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• Setting up VPN with Snow Leopard Server and Linksys router

  - by SueP

  I'd like to get VPN going so I can log in to the office securely from home. I'm using Snow Leopard machines everywhere, and currently have Airport Extremes set up at home and at the office. I have a mac mini with Snow Leopard Server that I'm going to move to the office to act as my server. I just bought a Linksys 4-port router because it says it does VPN (model RVS4000). My problem is, I don't have a clue how to set this thing up, and the more reading I do, the more confused I get. Do I need two of these routers, one at each end? My laptop and iPad claim they can do VPN, so I was assuming I only needed one VPN router? At this point, I literally don't know what questions to ask, or where to plug this thing in. Presumably, between the modem and the airport, but...? If somebody can walk me thru some really basic setup, I'd be very grateful. Right now, I feel like going outside and screaming for a while. But that might attract the local cougar, and after the prints I saw on the arena this afternoon, I don't want to draw its attention. :-)

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• Inkscape: Copying an object, retaining transparency

  - by dpk

  I'm looking for a way to copy objects from one window to another without losing the surrounding transparency. I have two Inkscape windows. The setup is pretty simple. In the first window I draw a filled circle and a filled rectangle in it, with the circle set on top of the rectangle to show that the area around the circle is transparent (that is, you can see the rectangle "under" the circle, see screenshot 1, left). In the second window I just drew a filled rectangle (screenshot 1, right). When I copy the circle from window 1 to window 2 the transparency around the circle is lost (screenshot 2). I've verified that the backgrounds of the documents are 0% alpha/white. This is a rather contrived example but is readily reproducible. The real graphics I am working with have a bunch of objects all in a single group, but I have the same results. I feel like I'm missing something. The circle no longer behaves like a circle at its destination. Instead, it acts kind of like a bitmap. I'm definitely not using the bitmap copy feature.

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• Encrypted WiFi with no password?

  - by Ian Boyd

  Is there any standard that allows a WiFi connection to be encrypted, but not require a password? i know that (old, weak) WEP, and newer WPA/WPA2 require a password (i.e. shared secret). Meanwhile my own wireless connections are "open", and therefore unencrypted. There is no technical reason why i can't have an encrypted link that doesn't require the user to enter any password. Such technology exists today (see public key encryption and HTTPS). But does such a standard exist for WiFi? Note: i only want to protect communications, not limit internet access. i get the sense that no such standard exists (since i'm pretty capable with Google), but i'd like it confirmed. Claraification: i want to protect communcations, not limit internet access. That means users are not required to have a password (or its moral equivalent). This means users are not required: to know a password to know a passphrase to enter a CAPTCHA to draw a secret to have a key fob to know a PIN to use a pre-shared key have a pre-shared file to possess a certificate In other words: it has the same accessibility as before, but is now encrypted.

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• Setting up VPN with Snow Leopard Server and Linksys router

  - by SueP

  I'd like to get VPN going so I can log in to the office securely from home. I'm using Snow Leopard machines everywhere, and currently have Airport Extremes set up at home and at the office. I have a mac mini with Snow Leopard Server that I'm going to move to the office to act as my server. I just bought a Linksys 4-port router because it says it does VPN (model RVS4000). My problem is, I don't have a clue how to set this thing up, and the more reading I do, the more confused I get. Do I need two of these routers, one at each end? My laptop and iPad claim they can do VPN, so I was assuming I only needed one VPN router? At this point, I literally don't know what questions to ask, or where to plug this thing in. Presumably, between the modem and the airport, but...? If somebody can walk me thru some really basic setup, I'd be very grateful. Right now, I feel like going outside and screaming for a while. But that might attract the local cougar, and after the prints I saw on the arena this afternoon, I don't want to draw its attention. :-)

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• How to transform a csv to combine matching rows?

  - by Christian Wolf

  I have a CSV file with some transaction data. Let's say date, volume, price and direction (sell/buy). Additionally there is a ID for each transaction and on each closing transaction (the newer one) there is a reference to the corresponding transaction. Classical database referencing. Now I want to do some statistics and draw some plots. This could be done via Octave, LaTeX/TikZ, Gnuplot or whatever. To do this I need both buy and sell price in one row. My thought was to preprocess the CSV to get another CSV containing the needed information and then to do the statistics. In the end I'd like to have a solution based on scripts and not on a spreadsheet as data might change often (exported from online DB). My actual solution (see http://paste.ubuntu.com/6262822/ ) is a bash script that parses the CSV line by line and checks if there exists a corresponding transaction. If found, a new row is written to the destination CSV. If not a warning is printed. The bad news: For each row in the source file I have to read the whole file a few times. This causes long running times of 10sec for 300 lines. As the line number might rise soon (10k lines), this is not perfect. I am aware, that there are many shells to be opened in the script which might cause the performance problems. Now my questions: Is bash/awk/sed/.... a good way to do things? Should I first import all data into a "real" local database to use SQL? Is there an easy way to achieve the desired results?

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• Out of memory errors but not actually out of memory...

  - by commradepolski

  So, myself and my fellow support techs have been fighting with this issue and we still dont know what the problem is. Lets start off with the system specs: Windows XP 32 bit Corporate (SP2 and SP3) Intel D975XBX2 Mobo 4gb of ram Intel Core 2 Quad Q6600 ATI Radeon HD 3600 - 512mb After a few hours of working on the machine, the end user will begin to see the following symptoms: Out of memory messages Title bars and menus dont draw in properly Problems accessing network resources Problems opening up documents such as MSWord and MSPowerpoint and text files Problems opening up explorer windows General instability We have looked at task manager while this issue was occurring, and all indicators, like PF usage, threads, handles, etc. are normal. We have been having trouble pinpointing the root cause of this issue. It is also not situated with one user, it affects 8-10. So far we have tried: Resetting CMOS (Waiting to see results) Replacing video card (didnt help) Windows updates (didnt help) Updating network drivers (didnt help) Switching user from 1gbps to 100mbps network connection (awaiting results) Swapping the affected user's hardware (waiting for results) Increasing desktop heap size (helped for a bit but then the issue became more frequent) Applying the /3 switch to XP (didnt help) Increasing and decreasing and setting PF to system managed state (didnt help) We did have a power outage at the office a couple weeks ago, and all these issues became more frequent. Prior to the power outage it may take a week or so for the users to experience the issues but since the power outage it takes 3-4 hours or less. We havent had reports of the above issues causing BSODs, although that would be easier to diagnose :). Any help is greatly appreciated.

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• How do I disable tablet gestures in windows 8?

  - by ???

  I'm using a Wacom Intuos4 and I have recently upgraded to Windows 8. I don't have a problem when using Photoshop however I occasionally draw on flash based online boards. The problem is, when I drag the pen in a direction repetitively (which is basically all I do when drawing) it's detected as a gesture, sometimes causing Chrome to go to the previous page (left drag) and making me lose the entire thing. Is there a way to disable these "gestures"? I believe this is not something caused by Windows 8 (or Charms) because I run Windows in English although it's not the initial language that Windows was installed in. I changed to English long after the installation. When Windows takes a move as a gesture, a small text pops up next to the cursor informing me about what I have just done and those pop ups are not even in English. I'm sorry for failing to be any more specific here but these gestures could be a feature of either Windows (unlikely), the tablet, Chrome or the computer itself. It's an Acer Aspire and it has one of those little stickers on it that specifies some of the features and one of them reads "Multi-Gesture" (referring to the touchpad, I guess). Could it be that this Multi-Gesture feature somehow decided to expand and apply for my tablet as well? If so, how do I disable it?

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• How to circle out something in a picture?

  - by T...

  What is the easiest way to circle out something in a picture, like this example This is accomplished in Gimp: Here are the steps necesary to draw an empty ellipse without clearing the contents of the image below it. 1 - Layer New layer 2 - Make the layer to be the same size as the image and layer fill type to transparency. This should be already selected by default. 3 - On the toolbox select the ellipse select tool and make an ellipse 4 - Use the bucket fill tool to paint the ellipse with your desired color. 5 - Right click on it and go to Select Shrink... 6 - Type in how many pixels you want the border to be and click ok. 7 - Go to the menu and click Edit Clear. I feel it is very indirect, in the sense that first fill out the region enclosed by the ellipse, and then shrink the region to the boundary. I wonder if there is a quicker and more direct way to circle out something, such as by directly drawing the boundary? My OS is Ubuntu. What I was asking may be done outside of gimp, but must be by some software under Ubuntu. Thanks!

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• Red Gate Coder interviews: Alex Davies

  - by Michael Williamson

  Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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• Problem rendering VBO

  - by Onno

  I'm developing a game engine using OpenTK. I'm trying to get to grips with the use of VBO's. I've run into some trouble because somehow it doesn't render correctly. Thus far I've used immediate mode to render a test object, a test cube with a texture. namespace SharpEngine.Utility.Mesh { using System; using System.Collections.Generic; using OpenTK; using OpenTK.Graphics; using OpenTK.Graphics.OpenGL; using SharpEngine.Utility; using System.Drawing; public class ImmediateFaceBasedCube : IMesh { private IList<Face> faces = new List<Face>(); public ImmediateFaceBasedCube() { IList<Vector3> allVertices = new List<Vector3>(); //rechtsbovenvoor allVertices.Add(new Vector3(1.0f, 1.0f, 1.0f)); //0 //rechtsbovenachter allVertices.Add(new Vector3(1.0f, 1.0f, -1.0f)); //1 //linksbovenachter allVertices.Add(new Vector3(-1.0f, 1.0f, -1.0f)); //2 //linksbovenvoor allVertices.Add(new Vector3(-1.0f, 1.0f, 1.0f)); //3 //rechtsondervoor allVertices.Add(new Vector3(1.0f, -1.0f, 1.0f)); //4 //rechtsonderachter allVertices.Add(new Vector3(1.0f, -1.0f, -1.0f)); //5 //linksonderachter allVertices.Add(new Vector3(-1.0f, -1.0f, -1.0f)); //6 //linksondervoor allVertices.Add(new Vector3(-1.0f, -1.0f, 1.0f)); //7 IList<Vector2> textureCoordinates = new List<Vector2>(); textureCoordinates.Add(new Vector2(0, 0)); //AA - 0 textureCoordinates.Add(new Vector2(0, 0.3333333f)); //AB - 1 textureCoordinates.Add(new Vector2(0, 0.6666666f)); //AC - 2 textureCoordinates.Add(new Vector2(0, 1)); //AD - 3 textureCoordinates.Add(new Vector2(0.3333333f, 0)); //BA - 4 textureCoordinates.Add(new Vector2(0.3333333f, 0.3333333f)); //BB - 5 textureCoordinates.Add(new Vector2(0.3333333f, 0.6666666f)); //BC - 6 textureCoordinates.Add(new Vector2(0.3333333f, 1)); //BD - 7 textureCoordinates.Add(new Vector2(0.6666666f, 0)); //CA - 8 textureCoordinates.Add(new Vector2(0.6666666f, 0.3333333f)); //CB - 9 textureCoordinates.Add(new Vector2(0.6666666f, 0.6666666f)); //CC -10 textureCoordinates.Add(new Vector2(0.6666666f, 1)); //CD -11 textureCoordinates.Add(new Vector2(1, 0)); //DA -12 textureCoordinates.Add(new Vector2(1, 0.3333333f)); //DB -13 textureCoordinates.Add(new Vector2(1, 0.6666666f)); //DC -14 textureCoordinates.Add(new Vector2(1, 1)); //DD -15 Vector3 copy1 = new Vector3(-2.0f, -2.5f, -3.5f); IList<Vector3> normals = new List<Vector3>(); normals.Add(new Vector3(0, 1.0f, 0)); //0 normals.Add(new Vector3(0, 0, 1.0f)); //1 normals.Add(new Vector3(1.0f, 0, 0)); //2 normals.Add(new Vector3(0, 0, -1.0f)); //3 normals.Add(new Vector3(-1.0f, 0, 0)); //4 normals.Add(new Vector3(0, -1.0f, 0)); //5 //todo: move vertex normal and texture data to datastructure //todo: VBO based rendering //top face //1 IList<VertexData> verticesT1 = new List<VertexData>(); VertexData T1a = new VertexData(); T1a.Normal = normals[0]; T1a.TexCoord = textureCoordinates[5]; T1a.Position = allVertices[3]; verticesT1.Add(T1a); VertexData T1b = new VertexData(); T1b.Normal = normals[0]; T1b.TexCoord = textureCoordinates[9]; T1b.Position = allVertices[0]; verticesT1.Add(T1b); VertexData T1c = new VertexData(); T1c.Normal = normals[0]; T1c.TexCoord = textureCoordinates[10]; T1c.Position = allVertices[1]; verticesT1.Add(T1c); Face F1 = new Face(verticesT1); faces.Add(F1); //2 IList<VertexData> verticesT2 = new List<VertexData>(); VertexData T2a = new VertexData(); T2a.Normal = normals[0]; T2a.TexCoord = textureCoordinates[10]; T2a.Position = allVertices[1]; verticesT2.Add(T2a); VertexData T2b = new VertexData(); T2b.Normal = normals[0]; T2b.TexCoord = textureCoordinates[6]; T2b.Position = allVertices[2]; verticesT2.Add(T2b); VertexData T2c = new VertexData(); T2c.Normal = normals[0]; T2c.TexCoord = textureCoordinates[5]; T2c.Position = allVertices[3]; verticesT2.Add(T2c); Face F2 = new Face(verticesT2); faces.Add(F2); //front face //3 IList<VertexData> verticesT3 = new List<VertexData>(); VertexData T3a = new VertexData(); T3a.Normal = normals[1]; T3a.TexCoord = textureCoordinates[1]; T3a.Position = allVertices[3]; verticesT3.Add(T3a); VertexData T3b = new VertexData(); T3b.Normal = normals[1]; T3b.TexCoord = textureCoordinates[0]; T3b.Position = allVertices[7]; verticesT3.Add(T3b); VertexData T3c = new VertexData(); T3c.Normal = normals[1]; T3c.TexCoord = textureCoordinates[5]; T3c.Position = allVertices[0]; verticesT3.Add(T3c); Face F3 = new Face(verticesT3); faces.Add(F3); //4 IList<VertexData> verticesT4 = new List<VertexData>(); VertexData T4a = new VertexData(); T4a.Normal = normals[1]; T4a.TexCoord = textureCoordinates[5]; T4a.Position = allVertices[0]; verticesT4.Add(T4a); VertexData T4b = new VertexData(); T4b.Normal = normals[1]; T4b.TexCoord = textureCoordinates[0]; T4b.Position = allVertices[7]; verticesT4.Add(T4b); VertexData T4c = new VertexData(); T4c.Normal = normals[1]; T4c.TexCoord = textureCoordinates[4]; T4c.Position = allVertices[4]; verticesT4.Add(T4c); Face F4 = new Face(verticesT4); faces.Add(F4); //right face //5 IList<VertexData> verticesT5 = new List<VertexData>(); VertexData T5a = new VertexData(); T5a.Normal = normals[2]; T5a.TexCoord = textureCoordinates[2]; T5a.Position = allVertices[0]; verticesT5.Add(T5a); VertexData T5b = new VertexData(); T5b.Normal = normals[2]; T5b.TexCoord = textureCoordinates[1]; T5b.Position = allVertices[4]; verticesT5.Add(T5b); VertexData T5c = new VertexData(); T5c.Normal = normals[2]; T5c.TexCoord = textureCoordinates[6]; T5c.Position = allVertices[1]; verticesT5.Add(T5c); Face F5 = new Face(verticesT5); faces.Add(F5); //6 IList<VertexData> verticesT6 = new List<VertexData>(); VertexData T6a = new VertexData(); T6a.Normal = normals[2]; T6a.TexCoord = textureCoordinates[1]; T6a.Position = allVertices[4]; verticesT6.Add(T6a); VertexData T6b = new VertexData(); T6b.Normal = normals[2]; T6b.TexCoord = textureCoordinates[5]; T6b.Position = allVertices[5]; verticesT6.Add(T6b); VertexData T6c = new VertexData(); T6c.Normal = normals[2]; T6c.TexCoord = textureCoordinates[6]; T6c.Position = allVertices[1]; verticesT6.Add(T6c); Face F6 = new Face(verticesT6); faces.Add(F6); //back face //7 IList<VertexData> verticesT7 = new List<VertexData>(); VertexData T7a = new VertexData(); T7a.Normal = normals[3]; T7a.TexCoord = textureCoordinates[4]; T7a.Position = allVertices[5]; verticesT7.Add(T7a); VertexData T7b = new VertexData(); T7b.Normal = normals[3]; T7b.TexCoord = textureCoordinates[9]; T7b.Position = allVertices[2]; verticesT7.Add(T7b); VertexData T7c = new VertexData(); T7c.Normal = normals[3]; T7c.TexCoord = textureCoordinates[5]; T7c.Position = allVertices[1]; verticesT7.Add(T7c); Face F7 = new Face(verticesT7); faces.Add(F7); //8 IList<VertexData> verticesT8 = new List<VertexData>(); VertexData T8a = new VertexData(); T8a.Normal = normals[3]; T8a.TexCoord = textureCoordinates[9]; T8a.Position = allVertices[2]; verticesT8.Add(T8a); VertexData T8b = new VertexData(); T8b.Normal = normals[3]; T8b.TexCoord = textureCoordinates[4]; T8b.Position = allVertices[5]; verticesT8.Add(T8b); VertexData T8c = new VertexData(); T8c.Normal = normals[3]; T8c.TexCoord = textureCoordinates[8]; T8c.Position = allVertices[6]; verticesT8.Add(T8c); Face F8 = new Face(verticesT8); faces.Add(F8); //left face //9 IList<VertexData> verticesT9 = new List<VertexData>(); VertexData T9a = new VertexData(); T9a.Normal = normals[4]; T9a.TexCoord = textureCoordinates[8]; T9a.Position = allVertices[6]; verticesT9.Add(T9a); VertexData T9b = new VertexData(); T9b.Normal = normals[4]; T9b.TexCoord = textureCoordinates[13]; T9b.Position = allVertices[3]; verticesT9.Add(T9b); VertexData T9c = new VertexData(); T9c.Normal = normals[4]; T9c.TexCoord = textureCoordinates[9]; T9c.Position = allVertices[2]; verticesT9.Add(T9c); Face F9 = new Face(verticesT9); faces.Add(F9); //10 IList<VertexData> verticesT10 = new List<VertexData>(); VertexData T10a = new VertexData(); T10a.Normal = normals[4]; T10a.TexCoord = textureCoordinates[8]; T10a.Position = allVertices[6]; verticesT10.Add(T10a); VertexData T10b = new VertexData(); T10b.Normal = normals[4]; T10b.TexCoord = textureCoordinates[12]; T10b.Position = allVertices[7]; verticesT10.Add(T10b); VertexData T10c = new VertexData(); T10c.Normal = normals[4]; T10c.TexCoord = textureCoordinates[13]; T10c.Position = allVertices[3]; verticesT10.Add(T10c); Face F10 = new Face(verticesT10); faces.Add(F10); //bottom face //11 IList<VertexData> verticesT11 = new List<VertexData>(); VertexData T11a = new VertexData(); T11a.Normal = normals[5]; T11a.TexCoord = textureCoordinates[10]; T11a.Position = allVertices[7]; verticesT11.Add(T11a); VertexData T11b = new VertexData(); T11b.Normal = normals[5]; T11b.TexCoord = textureCoordinates[9]; T11b.Position = allVertices[6]; verticesT11.Add(T11b); VertexData T11c = new VertexData(); T11c.Normal = normals[5]; T11c.TexCoord = textureCoordinates[14]; T11c.Position = allVertices[4]; verticesT11.Add(T11c); Face F11 = new Face(verticesT11); faces.Add(F11); //12 IList<VertexData> verticesT12 = new List<VertexData>(); VertexData T12a = new VertexData(); T12a.Normal = normals[5]; T12a.TexCoord = textureCoordinates[13]; T12a.Position = allVertices[5]; verticesT12.Add(T12a); VertexData T12b = new VertexData(); T12b.Normal = normals[5]; T12b.TexCoord = textureCoordinates[14]; T12b.Position = allVertices[4]; verticesT12.Add(T12b); VertexData T12c = new VertexData(); T12c.Normal = normals[5]; T12c.TexCoord = textureCoordinates[9]; T12c.Position = allVertices[6]; verticesT12.Add(T12c); Face F12 = new Face(verticesT12); faces.Add(F12); } public void draw() { GL.Begin(BeginMode.Triangles); foreach (Face face in faces) { foreach (VertexData datapoint in face.verticesWithTexCoords) { GL.Normal3(datapoint.Normal); GL.TexCoord2(datapoint.TexCoord); GL.Vertex3(datapoint.Position); } } GL.End(); } } } Gets me this very nice picture: The immediate mode cube renders nicely and taught me a bit on how to use OpenGL, but VBO's are the way to go. Since I read on the OpenTK forums that OpenTK has problems doing VA's or DL's, I decided to skip using those. Now, I've tried to change this cube to a VBO by using the same vertex, normal and tc collections, and making float arrays from them by using the coordinates in combination with uint arrays which contain the index numbers from the immediate cube. (see the private functions at end of the code sample) Somehow this only renders two triangles namespace SharpEngine.Utility.Mesh { using System; using System.Collections.Generic; using OpenTK; using OpenTK.Graphics; using OpenTK.Graphics.OpenGL; using SharpEngine.Utility; using System.Drawing; public class VBOFaceBasedCube : IMesh { private int VerticesVBOID; private int VerticesVBOStride; private int VertexCount; private int ELementBufferObjectID; private int textureCoordinateVBOID; private int textureCoordinateVBOStride; //private int textureCoordinateArraySize; private int normalVBOID; private int normalVBOStride; public VBOFaceBasedCube() { IList<Vector3> allVertices = new List<Vector3>(); //rechtsbovenvoor allVertices.Add(new Vector3(1.0f, 1.0f, 1.0f)); //0 //rechtsbovenachter allVertices.Add(new Vector3(1.0f, 1.0f, -1.0f)); //1 //linksbovenachter allVertices.Add(new Vector3(-1.0f, 1.0f, -1.0f)); //2 //linksbovenvoor allVertices.Add(new Vector3(-1.0f, 1.0f, 1.0f)); //3 //rechtsondervoor allVertices.Add(new Vector3(1.0f, -1.0f, 1.0f)); //4 //rechtsonderachter allVertices.Add(new Vector3(1.0f, -1.0f, -1.0f)); //5 //linksonderachter allVertices.Add(new Vector3(-1.0f, -1.0f, -1.0f)); //6 //linksondervoor allVertices.Add(new Vector3(-1.0f, -1.0f, 1.0f)); //7 IList<Vector2> textureCoordinates = new List<Vector2>(); textureCoordinates.Add(new Vector2(0, 0)); //AA - 0 textureCoordinates.Add(new Vector2(0, 0.3333333f)); //AB - 1 textureCoordinates.Add(new Vector2(0, 0.6666666f)); //AC - 2 textureCoordinates.Add(new Vector2(0, 1)); //AD - 3 textureCoordinates.Add(new Vector2(0.3333333f, 0)); //BA - 4 textureCoordinates.Add(new Vector2(0.3333333f, 0.3333333f)); //BB - 5 textureCoordinates.Add(new Vector2(0.3333333f, 0.6666666f)); //BC - 6 textureCoordinates.Add(new Vector2(0.3333333f, 1)); //BD - 7 textureCoordinates.Add(new Vector2(0.6666666f, 0)); //CA - 8 textureCoordinates.Add(new Vector2(0.6666666f, 0.3333333f)); //CB - 9 textureCoordinates.Add(new Vector2(0.6666666f, 0.6666666f)); //CC -10 textureCoordinates.Add(new Vector2(0.6666666f, 1)); //CD -11 textureCoordinates.Add(new Vector2(1, 0)); //DA -12 textureCoordinates.Add(new Vector2(1, 0.3333333f)); //DB -13 textureCoordinates.Add(new Vector2(1, 0.6666666f)); //DC -14 textureCoordinates.Add(new Vector2(1, 1)); //DD -15 Vector3 copy1 = new Vector3(-2.0f, -2.5f, -3.5f); IList<Vector3> normals = new List<Vector3>(); normals.Add(new Vector3(0, 1.0f, 0)); //0 normals.Add(new Vector3(0, 0, 1.0f)); //1 normals.Add(new Vector3(1.0f, 0, 0)); //2 normals.Add(new Vector3(0, 0, -1.0f)); //3 normals.Add(new Vector3(-1.0f, 0, 0)); //4 normals.Add(new Vector3(0, -1.0f, 0)); //5 //todo: VBO based rendering uint[] vertexElements = { 3,0,1, //01 1,2,3, //02 3,7,0, //03 0,7,4, //04 0,4,1, //05 4,5,1, //06 5,2,1, //07 2,5,6, //08 6,3,2, //09 6,7,5, //10 7,6,4, //11 5,4,6 //12 }; VertexCount = vertexElements.Length; IList<uint> vertexElementList = new List<uint>(vertexElements); uint[] normalElements = { 0,0,0, 0,0,0, 1,1,1, 1,1,1, 2,2,2, 2,2,2, 3,3,3, 3,3,3, 4,4,4, 4,4,4, 5,5,5, 5,5,5 }; IList<uint> normalElementList = new List<uint>(normalElements); uint[] textureIndexArray = { 5,9,10, 10,6,5, 1,0,5, 5,0,4, 2,1,6, 1,5,6, 4,9,5, 9,4,8, 8,13,9, 8,12,13, 10,9,14, 13,14,9 }; //textureCoordinateArraySize = textureIndexArray.Length; IList<uint> textureIndexList = new List<uint>(textureIndexArray); LoadVBO(allVertices, normals, textureCoordinates, vertexElements, normalElementList, textureIndexList); } public void draw() { //bind vertices //bind elements //bind normals //bind texture coordinates GL.EnableClientState(ArrayCap.VertexArray); GL.EnableClientState(ArrayCap.NormalArray); GL.EnableClientState(ArrayCap.TextureCoordArray); GL.BindBuffer(BufferTarget.ArrayBuffer, VerticesVBOID); GL.VertexPointer(3, VertexPointerType.Float, VerticesVBOStride, 0); GL.BindBuffer(BufferTarget.ArrayBuffer, normalVBOID); GL.NormalPointer(NormalPointerType.Float, normalVBOStride, 0); GL.BindBuffer(BufferTarget.ArrayBuffer, textureCoordinateVBOID); GL.TexCoordPointer(2, TexCoordPointerType.Float, textureCoordinateVBOStride, 0); GL.BindBuffer(BufferTarget.ElementArrayBuffer, ELementBufferObjectID); GL.DrawElements(BeginMode.Polygon, VertexCount, DrawElementsType.UnsignedShort, 0); } //loads a static VBO void LoadVBO(IList<Vector3> vertices, IList<Vector3> normals, IList<Vector2> texcoords, uint[] elements, IList<uint> normalIndices, IList<uint> texCoordIndices) { int size; //todo // To create a VBO: // 1) Generate the buffer handles for the vertex and element buffers. // 2) Bind the vertex buffer handle and upload your vertex data. Check that the buffer was uploaded correctly. // 3) Bind the element buffer handle and upload your element data. Check that the buffer was uploaded correctly. float[] verticesArray = convertVector3fListToFloatArray(vertices); float[] normalsArray = createFloatArrayFromListOfVector3ElementsAndIndices(normals, normalIndices); float[] textureCoordinateArray = createFloatArrayFromListOfVector2ElementsAndIndices(texcoords, texCoordIndices); GL.GenBuffers(1, out VerticesVBOID); GL.BindBuffer(BufferTarget.ArrayBuffer, VerticesVBOID); Console.WriteLine("load 1 - vertices"); VerticesVBOStride = BlittableValueType.StrideOf(verticesArray); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(verticesArray.Length * sizeof(float)), verticesArray, BufferUsageHint.StaticDraw); GL.GetBufferParameter(BufferTarget.ArrayBuffer, BufferParameterName.BufferSize, out size); if (verticesArray.Length * BlittableValueType.StrideOf(verticesArray) != size) { throw new ApplicationException("Vertex data not uploaded correctly"); } else { Console.WriteLine("load 1 finished ok"); size = 0; } Console.WriteLine("load 2 - elements"); GL.GenBuffers(1, out ELementBufferObjectID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, ELementBufferObjectID); GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(elements.Length * sizeof(uint)), elements, BufferUsageHint.StaticDraw); GL.GetBufferParameter(BufferTarget.ElementArrayBuffer, BufferParameterName.BufferSize, out size); if (elements.Length * sizeof(uint) != size) { throw new ApplicationException("Element data not uploaded correctly"); } else { size = 0; Console.WriteLine("load 2 finished ok"); } GL.GenBuffers(1, out normalVBOID); GL.BindBuffer(BufferTarget.ArrayBuffer, normalVBOID); Console.WriteLine("load 3 - normals"); normalVBOStride = BlittableValueType.StrideOf(normalsArray); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(normalsArray.Length * sizeof(float)), normalsArray, BufferUsageHint.StaticDraw); GL.GetBufferParameter(BufferTarget.ArrayBuffer, BufferParameterName.BufferSize, out size); Console.WriteLine("load 3 - pre check"); if (normalsArray.Length * BlittableValueType.StrideOf(normalsArray) != size) { throw new ApplicationException("Normal data not uploaded correctly"); } else { Console.WriteLine("load 3 finished ok"); size = 0; } GL.GenBuffers(1, out textureCoordinateVBOID); GL.BindBuffer(BufferTarget.ArrayBuffer, textureCoordinateVBOID); Console.WriteLine("load 4- texture coordinates"); textureCoordinateVBOStride = BlittableValueType.StrideOf(textureCoordinateArray); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(textureCoordinateArray.Length * textureCoordinateVBOStride), textureCoordinateArray, BufferUsageHint.StaticDraw); GL.GetBufferParameter(BufferTarget.ArrayBuffer, BufferParameterName.BufferSize, out size); if (textureCoordinateArray.Length * BlittableValueType.StrideOf(textureCoordinateArray) != size) { throw new ApplicationException("texture coordinate data not uploaded correctly"); } else { Console.WriteLine("load 3 finished ok"); size = 0; } } //used to convert vertex arrayss for use with VBO's private float[] convertVector3fListToFloatArray(IList<Vector3> input) { int arrayElementCount = input.Count * 3; float[] output = new float[arrayElementCount]; int fillCount = 0; foreach (Vector3 v in input) { output[fillCount] = v.X; output[fillCount + 1] = v.Y; output[fillCount + 2] = v.Z; fillCount += 3; } return output; } //used for converting texture coordinate arrays for use with VBO's private float[] convertVector2List_to_floatArray(IList<Vector2> input) { int arrayElementCount = input.Count * 2; float[] output = new float[arrayElementCount]; int fillCount = 0; foreach (Vector2 v in input) { output[fillCount] = v.X; output[fillCount + 1] = v.Y; fillCount += 2; } return output; } //used to create an array of floats from private float[] createFloatArrayFromListOfVector3ElementsAndIndices(IList<Vector3> inputVectors, IList<uint> indices) { int arrayElementCount = inputVectors.Count * indices.Count * 3; float[] output = new float[arrayElementCount]; int fillCount = 0; foreach (int i in indices) { output[fillCount] = inputVectors[i].X; output[fillCount + 1] = inputVectors[i].Y; output[fillCount + 2] = inputVectors[i].Z; fillCount += 3; } return output; } private float[] createFloatArrayFromListOfVector2ElementsAndIndices(IList<Vector2> inputVectors, IList<uint> indices) { int arrayElementCount = inputVectors.Count * indices.Count * 2; float[] output = new float[arrayElementCount]; int fillCount = 0; foreach (int i in indices) { output[fillCount] = inputVectors[i].X; output[fillCount + 1] = inputVectors[i].Y; fillCount += 2; } return output; } } } This code will only render two triangles and they're nothing like I had in mind: I've done some searching. In some other questions I read that, if I did something wrong, I'd get no rendering at all. Clearly, something gets sent to the GFX card, but it might be that I'm not sending the right data. I've tried altering the sequence in which the triangles are rendered by swapping some of the index numbers in the vert, tc and normal index arrays, but this doesn't seem to be of any effect. I'm slightly lost here. What am I doing wrong here?

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• Compare images after canny edge detection in OpenCV (C++)

  - by typoknig

  Hi all, I am working on an OpenCV project and I need to compare some images after canny has been applied to both of them. Before the canny was applied I had the gray scale images populating a histogram and then I compared the histograms, but when canny is added to the images the histogram does not populate. I have read that a canny image can populate a histogram, but have not found a way to make it happen. I do not necessairly need to keep using the histograms, I just want to know the best way to compare two canny images. SSCCE below for you to chew on. I have poached and patched about 75% of this code from books and various sites on the internet, so props to those guys... // SLC (Histogram).cpp : Defines the entry point for the console application. #include "stdafx.h" #include <cxcore.h> #include <cv.h> #include <cvaux.h> #include <highgui.h> #include <stdio.h> #include <sstream> #include <iostream> using namespace std; IplImage* image1= 0; IplImage* imgHistogram1 = 0; IplImage* gray1= 0; CvHistogram* hist1; int main(){ CvCapture* capture = cvCaptureFromCAM(0); if(!cvQueryFrame(capture)){ cout<<"Video capture failed, please check the camera."<<endl; } else{ cout<<"Video camera capture successful!"<<endl; }; CvSize sz = cvGetSize(cvQueryFrame(capture)); IplImage* image = cvCreateImage(sz, 8, 3); IplImage* imgHistogram = 0; IplImage* gray = 0; CvHistogram* hist; cvNamedWindow("Image Source",1); cvNamedWindow("gray", 1); cvNamedWindow("Histogram",1); cvNamedWindow("BG", 1); cvNamedWindow("FG", 1); cvNamedWindow("Canny",1); cvNamedWindow("Canny1", 1); image1 = cvLoadImage("image bin/use this image.jpg");// an image has to load here or the program will not run //size of the histogram -1D histogram int bins1 = 256; int hsize1[] = {bins1}; //max and min value of the histogram float max_value1 = 0, min_value1 = 0; //value and normalized value float value1; int normalized1; //ranges - grayscale 0 to 256 float xranges1[] = { 0, 256 }; float* ranges1[] = { xranges1 }; //create an 8 bit single channel image to hold a //grayscale version of the original picture gray1 = cvCreateImage( cvGetSize(image1), 8, 1 ); cvCvtColor( image1, gray1, CV_BGR2GRAY ); IplImage* canny1 = cvCreateImage(cvGetSize(gray1), 8, 1 ); cvCanny( gray1, canny1, 55, 175, 3 ); //Create 3 windows to show the results cvNamedWindow("original1",1); cvNamedWindow("gray1",1); cvNamedWindow("histogram1",1); //planes to obtain the histogram, in this case just one IplImage* planes1[] = { canny1 }; //get the histogram and some info about it hist1 = cvCreateHist( 1, hsize1, CV_HIST_ARRAY, ranges1,1); cvCalcHist( planes1, hist1, 0, NULL); cvGetMinMaxHistValue( hist1, &min_value1, &max_value1); printf("min: %f, max: %f\n", min_value1, max_value1); //create an 8 bits single channel image to hold the histogram //paint it white imgHistogram1 = cvCreateImage(cvSize(bins1, 50),8,1); cvRectangle(imgHistogram1, cvPoint(0,0), cvPoint(256,50), CV_RGB(255,255,255),-1); //draw the histogram :P for(int i=0; i < bins1; i++){ value1 = cvQueryHistValue_1D( hist1, i); normalized1 = cvRound(value1*50/max_value1); cvLine(imgHistogram1,cvPoint(i,50), cvPoint(i,50-normalized1), CV_RGB(0,0,0)); } //show the image results cvShowImage( "original1", image1 ); cvShowImage( "gray1", gray1 ); cvShowImage( "histogram1", imgHistogram1 ); cvShowImage( "Canny1", canny1); CvBGStatModel* bg_model = cvCreateFGDStatModel( image ); for(;;){ image = cvQueryFrame(capture); cvUpdateBGStatModel( image, bg_model ); //Size of the histogram -1D histogram int bins = 256; int hsize[] = {bins}; //Max and min value of the histogram float max_value = 0, min_value = 0; //Value and normalized value float value; int normalized; //Ranges - grayscale 0 to 256 float xranges[] = {0, 256}; float* ranges[] = {xranges}; //Create an 8 bit single channel image to hold a grayscale version of the original picture gray = cvCreateImage(cvGetSize(image), 8, 1); cvCvtColor(image, gray, CV_BGR2GRAY); IplImage* canny = cvCreateImage(cvGetSize(gray), 8, 1 ); cvCanny( gray, canny, 55, 175, 3 );//55, 175, 3 with direct light //Planes to obtain the histogram, in this case just one IplImage* planes[] = {canny}; //Get the histogram and some info about it hist = cvCreateHist(1, hsize, CV_HIST_ARRAY, ranges,1); cvCalcHist(planes, hist, 0, NULL); cvGetMinMaxHistValue(hist, &min_value, &max_value); //printf("Minimum Histogram Value: %f, Maximum Histogram Value: %f\n", min_value, max_value); //Create an 8 bits single channel image to hold the histogram and paint it white imgHistogram = cvCreateImage(cvSize(bins, 50),8,3); cvRectangle(imgHistogram, cvPoint(0,0), cvPoint(256,50), CV_RGB(255,255,255),-1); //Draw the histogram for(int i=0; i < bins; i++){ value = cvQueryHistValue_1D(hist, i); normalized = cvRound(value*50/max_value); cvLine(imgHistogram,cvPoint(i,50), cvPoint(i,50-normalized), CV_RGB(0,0,0)); } double correlation = cvCompareHist (hist1, hist, CV_COMP_CORREL); double chisquare = cvCompareHist (hist1, hist, CV_COMP_CHISQR); double intersection = cvCompareHist (hist1, hist, CV_COMP_INTERSECT); double bhattacharyya = cvCompareHist (hist1, hist, CV_COMP_BHATTACHARYYA); double difference = (1 - correlation) + chisquare + (1 - intersection) + bhattacharyya; printf("correlation: %f\n", correlation); printf("chi-square: %f\n", chisquare); printf("intersection: %f\n", intersection); printf("bhattacharyya: %f\n", bhattacharyya); printf("difference: %f\n", difference); cvShowImage("Image Source", image); cvShowImage("gray", gray); cvShowImage("Histogram", imgHistogram); cvShowImage( "Canny", canny); cvShowImage("BG", bg_model->background); cvShowImage("FG", bg_model->foreground); //Page 19 paragraph 3 of "Learning OpenCV" tells us why we DO NOT use "cvReleaseImage(&image)" in this section cvReleaseImage(&imgHistogram); cvReleaseImage(&gray); cvReleaseHist(&hist); cvReleaseImage(&canny); char c = cvWaitKey(10); //if ASCII key 27 (esc) is pressed then loop breaks if(c==27) break; } cvReleaseBGStatModel( &bg_model ); cvReleaseImage(&image); cvReleaseCapture(&capture); cvDestroyAllWindows(); }

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• Understanding and Implementing a Force based graph layout algorithm

  - by zcourts

  I'm trying to implement a force base graph layout algorithm, based on http://en.wikipedia.org/wiki/Force-based_algorithms_(graph_drawing) My first attempt didn't work so I looked at http://blog.ivank.net/force-based-graph-drawing-in-javascript.html and https://github.com/dhotson/springy I changed my implementation based on what I thought I understood from those two but I haven't managed to get it right and I'm hoping someone can help? JavaScript isn't my strong point so be gentle... If you're wondering why write my own. In reality I have no real reason to write my own I'm just trying to understand how the algorithm is implemented. Especially in my first link, that demo is brilliant. This is what I've come up with //support function.bind - https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Function/bind#Compatibility if (!Function.prototype.bind) { Function.prototype.bind = function (oThis) { if (typeof this !== "function") { // closest thing possible to the ECMAScript 5 internal IsCallable function throw new TypeError("Function.prototype.bind - what is trying to be bound is not callable"); } var aArgs = Array.prototype.slice.call(arguments, 1), fToBind = this, fNOP = function () {}, fBound = function () { return fToBind.apply(this instanceof fNOP ? this : oThis || window, aArgs.concat(Array.prototype.slice.call(arguments))); }; fNOP.prototype = this.prototype; fBound.prototype = new fNOP(); return fBound; }; } (function() { var lastTime = 0; var vendors = ['ms', 'moz', 'webkit', 'o']; for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) { window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame']; window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] || window[vendors[x]+'CancelRequestAnimationFrame']; } if (!window.requestAnimationFrame) window.requestAnimationFrame = function(callback, element) { var currTime = new Date().getTime(); var timeToCall = Math.max(0, 16 - (currTime - lastTime)); var id = window.setTimeout(function() { callback(currTime + timeToCall); }, timeToCall); lastTime = currTime + timeToCall; return id; }; if (!window.cancelAnimationFrame) window.cancelAnimationFrame = function(id) { clearTimeout(id); }; }()); function Graph(o){ this.options=o; this.vertices={}; this.edges={};//form {vertexID:{edgeID:edge}} } /** *Adds an edge to the graph. If the verticies in this edge are not already in the *graph then they are added */ Graph.prototype.addEdge=function(e){ //if vertex1 and vertex2 doesn't exist in this.vertices add them if(typeof(this.vertices[e.vertex1])==='undefined') this.vertices[e.vertex1]=new Vertex(e.vertex1); if(typeof(this.vertices[e.vertex2])==='undefined') this.vertices[e.vertex2]=new Vertex(e.vertex2); //add the edge if(typeof(this.edges[e.vertex1])==='undefined') this.edges[e.vertex1]={}; this.edges[e.vertex1][e.id]=e; } /** * Add a vertex to the graph. If a vertex with the same ID already exists then * the existing vertex's .data property is replaced with the @param v.data */ Graph.prototype.addVertex=function(v){ if(typeof(this.vertices[v.id])==='undefined') this.vertices[v.id]=v; else this.vertices[v.id].data=v.data; } function Vertex(id,data){ this.id=id; this.data=data?data:{}; //initialize to data.[x|y|z] or generate random number for each this.x = this.data.x?this.data.x:-100 + Math.random()*200; this.y = this.data.y?this.data.y:-100 + Math.random()*200; this.z = this.data.y?this.data.y:-100 + Math.random()*200; //set initial velocity to 0 this.velocity = new Point(0, 0, 0); this.mass=this.data.mass?this.data.mass:Math.random(); this.force=new Point(0,0,0); } function Edge(vertex1ID,vertex2ID){ vertex1ID=vertex1ID?vertex1ID:Math.random() vertex2ID=vertex2ID?vertex2ID:Math.random() this.id=vertex1ID+"->"+vertex2ID; this.vertex1=vertex1ID; this.vertex2=vertex2ID; } function Point(x, y, z) { this.x = x; this.y = y; this.z = z; } Point.prototype.plus=function(p){ this.x +=p.x this.y +=p.y this.z +=p.z } function ForceLayout(o){ this.repulsion = o.repulsion?o.repulsion:200; this.attraction = o.attraction?o.attraction:0.06; this.damping = o.damping?o.damping:0.9; this.graph = o.graph?o.graph:new Graph(); this.total_kinetic_energy =0; this.animationID=-1; } ForceLayout.prototype.draw=function(){ //vertex velocities initialized to (0,0,0) when a vertex is created //vertex positions initialized to random position when created cc=0; do{ this.total_kinetic_energy =0; //for each vertex for(var i in this.graph.vertices){ var thisNode=this.graph.vertices[i]; // running sum of total force on this particular node var netForce=new Point(0,0,0) //for each other node for(var j in this.graph.vertices){ if(thisNode!=this.graph.vertices[j]){ //net-force := net-force + Coulomb_repulsion( this_node, other_node ) netForce.plus(this.CoulombRepulsion( thisNode,this.graph.vertices[j])) } } //for each spring connected to this node for(var k in this.graph.edges[thisNode.id]){ //(this node, node its connected to) //pass id of this node and the node its connected to so hookesattraction //can update the force on both vertices and return that force to be //added to the net force this.HookesAttraction(thisNode.id, this.graph.edges[thisNode.id][k].vertex2 ) } // without damping, it moves forever // this_node.velocity := (this_node.velocity + timestep * net-force) * damping thisNode.velocity.x=(thisNode.velocity.x+thisNode.force.x)*this.damping; thisNode.velocity.y=(thisNode.velocity.y+thisNode.force.y)*this.damping; thisNode.velocity.z=(thisNode.velocity.z+thisNode.force.z)*this.damping; //this_node.position := this_node.position + timestep * this_node.velocity thisNode.x=thisNode.velocity.x; thisNode.y=thisNode.velocity.y; thisNode.z=thisNode.velocity.z; //normalize x,y,z??? //total_kinetic_energy := total_kinetic_energy + this_node.mass * (this_node.velocity)^2 this.total_kinetic_energy +=thisNode.mass*((thisNode.velocity.x+thisNode.velocity.y+thisNode.velocity.z)* (thisNode.velocity.x+thisNode.velocity.y+thisNode.velocity.z)) } cc+=1; }while(this.total_kinetic_energy >0.5) console.log(cc,this.total_kinetic_energy,this.graph) this.cancelAnimation(); } ForceLayout.prototype.HookesAttraction=function(v1ID,v2ID){ var a=this.graph.vertices[v1ID] var b=this.graph.vertices[v2ID] var force=new Point(this.attraction*(b.x - a.x),this.attraction*(b.y - a.y),this.attraction*(b.z - a.z)) // hook's attraction a.force.x += force.x; a.force.y += force.y; a.force.z += force.z; b.force.x += this.attraction*(a.x - b.x); b.force.y += this.attraction*(a.y - b.y); b.force.z += this.attraction*(a.z - b.z); return force; } ForceLayout.prototype.CoulombRepulsion=function(vertex1,vertex2){ //http://en.wikipedia.org/wiki/Coulomb's_law // distance squared = ((x1-x2)*(x1-x2)) + ((y1-y2)*(y1-y2)) + ((z1-z2)*(z1-z2)) var distanceSquared = ( (vertex1.x-vertex2.x)*(vertex1.x-vertex2.x)+ (vertex1.y-vertex2.y)*(vertex1.y-vertex2.y)+ (vertex1.z-vertex2.z)*(vertex1.z-vertex2.z) ); if(distanceSquared==0) distanceSquared = 0.001; var coul = this.repulsion / distanceSquared; return new Point(coul * (vertex1.x-vertex2.x),coul * (vertex1.y-vertex2.y), coul * (vertex1.z-vertex2.z)); } ForceLayout.prototype.animate=function(){ if(this.animating) this.animationID=requestAnimationFrame(this.animate.bind(this)); this.draw(); } ForceLayout.prototype.cancelAnimation=function(){ cancelAnimationFrame(this.animationID); this.animating=false; } ForceLayout.prototype.redraw=function(){ this.animating=true; this.animate(); } $(document).ready(function(){ var g= new Graph(); for(var i=0;i<=100;i++){ var v1=new Vertex(Math.random(), {}) var v2=new Vertex(Math.random(), {}) var e1= new Edge(v1.id,v2.id); g.addEdge(e1); } console.log(g); var l=new ForceLayout({ graph:g }); l.redraw(); });

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• how to make a function recursive

  - by tom smith

  i have this huge function and i am wondering how to make it recursive. i have the base case which should never come true, so it should always go to else and keep calling itself with the variable t increases. any help would be great thanks def draw(x, y, t, planets): if 'Satellites' in planets["Moon"]: print ("fillcircle", x, y, planets["Moon"]['Radius']*scale) else: while True: print("refresh") print("colour 0 0 0") print("clear") print("colour 255 255 255") print("fillcircle",x,y,planets['Sun']['Radius']*scale) print("text ", "\"Sun\"",x+planets['Sun']['Radius']*scale,y) if "Mercury" in planets: r_Mercury=planets['Mercury']['Orbital Radius']*scale; print("circle",x,y,r_Mercury) r_Xmer=x+math.sin(t*2*math.pi/planets['Mercury']['Period'])*r_Mercury r_Ymer=y+math.cos(t*2*math.pi/planets['Mercury']['Period'])*r_Mercury print("fillcircle",r_Xmer,r_Ymer,3) print("text ", "\"Mercury\"",r_Xmer+planets['Mercury']['Radius']*scale,r_Ymer) if "Venus" in planets: r_Venus=planets['Venus']['Orbital Radius']*scale; print("circle",x,y,r_Venus) r_Xven=x+math.sin(t*2*math.pi/planets['Venus']['Period'])*r_Venus r_Yven=y+math.cos(t*2*math.pi/planets['Venus']['Period'])*r_Venus print("fillcircle",r_Xven,r_Yven,3) print("text ", "\"Venus\"",r_Xven+planets['Venus']['Radius']*scale,r_Yven) if "Earth" in planets: r_Earth=planets['Earth']['Orbital Radius']*scale; print("circle",x,y,r_Earth) r_Xe=x+math.sin(t*2*math.pi/planets['Earth']['Period'])*r_Earth r_Ye=y+math.cos(t*2*math.pi/planets['Earth']['Period'])*r_Earth print("fillcircle",r_Xe,r_Ye,3) print("text ", "\"Earth\"",r_Xe+planets['Earth']['Radius']*scale,r_Ye) if "Moon" in planets: r_Moon=planets['Moon']['Orbital Radius']*scale; print("circle",r_Xe,r_Ye,r_Moon) r_Xm=r_Xe+math.sin(t*2*math.pi/planets['Moon']['Period'])*r_Moon r_Ym=r_Ye+math.cos(t*2*math.pi/planets['Moon']['Period'])*r_Moon print("fillcircle",r_Xm,r_Ym,3) print("text ", "\"Moon\"",r_Xm+planets['Moon']['Radius']*scale,r_Ym) if "Mars" in planets: r_Mars=planets['Mars']['Orbital Radius']*scale; print("circle",x,y,r_Mars) r_Xmar=x+math.sin(t*2*math.pi/planets['Mars']['Period'])*r_Mars r_Ymar=y+math.cos(t*2*math.pi/planets['Mars']['Period'])*r_Mars print("fillcircle",r_Xmar,r_Ymar,3) print("text ", "\"Mars\"",r_Xmar+planets['Mars']['Radius']*scale,r_Ymar) if "Phobos" in planets: r_Phobos=planets['Phobos']['Orbital Radius']*scale; print("circle",r_Xmar,r_Ymar,r_Phobos) r_Xpho=r_Xmar+math.sin(t*2*math.pi/planets['Phobos']['Period'])*r_Phobos r_Ypho=r_Ymar+math.cos(t*2*math.pi/planets['Phobos']['Period'])*r_Phobos print("fillcircle",r_Xpho,r_Ypho,3) print("text ", "\"Phobos\"",r_Xpho+planets['Phobos']['Radius']*scale,r_Ypho) if "Deimos" in planets: r_Deimos=planets['Deimos']['Orbital Radius']*scale; print("circle",r_Xmar,r_Ymar,r_Deimos) r_Xdei=r_Xmar+math.sin(t*2*math.pi/planets['Deimos']['Period'])*r_Deimos r_Ydei=r_Ymar+math.cos(t*2*math.pi/planets['Deimos']['Period'])*r_Deimos print("fillcircle",r_Xdei,r_Ydei,3) print("text ", "\"Deimos\"",r_Xpho+planets['Deimos']['Radius']*scale,r_Ydei) if "Ceres" in planets: r_Ceres=planets['Ceres']['Orbital Radius']*scale; print("circle",x,y,r_Ceres) r_Xcer=x+math.sin(t*2*math.pi/planets['Ceres']['Period'])*r_Ceres r_Ycer=y+math.cos(t*2*math.pi/planets['Ceres']['Period'])*r_Ceres print("fillcircle",r_Xcer,r_Ycer,3) print("text ", "\"Ceres\"",r_Xcer+planets['Ceres']['Radius']*scale,r_Ycer) if "Jupiter" in planets: r_Jupiter=planets['Jupiter']['Orbital Radius']*scale; print("circle",x,y,r_Jupiter) r_Xjup=x+math.sin(t*2*math.pi/planets['Jupiter']['Period'])*r_Jupiter r_Yjup=y+math.cos(t*2*math.pi/planets['Jupiter']['Period'])*r_Jupiter print("fillcircle",r_Xjup,r_Yjup,3) print("text ", "\"Jupiter\"",r_Xjup+planets['Jupiter']['Radius']*scale,r_Yjup) if "Io" in planets: r_Io=planets['Io']['Orbital Radius']*scale; print("circle",r_Xjup,r_Yjup,r_Io) r_Xio=r_Xjup+math.sin(t*2*math.pi/planets['Io']['Period'])*r_Io r_Yio=r_Yjup+math.cos(t*2*math.pi/planets['Io']['Period'])*r_Io print("fillcircle",r_Xio,r_Yio,3) print("text ", "\"Io\"",r_Xio+planets['Io']['Radius']*scale,r_Yio) if "Europa" in planets: r_Europa=planets['Europa']['Orbital Radius']*scale; print("circle",r_Xjup,r_Yjup,r_Europa) r_Xeur=r_Xjup+math.sin(t*2*math.pi/planets['Europa']['Period'])*r_Europa r_Yeur=r_Yjup+math.cos(t*2*math.pi/planets['Europa']['Period'])*r_Europa print("fillcircle",r_Xeur,r_Yeur,3) print("text ", "\"Europa\"",r_Xeur+planets['Europa']['Radius']*scale,r_Yeur) if "Ganymede" in planets: r_Ganymede=planets['Ganymede']['Orbital Radius']*scale; print("circle",r_Xjup,r_Yjup,r_Ganymede) r_Xgan=r_Xjup+math.sin(t*2*math.pi/planets['Ganymede']['Period'])*r_Ganymede r_Ygan=r_Yjup+math.cos(t*2*math.pi/planets['Ganymede']['Period'])*r_Ganymede print("fillcircle",r_Xgan,r_Ygan,3) print("text ", "\"Ganymede\"",r_Xgan+planets['Ganymede']['Radius']*scale,r_Ygan) if "Callisto" in planets: r_Callisto=planets['Callisto']['Orbital Radius']*scale; print("circle",r_Xjup,r_Yjup,r_Callisto) r_Xcal=r_Xjup+math.sin(t*2*math.pi/planets['Callisto']['Period'])*r_Callisto r_Ycal=r_Yjup+math.cos(t*2*math.pi/planets['Callisto']['Period'])*r_Callisto print("fillcircle",r_Xcal,r_Ycal,3) print("text ", "\"Callisto\"",r_Xcal+planets['Callisto']['Radius']*scale,r_Ycal) if "Saturn" in planets: r_Saturn=planets['Saturn']['Orbital Radius']*scale; print("circle",x,y,r_Saturn) r_Xsat=x+math.sin(t*2*math.pi/planets['Saturn']['Period'])*r_Saturn r_Ysat=y+math.cos(t*2*math.pi/planets['Saturn']['Period'])*r_Saturn print("fillcircle",r_Xsat,r_Ysat,3) print("text ", "\"Saturn\"",r_Xsat+planets['Saturn']['Radius']*scale,r_Ysat) if "Mimas" in planets: r_Mimas=planets['Mimas']['Orbital Radius']*scale; print("circle",r_Xsat,r_Ysat,r_Mimas) r_Xmim=r_Xsat+math.sin(t*2*math.pi/planets['Mimas']['Period'])*r_Mimas r_Ymim=r_Ysat+math.cos(t*2*math.pi/planets['Mimas']['Period'])*r_Mimas print("fillcircle",r_Xmim,r_Ymim,3) print("text ", "\"Mimas\"",r_Xmim+planets['Mimas']['Radius']*scale,r_Ymim) if "Enceladus" in planets: r_Enceladus=planets['Enceladus']['Orbital Radius']*scale; print("circle",r_Xsat,r_Ysat,r_Enceladus) r_Xenc=r_Xsat+math.sin(t*2*math.pi/planets['Enceladus']['Period'])*r_Enceladus r_Yenc=r_Ysat+math.cos(t*2*math.pi/planets['Enceladus']['Period'])*r_Enceladus print("fillcircle",r_Xenc,r_Yenc,3) print("text ", "\"Enceladus\"",r_Xenc+planets['Enceladus']['Radius']*scale,r_Yenc) if "Tethys" in planets: r_Tethys=planets['Tethys']['Orbital Radius']*scale; print("circle",r_Xsat,r_Ysat,r_Tethys) r_Xtet=r_Xsat+math.sin(t*2*math.pi/planets['Tethys']['Period'])*r_Tethys r_Ytet=r_Ysat+math.cos(t*2*math.pi/planets['Tethys']['Period'])*r_Tethys print("fillcircle",r_Xtet,r_Ytet,3) print("text ", "\"Tethys\"",r_Xtet+planets['Tethys']['Radius']*scale,r_Ytet) if "Dione" in planets: r_Dione=planets['Dione']['Orbital Radius']*scale; print("circle",r_Xsat,r_Ysat,r_Dione) r_Xdio=r_Xsat+math.sin(t*2*math.pi/planets['Dione']['Period'])*r_Dione r_Ydio=r_Ysat+math.cos(t*2*math.pi/planets['Dione']['Period'])*r_Dione print("fillcircle",r_Xdio,r_Ydio,3) print("text ", "\"Dione\"",r_Xdio+planets['Dione']['Radius']*scale,r_Ydio) if "Rhea" in planets: r_Rhea=planets['Rhea']['Orbital Radius']*scale; print("circle",r_Xsat,r_Ysat,r_Rhea) r_Xrhe=r_Xsat+math.sin(t*2*math.pi/planets['Rhea']['Period'])*r_Rhea r_Yrhe=r_Ysat+math.cos(t*2*math.pi/planets['Rhea']['Period'])*r_Rhea print("fillcircle",r_Xrhe,r_Yrhe,3) print("text ", "\"Rhea\"",r_Xrhe+planets['Rhea']['Radius']*scale,r_Yrhe) if "Titan" in planets: r_Titan=planets['Titan']['Orbital Radius']*scale; print("circle",r_Xsat,r_Ysat,r_Titan) r_Xtit=r_Xsat+math.sin(t*2*math.pi/planets['Titan']['Period'])*r_Titan r_Ytit=r_Ysat+math.cos(t*2*math.pi/planets['Titan']['Period'])*r_Titan print("fillcircle",r_Xtit,r_Ytit,3) print("text ", "\"Titan\"",r_Xtit+planets['Titan']['Radius']*scale,r_Ytit) if "Iapetus" in planets: r_Iapetus=planets['Iapetus']['Orbital Radius']*scale; print("circle",r_Xsat,r_Ysat,r_Iapetus) r_Xiap=r_Xsat+math.sin(t*2*math.pi/planets['Iapetus']['Period'])*r_Iapetus r_Yiap=r_Ysat+math.cos(t*2*math.pi/planets['Iapetus']['Period'])*r_Iapetus print("fillcircle",r_Xiap,r_Yiap,3) print("text ", "\"Iapetus\"",r_Xiap+planets['Iapetus']['Radius']*scale,r_Yiap) if "Uranus" in planets: r_Uranus=planets['Uranus']['Orbital Radius']*scale; print("circle",x,y,r_Uranus) r_Xura=x+math.sin(t*2*math.pi/planets['Uranus']['Period'])*r_Uranus r_Yura=y+math.cos(t*2*math.pi/planets['Uranus']['Period'])*r_Uranus print("fillcircle",r_Xura,r_Yura,3) print("text ", "\"Uranus\"",r_Xura+planets['Uranus']['Radius']*scale,r_Yura) if "Puck" in planets: r_Puck=planets['Puck']['Orbital Radius']*scale; print("circle",r_Xura,r_Yura,r_Puck) r_Xpuc=r_Xura+math.sin(t*2*math.pi/planets['Puck']['Period'])*r_Puck r_Ypuc=r_Yura+math.cos(t*2*math.pi/planets['Puck']['Period'])*r_Puck print("fillcircle",r_Xpuc,r_Ypuc,3) print("text ", "\"Puck\"",r_Xpuc+planets['Puck']['Radius']*scale,r_Ypuc) if "Miranda" in planets: r_Miranda=planets['Miranda']['Orbital Radius']*scale; print("circle",r_Xura,r_Yura,r_Miranda) r_Xmira=r_Xura+math.sin(t*2*math.pi/planets['Miranda']['Period'])*r_Miranda r_Ymira=r_Yura+math.cos(t*2*math.pi/planets['Miranda']['Period'])*r_Miranda print("fillcircle",r_Xmira,r_Ymira,3) print("text ", "\"Miranda\"",r_Xmira+planets['Miranda']['Radius']*scale,r_Ymira) if "Ariel" in planets: r_Ariel=planets['Ariel']['Orbital Radius']*scale; print("circle",r_Xura,r_Yura,r_Ariel) r_Xari=r_Xura+math.sin(t*2*math.pi/planets['Ariel']['Period'])*r_Ariel r_Yari=r_Yura+math.cos(t*2*math.pi/planets['Ariel']['Period'])*r_Ariel print("fillcircle",r_Xari,r_Yari,3) print("text ", "\"Ariel\"",r_Xari+planets['Ariel']['Radius']*scale,r_Yari) if "Umbriel" in planets: r_Umbriel=planets['Umbriel']['Orbital Radius']*scale; print("circle",r_Xura,r_Yura,r_Umbriel) r_Xumb=r_Xura+math.sin(t*2*math.pi/planets['Umbriel']['Period'])*r_Umbriel r_Yumb=r_Yura+math.cos(t*2*math.pi/planets['Umbriel']['Period'])*r_Umbriel print("fillcircle",r_Xumb,r_Yumb,3) print("text ", "\"Umbriel\"",r_Xumb+planets['Umbriel']['Radius']*scale,r_Yumb) if "Titania" in planets: r_Titania=planets['Titania']['Orbital Radius']*scale; print("circle",r_Xura,r_Yura,r_Titania) r_Xtita=r_Xura+math.sin(t*2*math.pi/planets['Titania']['Period'])*r_Titania r_Ytita=r_Yura+math.cos(t*2*math.pi/planets['Titania']['Period'])*r_Titania print("fillcircle",r_Xtita,r_Ytita,3) print("text ", "\"Titania\"",r_Xtita+planets['Titania']['Radius']*scale,r_Ytita) if "Oberon" in planets: r_Oberon=planets['Oberon']['Orbital Radius']*scale; print("circle",r_Xura,r_Yura,r_Oberon) r_Xober=r_Xura+math.sin(t*2*math.pi/planets['Oberon']['Period'])*r_Oberon r_Yober=r_Yura+math.cos(t*2*math.pi/planets['Oberon']['Period'])*r_Oberon print("fillcircle",r_Xober,r_Yober,3) print("text ", "\"Oberon\"",r_Xober+planets['Oberon']['Radius']*scale,r_Yober) if "Neptune" in planets: r_Neptune=planets['Neptune']['Orbital Radius']*scale; print("circle",x,y,r_Neptune) r_Xnep=x+math.sin(t*2*math.pi/planets['Neptune']['Period'])*r_Neptune r_Ynep=y+math.cos(t*2*math.pi/planets['Neptune']['Period'])*r_Neptune print("fillcircle",r_Xnep,r_Ynep,3) print("text ", "\"Neptune\"",r_Xnep+planets['Neptune']['Radius']*scale,r_Ynep) if "Titan" in planets: r_Titan=planets['Titan']['Orbital Radius']*scale; print("circle",r_Xnep,r_Ynep,r_Titan) r_Xtita=r_Xnep+math.sin(t*2*math.pi/planets['Titan']['Period'])*r_Titan r_Ytita=r_Ynep+math.cos(t*2*math.pi/planets['Titan']['Period'])*r_Titan print("fillcircle",r_Xtita,r_Ytita,3) print("text ", "\"Titan\"",r_Xtita+planets['Titan']['Radius']*scale,r_Ytita) t += 0.003 print(draw(x, y, t, planets))

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• Issues passing values to shader

  - by numerical25

  I am having issues passing values to my shader. My application compiles fine, but my cube object won't shade. Below is majority of my code. Most of my code for communicating with my shader is in createObject method myGame.cpp #include "MyGame.h" #include "OneColorCube.h" /* This code sets a projection and shows a turning cube. What has been added is the project, rotation and a rasterizer to change the rasterization of the cube. The issue that was going on was something with the effect file which was causing the vertices not to be rendered correctly.*/ typedef struct { ID3D10Effect* pEffect; ID3D10EffectTechnique* pTechnique; //vertex information ID3D10Buffer* pVertexBuffer; ID3D10Buffer* pIndicesBuffer; ID3D10InputLayout* pVertexLayout; UINT numVertices; UINT numIndices; }ModelObject; ModelObject modelObject; // World Matrix D3DXMATRIX WorldMatrix; // View Matrix D3DXMATRIX ViewMatrix; // Projection Matrix D3DXMATRIX ProjectionMatrix; ID3D10EffectMatrixVariable* pProjectionMatrixVariable = NULL; ID3D10EffectVectorVariable* pLightVarible = NULL; bool MyGame::InitDirect3D() { if(!DX3dApp::InitDirect3D()) { return false; } D3D10_RASTERIZER_DESC rastDesc; rastDesc.FillMode = D3D10_FILL_WIREFRAME; rastDesc.CullMode = D3D10_CULL_FRONT; rastDesc.FrontCounterClockwise = true; rastDesc.DepthBias = false; rastDesc.DepthBiasClamp = 0; rastDesc.SlopeScaledDepthBias = 0; rastDesc.DepthClipEnable = false; rastDesc.ScissorEnable = false; rastDesc.MultisampleEnable = false; rastDesc.AntialiasedLineEnable = false; ID3D10RasterizerState *g_pRasterizerState; mpD3DDevice->CreateRasterizerState(&rastDesc, &g_pRasterizerState); //mpD3DDevice->RSSetState(g_pRasterizerState); // Set up the World Matrix D3DXMatrixIdentity(&WorldMatrix); D3DXMatrixLookAtLH(&ViewMatrix, new D3DXVECTOR3(0.0f, 10.0f, -20.0f), new D3DXVECTOR3(0.0f, 0.0f, 0.0f), new D3DXVECTOR3(0.0f, 1.0f, 0.0f)); // Set up the projection matrix D3DXMatrixPerspectiveFovLH(&ProjectionMatrix, (float)D3DX_PI * 0.5f, (float)mWidth/(float)mHeight, 0.1f, 100.0f); if(!CreateObject()) { return false; } return true; } //These are actions that take place after the clearing of the buffer and before the present void MyGame::GameDraw() { static float rotationAngleY = 15.0f; static float rotationAngleX = 0.0f; static D3DXMATRIX rotationXMatrix; static D3DXMATRIX rotationYMatrix; // create the rotation matrix using the rotation angle D3DXMatrixRotationY(&rotationYMatrix, rotationAngleY); D3DXMatrixRotationX(&rotationXMatrix, rotationAngleX); //rotationAngleY += (float)D3DX_PI * 0.002f; //rotationAngleX += (float)D3DX_PI * 0.001f; WorldMatrix = rotationYMatrix * rotationXMatrix; // Set the input layout mpD3DDevice->IASetInputLayout(modelObject.pVertexLayout); // Set vertex buffer UINT stride = sizeof(VertexPos); UINT offset = 0; mpD3DDevice->IASetVertexBuffers(0, 1, &modelObject.pVertexBuffer, &stride, &offset); // Set primitive topology mpD3DDevice->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST); //ViewMatrix._43 += 0.005f; // Combine and send the final matrix to the shader D3DXMATRIX finalMatrix = (WorldMatrix * ViewMatrix * ProjectionMatrix); pProjectionMatrixVariable->SetMatrix((float*)&finalMatrix); // make sure modelObject is valid // Render a model object D3D10_TECHNIQUE_DESC techniqueDescription; modelObject.pTechnique->GetDesc(&techniqueDescription); // Loop through the technique passes for(UINT p=0; p < techniqueDescription.Passes; ++p) { modelObject.pTechnique->GetPassByIndex(p)->Apply(0); // draw the cube using all 36 vertices and 12 triangles mpD3DDevice->Draw(36,0); } } //Render actually incapsulates Gamedraw, so you can call data before you actually clear the buffer or after you //present data void MyGame::Render() { DX3dApp::Render(); } bool MyGame::CreateObject() { //Create Layout D3D10_INPUT_ELEMENT_DESC layout[] = { {"POSITION",0,DXGI_FORMAT_R32G32B32_FLOAT, 0 , 0, D3D10_INPUT_PER_VERTEX_DATA, 0}, {"COLOR",0,DXGI_FORMAT_R32G32B32A32_FLOAT, 0 , 12, D3D10_INPUT_PER_VERTEX_DATA, 0}, {"NORMAL",0,DXGI_FORMAT_R32G32B32A32_FLOAT, 0 , 24, D3D10_INPUT_PER_VERTEX_DATA, 0} }; UINT numElements = (sizeof(layout)/sizeof(layout[0])); modelObject.numVertices = sizeof(vertices)/sizeof(VertexPos); for(int i = 0; i < modelObject.numVertices; i += 3) { D3DXVECTOR3 out; D3DXVECTOR3 v1 = vertices[0 + i].pos; D3DXVECTOR3 v2 = vertices[1 + i].pos; D3DXVECTOR3 v3 = vertices[2 + i].pos; D3DXVECTOR3 u = v2 - v1; D3DXVECTOR3 v = v3 - v1; D3DXVec3Cross(&out, &u, &v); D3DXVec3Normalize(&out, &out); vertices[0 + i].normal = out; vertices[1 + i].normal = out; vertices[2 + i].normal = out; } //Create buffer desc D3D10_BUFFER_DESC bufferDesc; bufferDesc.Usage = D3D10_USAGE_DEFAULT; bufferDesc.ByteWidth = sizeof(VertexPos) * modelObject.numVertices; bufferDesc.BindFlags = D3D10_BIND_VERTEX_BUFFER; bufferDesc.CPUAccessFlags = 0; bufferDesc.MiscFlags = 0; D3D10_SUBRESOURCE_DATA initData; initData.pSysMem = vertices; //Create the buffer HRESULT hr = mpD3DDevice->CreateBuffer(&bufferDesc, &initData, &modelObject.pVertexBuffer); if(FAILED(hr)) return false; /* //Create indices DWORD indices[] = { 0,1,3, 1,2,3 }; ModelObject.numIndices = sizeof(indices)/sizeof(DWORD); bufferDesc.ByteWidth = sizeof(DWORD) * ModelObject.numIndices; bufferDesc.BindFlags = D3D10_BIND_INDEX_BUFFER; initData.pSysMem = indices; hr = mpD3DDevice->CreateBuffer(&bufferDesc, &initData, &ModelObject.pIndicesBuffer); if(FAILED(hr)) return false;*/ ///////////////////////////////////////////////////////////////////////////// //Set up fx files LPCWSTR effectFilename = L"effect.fx"; modelObject.pEffect = NULL; hr = D3DX10CreateEffectFromFile(effectFilename, NULL, NULL, "fx_4_0", D3D10_SHADER_ENABLE_STRICTNESS, 0, mpD3DDevice, NULL, NULL, &modelObject.pEffect, NULL, NULL); if(FAILED(hr)) return false; pProjectionMatrixVariable = modelObject.pEffect->GetVariableByName("Projection")->AsMatrix(); pLightVarible = modelObject.pEffect->GetVariableByName("lightSource")->AsVector(); //Dont sweat the technique. Get it! LPCSTR effectTechniqueName = "Render"; D3DXVECTOR3 vLight(10.0f, 10.0f, 10.0f); pLightVarible->SetFloatVector(vLight); modelObject.pTechnique = modelObject.pEffect->GetTechniqueByName(effectTechniqueName); if(modelObject.pTechnique == NULL) return false; //Create Vertex layout D3D10_PASS_DESC passDesc; modelObject.pTechnique->GetPassByIndex(0)->GetDesc(&passDesc); hr = mpD3DDevice->CreateInputLayout(layout, numElements, passDesc.pIAInputSignature, passDesc.IAInputSignatureSize, &modelObject.pVertexLayout); if(FAILED(hr)) return false; return true; } And below is my shader effect.fx matrix Projection; float3 lightSource; float4 lightColor = {0.5, 0.5, 0.5, 0.5}; // PS_INPUT - input variables to the pixel shader // This struct is created and fill in by the // vertex shader struct PS_INPUT { float4 Pos : SV_POSITION; float4 Color : COLOR0; float4 Normal : NORMAL; }; //////////////////////////////////////////////// // Vertex Shader - Main Function /////////////////////////////////////////////// PS_INPUT VS(float4 Pos : POSITION, float4 Color : COLOR, float4 Normal : NORMAL) { PS_INPUT psInput; // Pass through both the position and the color psInput.Pos = mul( Pos, Projection ); psInput.Color = Color; psInput.Normal = Normal; return psInput; } /////////////////////////////////////////////// // Pixel Shader /////////////////////////////////////////////// float4 PS(PS_INPUT psInput) : SV_Target { float4 finalColor = 0; finalColor = saturate(dot(lightSource, psInput.Normal) * lightColor); return finalColor; } // Define the technique technique10 Render { pass P0 { SetVertexShader( CompileShader( vs_4_0, VS() ) ); SetGeometryShader( NULL ); SetPixelShader( CompileShader( ps_4_0, PS() ) ); } }

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• How to hide graph on button click ?

  - by aman-gupta

  Hi, In my application I m using following codes to draw a graph but I want that graph will be displayed on button click :- import @interface frmGraphView : UIView { } @end ///////////////////// // // frmGraphView.m // UV Alarm // // Created by Aman on 4/4/10. // Copyright 2010 MyCompanyName. All rights reserved. // import "frmGraphView.h" @implementation frmGraphView struct TCo_ordinates { float x; float y; }; (id)initWithFrame:(CGRect)frame { if (self = [super initWithFrame:frame]) { // Initialization code } return self; } /* // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; } */ /* // Override to allow orientations other than the default portrait orientation. - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation == UIInterfaceOrientationPortrait); } */ -(void)drawHGrid { //struct gridForXYaxis *gridForX = (struct gridForX *) calloc(sizeof(struct gridFor)) } (void)drawRect:(CGRect)rect { ifdef _DEBUG NSLog(@"frmGraph_drawRect_start"); endif CGContextRef ctx = UIGraphicsGetCurrentContext(); struct TCo_ordinates *tCoordianates; //creating the object of structure. float fltX1,fltX2,fltY1,fltY2=0; //Dividing the Y-axis ifdef _DEBUG NSLog(@"Start drawing Y-Axis"); endif fltX1 = 25; fltY1 = 2; fltX2 = fltX1; fltY2 = 254; //CGContextSetRGBStrokeColor(ctx, 2.0, 2.0, 2.0, 1.0); CGContextSetLineWidth(ctx, 2.0); CGContextMoveToPoint(ctx, fltX1, fltY1); CGContextAddLineToPoint(ctx, fltX2, fltY2); NSArray *hoursInDays = [[NSArray alloc] initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",@"11",@"12", nil]; NSMutableArray *yAxisCoordinates = [[[NSMutableArray alloc] init] autorelease]; for(int intIndex = 0 ; intIndex < [hoursInDays count] ; fltY2-=20, intIndex++) { ifdef _DEBUG NSLog(@"Start of the partition of y axis"); endif //CGContextSetRGBStrokeColor(ctx, 2, 2, 2, 1); //CGContextSetRGBStrokeColor(ctx, 1.0f/255.0f, 1.0f/255.0f, 1.0f/255.0f, 1.0f); //to draw the black line. CGContextMoveToPoint(ctx, fltX1-3 , fltY2-20); CGContextAddLineToPoint(ctx, fltX1+3, fltY2-20); CGContextSelectFont(ctx, "Helvetica", 12.0, kCGEncodingMacRoman); CGContextSetTextDrawingMode(ctx, kCGTextFill); //CGContextSetRGBFillColor(ctx, 0, 255, 255, 1); CGContextSetStrokeColorWithColor(ctx, [UIColor blueColor].CGColor); CGAffineTransform xform = CGAffineTransformMake( 1.0, 0.0, 0.0, -1.0, 0.0, 0.0); CGContextSetTextMatrix(ctx, xform); const char *arrayDataForYAxis = [[hoursInDays objectAtIndex:intIndex] UTF8String]; CGContextShowTextAtPoint(ctx,fltX1-20 , fltY2-15, arrayDataForYAxis, strlen(arrayDataForYAxis)); CGContextStrokePath(ctx); ifdef _DEBUG NSLog(@"End of the partition of graph"); endif //NSValue *yAxis = [NSValue valueWithCGPoint:CGPointMake((tCoordianates-x = fltX1-21), (tCoordianates-y = fltY2-20))]; // [yAxisCoordinates addObject:yAxis]; ifdef _DEBUG // NSLog(@"The value of yAxisCoordintes: %@", yAxisCoordinates); endif } ifdef _DEBUG NSLog(@"End of drawing Y-Axis"); endif //Dividing the X-axis ifdef _DEBUG NSLog(@"Start drawing X-Axis"); endif fltX1 = 25; fltY1 = 255; fltX2 = 320; fltY2 = fltY1; CGContextMoveToPoint(ctx, fltX1, fltY1); CGContextAddLineToPoint(ctx, fltX2, fltY2); //CGContextSetRGBStrokeColor(ctx, 2, 2, 2, 1); CGContextSetLineWidth(ctx, 2.0); NSArray *weekDays =[[NSArray alloc] initWithObjects:@"Sun", @"Mon", @"Tue", @"Wed", @"Thu", @"Fri", @"Sat", nil]; NSMutableArray *xAxisCoordinates = [[[NSMutableArray alloc] init] autorelease]; for(int intIndex = 0 ; intIndex < [weekDays count] ; fltX1+=40, intIndex++) { //CGContextSetRGBStrokeColor(ctx, 2, 2, 2, 1); //CGContextSetStrokeColorWithColor(ctx, [UIColor orangeColor].CGColor); CGContextMoveToPoint(ctx, fltX1+40 , fltY2-3); CGContextAddLineToPoint(ctx, fltX1+40, fltY2+3); CGContextSelectFont(ctx, "Italic", 12.0, kCGEncodingMacRoman); CGContextSetTextDrawingMode(ctx, kCGTextFill); CGContextSetStrokeColorWithColor(ctx, [UIColor blueColor].CGColor); CGAffineTransform xform = CGAffineTransformMake( 1.0, 0.0, 0.0, -1.0, 0.0, 0.0); CGContextSetTextMatrix(ctx, xform); const char *arrayDataForXAxis = [[weekDays objectAtIndex:intIndex] UTF8String]; CGContextShowTextAtPoint(ctx, fltX1+27, fltY2+20 , arrayDataForXAxis, strlen(arrayDataForXAxis)); CGContextStrokePath(ctx); ifdef _DEBUG NSLog(@"End of drawing X-Axis"); endif //NSValue *xAxis = [NSValue valueWithCGPoint:CGPointMake((tCoordianates->x = fltX1+40), (tCoordianates->y = fltY2+18))]; // [xAxisCoordinates addObject:xAxis]; ifdef _DEBUG //NSLog(@"The value of xAxisCoordintes: %@", xAxisCoordinates); NSLog(@"frmGraph_drawRect_end"); endif } CGContextSetLineWidth(ctx, 10.0); fltX1 = 25; fltY1 = 235; fltX2 = 320; fltY2 = fltY1; NSArray *coordinate1 = [[NSArray alloc] initWithObjects:@"65",@"105",@"145",@"185",@"225",@"265",@"305",nil]; NSArray *coordinate2 = [[NSArray alloc] initWithObjects:@"214",@"174",@"154",@"134",@"114",@"74",@"34",nil]; ifdef _DEBUG NSLog(@"Fuction of Bar_start"); endif for(int intIndex = 0; intIndex < [coordinate1 count], intIndex < [coordinate2 count]; fltX1+=40, intIndex++) { //CGContextSetRGBFillColor(ctx, 0, 0, 245, 1); CGContextMoveToPoint(ctx, fltX1+40, fltY2+19); const char *arrayDataForCoordinate1 = [[coordinate1 objectAtIndex:intIndex] UTF8String]; const char *arrayDataForCoordinate2 = [[coordinate2 objectAtIndex:intIndex] UTF8String]; CGContextAddLineToPoint(ctx, (atof(arrayDataForCoordinate1)), atof(arrayDataForCoordinate2)); } ifdef _DEBUG NSLog(@"Fuction of Bar_end"); endif CGContextClosePath(ctx); CGContextStrokePath(ctx); [hoursInDays release]; [weekDays release]; [coordinate1 release]; [coordinate2 release]; hoursInDays = nil; weekDays = nil; coordinate1 = nil; coordinate2 = nil; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } (void)dealloc { [super dealloc]; } @end please help me out its urgent

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• Navigating MainMenu with arrow keys or controller

  - by Phil Royer

  I'm attempting to make my menu navigable with the arrow keys or via the d-pad on a controller. So Far I've had no luck. The question is: Can someone walk me through how to make my current menu or any libgdx menu keyboard accessible? I'm a bit noobish with some stuff and I come from a Javascript background. Here's an example of what I'm trying to do: http://dl.dropboxusercontent.com/u/39448/webgl/qb/qb.html For a simple menu that you can just add a few buttons to and it run out of the box use this: http://www.sadafnoor.com/blog/how-to-create-simple-menu-in-libgdx/ Or you can use my code but I use a lot of custom styles. And here's an example of my code: import aurelienribon.tweenengine.Timeline; import aurelienribon.tweenengine.Tween; import aurelienribon.tweenengine.TweenManager; import com.badlogic.gdx.Game; import com.badlogic.gdx.Gdx; import com.badlogic.gdx.Screen; import com.badlogic.gdx.graphics.GL20; import com.badlogic.gdx.graphics.Texture; import com.badlogic.gdx.graphics.g2d.Sprite; import com.badlogic.gdx.graphics.g2d.SpriteBatch; import com.badlogic.gdx.graphics.g2d.TextureAtlas; import com.badlogic.gdx.math.Vector2; import com.badlogic.gdx.scenes.scene2d.Actor; import com.badlogic.gdx.scenes.scene2d.InputEvent; import com.badlogic.gdx.scenes.scene2d.InputListener; import com.badlogic.gdx.scenes.scene2d.Stage; import com.badlogic.gdx.scenes.scene2d.ui.Skin; import com.badlogic.gdx.scenes.scene2d.ui.Table; import com.badlogic.gdx.scenes.scene2d.ui.TextButton; import com.badlogic.gdx.scenes.scene2d.utils.Align; import com.badlogic.gdx.scenes.scene2d.utils.ClickListener; import com.project.game.tween.ActorAccessor; public class MainMenu implements Screen { private SpriteBatch batch; private Sprite menuBG; private Stage stage; private TextureAtlas atlas; private Skin skin; private Table table; private TweenManager tweenManager; @Override public void render(float delta) { Gdx.gl.glClearColor(0, 0, 0, 1); Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); batch.begin(); menuBG.draw(batch); batch.end(); //table.debug(); stage.act(delta); stage.draw(); //Table.drawDebug(stage); tweenManager.update(delta); } @Override public void resize(int width, int height) { menuBG.setSize(width, height); stage.setViewport(width, height, false); table.invalidateHierarchy(); } @Override public void resume() { } @Override public void show() { stage = new Stage(); Gdx.input.setInputProcessor(stage); batch = new SpriteBatch(); atlas = new TextureAtlas("ui/atlas.pack"); skin = new Skin(Gdx.files.internal("ui/menuSkin.json"), atlas); table = new Table(skin); table.setBounds(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); // Set Background Texture menuBackgroundTexture = new Texture("images/mainMenuBackground.png"); menuBG = new Sprite(menuBackgroundTexture); menuBG.setSize(Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); // Create Main Menu Buttons // Button Play TextButton buttonPlay = new TextButton("START", skin, "inactive"); buttonPlay.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new LevelMenu()); } }); buttonPlay.addListener(new InputListener() { public boolean keyDown (InputEvent event, int keycode) { System.out.println("down"); return true; } }); buttonPlay.padBottom(12); buttonPlay.padLeft(20); buttonPlay.getLabel().setAlignment(Align.left); // Button EXTRAS TextButton buttonExtras = new TextButton("EXTRAS", skin, "inactive"); buttonExtras.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new ExtrasMenu()); } }); buttonExtras.padBottom(12); buttonExtras.padLeft(20); buttonExtras.getLabel().setAlignment(Align.left); // Button Credits TextButton buttonCredits = new TextButton("CREDITS", skin, "inactive"); buttonCredits.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new Credits()); } }); buttonCredits.padBottom(12); buttonCredits.padLeft(20); buttonCredits.getLabel().setAlignment(Align.left); // Button Settings TextButton buttonSettings = new TextButton("SETTINGS", skin, "inactive"); buttonSettings.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new Settings()); } }); buttonSettings.padBottom(12); buttonSettings.padLeft(20); buttonSettings.getLabel().setAlignment(Align.left); // Button Exit TextButton buttonExit = new TextButton("EXIT", skin, "inactive"); buttonExit.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { Gdx.app.exit(); } }); buttonExit.padBottom(12); buttonExit.padLeft(20); buttonExit.getLabel().setAlignment(Align.left); // Adding Heading-Buttons to the cue table.add().width(190); table.add().width((table.getWidth() / 10) * 3); table.add().width((table.getWidth() / 10) * 5).height(140).spaceBottom(50); table.add().width(190).row(); table.add().width(190); table.add(buttonPlay).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonExtras).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonCredits).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonSettings).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonExit).width(460).height(110); table.add().row(); stage.addActor(table); // Animation Settings tweenManager = new TweenManager(); Tween.registerAccessor(Actor.class, new ActorAccessor()); // Heading and Buttons Fade In Timeline.createSequence().beginSequence() .push(Tween.set(buttonPlay, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonExtras, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonCredits, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonSettings, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonExit, ActorAccessor.ALPHA).target(0)) .push(Tween.to(buttonPlay, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonExtras, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonCredits, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonSettings, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonExit, ActorAccessor.ALPHA, .5f).target(1)) .end().start(tweenManager); tweenManager.update(Gdx.graphics.getDeltaTime()); } public static Vector2 getStageLocation(Actor actor) { return actor.localToStageCoordinates(new Vector2(0, 0)); } @Override public void dispose() { stage.dispose(); atlas.dispose(); skin.dispose(); menuBG.getTexture().dispose(); } @Override public void hide() { dispose(); } @Override public void pause() { } }

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• Android App Crashes On Second Run

  - by user1091286

  My app runs fine on first run. On the Menu I added two choices options and quit. options which set up a new intent who goes to a PreferenceActivity and quit which simply call: "android.os.Process.killProcess(android.os.Process.myPid());" On the second time I run my app (after I quit from inside the emulator) it crashes.. Ideas? the menu is called by the foolowing code: @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.menu , menu); return true; } - @Override public boolean onOptionsItemSelected(MenuItem item) { // Set up a new intent between the updater service and the main screen Intent options = new Intent(this, OptionsScreenActivity.class); // Switch case on the options switch (item.getItemId()) { case R.id.options: startActivity(options); return true; case R.id.quit: android.os.Process.killProcess(android.os.Process.myPid()); return true; default: return false; } Code for SeekBarPreference: package com.testapp.logic; import com.testapp.R; import android.content.Context; import android.content.res.TypedArray; import android.preference.Preference; import android.util.AttributeSet; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.widget.RelativeLayout; import android.widget.SeekBar; import android.widget.SeekBar.OnSeekBarChangeListener; import android.widget.TextView; public class SeekBarPreference extends Preference implements OnSeekBarChangeListener { private final String TAG = getClass().getName(); private static final String ANDROIDNS="http://schemas.android.com/apk/res/android"; private static final String PREFS="com.testapp.logic"; private static final int DEFAULT_VALUE = 5; private int mMaxValue = 100; private int mMinValue = 1; private int mInterval = 1; private int mCurrentValue; private String mUnitsLeft = ""; private String mUnitsRight = ""; private SeekBar mSeekBar; private TextView mStatusText; public SeekBarPreference(Context context, AttributeSet attrs) { super(context, attrs); initPreference(context, attrs); } public SeekBarPreference(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); initPreference(context, attrs); } private void initPreference(Context context, AttributeSet attrs) { setValuesFromXml(attrs); mSeekBar = new SeekBar(context, attrs); mSeekBar.setMax(mMaxValue - mMinValue); mSeekBar.setOnSeekBarChangeListener(this); } private void setValuesFromXml(AttributeSet attrs) { mMaxValue = attrs.getAttributeIntValue(ANDROIDNS, "max", 100); mMinValue = attrs.getAttributeIntValue(PREFS, "min", 0); mUnitsLeft = getAttributeStringValue(attrs, PREFS, "unitsLeft", ""); String units = getAttributeStringValue(attrs, PREFS, "units", ""); mUnitsRight = getAttributeStringValue(attrs, PREFS, "unitsRight", units); try { String newInterval = attrs.getAttributeValue(PREFS, "interval"); if(newInterval != null) mInterval = Integer.parseInt(newInterval); } catch(Exception e) { Log.e(TAG, "Invalid interval value", e); } } private String getAttributeStringValue(AttributeSet attrs, String namespace, String name, String defaultValue) { String value = attrs.getAttributeValue(namespace, name); if(value == null) value = defaultValue; return value; } @Override protected View onCreateView(ViewGroup parent){ RelativeLayout layout = null; try { LayoutInflater mInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); layout = (RelativeLayout)mInflater.inflate(R.layout.seek_bar_preference, parent, false); } catch(Exception e) { Log.e(TAG, "Error creating seek bar preference", e); } return layout; } @Override public void onBindView(View view) { super.onBindView(view); try { // move our seekbar to the new view we've been given ViewParent oldContainer = mSeekBar.getParent(); ViewGroup newContainer = (ViewGroup) view.findViewById(R.id.seekBarPrefBarContainer); if (oldContainer != newContainer) { // remove the seekbar from the old view if (oldContainer != null) { ((ViewGroup) oldContainer).removeView(mSeekBar); } // remove the existing seekbar (there may not be one) and add ours newContainer.removeAllViews(); newContainer.addView(mSeekBar, ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); } } catch(Exception ex) { Log.e(TAG, "Error binding view: " + ex.toString()); } updateView(view); } /** * Update a SeekBarPreference view with our current state * @param view */ protected void updateView(View view) { try { RelativeLayout layout = (RelativeLayout)view; mStatusText = (TextView)layout.findViewById(R.id.seekBarPrefValue); mStatusText.setText(String.valueOf(mCurrentValue)); mStatusText.setMinimumWidth(30); mSeekBar.setProgress(mCurrentValue - mMinValue); TextView unitsRight = (TextView)layout.findViewById(R.id.seekBarPrefUnitsRight); unitsRight.setText(mUnitsRight); TextView unitsLeft = (TextView)layout.findViewById(R.id.seekBarPrefUnitsLeft); unitsLeft.setText(mUnitsLeft); } catch(Exception e) { Log.e(TAG, "Error updating seek bar preference", e); } } public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { int newValue = progress + mMinValue; if(newValue > mMaxValue) newValue = mMaxValue; else if(newValue < mMinValue) newValue = mMinValue; else if(mInterval != 1 && newValue % mInterval != 0) newValue = Math.round(((float)newValue)/mInterval)*mInterval; // change rejected, revert to the previous value if(!callChangeListener(newValue)){ seekBar.setProgress(mCurrentValue - mMinValue); return; } // change accepted, store it mCurrentValue = newValue; mStatusText.setText(String.valueOf(newValue)); persistInt(newValue); } public void onStartTrackingTouch(SeekBar seekBar) {} public void onStopTrackingTouch(SeekBar seekBar) { notifyChanged(); } @Override protected Object onGetDefaultValue(TypedArray ta, int index){ int defaultValue = ta.getInt(index, DEFAULT_VALUE); return defaultValue; } @Override protected void onSetInitialValue(boolean restoreValue, Object defaultValue) { if(restoreValue) { mCurrentValue = getPersistedInt(mCurrentValue); } else { int temp = 0; try { temp = (Integer)defaultValue; } catch(Exception ex) { Log.e(TAG, "Invalid default value: " + defaultValue.toString()); } persistInt(temp); mCurrentValue = temp; } } } Logcat: E/AndroidRuntime( 4525): FATAL EXCEPTION: main E/AndroidRuntime( 4525): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.ui.testapp/com.logic.testapp.SeekBarPreferen ce}: java.lang.InstantiationException: can't instantiate class com.logic.testapp.SeekBarPreference; no empty constructor E/AndroidRuntime( 4525): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1879) E/AndroidRuntime( 4525): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980) E/AndroidRuntime( 4525): at android.app.ActivityThread.access$600(ActivityThread.java:122) E/AndroidRuntime( 4525): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146) E/AndroidRuntime( 4525): at android.os.Handler.dispatchMessage(Handler.java:99) E/AndroidRuntime( 4525): at android.os.Looper.loop(Looper.java:137) E/AndroidRuntime( 4525): at android.app.ActivityThread.main(ActivityThread.java:4340) E/AndroidRuntime( 4525): at java.lang.reflect.Method.invokeNative(Native Method) E/AndroidRuntime( 4525): at java.lang.reflect.Method.invoke(Method.java:511) E/AndroidRuntime( 4525): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) E/AndroidRuntime( 4525): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) E/AndroidRuntime( 4525): at dalvik.system.NativeStart.main(Native Method) E/AndroidRuntime( 4525): Caused by: java.lang.InstantiationException: can't instantiate class com.logic.testapp.SeekBarPreference; no empty construc tor E/AndroidRuntime( 4525): at java.lang.Class.newInstanceImpl(Native Method) E/AndroidRuntime( 4525): at java.lang.Class.newInstance(Class.java:1319) E/AndroidRuntime( 4525): at android.app.Instrumentation.newActivity(Instrumentation.java:1023) E/AndroidRuntime( 4525): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1870) E/AndroidRuntime( 4525): ... 11 more W/ActivityManager( 84): Force finishing activity com.ui.testapp/com.logic.testapp.SeekBarPreference W/ActivityManager( 84): Force finishing activity com.ui.testapp/.MainScreen I/WindowManager( 84): createSurface Window{41a90320 paused=false}: DRAW NOW PENDING W/ActivityManager( 84): Activity pause timeout for ActivityRecord{4104a848 com.ui.testapp/com.logic.testapp.SeekBarPreference} W/NetworkManagementSocketTagger( 84): setKernelCountSet(10021, 1) failed with errno -2 I/WindowManager( 84): createSurface Window{412bcc10 com.android.launcher/com.android.launcher2.Launcher paused=false}: DRAW NOW PENDING W/NetworkManagementSocketTagger( 84): setKernelCountSet(10045, 0) failed with errno -2 I/Process ( 4525): Sending signal. PID: 4525 SIG: 9 I/ActivityManager( 84): Process com.ui.testapp (pid 4525) has died. I/WindowManager( 84): WIN DEATH: Window{41a6c9c0 com.ui.testapp/com.ui.testapp.MainScreen paused=true}

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• UPK 3.6.1 (is Coming)

  - by marc.santosusso

  In anticipation of the release of UPK 3.6.1, I'd like to briefly describe some of the features that will be available in this new version. Topic Editor in Tabs Topic Editors now open in tabs instead of separate Developer windows. This offers several improvements: First, the bubble editor can be docked and resized in the same way as other editor panes. That's right, you can resize the bubble editor! The second enhancement that this changes brings is an improved undo and redo which allows each action to be undone and redone in the Topic Editor. New Sound Editor The topic and web page editors include a new sound editor with all the bells and whistles necessary to record, edit, import, and export, sound. Sound can be captured during topic recording--which is great for a Subject Matter Expert (SME) to narrate what they're recording--or after the topic has been recorded. Sound can also be added to web pages and played on the concept panes of modules, sections and topics. Turn off bubbles in Topics Authors may opt to hide bubbles either per frame or for an entire topic. When you want to draw a user's attention to the content on the screen instead of the bubble. This feature works extremely well in conjunction with the new sound capabilities. For instance, consider recording conceptual information with narration and no bubbles. Presentation Output UPK content can be published as a Presentation in Microsoft PowerPoint format. Publishing for Presentation will create a presentation for each topic published. The presentation template can be customized Using the same methods offered for the UPK document outputs, allowing your UPK-generated presentations to match your corporate branding. Autosave and Recovery The Developer will automatically save your work as often as you would like. This affords authors the ability to recover these automatically saved documents if their system or UPK were to close unexpectedly. The Developer defaults to save open documents every ten minutes. Package Editor Enhancement Files in packages will now open in the associated application when double-clicked. Authors can also choose to "Open with..." from the context menu (AKA right click menu.) See It! Window See It! mode may now be launched in a non-fullscreen window. This is available from the kp.html file in any Player package. This version of See It! mode offers on-screen navigation controls including previous frame, next frame, pause etc. Firefox Enhancments The UPK Player will now offer both Do It! mode and sound playback when viewed using Firefox web browser. Player Support for Safari The UPK Player is now fully supported on the Safari web browser for both Mac OS and Windows platforms. Keep document checked out Authors may choose to keep a document checked out when performing a check in. This allows an author to have a new version created on the server and continue editing. Close button on individual tabs A close button has been added to the tabs making it easier to close a specific tab. Outline Editor Enhancements Authors will have the option to prevent concepts from immediately displaying in the Developer when an outline item is selected. This makes it faster to move around in the outline editor. Tell us which feature you're most excited to use in the comments.

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• How to use caching to increase render performance?

  - by Christian Ivicevic

  First of all I am going to cover the basic design of my 2d tile-based engine written with SDL in C++, then I will point out what I am up to and where I need some hints. Concept of my engine My engine uses the concept of GameScreens which are stored on a stack in the main game class. The main methods of a screen are usually LoadContent, Render, Update and InitMultithreading. (I use the last one because I am using v8 as a JavaScript bridge to the engine. The main game loop then renders the top screen on the stack (if there is one; otherwise, it exits the game) - actually it calls the render methods, but stores all items to be rendered in a list. After gathering all this information the methods like SDL_BlitSurface are called by my GameUIRenderer which draws the enqueued content and then draws some overlay. The code looks like this: while(Game is running) { Handle input if(Screens on stack == 0) exit Update timer etc. Clear the screen Peek the screen on the stack and collect information on what to render Actually render the enqueue screen stuff and some overlay etc. Flip the screen } The GameUIRenderer uses as hinted a std::vector<std::shared_ptr<ImageToRender>> to hold all necessary information described by this class: class ImageToRender { private: SDL_Surface* image; int x, y, w, h, xOffset, yOffset; }; This bunch of attributes is usually needed if I have a texture atlas with all tiles in one SDL_Surface and then the engine should crop one specific area and draw this to the screen. The GameUIRenderer::Render() method then just iterates over all elements and renders them something like this: std::for_each( this->m_vImageVector.begin(), this->m_vImageVector.end(), [this](std::shared_ptr<ImageToRender> pCurrentImage) { SDL_Rect rc = { pCurrentImage->x, pCurrentImage->y, 0, 0 }; // For the sake of simplicity ignore offsets... SDL_Rect srcRect = { 0, 0, pCurrentImage->w, pCurrentImage->h }; SDL_BlitSurface(pCurrentImage->pImage, &srcRect, g_pFramework->GetScreen(), &rc); } ); this->m_vImageVector.clear(); Current ideas which need to be reviewed The specified approach works really good and IMHO it is really has a good structure, however the performance could be definitely increased. I would like to know what do you suggest, how to implement efficient caching of surfaces etc so that there is no need to redraw the same scene over and over again? The map itself would be almost static, only when the player moves, we would need to move the map. Furthermore animated entities would either require updates of the whole map or updates of only the specific areas the entities are currently moving in. My first approaches were to include a flag IsTainted which should be used by the GameUIRenderer to decide whether to redraw everything or use cached version (or to not render anything so that we do not have to Clear the screen and let the last frame persist). However this seems to be quite messy if I have to manually handle in my Render method of the screen class if something has changed or not.

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• ArcGIS–Getting the Legend Labels out

  - by Avner Kashtan

  Working with ESRI’s ArcGIS package, especially the WPF API, can be confusing. There’s the REST API, the SOAP APIs, and the WPF classes themselves, which expose some web service calls and information, but not everything. With all that, it can be hard to find specific features between the different options. Some functionality is handed to you on a silver platter, while some is maddeningly hard to implement. Today, for instance, I was working on adding a Legend control to my map-based WPF application, to explain the different symbols that can appear on the map. This is how the legend looks on ESRI’s own map-editing tools:   but this is how it looks when I used the Legend control, supplied out of the box by ESRI:   Very pretty, but unfortunately missing the option to display the name of the fields that make up the symbology. Luckily, the WPF controls have a lot of templating/extensibility points, to allow you to specify the layout of each field: 1: <esri:Legend> 2: <esri:Legend.MapLayerTemplate> 3: <DataTemplate> 4: <TextBlock Text="{Binding Layer.ID}"/> 5: </DataTemplate> 6: </esri:Legend.MapLayerTemplate> 7: </esri:Legend> but that only replicates the same built in behavior. I could now add any additional fields I liked, but unfortunately, I couldn’t find them as part of the Layer, GraphicsLayer or FeatureLayer definitions. This is the part where ESRI’s lack of organization is noticeable, since I can see this data easily when accessing the ArcGis Server’s web-interface, but I had no idea how to find it as part of the built-in class. Is it a part of Layer? Of LayerInfo? Of the LayerDefinition class that exists only in the SOAP service? As it turns out, neither. Since these fields are used by the symbol renderer to determine which symbol to draw, they’re actually a part of the layer’s Renderer. Since I already had a MyFeatureLayer class derived from FeatureLayer that added extra functionality, I could just add this property to it: 1: public string LegendFields 2: { 3: get 4: { 5: if (this.Renderer is UniqueValueRenderer) 6: { 7: return (this.Renderer as UniqueValueRenderer).Field; 8: } 9: else if (this.Renderer is UniqueValueMultipleFieldsRenderer) 10: { 11: var renderer = this.Renderer as UniqueValueMultipleFieldsRenderer; 12: return string.Join(renderer.FieldDelimiter, renderer.Fields); 13: } 14: else return null; 15: } For my scenario, all of my layers used symbology derived from a single field or, as in the examples above, from several of them. The renderer even kindly supplied me with the comma to separate the fields with. Now it was a simple matter to get the Legend control in line – assuming that it was bound to a collection of MyFeatureLayer: 1: <esri:Legend> 2: <esri:Legend.MapLayerTemplate> 3: <DataTemplate> 4: <StackPanel> 5: <TextBlock Text="{Binding Layer.ID}"/> 6: <TextBlock Text="{Binding Layer.LegendFields}" Margin="10,0,0,0" TextStyle="Italic"/> 7: </StackPanel> 8: </DataTemplate> 9: </esri:Legend.MapLayerTemplate> 10: </esri:Legend> and get the look I wanted – the list of fields below the layer name, indented.

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• Tips to Make Your Website Cell Phone Friendly

  - by Aditi

  Working on a new website design? or Redesigning your website? There is a lot more to consider now a days not just user experience, clean code, CSS etc. one of the important attribute one must not miss, which is making them mobile friendly! With the growing use of handhelds & unlimited data plans, people browse on their cellphones! and All come in different sizes! it is tough to make a website that would look great not just on a high resolution widescreen monitor/LCD, but also should look equally impressive on the low resolutions of cellphones. We are today going to discuss about such factors that can help you make a website Cellphone Friendly. Fluid Width Layouts As we start discussing about this, Most people speak of the Fluid Width Layouts as vital step in moving your website to be mobile friendly. Fluid width allows the width of your website stretch or shrink depending on the browser size. However, having a layout which flows with the width of the screen’s resolution is certainly convenient, more often than not the website was originally laid out for a desktop in mind. Compressing a fluid layout to 320 pixels can do some serious damage to layout, Thus some people strongly believe it is far better to have a mobile style sheet and lay out the content specifically for that screen and have more control on the display. The best thing to do is to detect the type of platform that is connected to your website and disabling or changing some tools and effects to make it look better if not perfect. Keep Your Web Pages Short length One must avoid long pages on their website, a lot of scroll makes it very non user friendly for people, especially on mobile devices this is a huge draw back because of the longer load time it takes to download the webpage. Everyone likes crisp & concise content such pages are easier to load & browse. This makes your website accessible across all platforms. Also try to keep shorter urls, if they have to type..save them from that much work especially if someone is using a cellphone with no QWERTY keyboard it can be tough. Usable Navigation & Search Unlike Desktops, your website’s Navigation won’t super work on a cellphone. Keep in mind the user experience for cellphone users as you design your Navigation. Try to keep your content centered as they do have difficulty in reading the webpage. I always look upto Google and their pages as available on mobile as a great example. Keeping a functional & very visible search bar helps mobile users navigate by searching. Understanding Clean Website Code : Evolved for Mobile Clean code is important when you consider the diversity out there for handheld devices. Some cell phones may only understand WAP. More capable phones may understand WAP2, which allows rendering websites with XHTML and CSS. Most mobiles won’t display tables, floats, frames, JavaScript, and dynamic menus. Most cellphone will not support cookies. Devices at the high end of the mobile market such as BlackBerry, Palm, or the upcoming iPhone are highly capable and support nearly as much as a standard computer..but masses still do not have such phones. You can use specific emulators to test your website on mobile devices. Make sure your color combinations provide good contrast between foreground and background colors, particularly for devices with fewer color options.

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• PDF Converter Elite Giveaway – Lets you create, convert and edit any type of PDF with ease

  - by Gopinath

  Are you looking for a PDF editing software that lets you create, edit and convert  any type of PDF with ease? Then here is a chance for you to win a lifetime free license of PDF Converter Elite software. Tech Dreams in partnership with pdfconverter.com  brings a giveaway contest exclusively for our readers. Continue reading to know the features of the application and giveaway contest details Adobe Acrobat  is the best software for creating, editing and converting PDF files, but you need spend a lot of money to buy it. PDF Converter Elite, which is priced at $100 has a rich set of features that satisfies most of your PDF management needs. Here is a quick run down of the feature of the application Create PDF files from almost every popular Windows file format – You can create a PDF  from almost 300 popular file formats supported by Windows. Want to convert a word document to PDF? It’s just a click away. How about converting Excels, PowerPoint presentations, text files, images, etc? Yes, with a single click you will be able to turn them to PDF Files. Convert PDF to Word, Excel, PowerPoint, Publisher, HTML – This is one of the best features i liked in this software. You can convert a PDF to any MS Office file format without loosing alignment and quality of the document. The converted documents looks exactly same as your PDF documents and you would be surprised to see near 100% layout replication in the converted document. I feel in love with the perfection at which the files are converted. Edit PDF files easily – You can rework with your PDF documents by inserting watermarks, numbers, headers, footers and more. Also you will be able to merge two PDF files, overlay pages, remove unwanted pages, split a single PDF in to multiple files. Secure PDF files by setting password – You can secure PDF files by limiting how others can use them – set password to open the documents, restrict various activities like printing, copy & paste, screen reading, form filling, etc.. If you are looking for an affordable PDF editing application then PDF Converter Elite is there for you. 10 x PDF Converter Elite Licenses Giveaway Here comes the details on wining a free single user license for our readers – we have 10 PDF Converter Elite single user licenses worth of $100 each. To win a license all you need to do is Like Tech Dreams Fan page on Facebook Tweet or Like this post – buttons are available just below the post heading in the top section of this page Finally drop a comment on how you would like to use PDF Converter Elite We will choose 10 winners through a lucky draw and the licenses will be sent to them in a personal email. Names of the winners will also be announced on Tech Dreams. So are you ready to grab a free copy of PDF Converter worth of $100?

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• Improving performance of a particle system (OpenGL ES)

  - by Jason

  I'm in the process of implementing a simple particle system for a 2D mobile game (using OpenGL ES 2.0). It's working, but it's pretty slow. I start getting frame rate battering after about 400 particles, which I think is pretty low. Here's a summary of my approach: I start with point sprites (GL_POINTS) rendered in a batch just using a native float buffer (I'm in Java-land on Android, so that translates as a java.nio.FloatBuffer). On GL context init, the following are set: GLES20.glViewport(0, 0, width, height); GLES20.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); GLES20.glEnable(GLES20.GL_CULL_FACE); GLES20.glDisable(GLES20.GL_DEPTH_TEST); Each draw frame sets the following: GLES20.glEnable(GLES20.GL_BLEND); GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA); And I bind a single texture: GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle); GLES20.glUniform1i(mUniformTextureHandle, 0); Which is just a simple circle with some blur (and hence some transparency) http://cl.ly/image/0K2V2p2L1H2x Then there are a bunch of glVertexAttribPointer calls: mBuffer.position(position); mGlEs20.glVertexAttribPointer(mAttributeRGBHandle, valsPerRGB, GLES20.GL_FLOAT, false, stride, mBuffer); ...4 more of these Then I'm drawing: GLES20.glUniformMatrix4fv(mUniformProjectionMatrixHandle, 1, false, Camera.mProjectionMatrix, 0); GLES20.glDrawArrays(GLES20.GL_POINTS, 0, drawCalls); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, 0); My vertex shader does have some computation in it, but given that they're point sprites (with only 2 coordinate values) I'm not sure this is the problem: #ifdef GL_ES // Set the default precision to low. precision lowp float; #endif uniform mat4 u_ProjectionMatrix; attribute vec4 a_Position; attribute float a_PointSize; attribute vec3 a_RGB; attribute float a_Alpha; attribute float a_Burn; varying vec4 v_Color; void main() { vec3 v_FGC = a_RGB * a_Alpha; v_Color = vec4(v_FGC.x, v_FGC.y, v_FGC.z, a_Alpha * (1.0 - a_Burn)); gl_PointSize = a_PointSize; gl_Position = u_ProjectionMatrix * a_Position; } My fragment shader couldn't really be simpler: #ifdef GL_ES // Set the default precision to low. precision lowp float; #endif uniform sampler2D u_Texture; varying vec4 v_Color; void main() { gl_FragColor = texture2D(u_Texture, gl_PointCoord) * v_Color; } That's about it. I had read that transparent pixels in point sprites can cause issues, but surely not at only 400 points? I'm running on a fairly new device (12 month old Galaxy Nexus). My question is less about my approach (although I'm open to suggestion) but more about whether there are any specific OpenGL "no no's" that have leaked into my code. I'm sure there's GL master out there facepalming right now... I'd love to hear any critique.

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• Unclaimed user group prizes, Live meeting on Monday, Next weeks UG, SQLRelay and more prizes

  - by Testas

    Hi Everyone Firstly I want to let you know that I finally found the LINQ book prize winners and the list of people at the bottom of this email are owed a LINQ book. This will be given out at next week’s UG meeting Live meeting with Carolyn Chau, Program Manager at Microsoft on Monday! It is very rare that we get the opportunity to have a Live meeting with a Program Manager in Redmond. Carolyn Chau will be presenting PowerView next Monday at 8pm. Live meeting details can be found on http://sqlserverfaq.com/events/388/Live-Meeting-on-SQL-Server-2012-PowerView-with-Carolyn-Chau-Principal-Program-Manager-in-the-Reporting-Services-in-association-with-SQLPASS-SQLServerFAQ-and-SQLBits.aspx Next week’s UG!! We welcome Mark Broadbent to Manchester next week where he will be presenting his session on SQL Server 2012 on Windows Core. We also hand out the unclaimed prizes. Register at http://sqlserverfaq.com/events/369/Thursday-night-meeting-at-BSS-with-Chris-TestaONeill-and-Mark-Broadbent.aspx Chris Webb is in Manchester!!! Chris Webb will be speaking at the Manchester SQL Server UG on 4th July. He will also be running his Real World Cube Design and Performance Tuning with Analysis Services between the 3rd – 5th July. If you want to attend then you can sign up at the link below http://www.technitrain.com/coursedetail.php?c=13&trackingcode=FAQ SQLRelay and a Special Prize and Jamie Thomson comes to Manchester!!!! SQLRelay takes place in Manchester on the 22nd. We have a special guest, after years of asking Jamie Thomson is coming to Manchester. The SSIS Junkie will be gracing us with his presence with a talk on SSIS 2012. Also we have a prize. Know a friend or colleague who would benefit from SQLRelay? Get them to register at www.sqlserverfaq.com and then register for the event http://sqlserverfaq.com/events/373/ALL-DAY-TUESDAY-EVENT-12-hours-of-SQL-Server-2012-at-the-SQLRelay-meeting-at-the-COOP-Manchester.aspx Then send an email to [email protected] with the subject of SQLFriend with the name of your friend. If you are both at the SQLRelay event on the day and your names are pulled out of the hat you will win a PASS 2011 DVD and your friend will win the “Best of PASS DVD 2011” worth  $1000 courtesy of SQLPASS. The draw will take place between 4.30pm – 5pm on the day. SQLBits feedback!!!!! Attended SQLBits? We really need to know your opinion. Please fill out the survey for the days you attended If you attended any of the days at SQLBits please can you all fill out the following survey http://www.sqlbits.com/SQLBitsX If you attended the Thursday Training day then please fill out the following survey: http://www.sqlbits.com/SQLBitsXThursday If you attended the Friday Deep Dives day then please fill out the following survey: http://www.sqlbits.com/SQLBitsXFriday If you attended the Saturday Community day then please fill out the following survey: http://www.sqlbits.com/SQLBitsXSaturday Thanks   Chris and Martin   LINQ BOOK winners Andrew Birds Chris Kennedy Dave Carpenter David Forrester Ian Ringrose James Cullen James Simpson Kevan Riley Kirsty Hunter Martin Bell Martin Croft Michael Docherty Naga Anand Ram Mangipudi Neal Atkinson Nick Colebourn Pavel Nefyodov Ralph Baines Rick Hibbert saad saleh Simon Enion Stan Venn Steve Powell Stuart Quinn

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• MIXing it Up a Bit

  - by andrewbrust

  Another March, another MIX.  For the fifth year running now, Microsoft has chosen to put on a conference aimed less at software development, per se, and more at the products, experiences and designs that software development can generate.  In all four prior MIX events, the focus of the show, its keynotes and breakout sessions has been on Web products.  On day 1 of MIX 2010 that focus shifted to Windows Phone 7 Series (WP7). What little we had seen of WP7 had been shown to us in a keynote presentation, given by Microsoft’s Joe Belfiore, at the Mobile World Congress in Barcelona, Spain last month.  And today, Mr. Belfiore reprised his showmanship for the MIX 2010 audience.  Joe showed us the ins and outs of WP7 and, in a breakout session, even gave us a sneak peek of Office (specifically, Excel) on WP7.  We didn’t get to see that one month ago in Barcelona, nor did get to see email messages opened for reading, which we saw today. But beyond a tour of the phone itself, impressive though that is, we got to see apps running on it.  Those apps included Associated Press news, Seesmic (a major Twitter client) and Foursquare (a social media darling).  All three ran, ran well, and looked markedly different and better from their corresponding versions on iPhone and Android.  And the games we saw looked even better. To me though, the best demos involved the creation of WP7 apps, using Silverlight in Visual Studio and Expression Blend.  These demos were so effective because they showed important apps being built in very few steps, and by Microsoft executives to boot.  Scott Guthrie showed us how to build a Twitter API app in Visual Strudio.   Jon Harris showed us how to build a photo management and viewer application in Expression Blend, using virtually no code.  Demos of apps built from scratch to F5 without the benefit of a teacher, could be challenging.  But they went off fine, without a hitch and without a ton of opaque, generated code.  Everything written, be it C# or XAML, was easily understood, and the results were impressive. That means lots of developers can do this, and I think it means a lot will.  What I’ve seen, thus far, of iPhone and Android development looks very tedious by comparison.  Development for those platforms involve a collection of tools that integrate only to a point.  Dev work for WP7 involves use of Visual Studio, Silverlight and the same debugging experience .NET developers already know.  This was very exciting for me. All the demos harkened back to days of building apps for with Visual Basic…design the front-end, put in code-behind and then hit F5.  And that makes sense, because the phone platform, and the PC of the early 90s are both, essentially, client OS machines.  The Web was minimal and the “device” was everything. Same is true of this phone.  It’s a client app contraption that fits in your pocket. And if the platforms are comparable, hopefully so too will be the draw of ease-of-development.   WP7 has the potential to make mobile developers want to switch over, and to convince enterprise developers to get into the phone scene.  Will this propel the new phone platform to new heights, and restore Microsoft’s competiveness in the mobile arena? I hope so.  I think so.  And if Microsoft uses developers to build themselves a victory, that would be beneficial and would show that Microsoft has learned from its failures, as well as its successes.  Today I saw a few beautiful apps.  Tomorrow I hope I see a slew of others; maybe not as polished, but plentiful, attractive and stable.  That would be a victory for Microsoft, and for developers.  And it would show everyone else that developers are the kingmakers.  They need cheap, efficient dev tools and lots of respect.  Microsoft has always been the company to provide that.  Hopefully, with WP7, they will return to that persona and see how very timeless it is.

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