which needs to be sorted by depth in the game exposes the interface IDepthDrawable and is added to a list owned by the DepthDrawer object. IDepthDrawable contains: public interface IDepthDrawable { Rectangle Bounds { get; } //possibly change this to a class if struct copying of the xna Rectangle type becomes an issue DepthDrawShape DepthShape { get; } void Draw(SpriteBatch spriteBatch); } The Bounds Rectangle of each IDepthDrawable object represents the 2D Axis-Aligned Bounding Box it will take up when drawn to the screen. Anything that doesn't intersect the screen will be culled at this stage and the remaining on-screen IDepthDrawables will be Bounds tested for intersections with each other. This is where I get a little less sure of what I'm doing. Each group of collisions will be added to a list or other collection, and each list will sort itself based on its DepthShape property, which will have access to the object-to-be-drawn's physics information. For starting out, lets assume everything in the game is an axis aligned 3D Box shape. Boxes are pretty easy to sort. Something like: if (depthShape1.Back > depthShape2.Front) //if depthShape1 is in front of depthShape2. //depthShape1 goes on top. else if (depthShape1.Bottom > depthShape2.Top) //if depthShape1 is above depthShape2. //depthShape1 goes on top. //if neither of these are true, depthShape2 must be in front or above. So, by sorting draw order by several different factors from the physics engine, I believe I can get a really correct draw order. My question is, is this a good way of going about this, or is there some tried and true, tested way which is completely different and has somehow completely eluded me on the internets? And, if this does seem like a good way to remake my draw order sorting, what's the right sorting algorithm for reordering the Bounds Rectangle collision lists, and how do you deal with a Bounds Rectangle colliding with two different object which don't collide with eachother. I know these are solved problems, but I've only been programming for a year so any specific input here will be greatly appreciated. Thanks for reading this far, ye who made it -- sorry it was so long!

  Read the article

• ArchBeat Link-o-Rama for 2012-06-01

  - by Bob Rhubart

  Complexity of Social Computing - Is it a Consideration for EA's? | Pat Shepherd blogs.oracle.com Pat Shepherd asks, "Does Enterprise Architecture need to consider Social Computing in its scope?" Who should own the Enterprise Architecture? | Michael Glas blogs.oracle.com "Instead of looking at just who owns the architecture," suggests Michael Glas, "think about what the person/role/organization should do." The Application Architecture Domain | Michael Glas blogs.oracle.com Michael Glas asks—and answers: "As an Enterprise Architect, what do I need to consider when looking at/defining/designing the Application Architecture Domain?" CAP Twelve Years Later: How the "Rules" Have Changed | Eric Brewer www.infoq.com The CAP theorem asserts that any net­worked shared-data system can have only two of three desirable properties. How­ever, by explicitly handling partitions, designers can optimize consistency and availability, thereby achieving some trade-off of all three. Oracle DB with OEM in Amazon Cloud | Dr. Frank Munz www.munzandmore.com Dr. Frank Munz shares a video that screencast that explains "how to create an Oracle DB instance in AWS, how to enable OEM...and how to connect to your cloud instance with a local installation of NetBeans." Sample External Login.jsp page for Oracle Access Manager 11g | Brian Eidelman fusionsecurity.blogspot.com A-Team blogger Brian Eidelman expands on a previous post dealing with configuring OAM 11g to use an externally hosted custom login page. Bay Area Coherence Special Interest Group (BACSIG) Meeting June 7 coherence.oracle.com Date: Thursday, June 7, 2012 Time: 5:30pm – 9:00pm PT Where: Oracle Conference Center Room # 103 350 Oracle Parkway Redwood, Shores, CA Presentations: 6:00 p.m. - Coherence 101, The Evolution of Distributed Caching - Noah Arliss (Oracle) 7:00 p.m. - Optimizing Performance for Oracle Coherence and TopLink Grid at OOCL - Matt Rosen, Leo Limqueco (OOCL) 8:00 p.m. - Oracle Coherence Message Bus - Extreme Performance on Oracle Exalogic - Ballav Bihani (Oracle) Thought for the Day "I can't be left unsupervised." — Ron Wood (Born 06/01/1947 Source: Brainy Quote

  Read the article

• Problems with moving 2D circle/box collision detection

  - by dario3004

  This is my first game ever and I'm a newbie in computer physics. I've got this code for the collision detection and it works fine for BOTTOM and TOP collision.It miss the collision detection with the paddle's edge and angles so I've (roughly) tried to implement it. Main method that is called for bouncing, it checks if it bounce with wall, or with top (+ right/left side) or with bottom (+ right/left side): protected void handleBounces(float px, float py) { handleWallBounce(px, py); if(mBall.y < getHeight()/4){ if (handleRedFastBounce(mRed, px, py)) return; if (handleRightSideBounce(mRed,px,py)) return; if (handleLeftSideBounce(mRed,px,py)) return; } if(mBall.y > getHeight()/4 * 3){ if (handleBlueFastBounce(mBlue, px, py)) return; if (handleRightSideBounce(mBlue,px,py)) return; if (handleLeftSideBounce(mBlue,px,py)) return; } } This is the code for the BOTTOM bounce: protected boolean handleRedFastBounce(Paddle paddle, float px, float py) { if (mBall.goingUp() == false) return false; // next position tx = mBall.x; ty = mBall.y - mBall.getRadius(); // actual position ptx = px; pty = py - mBall.getRadius(); dyp = ty - paddle.getBottom(); xc = tx + (tx - ptx) * dyp / (ty - pty); if ((ty < paddle.getBottom() && pty > paddle.getBottom() && xc > paddle.getLeft() && xc < paddle.getRight())) { mBall.x = xc; mBall.y = paddle.getBottom() + mBall.getRadius(); mBall.bouncePaddle(paddle); playSound(mPaddleSFX); increaseDifficulty(); return true; } else return false; } As long as I understood it should be something like this: So I tried to make the "left side" and "right side" bounce method: protected boolean handleLeftSideBounce(Paddle paddle, float px, float py){ // next position tx = mBall.x + mBall.getRadius(); ty = mBall.y; // actual position ptx = px + mBall.getRadius(); pty = py; dyp = tx - paddle.getLeft(); yc = ty + (pty - ty) * dyp / (ptx - tx); if (ptx < paddle.getLeft() && tx > paddle.getLeft()){ System.out.println("left side bounce1"); System.out.println("yc: " + yc + "top: " + paddle.getTop() + " bottom: " + paddle.getBottom()); if (yc > paddle.getTop() && yc < paddle.getBottom()){ System.out.println("left side bounce2"); mBall.y = yc; mBall.x = paddle.getLeft() - mBall.getRadius(); mBall.bouncePaddle(paddle); playSound(mPaddleSFX); increaseDifficulty(); return true; } } return false; } I think I'm quite near to the solution but I'm having big troubles with the new "yc" formula. I tried so many versions of it but since I don't know the theory behind it I can't adjust for the Y axis. Since the Y axis is inverted I even tried this: yc = ty - (pty - ty) * dyp / (ptx - tx); I tried Googling it but I can't seem to find a solution for it. Also this method fails when ball touches the angle and I don't think is a nice way because it just test "one" point of the ball and probably there will be many cases in which the ball won't bounce.

  Read the article

• Conflict resolution for two-way sync

  - by K.Steff

  How do you manage two-way synchronization between a 'main' database server and many 'secondary' servers, in particular conflict resolution, assuming a connection is not always available? For example, I have an mobile app that uses CoreData as the 'database' on the iOS and I'd like to allow users to edit the contents without Internet connection. In the same time, this information is available on a website the devices will connect to. What do I do if/when the data on the two DB servers is in conflict? (I refer to CoreData as a DB server, though I am aware it is something slightly different.) Are there any general strategies for dealing with this sort of issue? These are the options I can think of: 1. Always use the client-side data as higher-priority 2. Same for server-side 3. Try to resolve conflicts by marking each field's edit timestamp and taking the latest edit Though I'm certain the 3rd option will open room for some devastating data corruption. I'm aware that the CAP theorem concerns this, but I only want eventual consistency, so it doesn't rule it out completely, right? Related question: Best practice patterns for two-way data synchronization. The second answer to this question says it probably can't be done.

  Read the article

• How can I be certain that my code is flawless? [duplicate]

  - by David

  This question already has an answer here: Theoretically bug-free programs 5 answers I have just completed an exercise from my textbook which wanted me to write a program to check if a number is prime or not. I have tested it and seems to work fine, but how can I be certain that it will work for every prime number? public boolean isPrime(int n) { int divisor = 2; int limit = n-1 ; if (n == 2) { return true; } else { int mod = 0; while (divisor <= limit) { mod = n % divisor; if (mod == 0) { return false; } divisor++; } if (mod > 0) { return true; } } return false; } Note that this question is not a duplicate of Theoretically Bug Free Programs because that question asks about whether one can write bug free programs in the face of the the limitative results such as Turing's proof of the incomputability of halting, Rice's theorem and Godel's incompleteness theorems. This question asks how a program can be shown to be bug free.

  Read the article

• Heavily customized split view controller in iPad app -- how?

  - by Macatomy

  I was going through some of the early screenshots of the first iPad apps and I came upon this: I'm just wondering, how is this done? Mainly, how has the detail view section of the split view been given a drop shadow and rounded corners, and for lack of better phrasing, how has it been "separated" from the master view (the default split view template has the master and detail view joined together with nothing but a vertical line separating the two)?

  Read the article

• global.asax and ASP.NET MVC solution Organization

  - by nachid

  I am refering to this article from Jimmy Bogard He is suggesting two projects to organize your ASP.NET MVC solution. Basically, one project for the code and another for the rendering My concern is about global.asax file. Jimmy suggested separating global.asax from global.asax.cs and put them in two differents projects When I did this, I could not compile my solution. I got this error : Could not load type 'MyProject.Web.Global'. Can someone help and show me how to solve this? Thanks

  Read the article

• How to trigger a Symbian C++ application within a J2ME application for Nokia phones using J2ME API?

  - by kennykee

  Hi all, Anyone knows how to trigger a Symbian C++ application using any J2ME API call? I have a J2ME application that needs a customized photo taking application in Symbian C++. The reason for separating into two applications is because J2ME has a limit in heap size and the J2ME needs to know the path of photo after taking it. Thanks a lot for your help. Regards, Kenny

  Read the article

• Android List with section headers

  - by user324661

  Hi, I'm trying to create a list with headers above a grouping of items. I was looking at SeperatedListAdapter available here: http://jsharkey.org/blog/2008/08/18/separating-lists-with-headers-in-android-09/ but I ran into an error (ERROR/AndroidRuntime(2025): java.lang.IllegalStateException: ArrayAdapter requires the resource ID to be a TextView ) Now I'm looking into more options including making a new one. Do you guys have any hints? Thanks, Bryon

  Read the article

• Regex fix for this? [extension]

  - by Yeti

  Sorry for the redundancy, I should've asked this in my previous question here: http://stackoverflow.com/questions/3061407/whats-the-regex-to-solve-this-problem This question is an extension: From the elements in an array below: http://example.com/apps/1235554/ http://example.com/apps/apple/ http://example.com/apps/126734 http://example.com/images/a.jpg I'm separating out apps/{number}/ and apps/{number} using: foreach ($urls as $url) { if (preg_match('~apps/[0-9]~', $url)) echo $url; } Now, how do I also push {number} to another array with the same regex?

  Read the article

• Can any body help to split php source code

  - by joe-on-wp

  hi, can any body help me on separating this example of data that i need to parse and seperate text just like PHPDoc. It is PHP source code. The example string : function one_to_tree() { //bla bla bla return FALSE; } function two_to_tree() { //bla bla bla return FALSE; } function three_to_tree() { if ($sample){ //bla bla bla } return FALSE; } can anybody help me how to seperate above string based on "function" word and create and array. Thank you

  Read the article

• How to search multiple columns in MySQL?

  - by George

  I'm trying to make a search feature that will search multiple columns to find a keyword based match. This query: SELECT title FROM pages LIKE %$query%; works only for searching one column, I noticed separating column names with commas results in an error. So is it possible to search multiple columns in mysql?

  Read the article

• If you use MVC in your web app then you dont need to use Smarty(TemplateEngine) Right?

  - by Imran

  I'm just trying to understand the Templating(system). If you use MVC in your web application then you don't need to use something like Smarty(template engine) as you are already separating application code from presentation code anyway by using MVC right? please correct me? So am i correct in thinking it's MVC OR Templating or do you use both in your apps?If any one could explain this in detail it would be great. Thank you in advance;-)

  Read the article

• Nested if statements or not

  - by Zaps

  Hi, I hope this hasn't been asked before. I have a nullable boolean called boolIsAllowed and a if condition like so: if(boolIsAllowed.HasValue && boolIsAllowed.Value) { //do something } My question is this good code or would I be better separating it into a nested if statement? Will the second condition get checked if boolIsAllowed.HasValue is equal to false and then throw an exception? I hope this question is too stupid. Thanks in advance.

  Read the article

• How to add separator between items in a Spark List control

  - by simms2k

  I have a s:List where I've defined my own itemRenderer, and would like to insert a horizontal line separating items, similar to the way the mx:LinkBar works. I don't want to have a line at the top or bottom of the list, so I can't just include an upper or lower border in the itemRenderer. I was hoping the itemRenderer could be made aware of its index in the list, but I don't see how. Is there a way to do this?

  Read the article

• Is there a tool that can convert C# 1.1 Forms design to the more recent standard?

  - by Hamish Grubijan

  The old code, as we know, is dangerous because both GUI layout and business logic are mixed into one. Separating the two can be a tedious and an error-prone task. Is there a tool that can do this for me? Thanks.

  Read the article

• PHP: How to forward on $_FILES using cURL

  - by Toby

  Hi. I'm trying to use cURL to forward on a http request from a form in a web application I'm developing. Essentially I need to submit the same form twice on different servers, for the second server I'm adding some security measures to the post data. I can receive $_POST information on the second form perfectly fine, however I'm having major troubles with my $_FILES - I've tried separating the two so there's a separate request for post and files data but still no luck. Is this possible?

  Read the article

• Change a name field from LAST FIRST ordered to FIRST LAST ordered.

  - by tyebud

  I have an excel spreadsheet with about 700 entries. The names are listed as "DOE JOHN" (no comma separating the names). I need to format them so they read JOHN DOE. 1.) I would like to learn how to do this in excel. 2.) I would like to learn how to do this in linux. Thanks!

  Read the article

• Where to put the star in C and C++ pointer notation

  - by Martin Kristiansen

  For some time the following has been annoing me, where should I put the star in my pointer notation. int *var; // 1 and int* var; // 2 obviously do the same thing, and both notations are correct, but I find that most literature and code I look at use the 1th notation. wouldn't it be more 'correct' to use the 2th notation, separating the type and the variable name by a whitespace, rather than mixing the type and variable tokens?

  Read the article

• Creating multiple objects of a view defined in the xml

  - by user362953

  I have to dynamically add a list of views (the views use RelativeLayout). Can I do this by specifying the view definition in xml and instantiate multiple objects off it? This gives the usual benefits of separating the view part from the code (for e.g., making it easy for the UI guys to alter things) or Is going the ArrayAdapter the suggested/only route?

  Read the article

< Previous Page | 25 26 27 28 29 30 31 32 33 34 35 36  | Next Page >