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• Software Architecture verses Software Design

  Recently, I was asked what the differences between software architecture and software design are. At a very superficial level both architecture and design seem to mean relatively the same thing. However, if we examine both of these terms further we will find that they are in fact very different due to the level of details they encompass. Software Architecture can be defined as the essence of an application because it deals with high level concepts that do not include any details as to how they will be implemented. To me this gives stakeholders a view of a system or application as if someone was viewing the earth from outer space. At this distance only very basic elements of the earth can be detected like land, weather and water. As the viewer comes closer to earth the details in this view start to become more defined. Details about the earth’s surface will start to actually take form as well as mane made structures will be detected. The process of transitioning a view from outer space to inside our earth’s atmosphere is similar to how an architectural concept is transformed to an architectural design. From this vantage point stakeholders can start to see buildings and other structures as if they were looking out of a small plane window. This distance is still high enough to see a large area of the earth’s surface while still being able to see some details about the surface. This viewing point is very similar to the actual design process of an application in that it takes the very high level architectural concept or concepts and applies concrete design details to form a software design that encompasses the actual implementation details in the form of responsibilities and functions. Examples of these details include: interfaces, components, data, and connections. In review, software architecture deals with high level concepts without regard to any implementation details. Software design on the other hand takes high level concepts and applies concrete details so that software can be implemented. As part of the transition between software architecture to the creation of software design an evaluation on the architecture is recommended. There are several benefits to including this step as part of the transition process. It allows for projects to ensure that they are on the correct path as to meeting the stakeholder’s requirement goals, identifies possible cost savings and can be used to find missing or nonspecific requirements that cause ambiguity in a design. In the book “Evaluating Software Architectures: Methods and Case Studies”, they define key benefits to adding an architectural review process to ensure that an architecture is ready to move on to the design phase. Benefits to evaluating software architecture: Gathers all stakeholders to communicate about the project Goals are clearly defined in regards to the creation or validation of specific requirements Goals are prioritized so that when conflicts occur decisions will be made based on goal priority Defines a clear expectation of the architecture so that all stakeholders have a keen understanding of the project Ensures high quality documentation of the architecture Enables discoveries of architectural reuse  Increases the quality of architecture practices. I can remember a few projects that I worked on that could have really used an architectural review prior to being passed on to developers. This project was to create some new advertising space on the company’s website in order to sell space based on the location and some other criteria. I was one of the developer selected to lead this project and I was given a high level design concept and a long list of ever changing requirements due to the fact that sales department had no clear direction as to what exactly the project was going to do or how they were going to bill the clients once they actually agreed to purchase the Ad space. In my personal opinion IT should have pushed back to have the requirements further articulated instead of forcing programmers to code blindly attempting to build such an ambiguous project.  Unfortunately, we had to suffer with this project for about 4 months when it should have only taken 1.5 to complete due to the constantly changing and unclear requirements. References  Clements, P., Kazman, R., & Klein, M. (2002). Evaluating Software Architectures. Westford, Massachusetts: Courier Westford. 

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• MvcExtensions - ActionFilter

  - by kazimanzurrashid

  One of the thing that people often complains is dependency injection in Action Filters. Since the standard way of applying action filters is to either decorate the Controller or the Action methods, there is no way you can inject dependencies in the action filter constructors. There are quite a few posts on this subject, which shows the property injection with a custom action invoker, but all of them suffers from the same small bug (you will find the BuildUp is called more than once if the filter implements multiple interface e.g. both IActionFilter and IResultFilter). The MvcExtensions supports both property injection as well as fluent filter configuration api. There are a number of benefits of this fluent filter configuration api over the regular attribute based filter decoration. You can pass your dependencies in the constructor rather than property. Lets say, you want to create an action filter which will update the User Last Activity Date, you can create a filter like the following: public class UpdateUserLastActivityAttribute : FilterAttribute, IResultFilter { public UpdateUserLastActivityAttribute(IUserService userService) { Check.Argument.IsNotNull(userService, "userService"); UserService = userService; } public IUserService UserService { get; private set; } public void OnResultExecuting(ResultExecutingContext filterContext) { // Do nothing, just sleep. } public void OnResultExecuted(ResultExecutedContext filterContext) { Check.Argument.IsNotNull(filterContext, "filterContext"); string userName = filterContext.HttpContext.User.Identity.IsAuthenticated ? filterContext.HttpContext.User.Identity.Name : null; if (!string.IsNullOrEmpty(userName)) { UserService.UpdateLastActivity(userName); } } } As you can see, it is nothing different than a regular filter except that we are passing the dependency in the constructor. Next, we have to configure this filter for which Controller/Action methods will execute: public class ConfigureFilters : ConfigureFiltersBase { protected override void Configure(IFilterRegistry registry) { registry.Register<HomeController, UpdateUserLastActivityAttribute>(); } } You can register more than one filter for the same Controller/Action Methods: registry.Register<HomeController, UpdateUserLastActivityAttribute, CompressAttribute>(); You can register the filters for a specific Action method instead of the whole controller: registry.Register<HomeController, UpdateUserLastActivityAttribute, CompressAttribute>(c => c.Index()); You can even set various properties of the filter: registry.Register<ControlPanelController, CustomAuthorizeAttribute>( attribute => { attribute.AllowedRole = Role.Administrator; }); The Fluent Filter registration also reduces the number of base controllers in your application. It is very common that we create a base controller and decorate it with action filters and then we create concrete controller(s) so that the base controllers action filters are also executed in the concrete controller. You can do the  same with a single line statement with the fluent filter registration: Registering the Filters for All Controllers: registry.Register<ElmahHandleErrorAttribute>(new TypeCatalogBuilder().Add(GetType().Assembly).Include(type => typeof(Controller).IsAssignableFrom(type))); Registering Filters for selected Controllers: registry.Register<ElmahHandleErrorAttribute>(new TypeCatalogBuilder().Add(GetType().Assembly).Include(type => typeof(Controller).IsAssignableFrom(type) && (type.Name.StartsWith("Home") || type.Name.StartsWith("Post")))); You can also use the built-in filters in the fluent registration, for example: registry.Register<HomeController, OutputCacheAttribute>(attribute => { attribute.Duration = 60; }); With the fluent filter configuration you can even apply filters to controllers that source code is not available to you (may be the controller is a part of a third part component). That’s it for today, in the next post we will discuss about the Model binding support in MvcExtensions. So stay tuned.

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• SQL SERVER – Introduction to LEAD and LAG – Analytic Functions Introduced in SQL Server 2012

  - by pinaldave

  SQL Server 2012 introduces new analytical function LEAD() and LAG(). This functions accesses data from a subsequent row (for lead) and previous row (for lag) in the same result set without the use of a self-join . It will be very difficult to explain this in words so I will attempt small example to explain you this function. Instead of creating new table, I will be using AdventureWorks sample database as most of the developer uses that for experiment. Let us fun following query. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID) OVER (ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID) OVER (ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result. When we look at above resultset it is very clear that LEAD function gives us value which is going to come in next line and LAG function gives us value which was encountered in previous line. If we have to generate the same result without using this function we will have to use self join. In future blog post we will see the same. Let us explore this function a bit more. This function not only provide previous or next line but it can also access any line before or after using offset. Let us fun following query, where LEAD and LAG function accesses the row with offset of 2. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID,2) OVER (ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID,2) OVER (ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result. You can see the LEAD and LAG functions  now have interval of  rows when they are returning results. As there is interval of two rows the first two rows in LEAD function and last two rows in LAG function will return NULL value. You can easily replace this NULL Value with any other default value by passing third parameter in LEAD and LAG function. Let us fun following query. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID,2,0) OVER (ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID,2,0) OVER (ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result, where NULL are now replaced with value 0. Just like any other analytic function we can easily partition this function as well. Let us see the use of PARTITION BY in this clause. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, LEAD(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY SalesOrderDetailID ) LeadValue, LAG(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY SalesOrderDetailID ) LagValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Above query will give us following result, where now the data is partitioned by SalesOrderID and LEAD and LAG functions are returning the appropriate result in that window. As now there are smaller partition in my query, you will see higher presence of NULL. In future blog post we will see how this functions are compared to SELF JOIN. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Merge sort versus quick sort performance

  - by Giorgio

  I have implemented merge sort and quick sort using C (GCC 4.4.3 on Ubuntu 10.04 running on a 4 GB RAM laptop with an Intel DUO CPU at 2GHz) and I wanted to compare the performance of the two algorithms. The prototypes of the sorting functions are: void merge_sort(const char **lines, int start, int end); void quick_sort(const char **lines, int start, int end); i.e. both take an array of pointers to strings and sort the elements with index i : start <= i <= end. I have produced some files containing random strings with length on average 4.5 characters. The test files range from 100 lines to 10000000 lines. I was a bit surprised by the results because, even though I know that merge sort has complexity O(n log(n)) while quick sort is O(n^2), I have often read that on average quick sort should be as fast as merge sort. However, my results are the following. Up to 10000 strings, both algorithms perform equally well. For 10000 strings, both require about 0.007 seconds. For 100000 strings, merge sort is slightly faster with 0.095 s against 0.121 s. For 1000000 strings merge sort takes 1.287 s against 5.233 s of quick sort. For 5000000 strings merge sort takes 7.582 s against 118.240 s of quick sort. For 10000000 strings merge sort takes 16.305 s against 1202.918 s of quick sort. So my question is: are my results as expected, meaning that quick sort is comparable in speed to merge sort for small inputs but, as the size of the input data grows, the fact that its complexity is quadratic will become evident? Here is a sketch of what I did. In the merge sort implementation, the partitioning consists in calling merge sort recursively, i.e. merge_sort(lines, start, (start + end) / 2); merge_sort(lines, 1 + (start + end) / 2, end); Merging of the two sorted sub-array is performed by reading the data from the array lines and writing it to a global temporary array of pointers (this global array is allocate only once). After each merge the pointers are copied back to the original array. So the strings are stored once but I need twice as much memory for the pointers. For quick sort, the partition function chooses the last element of the array to sort as the pivot and scans the previous elements in one loop. After it has produced a partition of the type start ... {elements <= pivot} ... pivotIndex ... {elements > pivot} ... end it calls itself recursively: quick_sort(lines, start, pivotIndex - 1); quick_sort(lines, pivotIndex + 1, end); Note that this quick sort implementation sorts the array in-place and does not require additional memory, therefore it is more memory efficient than the merge sort implementation. So my question is: is there a better way to implement quick sort that is worthwhile trying out? If I improve the quick sort implementation and perform more tests on different data sets (computing the average of the running times on different data sets) can I expect a better performance of quick sort wrt merge sort? EDIT Thank you for your answers. My implementation is in-place and is based on the pseudo-code I have found on wikipedia in Section In-place version: function partition(array, 'left', 'right', 'pivotIndex') where I choose the last element in the range to be sorted as a pivot, i.e. pivotIndex := right. I have checked the code over and over again and it seems correct to me. In order to rule out the case that I am using the wrong implementation I have uploaded the source code on github (in case you would like to take a look at it). Your answers seem to suggest that I am using the wrong test data. I will look into it and try out different test data sets. I will report as soon as I have some results.

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• SQL SERVER – Updating Data in A Columnstore Index

  - by pinaldave

  So far I have written two articles on Columnstore Indexes, and both of them got very interesting readership. In fact, just recently I got a query on my previous article on Columnstore Index. Read the following two articles to get familiar with the Columnstore Index. They will give you a reference to the question which was asked by a certain reader: SQL SERVER – Fundamentals of Columnstore Index SQL SERVER – How to Ignore Columnstore Index Usage in Query Here is the reader’s question: ” When I tried to update my table after creating the Columnstore index, it gives me an error. What should I do?” When the Columnstore index is created on the table, the table becomes Read-Only table and it does not let any insert/update/delete on the table. The basic understanding is that Columnstore Index will be created on the table that is very huge and holds lots of data. If a table is small enough, there is no need to create a Columnstore index. The regular index should just help it. The reason why Columnstore index was needed is because the table was so big that retrieving the data was taking a really, really long time. Now, updating such a huge table is always a challenge by itself. If the Columnstore Index is created on the table, and the table needs to be updated, you need to know that there are various ways to update it. The easiest way is to disable the Index and enable it. Consider the following code: USE AdventureWorks GO -- Create New Table CREATE TABLE [dbo].[MySalesOrderDetail]( [SalesOrderID] [int] NOT NULL, [SalesOrderDetailID] [int] NOT NULL, [CarrierTrackingNumber] [nvarchar](25) NULL, [OrderQty] [smallint] NOT NULL, [ProductID] [int] NOT NULL, [SpecialOfferID] [int] NOT NULL, [UnitPrice] [money] NOT NULL, [UnitPriceDiscount] [money] NOT NULL, [LineTotal] [numeric](38, 6) NOT NULL, [rowguid] [uniqueidentifier] NOT NULL, [ModifiedDate] [datetime] NOT NULL ) ON [PRIMARY] GO -- Create clustered index CREATE CLUSTERED INDEX [CL_MySalesOrderDetail] ON [dbo].[MySalesOrderDetail] ( [SalesOrderDetailID]) GO -- Create Sample Data Table -- WARNING: This Query may run upto 2-10 minutes based on your systems resources INSERT INTO [dbo].[MySalesOrderDetail] SELECT S1.* FROM Sales.SalesOrderDetail S1 GO 100 -- Create ColumnStore Index CREATE NONCLUSTERED COLUMNSTORE INDEX [IX_MySalesOrderDetail_ColumnStore] ON [MySalesOrderDetail] (UnitPrice, OrderQty, ProductID) GO -- Attempt to Update the table UPDATE [dbo].[MySalesOrderDetail] SET OrderQty = OrderQty +1 WHERE [SalesOrderID] = 43659 GO /* It will throw following error Msg 35330, Level 15, State 1, Line 2 UPDATE statement failed because data cannot be updated in a table with a columnstore index. Consider disabling the columnstore index before issuing the UPDATE statement, then rebuilding the columnstore index after UPDATE is complete. */ A similar error also shows up for Insert/Delete function. Here is the workaround. Disable the Columnstore Index and performance update, enable the Columnstore Index: -- Disable the Columnstore Index ALTER INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] DISABLE GO -- Attempt to Update the table UPDATE [dbo].[MySalesOrderDetail] SET OrderQty = OrderQty +1 WHERE [SalesOrderID] = 43659 GO -- Rebuild the Columnstore Index ALTER INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] REBUILD GO This time it will not throw an error while the update of the table goes successfully. Let us do a cleanup of our tables using this code: -- Cleanup DROP INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] GO TRUNCATE TABLE dbo.MySalesOrderDetail GO DROP TABLE dbo.MySalesOrderDetail GO In the next post we will see how we can use Partition to update the Columnstore Index. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Index, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Skewed: a rotating camera in a simple CPU-based voxel raycaster/raytracer

  - by voxelizr

  TL;DR -- in my first simple software voxel raycaster, I cannot get camera rotations to work, seemingly correct matrices notwithstanding. The result is skewed: like a flat rendering, correctly rotated, however distorted and without depth. (While axis-aligned ie. unrotated, depth and parallax are as expected.) I'm trying to write a simple voxel raycaster as a learning exercise. This is purely CPU based for now until I figure out how things work exactly -- fow now, OpenGL is just (ab)used to blit the generated bitmap to the screen as often as possible. Now I have gotten to the point where a perspective-projection camera can move through the world and I can render (mostly, minus some artifacts that need investigation) perspective-correct 3-dimensional views of the "world", which is basically empty but contains a voxel cube of the Stanford Bunny. So I have a camera that I can move up and down, strafe left and right and "walk forward/backward" -- all axis-aligned so far, no camera rotations. Herein lies my problem. Screenshot #1: correct depth when the camera is still strictly axis-aligned, ie. un-rotated. Now I have for a few days been trying to get rotation to work. The basic logic and theory behind matrices and 3D rotations, in theory, is very clear to me. Yet I have only ever achieved a "2.5 rendering" when the camera rotates... fish-eyey, bit like in Google Streetview: even though I have a volumetric world representation, it seems --no matter what I try-- like I would first create a rendering from the "front view", then rotate that flat rendering according to camera rotation. Needless to say, I'm by now aware that rotating rays is not particularly necessary and error-prone. Still, in my most recent setup, with the most simplified raycast ray-position-and-direction algorithm possible, my rotation still produces the same fish-eyey flat-render-rotated style looks: Screenshot #2: camera "rotated to the right by 39 degrees" -- note how the blue-shaded left-hand side of the cube from screen #2 is not visible in this rotation, yet by now "it really should"! Now of course I'm aware of this: in a simple axis-aligned-no-rotation-setup like I had in the beginning, the ray simply traverses in small steps the positive z-direction, diverging to the left or right and top or bottom only depending on pixel position and projection matrix. As I "rotate the camera to the right or left" -- ie I rotate it around the Y-axis -- those very steps should be simply transformed by the proper rotation matrix, right? So for forward-traversal the Z-step gets a bit smaller the more the cam rotates, offset by an "increase" in the X-step. Yet for the pixel-position-based horizontal+vertical-divergence, increasing fractions of the x-step need to be "added" to the z-step. Somehow, none of my many matrices that I experimented with, nor my experiments with matrix-less hardcoded verbose sin/cos calculations really get this part right. Here's my basic per-ray pre-traversal algorithm -- syntax in Go, but take it as pseudocode: fx and fy: pixel positions x and y rayPos: vec3 for the ray starting position in world-space (calculated as below) rayDir: vec3 for the xyz-steps to be added to rayPos in each step during ray traversal rayStep: a temporary vec3 camPos: vec3 for the camera position in world space camRad: vec3 for camera rotation in radians pmat: typical perspective projection matrix The algorithm / pseudocode: // 1: rayPos is for now "this pixel, as a vector on the view plane in 3d, at The Origin" rayPos.X, rayPos.Y, rayPos.Z = ((fx / width) - 0.5), ((fy / height) - 0.5), 0 // 2: rotate around Y axis depending on cam rotation. No prob since view plane still at Origin 0,0,0 rayPos.MultMat(num.NewDmat4RotationY(camRad.Y)) // 3: a temp vec3. planeDist is -0.15 or some such -- fov-based dist of view plane from eye and also the non-normalized, "in axis-aligned world" traversal step size "forward into the screen" rayStep.X, rayStep.Y, rayStep.Z = 0, 0, planeDist // 4: rotate this too -- 0,zstep should become some meaningful xzstep,xzstep rayStep.MultMat(num.NewDmat4RotationY(CamRad.Y)) // set up direction vector from still-origin-based-ray-position-off-rotated-view-plane plus rotated-zstep-vector rayDir.X, rayDir.Y, rayDir.Z = -rayPos.X - me.rayStep.X, -rayPos.Y, rayPos.Z + rayStep.Z // perspective projection rayDir.Normalize() rayDir.MultMat(pmat) // before traversal, the ray starting position has to be transformed from origin-relative to campos-relative rayPos.Add(camPos) I'm skipping the traversal and sampling parts -- as per screens #1 through #3, those are "basically mostly correct" (though not pretty) -- when axis-aligned / unrotated.

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• Give a session on C++ AMP – here is how

  - by Daniel Moth

  Ever since presenting on C++ AMP at the AMD Fusion conference in June, then the Gamefest conference in August, and the BUILD conference in September, I've had numerous requests about my material from folks that want to re-deliver the same session. The C++ AMP session I put together has evolved over the 3 presentations to its final form that I used at BUILD, so that is the one I recommend you base yours on. Please get the slides and the recording from channel9 (I'll refer to slide numbers below). This is how I've been presenting the C++ AMP session: Context (slide 3, 04:18-08:18) Start with a demo, on my dual-GPU machine. I've been using the N-Body sample (for VS 11 Developer Preview). (slide 4) Use an nvidia slide that has additional examples of performance improvements that customers enjoy with heterogeneous computing. (slide 5) Talk a bit about the differences today between CPU and GPU hardware, leading to the fact that these will continue to co-exist and that GPUs are great for data parallel algorithms, but not much else today. One is a jack of all trades and the other is a number cruncher. (slide 6) Use the APU example from amd, as one indication that the hardware space is still in motion, emphasizing that the C++ AMP solution is a data parallel API, not a GPU API. It has a future proof design for hardware we have yet to see. (slide 7) Provide more meta-data, as blogged about when I first introduced C++ AMP. Code (slide 9-11) Introduce C++ AMP coding with a simplistic array-addition algorithm – the slides speak for themselves. (slide 12-13) index<N>, extent<N>, and grid<N>. (Slide 14-16) array<T,N>, array_view<T,N> and comparison between them. (Slide 17) parallel_for_each. (slide 18, 21) restrict. (slide 19-20) actual restrictions of restrict(direct3d) – the slides speak for themselves. (slide 22) bring it altogether with a matrix multiplication example. (slide 23-24) accelerator, and accelerator_view. (slide 26-29) Introduce tiling incl. tiled matrix multiplication [tiling probably deserves a whole session instead of 6 minutes!]. IDE (slide 34,37) Briefly touch on the concurrency visualizer. It supports GPU profiling, but enhancements specific to C++ AMP we hope will come at the Beta timeframe, which is when I'll be spending more time talking about it. (slide 35-36, 51:54-59:16) Demonstrate the GPU debugging experience in VS 11. Summary (slide 39) Re-iterate some of the points of slide 7, and add the point that the C++ AMP spec will be open for other compiler vendors to implement, even on other platforms (in fact, Microsoft is actively working on that). (slide 40) Links to content – see slide – including where all your questions should go: http://social.msdn.microsoft.com/Forums/en/parallelcppnative/threads.   "But I don't have time for a full blown session, I only need 2 (or just 1, or 3) C++ AMP slides to use in my session on related topic X" If all you want is a small number of slides, you can take some from the session above and customize them. But because I am so nice, I have created some slides for you, including talking points in the notes section. Download them here. Comments about this post by Daniel Moth welcome at the original blog.

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• Why I&rsquo;m Getting an iPad

  - by andrewbrust

  I have never purchased an Apple product in my life.  That’s a “true fact.”  And, for that matter, the last Apple product I really wanted was an Apple IIe, back in the 1980s.  I couldn’t afford it though (I was in high school), so I got a Commodore 64 instead…it had the same microprocessor, after all.  If the iPhone were on Verizon, I probably would have picked one up in December, when I got my Droid.  And if the iPod Touch worked with my Napster subscription (which of course it does not, but my Sonos does) I might have picked on of those instead. That’s three strikes, but Apple’s not out.  I’ve decided I want the iPad.  Why?  Well, to start with, my birthday is March 31st…the iPad comes out on April 3rd, and my wife wanted to know what to get me.  Also, my house is a 7-minute walk from the Apple Store on West 14th Street in Manhattan.  This makes it easy to get my pre-ordered device on launch day, and get home quickly with it.  Oh, and I agreed to write an article for Redmond Magazine, the fee for which will pay for the device…that way the birthday present doesn’t have to be an extravagant expense.  Plus, I’m a contrarian, so I want to buy the one device from Apple that the fanboys have actually panned. Think those are bad reasons? How about this: I want to experience iPhone and iPad development and, although my app will probably never hit the App Store and run on the actual device, I still think owning one will help me develop something better.  i want to see if the slate form factor has good business usage scenarios.  I want to see if Business Intelligence technology on a device like this can work.  Imagine a dashboard on this thing. And, for the consumer experience, I really want a touch device on which I can surf the Web while I’m in the kitchen, or on the couch.  I don’t want the small form factor of my phone, I don’t want to use my TV, and I don’t want a keyboard that will get dirty or in my way. I don’t want to watch movies on it (my TV is good for that), so I don’t care that the iPad has a 4:3 screen.  I don’t want to read books on it, so I don’t care that the display is backlit LCD, rather than eInk. But really what I want is to understand, first hand, why people have such brand loyalty to Apple.  I know the big reasons; I’m not detached from society.  But I want to know the subtle points of what Apple does really well, and also what they do poorly.  And I’d like to know, once and for all, if Microsoft can beat Apple, if Microsoft can think the right way to beat Apple and if Microsoft should  even try to beat Apple. I expect to share my thoughts on these questions, as they develop.

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• BizTalk 2009 - Pipeline Component Wizard

  - by Stuart Brierley

  Recently I decided to try out the BizTalk Server Pipeline Component Wizard when creating a new pipeline component for BizTalk 2009. There are different versions of the wizard available, so be sure to download the appropriate version for the BizTalk environment that you are working with. Following the download and expansion of the zip file, you should be left with a Visual Studio solution.  Open this solution and build the project. Following this installation is straight foward - locate and run the built setup.exe file in the PipelineComponentWizard Setup project and click through the small number of installation screens. Once you have completed installation you will be ready to use the wizard in Visual Studio to create your BizTalk Pipeline Component. Start by creating a new project, selecting BizTalk Projects then BizTalk Server Pipeline Component.  You will then be presented with the splash screen. The next step is General Setup, where you will detail the classname, namespace, pipeline and component types, and the implementation language for your Pipeline Component. The options for pipeline type are Receive, Send or Any. Depending on the pipeline type chosen there are different options presented for the component type, matching those available within the BizTalk Pipelines themselves: Receive - Decoder, Disassembling Parser, Validate, Party Resolver, Any. Send -  Encoder, Assembling Serializer, Any. Any - Any. The options for implementation language are C# or VB.Net Next you must set up the UI settings - these are the settings that affect the appearance of the pipeline component within Visual Studio. You must detail the component name, version, description and icon.  Next is the definition of the variables that the pipeline component will use.  The values for these variables will be defined in Visual Studio when creating a pipeline. The options for each variable you require are: Designer Property - The name of the variable. Data Type - String, Boolean, Integer, Long, Short, Schema List, Schema With None Clicking finish now will complete the wizard stage of the creation of your pipeline component. Once the wizard has completed you will be left with a BizTalk Server Pipeline Component project containing a skeleton code file for you to complete.   Within this code file you will mainly be interested in the execute method, which is left mostly empty ready for you to implement your custom pipeline code:          #region IComponent members         /// <summary>         /// Implements IComponent.Execute method.         /// </summary>         /// <param name="pc">Pipeline context</param>         /// <param name="inmsg">Input message</param>         /// <returns>Original input message</returns>         /// <remarks>         /// IComponent.Execute method is used to initiate         /// the processing of the message in this pipeline component.         /// </remarks>         public Microsoft.BizTalk.Message.Interop.IBaseMessage Execute(Microsoft.BizTalk.Component.Interop.IPipelineContext pc, Microsoft.BizTalk.Message.Interop.IBaseMessage inmsg)         {             //             // TODO: implement component logic             //             // this way, it's a passthrough pipeline component             return inmsg;         }         #endregion Once you have implemented your custom code, build and compile your Custom Pipeline Component then add the compiled .dll to C:\Program Files\Microsoft BizTalk Server 2009\Pipeline Components . When creating a new pipeline, in Visual Studio reset the toolbox and the custom pipeline component should appear ready for you to use in your Biztalk Pipeline. Drop the pipeline component into the relevant pipeline stage and configure the component properties (the variables defined in the wizard). You can now deploy and use the pipeline as you would any other custom pipeline.

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• Oracle and Partners release CAMP specification for PaaS Management

  - by macoracle

  Cloud Application Management for Platforms The public release of the Cloud Application Management for Platforms (CAMP) specification, an initial draft of what is expected to become an industry standard self service interface specification for Platform as a Service (PaaS) management, represents a significant milestone in cloud standards development. Created by several players in the emerging cloud industry, including Oracle, the specification is being submitted to the OASIS standards organization (draft charter) where it will be finalized in an open development process. CAMP is targeted at application developers and deployers for self service management of their application on a Platform-as-a-Service cloud. It is closely aligned with the application development process where applications are typically developed in an Application Development Environment (ADE) and then deployed into a private or public platform cloud. CAMP standardizes the model behind an application’s dependencies on platform components and provides a standardized format for moving applications between the ADE and the cloud, and if and when desirable, between clouds. Once an application is deployed, CAMP provides users with a standardized self service interface to the PaaS offering, allowing the cloud consumer to manage the lifecycle of the application on that platform and the use of the underlying platform services. The CAMP interface includes a RESTful binding of the CAMP model onto the standard HTTP protocol, using JSON as the encoding for the model resources. The model for CAMP includes resources that represent the Application, its Components and any Platform Components that they depend on. It's important PaaS Cloud consumers understand that for a PaaS cloud, these are the abstractions that the user would prefer to work with, not Virtual Machines and the various resources such as compute power, storage and networking. PaaS cloud consumers would also not like to become system administrators for the infrastructure that is hosting their applications and component services. CAMP works on this more abstract level, and yet still accommodates platforms that are built using an underlying infrastructure cloud. With CAMP, it is up to the cloud provider whether or not this underlying infrastructure is exposed to the consumer. One major challenge addressed by the CAMP specification is that of ensuring that application deployment on a new platform is as seamless and error free as possible. This becomes even more difficult when the application may have been developed for a different platform and is now moving to a new one. In CAMP this is accomplished by matching the requirements of the application and its components to the specific capabilities of the underlying platform. This needs to be done regardless of whether there are existing pools of virtualized platform resources (such as a database pool) which are provisioned(on the basis of a schema for example), or whether the platform component is really just a set of virtual machines drawn from an infrastructure pool. The interoperability between platform clouds that CAMP offers means that a CAMP client such as an ADE can target multiple clouds with a single common interface. Applications can even be spread across multiple platform clouds and then managed without needing to create a specialized adapter to manage the components running in each cloud. The development of CAMP has been an effort by a small set of companies, but there are significant advantages to this approach. For example, the way that each of these companies creates their platforms is different enough, to ensure that CAMP can cover a wide range of actual deployments. CAMP is now entering the next phase of development under the guidance of an open standards organization, OASIS, which will likely broaden it’s capabilities. We hope is to keep it concise and minimal, however, to ease implementation and adoption. Over time there will be many different types of platform components that applications can use and which need management. CAMP at this point only includes one example of this (in an appendix) – DataBase as a Service. I am looking forward to the start of the CAMP Technical Committee in OASIS and will do my best to ensure a successful development process. Hope to see you there.

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• Creating shapes on the fly

  - by Bertrand Le Roy

  Most Orchard shapes get created from part drivers, but they are a lot more versatile than that. They can actually be created from pretty much anywhere, including from templates. One example can be found in the Layout.cshtml file of the ThemeMachine theme: WorkContext.Layout.Footer .Add(New.BadgeOfHonor(), "5"); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } What this is really doing is create a new shape called BadgeOfHonor and injecting it into the Footer global zone (that has not yet been defined, which in itself is quite awesome) with an ordering rank of "5". We can actually come up with something simpler, if we want to render the shape inline instead of sending it into a zone: @Display(New.BadgeOfHonor()) Now let's try something a little more elaborate and create a new shape for displaying a date and time: @Display(New.DateTime(date: DateTime.Now, format: "d/M/yyyy")) For the moment, this throws a "Shape type DateTime not found" exception because the system has no clue how to render a shape called "DateTime" yet. The BadgeOfHonor shape above was rendering something because there is a template for it in the theme: Themes/ThethemeMachine/Views/BadgeOfHonor.cshtml. We need to provide a template for our new shape to get rendered. Let's add a DateTime.cshtml file into our theme's Views folder in order to make the exception go away: Hi, I'm a date time shape. Now we're just missing one thing. Instead of displaying some static text, which is not very interesting, we can display the actual time that got passed into the shape's dynamic constructor. Those parameters will get added to the template's Model, so they are easy to retrieve: @(((DateTime)Model.date).ToString(Model.format)) Now that may remind you a little of WebForm's user controls. That's a fair comparison, except that these shapes are much more flexible (you can add properties on the fly as necessary), and that the actual rendering is decoupled from the "control". For example, any theme can override the template for a shape, you can use alternates, wrappers, etc. Most importantly, there is no lifecycle and protocol abstraction like there was in WebForms. I think this is a real improvement over previous attempts at similar things.

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• TechEd Israel 2010 may only accept speakers from sponsors

  - by RoyOsherove

  A month or so ago, Microsoft Israel started sending out emails to its partners and registered event users to “Save the date!” – Micraoft Teched Israel is coming, and it’s going to be this november! “Great news” I thought to myself. I’d been to a couple of the MS teched events, as a speaker and as an attendee, and it was lovely and professionally done. Israel is an amazing place for technology and development and TechEd hosted some big names in the world of MS software. A couple of weeks ago, I was shocked to hear from a couple of people that Microsoft Israel plans to only accept non-MS teched speakers, only from sponsors of the event. That means that according to the amount that you have paid, you get to insert one or more of your own selected speakers as part of teched. I’ve spent the past couple of weeks trying to gather more evidence of this, and have gotten some input from within MS about this information. It looks like that is indeed the case, though no MS rep. was prepared to answer any email I had publicly. If they approach me now I’d be happy to print their response. What does this mean? If this is true, it means that Microsoft Israel is making a grave mistake – They are diluting the quality of the speakers for pure money factors. That means, that as a teched attendee, who paid good money, you might be sitting down to watch nothing more that a bunch of infomercials, or sub-standard speakers – since speakers are no longer selected on quality or interest in their topic. They are turning the conference from a learning event to a commercial driven event They are closing off the stage to the community of speakers who may not be associated with any organization  willing to be a sponsor They are losing speakers (such as myself) who will not want to be part of such an event. (yes – even if my company ends up sponsoring the event, I will not take part in it, Sorry Eli!) They are saying “F&$K you” to the community of MVPs who should be the people to be approached first about technical talks (my guess is many MVPs wouldn’t want to talk at an event driven that way anyway ) I do hope this ends up not being true, but it looks like it is. MS Israel had already done such a thing with the Developer Days event previouly held in Israel – only sponsors were allowed to insert speakers into the event. If this turns out to be true I would urge the MS community in Israel to NOT TAKE PART AT THIS EVENT in any form (attendee, speaker, sponsor or otherwise). by taking part, you will be telling MS Israel it’s OK to piss all over the community that they are quietly suffocating anyway. The MVP case MS Israel has managed to screw the MVP program as well. MS MVPs (I’m one) have had a tough time here in Israel the past couple of years. ever since yosi taguri left the blue badge ranks, there was not real community leader left. Whoever runs things right now has their eyes and minds set elsewhere, with the software MVP community far from mind and heart. No special MVP events (except a couple of small ones this year). No real MVP leadership happens here, with the MVP MEA lead (Ruari) being on a remote line, is not really what’s needed. “MVP? What’s that?” I’m sure many MS Israel employees would say. Exactly my point. Last word I’ve been disappointed by the MS machine for a while now, but their slowness to realize what real community means in the past couple of years really turns me off. Maybe it’s time to move on. Maybe I shouldn’t be chasing people at MS Israel begging for a room to host the Agile Israel user group. Maybe it’s time to say a big bye bye and start looking at a life a bit more disconnected.

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• Low level programming - what's in it for me?

  - by back2dos

  For years I have considered digging into what I consider "low level" languages. For me this means C and assembly. However I had no time for this yet, nor has it EVER been neccessary. Now because I don't see any neccessity arising, I feel like I should either just schedule some point in time when I will study the subject or drop the plan forever. My Position For the past 4 years I have focused on "web technologies", which may change, and I am an application developer, which is unlikely to change. In application development, I think usability is the most important thing. You write applications to be "consumed" by users. The more usable those applications are, the more value you have produced. In order to achieve good usability, I believe the following things are viable Good design: Well-thought-out features accessible through a well-thought-out user interface. Correctness: The best design isn't worth anything, if not implemented correctly. Flexibility: An application A should constantly evolve, so that its users need not switch to a different application B, that has new features, that A could implement. Applications addressing the same problem should not differ in features but in philosophy. Performance: Performance contributes to a good user experience. An application is ideally always responsive and performs its tasks reasonably fast (based on their frequency). The value of performance optimization beyond the point where it is noticeable by the user is questionable. I think low level programming is not going to help me with that, except for performance. But writing a whole app in a low level language for the sake of performance is premature optimization to me. My Question What could low level programming teach me, what other languages wouldn't teach me? Am I missing something, or is it just a skill, that is of very little use for application development? Please understand, that I am not questioning the value of C and assembly. It's just that in my everyday life, I am quite happy that all the intricacies of that world are abstracted away and managed for me (mostly by layers written in C/C++ and assembly themselves). I just don't see any concepts, that could be new to me, only details I would have to stuff my head with. So what's in it for me? My Conclusion Thanks to everyone for their answers. I must say, nobody really surprised me, but at least now I am quite sure I will drop this area of interest until any need for it arises. To my understanding, writing assembly these days for processors as they are in use in today's CPUs is not only unneccesarily complicated, but risks to result in poorer runtime performance than a C counterpart. Optimizing by hand is nearly impossible due to OOE, while you do not get all kinds of optimizations a compiler can do automatically. Also, the code is either portable, because it uses a small subset of available commands, or it is optimized, but then it probably works on one architecture only. Writing C is not nearly as neccessary anymore, as it was in the past. If I were to write an application in C, I would just as much use tested and established libraries and frameworks, that would spare me implementing string copy routines, sorting algorithms and other kind of stuff serving as exercise at university. My own code would execute faster at the cost of type safety. I am neither keen on reeinventing the wheel in the course of normal app development, nor trying to debug by looking at core dumps :D I am currently experimenting with languages and interpreters, so if there is anything I would like to publish, I suppose I'd port a working concept to C, although C++ might just as well do the trick. Again, thanks to everyone for your answers and your insight.

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• 24 Hours of PASS: Whine, Whine, Whine

  - by Most Valuable Yak (Rob Volk)

  24 Hours of Pass (or 24HOP) is a great program offered by PASS to provide free, online training for anyone who wants to learn more about SQL Server.  They routinely have the best SQL Server presenters available for these sessions, and attract hundreds, perhaps even a thousand attendees from around the world.  This is definitely one of the best things they've started doing in the past few years, and every session I've attended has been excellent. So why am I so grumpy about it? I'm not really, pretty much everything here is a minor annoyance that I can deal with.  However since they're so minor they seem to be things that can be easily corrected and would make the process much better. First off, this is my biggest gripe, the registration page: https://www323.livemeeting.com/lrs/8000181573/Registration.aspx?pageName=lj6378f4fhf5hpdm What grinds my gears about this?  I have to scroll alllllllllllllllllllllllllllll the way to bottom to actually register for the sessions.  This wouldn't be so bad except all the details of the session, including the presenter, is in a separate list at the top.  Both lists contain info the other does not, and scrolling between them to determine "Should I make time to listen to this?  Who is speaking at this time anyway?" is really unnecessary. My preference would be to keep the top list and add the checkboxes and schedule info in separate columns.  This is a full-width design, so there's plenty of space for this data, which is pretty small anyway.  The other huge benefit is halving the size of the page, which improves performance and lowers bandwidth usage considerably.  And if you know HTML/ASP.Net, and you view the page source, you can find PLENTY of other things that can be reduced even further.  (not just viewstate) One nice thing that PASS does is send iCal reminders to your email address so you can accept them to your calendar.  Again, they leave off the presenter in the appointment details, while still duplicating the meeting title in the body.  Sometimes I make decisions based on speaker rather than content (Natalie Portman is reading the Yellow Pages??? I'M THERE!) and having the speaker in the iCal is helpful. Next minor annoyances are the necessity for providing a company name, and the survey questions.  I know PASS needs to market themselves effectively, and they need information to do that, and since this is a free event it's really not worth complaining about, but why ask the survey question twice? (once at registration, once again when joining the LiveMeeting)  Same thing for the company name.  All of this should be tied to email address, so that's all I should need to enter when joining the LiveMeeting. The last one is also minor, but it irks me in this day and age of multiple browsers and the decline of Internet Explorer as a dominant platform.  The registration page was originally created in Visual Studio 2003, and has a lot of IE-specific crud representative of the browser situation of 2003. (IE5 references? really? and is the aforementioned viewstate big enough?)  This causes some grief with other browsers like Firefox, Chrome, and sometimes IE8 or 9.  And don't get me started on using the page on a Mac or in Safari. My main point is that PASS is an international organization, welcoming everyone from all levels of SQL Server proficiency, and in that spirit I think it would help to accommodate a wider range of browser software, especially since the registration page is extremely simple.  I recognize that this page is not hosted on the PASS website and may be maintained by some division of Microsoft, but to me that's even worse if MS can't update their own pages.  They've deprecated IE6, so they don't need to maintain support on their own websites anymore. OK, I'll shut up now. #sqlpass #24HOP

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• Create bullet physics rigid body along the vertices of a blender model

  - by Krishnabhadra

  I am working on my first 3D game, for iphone, and I am using Blender to create models, Cocos3D game engine and Bullet for physics simulation. I am trying to learn the use of physics engine. What I have done I have created a small model in blender which contains a Cube (default blender cube) at the origin and a UVSphere hovering exactly on top of this cube (without touching the cube) I saved the file to get MyModel.blend. Then I used File -> Export -> PVRGeoPOD (.pod/.h/.cpp) in Blender to export the model to .pod format to use along with Cocos3D. In the coding side, I added necessary bullet files to my Cocos3D template project in XCode. I am also using a bullet objective C wrapper. -(void) initializeScene { _physicsWorld = [[CC3PhysicsWorld alloc] init]; [_physicsWorld setGravity:0 y:-9.8 z:0]; /*Setup camera, lamp etc.*/ .......... ........... /*Add models created in blender to scene*/ [self addContentFromPODFile: @"MyModel.pod"]; /*Create OpenGL ES buffers*/ [self createGLBuffers]; /*get models*/ CC3MeshNode* cubeNode = (CC3MeshNode*)[self getNodeNamed:@"Cube"]; CC3MeshNode* sphereNode = (CC3MeshNode*)[self getNodeNamed:@"Sphere"]; /*Those boring grey colors..*/ [cubeNode setColor:ccc3(255, 255, 0)]; [sphereNode setColor:ccc3(255, 0, 0)]; float *cVertexData = (float*)((CC3VertexArrayMesh*)cubeNode.mesh).vertexLocations.vertices; int cVertexCount = (CC3VertexArrayMesh*)cubeNode.mesh).vertexLocations.vertexCount; btTriangleMesh* cTriangleMesh = new btTriangleMesh(); // for (int i = 0; i < cVertexCount * 3; i+=3) { // printf("\n%f", cVertexData[i]); // printf("\n%f", cVertexData[i+1]); // printf("\n%f", cVertexData[i+2]); // } /*Trying to create a triangle mesh that curresponds the cube in 3D space.*/ int offset = 0; for (int i = 0; i < (cVertexCount / 3); i++){ unsigned int index1 = offset; unsigned int index2 = offset+6; unsigned int index3 = offset+12; cTriangleMesh->addTriangle( btVector3(cVertexData[index1], cVertexData[index1+1], cVertexData[index1+2] ), btVector3(cVertexData[index2], cVertexData[index2+1], cVertexData[index2+2] ), btVector3(cVertexData[index3], cVertexData[index3+1], cVertexData[index3+2] )); offset += 18; } [self releaseRedundantData]; /*Create a collision shape from triangle mesh*/ btBvhTriangleMeshShape* cTriMeshShape = new btBvhTriangleMeshShape(cTriangleMesh,true); btCollisionShape *sphereShape = new btSphereShape(1); /*Create physics objects*/ gTriMeshObject = [_physicsWorld createPhysicsObjectTrimesh:cubeNode shape:cTriMeshShape mass:0 restitution:1.0 position:cubeNode.location]; sphereObject = [_physicsWorld createPhysicsObject:sphereNode shape:sphereShape mass:1 restitution:0.1 position:sphereNode.location]; sphereObject.rigidBody->setDamping(0.1,0.8); } When I run the sphere and cube shows up fine. I expect the sphere object to fall directly on top of the cube, since I have given it a mass of 1 and the physics world gravity is given as -9.8 in y direction. But What is happening the spere rotates around cube three or times and then just jumps out of the scene. Then I know I have some basic misunderstanding about the whole process. So my question is, how can I create a physics collision shape which corresponds to the shape of a particular mesh model. I may need complex shapes than cube and sphere, but before going into them I want to understand the concepts.

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• SAB BizTalk Archiving Pipeline Component - Codeplex

  - by Stuart Brierley

  In an effort to give a little more to the BizTalk development community, I have created my first Codeplex project. The SAB BizTalk Archiving Pipeline Component was written using Visual Studio 2010 with BizTalk Server 2010 intended as the target platform.  It is currently at version 0.1, meaning that I have not yet completed all the intended functionality and have so far carried out a limited number of tests.  It does however archive files within the bounds of the functionailty so far implemented and seems to be stable in use. It is based on a recent evolution of a basic archiving component that I wrote in the past, and it is my hope that it will continue to evolve in the coming months. This work was inspired by some old posts by Gilles Zunino and Jeff Lynch.   You can download the documentation, source code or component dll from Codeplex, but to give you a taste here is the first section of the documentation to whet your appetite: SAB BizTalk Archiving Pipeline Component   The SAB BizTalk Archiving Pipeline Component has been developed to allow custom piplelines to be created that can archive messages at any stage of pipeline processing.   It works in both receive and send pipelines and will archive messages to file based on the configuration applied to the component in the BizTalk Administration Console.   The Archiving Pipeline Component has been coded for use with BizTalk Server 2010. Use with other versions of BizTalk has not been tested.   The Archiving Pipeline component is supplied as a dll file that should be placed in the BizTalk Server Pipeline Components folder. It can then be used when developing custom pipelines to be deployed as a part of your BizTalk Server applications.   This version of the component allows you to use a number of generic messaging macros and also a small number that are specific to the FILE adapter. It is intended to extend these macros to cover context properties from other adapters in future releases.     Archive Pipeline Parameters As with all pipeline components, the following parameters can be set when creating your custom pipeline and at runtime via the administration console.   Enabled:              Enables and disables the archive process.                                 True; messages will be archived.   False; messages will be passed to the next stage in the pipeline without performing any processing.   File Name:          The file name of the archived message.   Allows the component to build the archive filename at run-time; based on the values entered, the permitted macros and data extracted from the message context properties.   e.g.        %FileReceivedFileName%-%InterchangeSequenceNumber%   File Mask:           The extension to be added to the File Name following all Macro processing.   e.g.        .xml   File Path:             The path on which the archived message should be saved.   Allows the component to build the archive directory at run-time; based on the values entered, permitted macros and data extracted from the message context properties.   e.g.        C:\Archive\%ReceivePortName%\%Year%\%Month%\%Day%\                   \\ArchiveShare\%ReceivePortName%\%Date%\     Overwrite:          Enables and disables existing file overwrites.   True; any existing file with the same File Path/Name combination (following macro replacement) will be overwritten.   False; any existing file with the same File Path/Name combination (following macro replacement) will not be overwritten.  The current message will be archived with a GUID appended to the File Name.

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• Serving up a RSS feed in MVC using WCF Syndication

  - by brian_ritchie

  With .NET 3.5, Microsoft added the SyndicationFeed class to WCF for generating ATOM 1.0 & RSS 2.0 feeds.  In .NET 3.5, it lives in System.ServiceModel.Web but was moved into System.ServiceModel in .NET 4.0. Here's some sample code on constructing a feed: .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: Consolas, "Courier New", Courier, Monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } 1: SyndicationFeed feed = new SyndicationFeed(title, description, new Uri(link)); 2: feed.Categories.Add(new SyndicationCategory(category)); 3: feed.Copyright = new TextSyndicationContent(copyright); 4: feed.Language = "en-us"; 5: feed.Copyright = new TextSyndicationContent(DateTime.Now.Year + " " + ownerName); 6: feed.ImageUrl = new Uri(imageUrl); 7: feed.LastUpdatedTime = DateTime.Now; 8: feed.Authors.Add(new SyndicationPerson() { Name = ownerName, Email = ownerEmail }); 9:   10: var feedItems = new List<SyndicationItem>(); 11: foreach (var item in Items) 12: { 13: var sItem = new SyndicationItem(item.title, null, new Uri(link)); 14: sItem.Summary = new TextSyndicationContent(item.summary); 15: sItem.Id = item.id; 16: if (item.publishedDate != null) 17: sItem.PublishDate = (DateTimeOffset)item.publishedDate; 18: sItem.Links.Add(new SyndicationLink() { Title = item.title, Uri = new Uri(link), Length = item.size, MediaType = item.mediaType }); 19: feedItems.Add(sItem); 20: } 21: feed.Items = feedItems;   Then, we create a custom ContentResult to serialize the feed & stream it to the client: 1: public class SyndicationFeedResult : ContentResult 2: { 3: public SyndicationFeedResult(SyndicationFeed feed) 4: : base() 5: { 6: using (var memstream = new MemoryStream()) 7: using (var writer = new XmlTextWriter(memstream, System.Text.UTF8Encoding.UTF8)) 8: { 9: feed.SaveAsRss20(writer); 10: writer.Flush(); 11: memstream.Position = 0; 12: Content = new StreamReader(memstream).ReadToEnd(); 13: ContentType = "application/rss+xml" ; 14: } 15: } 16: } Finally, we wire it up through the controller: 1: public class RssController : Controller 2: { 3: public SyndicationFeedResult Feed() 4: { 5: var feed = new SyndicationFeed(); 6: // populate feed... 7: return new SyndicationFeedResult(feed); 8: } 9: }   In the next post, I'll discuss how to add iTunes markup to the feed to publish it on iTunes as a Podcast. 

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• How do you educate your teammates without seeming condescending or superior?

  - by Dan Tao

  I work with three other guys; I'll call them Adam, Brian, and Chris. Adam and Brian are bright guys. Give them a problem; they will figure out a way to solve it. When it comes to OOP, though, they know very little about it and aren't particularly interested in learning. Pure procedural code is their MO. Chris, on the other hand, is an OOP guy all the way -- and a cocky, condescending one at that. He is constantly criticizing the work Adam and Brian do and talking to me as if I must share his disdain for the two of them. When I say that Adam and Brian aren't interested in learning about OOP, I suspect Chris is the primary reason. This hasn't bothered me too much for the most part, but there have been times when, looking at some code Adam or Brian wrote, it has pained me to think about how a problem could have been solved so simply using inheritance or some other OOP concept instead of the unmaintainable mess of 1,000 lines of code that ended up being written instead. And now that the company is starting a rather ambitious new project, with Adam assigned to the task of getting the core functionality in place, I fear the result. Really, I just want to help these guys out. But I know that if I come across as just another holier-than-thou developer like Chris, it's going to be massively counterproductive. I've considered: Team code reviews -- everybody reviews everybody's code. This way no one person is really in a position to look down on anyone else; besides, I know I could learn plenty from the other members on the team as well. But this would be time-consuming, and with such a small team, I have trouble picturing it gaining much traction as a team practice. Periodic e-mails to the team -- this would entail me sending out an e-mail every now and then discussing some concept that, based on my observation, at least one team member would benefit from learning about. The downside to this approach is I do think it could easily make me come across as a self-appointed expert. Keeping a blog -- I already do this, actually; but so far my blog has been more about esoteric little programming tidbits than straightforward practical advice. And anyway, I suspect it would get old pretty fast if I were constantly telling my coworkers, "Hey guys, remember to check out my new blog post!" This question doesn't need to be specifically about OOP or any particular programming paradigm or technology. I just want to know: how have you found success in teaching new concepts to your coworkers without seeming like a condescending know-it-all? It's pretty clear to me there isn't going to be a sure-fire answer, but any helpful advice (including methods that have worked as well as those that have proved ineffective or even backfired) would be greatly appreciated. UPDATE: I am not the Team Lead on this team. Chris is. UPDATE 2: Made community wiki to accord with the general sentiment of the community (fancy that).

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• General website publishing questions involving domain forwarding issue

  - by Gorgeousyousuf

  Even though I have been having a certain level of knowledge and experience about web development I have never interested in obtaining a domain and publishing a website from my own server. Since today I have been struggling with getting my own domain and configuring it utilizing web sources. I started with learning the outline of web publishing process including web server installation, deploying a website for testing purpose,router port forwarding, getting a domain and forwarding domain to my router which will also forward http requests to my web server I am confused about some parts and so far could not get the web site accessed from outside of the network. All I try to do is just for learning purpose so I do not pay much attention to security issues for now. I have Server 2008 and IIS 7.5 installed. I use a laptop and have access to the modem over wireless and my modem is Zoom x6 5590. Well I will continue explaining what I have done so far and what I think will be after each action I did, I have successfully had access to my website on any local computer entering the internal ip address and port pair of the host machine in a browser. Next, I forwarded port 80 of my host machine creating a virtual server like 10.0.0.x(internal ip(static) of the host) - tcp - start port : 80 - end port : 80 in router options. Now I suppose every request that will come to the public Ip on port 80 will be forwarded to my host machine(10.0.0.x) over port 80. So If everyhing went as desired, the website listening on port 80 will accept the request and process the issue and finally respond bla bla bla... I suppose to access my website from outside of the network by entering http://MyPublicIp:80 in a browser but I couldn't accomplish this task by now despite using godady's domain forwarding tool,I see a small view of my website when I click the "preview" button that checks whether the address(http://publicip/Index.aspx) I entered where my domain will be forwarded is available or not. I am sure that configuring domain does not play a role in solving such a problem since using public ip and port matching does not help. So here is the first question, What is the fact that I face this problem? After that, I have couple of question regarding domain forwarding using godaddy tool. Can I forward my domain to a any port for example port 8080 other than default http port 80? Additionally, can I use a sub-domain to forward to a different port of the host? What I want to design is if the client enters www.mydomain.com, website1 will respond over a specified port and after when a client enters info.mydomain.com, another website which listens on different port will respond. I tried to add a sub-domain and forward it to a address like http://www.mydomain.com:8080/Index.aspx with no success. Can I really do that? Finally, what if I have a ftp site listening on the default port 21 and I create a domain like ftp.mydomain.com that will forward to that ftp site address. Is it possible to use sub-domains for ftp site access? I know I am more than confused but no matter whatever and however you reply to me, you will help me have a more clear view on this subject. Thank you very much from now.

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• 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

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• How to store a shmup level?

  - by pek

  I am developing a 2D shmup (i.e. Aero Fighters) and I was wondering what are the various ways to store a level. Assuming that enemies are defined in their own xml file, how would you define when an enemy spawns in the level? Would it be based on time? Updates? Distance? Currently I do this based on "level time" (the amount of time the level is running - pausing doesn't update the time). Here is an example (the serialization was done by XNA): <?xml version="1.0" encoding="utf-8"?> <XnaContent xmlns:level="pekalicious.xanor.XanorContentShared.content.level"> <Asset Type="level:Level"> <Enemies> <Enemy> <EnemyType>data/enemies/smallenemy</EnemyType> <SpawnTime>PT0S</SpawnTime> <NumberOfSpawns>60</NumberOfSpawns> <SpawnOffset>PT0.2S</SpawnOffset> </Enemy> <Enemy> <EnemyType>data/enemies/secondenemy</EnemyType> <SpawnTime>PT0S</SpawnTime> <NumberOfSpawns>10</NumberOfSpawns> <SpawnOffset>PT0.5S</SpawnOffset> </Enemy> <Enemy> <EnemyType>data/enemies/secondenemy</EnemyType> <SpawnTime>PT20S</SpawnTime> <NumberOfSpawns>10</NumberOfSpawns> <SpawnOffset>PT0.5S</SpawnOffset> </Enemy> <Enemy> <EnemyType>data/enemies/boss1</EnemyType> <SpawnTime>PT30S</SpawnTime> <NumberOfSpawns>1</NumberOfSpawns> <SpawnOffset>PT0S</SpawnOffset> </Enemy> </Enemies> </Asset> </XnaContent> Each Enemy element is basically a wave of specific enemy types. The type is defined in EnemyType while SpawnTime is the "level time" this wave should appear. NumberOfSpawns and SpawnOffset is the number of enemies that will show up and the time it takes between each spawn respectively. This could be a good idea or there could be better ones out there. I'm not sure. I would like to see some opinions and ideas. I have two problems with this: spawning an enemy correctly and creating a level editor. The level editor thing is an entirely different problem (which I will probably post in the future :P). As for spawning correctly, the problem lies in the fact that I have a variable update time and so I need to make sure I don't miss an enemy spawn because the spawn offset is too small, or because the update took a little more time. I kinda fixed it for the most part, but it seems to me that the problem is with how I store the level. So, any ideas? Comments? Thank you in advance.

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• Ubuntu 12.04 Bootloader failed to install

  - by Chris

  Sorry about the excessively long question, but I figured giving more information would be better. I recently bought a new desktop for myself, running Windows 7. It has two hard drives, and I wanted to install Ubuntu on a small partition on the second hard drive. I created 25GB "free space" in Windows and ran a LiveCD install. I wanted to select the install options myself but accidentally selected "Install alongside Windows 7," but it seemed to pick up the free space and installed itself there as I wanted it to. However, I was told that the bootloader installation had failed. I chose to "Cancel installation," leaving my computer unable to boot. I wiped my computer and reinstalled Windows. After that, I tried installing Ubuntu through Windows using WUBI, once using files from my LiveCD and once downloading everything again. Both times the install succeeded, but both times when I restarted and tried to load Ubuntu, it gave me an error - wubildr.mbr was corrupt or missing. I checked in Windows - it was indeed present on the C:\ drive. I went back to the LiveCD installation, this time going the custom options route. I assigned 16GB to an Ext4 journaling file system and 10GB to a swap file. I got the same bootloader error as before. Being prompted to select a different partition to install the bootloader to, I first tried the partition Ubuntu was installed on. A window came up saying that the install had succeeded, but a second window gave me the same error and choices as before. I went through every single option it gave me, including the Windows partition and the hard drives themselves (dev/sda, dev/sdb). Same result. I then chose to not install a bootloader. Windows still works fine, and I assume Ubuntu has installed but is unbootable. Knowing that my computer could potentially brick itself again - and, this time around, with a lot of data to lose and hassle to go through if I mess it up - I really don't want to do anything without some advice. So I'll ask this: a) Why did the bootloader fail to install? Can I fix the error and install Ubuntu fresh? b) Is there any way to get around the error, install the bootloader, and point it towards an existing installation of Ubuntu? c) Is there a quicker and easier solution I might have missed? EDIT: Thanks for the tip, AthloX. After testing the liveCD in Virtualbox with no installation problems, I looked around for some alternate bootloaders but had no success. I attempted another install, which installed the bootloader and Ubuntu just fine but bricked Windows 7. I wiped both hard disks clean, including some "System Reserved" partitions I hadn't noticed before, before re-installing Windows 7 on one hard drive and immediately afterwards installing Ubuntu on the other. Now the computer boots into Windows, but I can pop into the BIOS at startup to boot into Ubunbtu via it's bootloader, and I'm guessing it'll only take a bit of poking at the BIOS to swap the load order. Many thanks!

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• 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.

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• ORA-4031 Troubleshooting

  - by [email protected]

    QUICKLINK: Note 396940.1 Troubleshooting and Diagnosing ORA-4031 Error Note 1087773.1 : ORA-4031 Diagnostics Tools [Video]   Have you observed an ORA-04031 error reported in your alert log? An ORA-4031 error is raised when memory is unavailable for use or reuse in the System Global Area (SGA).  The error message will indicate the memory pool getting errors and high level information about what kind of allocation failed and how much memory was unavailable.  The challenge with ORA-4031 analysis is that the error and associated trace is for a "victim" of the problem.   The failing code ran into the memory limitation, but in almost all cases it was not part of the root problem.    Looking for the best way to diagnose? When an ORA-4031 error occurs, a trace file is raised and noted in the alert log if the process experiencing the error is a background process.   User processes may experience errors without reports in the alert log or traces generated.   The V$SHARED_POOL_RESERVED view will show reports of misses for memory over the life of the database. Diagnostics scripts are available in Note 430473.1 to help in analysis of the problem.  There is also a training video on using and interpreting the script data Note 1087773.1. 11g DiagnosabilityStarting with Oracle Database 11g Release 1, the Diagnosability infrastructure was introduced which places traces and core files into a location controlled by the DIAGNOSTIC_DEST initialization parameter when an incident, such as an ORA-4031 occurs. For earlier versions, the trace file will be written to either USER_DUMP_DEST (if the error was caught in a user process) or BACKGROUND_DUMP_DEST (if the error was caught in a background process like PMON or SMON). The trace file contains vital information about what led to the error condition.  Note 443529.1 11g Quick Steps to Package and Send Critical Error Diagnostic Information to Support[Video]Oracle Configuration Manager (OCM)Oracle Configuration Manager (OCM) works with My Oracle Support to enable proactive support capability that helps you organize, collect and manage your Oracle configurations.Oracle Configuration Manager Quick Start GuideNote 548815.1: My Oracle Support Configuration Management FAQ Note 250434.1: BULLETIN: Learn More About My Oracle Support Configuration Manager    Common Causes/Solutions The ORA-4031 can occur for many different reasons.  Some possible causes are: SGA components too small for workload Auto-tuning issues Fragmentation due to application design Bug/leaks in memory allocationsFor more on the 4031 and how this affects the SGA, see Note 396940.1 Troubleshooting and Diagnosing ORA-4031 Error Because of the multiple potential causes, it is important to gather enough diagnostics so that an appropriate solution can be identified.  However, most commonly the cause is associated with configuration tuning.   Ensuring that MEMORY_TARGET or SGA_TARGET are large enough to accommodate workload can get around many scenarios.  The default trace associated with the error provides very high level information about the memory problem and the "victim" that ran into the issue.   The data in the default trace is not going to point to the root cause of the problem. When migrating from 9i to 10g and higher, it is necessary to increase the size of the Shared Pool due to changes in the basic design of the shared memory area. Note 270935.1 Shared pool sizing in 10gNOTE: Diagnostics on the errors should be investigated as close to the time of the error(s) as possible.  If you must restart a database, it is not feasible to diagnose the problem until the database has matured and/or started seeing the problems again. Note 801787.1 Common Cause for ORA-4031 in 10gR2, Excess "KGH: NO ACCESS" Memory Allocation ***For reference to the content in this blog, refer to Note.1088239.1 Master Note for Diagnosing ORA-4031 

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• Drawing transparent glyphs on the HTML canvas

  - by Bertrand Le Roy

  The HTML canvas has a set of methods, createImageData and putImageData, that look like they will enable you to draw transparent shapes pixel by pixel. The data structures that you manipulate with these methods are pseudo-arrays of pixels, with four bytes per pixel. One byte for red, one for green, one for blue and one for alpha. This alpha byte makes one believe that you are going to be able to manage transparency, but that’s a lie. Here is a little script that attempts to overlay a simple generated pattern on top of a uniform background: var wrong = document.getElementById("wrong").getContext("2d"); wrong.fillStyle = "#ffd42a"; wrong.fillRect(0, 0, 64, 64); var overlay = wrong.createImageData(32, 32), data = overlay.data; fill(data); wrong.putImageData(overlay, 16, 16); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } where the fill method is setting the pixels in the lower-left half of the overlay to opaque red, and the rest to transparent black. And here’s how it renders: As you can see, the transparency byte was completely ignored. Or was it? in fact, what happens is more subtle. What happens is that the pixels from the image data, including their alpha byte, replaced the existing pixels of the canvas. So the alpha byte is not lost, it’s just that it wasn’t used by putImageData to combine the new pixels with the existing ones. This is in fact a clue to how to write a putImageData that works: we can first dump that image data into an intermediary canvas, and then compose that temporary canvas onto our main canvas. The method that we can use for this composition is drawImage, which works not only with image objects, but also with canvas objects. var right = document.getElementById("right").getContext("2d"); right.fillStyle = "#ffd42a"; right.fillRect(0, 0, 64, 64); var overlay = wrong.createImageData(32, 32), data = overlay.data; fill(data); var overlayCanvas = document.createElement("canvas"); overlayCanvas.width = overlayCanvas.height = 32; overlayCanvas.getContext("2d").putImageData(overlay, 0, 0); right.drawImage(overlayCanvas, 16, 16); And there is is, a version of putImageData that works like it should always have:

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