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  • DateTime.Now.Millisecond always return 0 on compact framework

    - by Sachin
    I need some way to find the elapsed time or time taken in milliseconds for a function to execute in compact framework. For the same I tried DateTime.Now.Millisecond. But DateTime.Now.Millisecond always return 0. Also I tried with Now.Tick. But it also returns the value in multiplication of 1,00,00,000 which means it always returns seconds part ignoring the milliseconds. My question is how to determine the time elapsed in millisecond on compact framework.

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  • Counting FLOPS/GFLOPS in program - CUDA

    - by msx
    Already finished my application which multiplies CRS matrix and vector (SpMV) and the only thing to do now is to count FLOPS my application did. In my opinion it's really hard to estimate number of floating point operation in case of sparse matrix - vector multiplication, because the number of multiplies in one row is really "jumpy" or fluent. I only tried to measure time using "cudaprof" ( available in ./CUDA/bin directory) - it works fine. Any sugestions and instruction pastes appreciated !

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  • Weird interview question from MS

    - by didxga
    There are two numbers, which are both between 1 and 30 inclusive. Person A knew the addition of the two numbers; Person B knew the multiplication of the two numbers; A said:"do you know what numbers are they?" B replied:"I don't know, do you know?" A:"I don't know either" then B said:"so, I knew already" then A said:"I knew either" What are the two numbers?

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  • Windows Azure: Parallelization of the code

    - by veda
    I have some matrix multiplication operation. I want to parallelize the execution of those operations through multiple processors.. This can be done on high performance computing cluster using MPI (Message Passing Interface). Like wise, can I do some parallelization in the cloud using multiple worker roles. Is there any means for doing that.

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  • simple dividing

    - by dontoo
    Lets say I am dividing 2592 / 324 = 8 Practically I must guess that 324 goes 8 times in 2592 without reminder. For example, first I try with 7 ( 7*324 = 2268, reminder 324, so 7 is wrong, so I try with 8 and 8 is correct) Is there anyway to do dividing without guessing( trying ), like multiplication ( all mechanically, digit by digit )?

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  • Why is sys+user > real in "time command"?

    - by shadyabhi
    I have a program that uses pthread library to do the matrix multiplication of 500x500 matrix. Each thread calculates 50 rows of the matrix. When I run tiem command:- shadyabhi@shadyabhi-desktop:~$ time ./a.out real 0m0.383s user 0m0.810s sys 0m0.000s shadyabhi@shadyabhi-desktop:~$ How come sys+user is greater than real time?

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  • Adding to a bit array

    - by Martin
    In my program, I am using BitArrays to represent 160 bit numbers. I want to be able to add, subtract, increment and decrement these numbers, what is the algorithm for doing this? At the moment I'm not interested in multiplication and division, but I might be in the future so bonus points for that. I'm implementing in C#, but pseudocode is fine if you're not familiar with the language

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  • Community Outreach - Where Should I Go

    - by Roger Brinkley
    A few days ago I was talking to person new to community development and they asked me what guidelines I used to determine the worthiness of a particular event. After our conversation was over I thought about it a little bit more and figured out there are three ways to determine if any event (be it conference, blog, podcast or other social medias) is worth doing: Transferability, Multiplication, and Impact. Transferability - Is what I have to say useful to the people that are going to hear it. For instance, consider a company that has product offering that can connect up using a number of languages like Scala, Grovey or Java. Sending a Scala expert to talk about Scala and the product is not transferable to a Java User Group, but a Java expert doing the same talk with a Java slant is. Similarly, talking about JavaFX to any Java User Group meeting in Brazil was pretty much a wasted effort until it was open sourced. Once it was open sourced it was well received. You can also look at transferability in relation to the subject matter that you're dealing with. How transferable is a presentation that I create. Can I, or a technical writer on the staff, turn it into some technical document. Could it be converted into some type of screen cast. If we have a regular podcast can we make a reference to the document, catch the high points or turn it into a interview. Is there a way of using this in the sales group. In other words is the document purely one dimensional or can it be re-purposed in other forms. Multiplication - On every trip I'm looking for 2 to 5 solid connections that I can make with developers. These are long term connections, because I know that once that relationship is established it will lead to another 2 - 5 from that connection and within a couple of years were talking about some 100 connections from just one developer. For instance, when I was working on JavaHelp in 2000 I hired a science teacher with a programming background. We've developed a very tight relationship over the year though we rarely see each other more than once a year. But at this JavaOne, one of his employees came up to me and said, "Richard (Rick Hard in Czech) told me to tell you that he couldn't make it to JavaOne this year but if I saw you to tell you hi". Another example is from my Mobile & Embedded days in Brasil. On our very first FISL trip about 5 years ago there were two university students that had created a project called "Marge". Marge was a Bluetooth framework that made connecting bluetooth devices easier. I invited them to a "Sun" dinner that evening. Originally they were planning on leaving that afternoon, but they changed their plans recognizing the opportunity. Their eyes were as big a saucers when they realized the level of engineers at the meeting. They went home started a JUG in Florianoplis that we've visited more than a couple of times. One of them went to work for Brazilian government lab like Berkley Labs, MIT Lab, John Hopkins Applied Physicas Labs or Lincoln Labs in the US. That presented us with an opportunity to show Embedded Java as a possibility for some of the work they were doing there. Impact - The final criteria is how life changing is what I'm going to say be to the individuals I'm reaching. A t-shirt is just a token, but when I reach down and tug at their developer hearts then I know I've succeeded. I'll never forget one time we flew all night to reach Joan Pasoa in Northern Brazil. We arrived at 2am went immediately to our hotel only to be woken up at 6 am to travel 2 hours by car to the presentation hall. When we arrived we were totally exhausted. Outside the facility there were 500 people lined up to hear 6 speakers for the day. That itself was uplifting.  I delivered one of my favorite talks on "I have passion". It was a talk on golf and embedded java development, "Find your passion". When we finished a couple of first year students came up to me and said how much my talk had inspired them. FISL is another great example. I had been about 4 years in a row. FISL is a very young group of developers so capturing their attention is important. Several of the students will come back 2 or 3 years later and ask me questions about research or jobs. And then there's Louis. Louis is one my favorite Brazilians. I can only describe him as a big Brazilian teddy bear. I see him every year at FISL. He works primarily in Java EE but he's attended every single one of my talks over the last 4 years. I can't tell you why, but he always greets me and gives me a hug. For some reason I've had a real impact. And of course when it comes to impact you don't just measure a presentation but every single interaction you have at an event. It's the hall way conversations, the booth conversations, but more importantly it's the conversations at dinner tables or in the cars when you're getting transported to an event. There's a good story that illustrates this. Last year in the spring I was traveling to Goiânia in Brazil. I've been there many times and leaders there no me well. One young man has picked me up at the airport on more than one occasion. We were going out to dinner one evening and he brought his girl friend along. One thing let to another and I eventually asked him, in front of her, "Why haven't you asked her to marry you?" There were all kinds of excuses and she just looked at him and smiled. When I came back in December for JavaOne he came and sought me. "I just want to tell you that I thought a lot about what you said, and I asked her to marry me. We're getting married next Spring." Sometimes just one presentation is all it takes to make an impact. Other times it takes years. Some impacts are directly related to the company and some are more personal in nature. It doesn't matter which it is because it's having the impact that matters.

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  • How to use Cambria as basic font when math symbols are needed?

    - by Jukka K. Korpela
    I first thought one could use Cambria for copy text (in Word), switching to Cambria Math only when needed (when a character is needed that is not present in Cambria). This does not seem to work that well. For example, if I need the minus-or-plus sign “±”, I cannot take it from Cambria, but if I use it from Cambria Math, it has a shape rather different from the style of “±”, “+”, and “–” in the text, if it is written in Cambria. Similarly, the multiplication sign “×” is much larger in Cambria Math than in Cambria. The obvious solution would be to use Cambria Math as copy text font, for uniformity. But Cambria Math lacks italic and bold. (Word’s formula editor uses Cambria Math by default and can do italic and bold, but it gets them from Plane 1 – they are special mathematic italic and mathematic bold characters, not italic and bold glyphs for normal characters.) Is there any better approach than using Cambria Math for copy text and switching to Cambria when italic or bold is needed?

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  • Points on lines where the two lines are the closest together

    - by James Bedford
    Hey guys, I'm trying to find the points on two lines where the two lines are the closest. I've implemented the following method (Points and Vectors are as you'd expect, and a Line consists of a Point on the line and a non-normalized direction Vector from that point): void CDClosestPointsOnTwoLines(Line line1, Line line2, Point* closestPoints) { closestPoints[0] = line1.pointOnLine; closestPoints[1] = line2.pointOnLine; Vector d1 = line1.direction; Vector d2 = line2.direction; float a = d1.dot(d1); float b = d1.dot(d2); float e = d2.dot(d2); float d = a*e - b*b; if (d != 0) // If the two lines are not parallel. { Vector r = Vector(line1.pointOnLine) - Vector(line2.pointOnLine); float c = d1.dot(r); float f = d2.dot(r); float s = (b*f - c*e) / d; float t = (a*f - b*c) / d; closestPoints[0] = line1.positionOnLine(s); closestPoints[1] = line2.positionOnLine(t); } else { printf("Lines were parallel.\n"); } } I'm using OpenGL to draw three lines that move around the world, the third of which should be the line that most closely connects the other two lines, the two end points of which are calculated using this function. The problem is that the first point of closestPoints after this function is called will lie on line1, but the second point won't lie on line2, let alone at the closest point on line2! I've checked over the function many times but I can't see where the mistake in my implementation is. I've checked my dot product function, scalar multiplication, subtraction, positionOnLine() etc. etc. So my assumption is that the problem is within this method implementation. If it helps to find the answer, this is function supposed to be an implementation of section 5.1.8 from 'Real-Time Collision Detection' by Christer Ericson. Many thanks for any help!

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  • Converting to and from local and world 3D coordinate spaces?

    - by James Bedford
    Hey guys, I've been following a guide I found here (http://knol.google.com/k/matrices-for-3d-applications-view-transformation) on constructing a matrix that will allow me to 3D coordinates to an object's local coordinate space, and back again. I've tried to implement these two matrices using my object's look, side, up and location vectors and it seems to be working for the first three coordinates. I'm a little confused as to what I should expect for the w coordinate. Here are couple of examples from the print outs I've made of the matricies that are constructed. I'm passing a test vector of [9, 8, 14, 1] each time to see if I can convert both ways: Basic example: localize matrix: Matrix: 0.000000 -0.000000 1.000000 0.000000 0.000000 1.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 5.237297 -45.530716 11.021271 1.000000 globalize matrix: Matrix: 0.000000 0.000000 1.000000 0.000000 -0.000000 1.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 -11.021271 -45.530716 -5.237297 1.000000 test: Vector4f(9.000000, 8.000000, 14.000000, 1.000000) localTest: Vector4f(14.000000, 8.000000, 9.000000, -161.812256) worldTest: Vector4f(9.000000, 8.000000, 14.000000, -727.491455) More complicated example: localize matrix: Matrix: 0.052504 -0.000689 -0.998258 0.000000 0.052431 0.998260 0.002068 0.000000 0.997241 -0.052486 0.052486 0.000000 58.806095 2.979346 -39.396252 1.000000 globalize matrix: Matrix: 0.052504 0.052431 0.997241 0.000000 -0.000689 0.998260 -0.052486 0.000000 -0.998258 0.002068 0.052486 0.000000 -42.413120 5.975957 -56.419727 1.000000 test: Vector4f(9.000000, 8.000000, 14.000000, 1.000000) localTest: Vector4f(-13.508600, 8.486917, 9.290090, 2.542114) worldTest: Vector4f(9.000190, 7.993863, 13.990230, 102.057129) As you can see in the more complicated example, the coordinates after converting both ways loose some precision, but this isn't a problem. I'm just wondering how I should deal with the last (w) coordinate? Should I just set it to 1 after performing the matrix multiplication, or does it look like I've done something wrong? Thanks in advance for your help!

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  • Duck checker in Python: does one exist?

    - by elliot42
    Python uses duck-typing, rather than static type checking. But many of the same concerns ultimately apply: does an object have the desired methods and attributes? Do those attributes have valid, in-range values? Whether you're writing constraints in code, or writing test cases, or validating user input, or just debugging, inevitably somewhere you'll need to verify that an object is still in a proper state--that it still "looks like a duck" and "quacks like a duck." In statically typed languages you can simply declare "int x", and anytime you create or mutate x, it will always be a valid int. It seems feasible to decorate a Python object to ensure that it is valid under certain constraints, and that every time that object is mutated it is still valid under those constraints. Ideally there would be a simple declarative syntax to express "hasattr length and length is non-negative" (not in those words. Not unlike Rails validators, but less human-language and more programming-language). You could think of this as ad-hoc interface/type system, or you could think of it as an ever-present object-level unit test. Does such a library exist to declare and validate constraint/duck-checking on Python-objects? Is this an unreasonable tool to want? :) (Thanks!) Contrived example: rectangle = {'length': 5, 'width': 10} # We live in a fictional universe where multiplication is super expensive. # Therefore any time we multiply, we need to cache the results. def area(rect): if 'area' in rect: return rect['area'] rect['area'] = rect['length'] * rect['width'] return rect['area'] print area(rectangle) rectangle['length'] = 15 print area(rectangle) # compare expected vs. actual output! # imagine the same thing with object attributes rather than dictionary keys.

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  • The best cross platform (portable) arbitrary precision math library

    - by Siu Ching Pong - Asuka Kenji
    Dear ninjas / hackers / wizards, I'm looking for a good arbitrary precision math library in C or C++. Could you please give me some advices / suggestions? The primary requirements: It MUST handle arbitrarily big integers (my primary interest is on integers). In case that you don't know what the word arbitrarily big means, imagine something like 100000! (the factorial of 100000). The precision MUST NOT NEED to be specified during library initialization / object creation. The precision should ONLY be constrained by the available resources of the system. It SHOULD utilize the full power of the platform, and should handle "small" numbers natively. That means on a 64-bit platform, calculating 2^33 + 2^32 should use the available 64-bit CPU instructions. The library SHOULD NOT calculate this in the same way as it does with 2^66 + 2^65 on the same platform. It MUST handle addition (+), subtraction (-), multiplication (*), integer division (/), remainder (%), power (**), increment (++), decrement (--), gcd(), factorial(), and other common integer arithmetic calculations efficiently. Ability to handle functions like sqrt() (square root), log() (logarithm) that do not produce integer results is a plus. Ability to handle symbolic computations is even better. Here are what I found so far: Java's BigInteger and BigDecimal class: I have been using these so far. I have read the source code, but I don't understand the math underneath. It may be based on theories / algorithms that I have never learnt. The built-in integer type or in core libraries of bc / Python / Ruby / Haskell / Lisp / Erlang / OCaml / PHP / some other languages: I have ever used some of these, but I have no idea on which library they are using, or which kind of implementation they are using. What I have already known: Using a char as a decimal digit, and a char* as a decimal string and do calculations on the digits using a for-loop. Using an int (or a long int, or a long long) as a basic "unit" and an array of it as an arbitrary long integer, and do calculations on the elements using a for-loop. Booth's multiplication algorithm What I don't know: Printing the binary array mentioned above in decimal without using naive methods. Example of a naive method: (1) add the bits from the lowest to the highest: 1, 2, 4, 8, 16, 32, ... (2) use a char* string mentioned above to store the intermediate decimal results). What I appreciate: Good comparisons on GMP, MPFR, decNumber (or other libraries that are good in your opinion). Good suggestions on books / articles that I should read. For example, an illustration with figures on how a un-naive arbitrarily long binary to decimal conversion algorithm works is good. Any help. Please DO NOT answer this question if: you think using a double (or a long double, or a long long double) can solve this problem easily. If you do think so, it means that you don't understand the issue under discussion. you have no experience on arbitrary precision mathematics. Thank you in advance! Asuka Kenji

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  • Programming as a minor

    - by Tomas Cokis
    Hello Everyone! I've never asked a question here at programmers, and for reasons which will become obvious later I've never answered one here, but I do poke around in short bursts. Anyway, I'm 15 right now, and I've been programming in C++ for 4 years, just working on my own projects that are aim so high as to never be finished. I've been working on a single project for the last year, and every 3 months, I add a new system into it. It might be a value tabling directory enabled log system, or a render system, or a class to load up xml files, whatever it is, I don't mind too much that the overall project (a 3d engine) isn't ever going to get finished, I just get some satisfaction from getting what I have done building and running. I don't know what I want to do when I grow up, although I suspect I'll go into some form of engineering, but I was interested in knowing if I do choose to go into a career as a developer, what kind of material I could look at to push myself up and get myself experience that might help my career later. I'm not talking about books in particular, I'm more interested in subjects areas that will get me access to good job opportunities, or that will give me a hand-up if I do computer science and software related courses at uni. One of the things I was thinking of doing was designing some of the logic gate components of a small computer - which I started briefly over the holidays, working out integer addition, subtraction and multiplication. That kind of stuff interests me, but is it really useful - or more useful then just more programming? But anyway, Any advice? Should I continue on my perpetual 3d engine? Are there any other projects or particular accomplishments that would help my education? Perhaps I should mention that I live in Perth, Australia, so local software companies are likely to be more scarce then usual.

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  • Blender - creating bones from transform matrices

    - by user975135
    Notice: this is for the Blender 2.5/2.6 API. Back in the old days in the Blender 2.4 API, you could easily create a bone from a transform matrix in your 3d file as EditBones had an attribute named "matrix", which was an armature-space matrix you could access and modify. The new 2.5+ API still has the "matrix" attribute for EditBones, but for some unknown reason it is now read-only. So how to create EditBones from transform matrices? I could only find one thing: a new "transform()" function, which takes a Matrix too. Transform the the bones head, tail, roll and envelope (when the matrix has a scale component). Perfect, but you already need to have some values (loc/rot/scale) for your bone, otherwise transforming with a matrix like this will give you nothing, your bone will be a zero-sized bone which will be deleted by Blender. if you create default bone values first, like this: bone.tail = mathutils.Vector([0,1,0]) Then transform() will work on your bone and it might seem to create correct bones, but setting a tail position actually generates a matrix itself, use transform() and you don't get the matrix from your model file on your EditBone, but the multiplication of your matrix with the bone's existing one. This can be easily proven by comparing the matrices read from the file with EditBone.matrix. Again it might seem correct in Blender, but now export your model and you see your animations are messed up, as the bind pose rotations of the bones are wrong. I've tried to find an alternative way to assign the transformation matrix from my file to my EditBone with no luck.

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  • How to handle monetary values in PHP and MySql?

    - by Songo
    I've inherited a huge pile of legacy code written in PHP on top of a MySQL database. The thing I noticed is that the application uses doubles for storage and manipulation of data. Now I came across of numerous posts mentioning how double are not suited for monetary operations because of the rounding errors. However, I have yet to come across a complete solution to how monetary values should be handled in PHP code and stored in a MySQL database. Is there a best practice when it comes to handling money specifically in PHP? Things I'm looking for are: How should the data be stored in the database? column type? size? How should the data be handling in normal addition, subtraction. multiplication or division? When should I round the values? How much rounding is acceptable if any? Is there a difference between handling large monetary values and low ones? Note: A VERY simplified sample code of how I might encounter money values in everyday life: $a= $_POST['price_in_dollars']; //-->(ex: 25.06) will be read as a string should it be cast to double? $b= $_POST['discount_rate'];//-->(ex: 0.35) value will always be less than 1 $valueToBeStored= $a * $b; //--> any hint here is welcomed $valueFromDatabase= $row['price']; //--> price column in database could be double, decimal,...etc. $priceToPrint=$valueFromDatabase * 0.25; //again cast needed or not? I hope you use this sample code as a means to bring out more use cases and not to take it literally of course. Bonus Question If I'm to use an ORM such as Doctrine or PROPEL, how different will it be to use money in my code.

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  • Trouble with Collada bones

    - by KyleT
    I have a Collada file with a rigged mesh. I've read the node tags in the library_visual_scenes tag and extracted the matrix for each node and stored everything in a hierarchical bone structure. My Matrix container is "row major", so I'd store the first float of a matrix tag in the 1st row, 1st column, the second in the 1st row, 2nd column, etc. From what I gather this is the Bind Pose Matrix. After that I went through the tag and extracted the float array in the source tag of the skin tag of the controller for the mesh. I stored each matrix from this float array in their corresponding Bone as the Inverse Bind Matrix. I also extracted the bind-shape-matrix and stored it. Now I'd like to draw the skeleton with OpenGL to see if everything is working correctly before I go about skinning. I iterate once over my bones and multiply a bone's Bind Pose Matrix by it's parents and store that. After that I iterate again over the bones and multiply the result of the previous matrix multiplication by the Inverse Bind Matrix and then by the Bind Shape Matrix. The results look something like this: [0.2, 9.2, 5.8, 1.2 ] [4.6, -3.3, -0.2, -0.1 ] [-1.8, 0.2, -4.2, -3.9 ] [0, 0, 0, 1 ] I've had to go to various sources to get the little understanding of Collada I have and books about 3d transform matricies can get pretty intense. I've hit a brick wall and if you could please read through this and see if there is something I'm doing wrong, and how I'd go about getting an X,Y,Z to draw a point for each of these joints once I've calculated the final transform, I'd really appreciate it.

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  • How to ask developers to think about high resolution screens

    - by WhiteWind
    I just got a ASUS N56VZ laptop, and it`s all good, but the screen resolution 1920x1080px. I am not asking, how to scale ui elements. If someone is interested I have found some tricks: increase font size in system settings increase unity dock size in MyUnity or system settings in modern Ubuntu versions. tweak userChrome.js of FireFox to make buttons|panels|icons larger add DefaultZoomLevel extension to FireFox to make it zoom pages initially. But all of it is miserable, because there are some big bugs: window decoration elements are way too small to pick them with mouse. I can't scale window easily and I can't position my cursor fast on the close|maximize buttons. Tuning lines like in sound volume dialog are hardly clickable at all. Unity top panel (status panel & tray) hardly can contain the bigger font, so it looks ugly, but icons are still the same. Sometimes I can`t read text, as it is cropped (and I cant scale some dialogs as it has fixed size) Chromium is not usable at all (ok, it's not Ubuntu problem, but the problem still exists) JAVA applications are not scalable (same as above) In FF I am able to get descent results in most cases, but multiplication of system font increase and browser font increase makes system controls (combobox, lists, drop down lists) extremely big, so I cant even control the zoom level on the page. IMHO, we should post a bug report (but what kind of bug?) and vote for it! The problem is even deeper, but at least we should ask developers to think about it. So my question is: how can I post a report (the right words and right place) and how can we (who already has that problem, or who want it to be solved before hardware upgrade) vote for faster solution. Any ideas?

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  • Common way to store model transformations

    - by redreggae
    I ask myself what's the best way to store the transformations in a model class. What I came up with is to store the translation and scaling in a Vector3 and the rotation in a Matrix4. On each update (frame) I multiply the 3 matrices (first build a Translation and Scaling Matrix) to get the world matrix. In this way I have no accumulated error. world = translation * scaling * rotation Another way would be to store the rotation in a quaternion but then I would have a high cost to convert to a matrix every time step. If I lerp the model I convert the rotation matrix to quaternion and then back to matrix. For speed optimization I have a dirty flag for each transformation so that I only do a matrix multiplication if necessary. world = translation if (isScaled) { world *= scaling } if (isRotated) { world *= rotation } Is this a common way or is it more common to have only one Matrix4 for all transformations? And is it better to store the rotation only as quaternion? For info: Currently I'm building a CSS3D engine in Javascript but these questions are relevant for every 3D engine.

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  • Create a rectangle struct to be rotated and have a .Intersects() function

    - by MintyAnt
    In my XNA program, I am trying to swing a sword. The sword starts at an angle of 180 degrees, then rotates (clockwise) to an angle of 90 degrees. The Rectangle struct that XNA provides, Rectangle mAttackBox = new Rectangle(int x, int y, int width, int height); However, this struct has two problems: Holds position and size in Integers, not Floats Cannot be rotated I was hoping someone could help me in either telling me that i'm wrong and the Rectangle can be used for both these methods, or can lead me down the right path for rotating a rectangle. I know how to create a Struct. I believe that I can make methods like classes. I can determine the 4 vertices of a 2D rectangle by calculating out the x,y of the other 3 given the length, width. I'm sure theres a Matrix class I can use to multiply each point against a Rotation matrix. But once i have my 4 vertices, I got two other problems: - How do I test other rectangles against it? How does .Intersects() work for the rectangle struct? - Is this even the fastest way to do it? I'd be constantly doing matrix multiplication, wouldnt that slow things down?

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  • Is there any professional way to illustrate difference between 2 diagrams?

    - by lamwaiman1988
    I made a documented which is to describe the difference between the same logical structure from different version ( e.g Structure A from version 8 and Structure A from version 9 ). Luckily I've got the logical structure diagram from the 2 functional specification. I've managed to copy the image of each logical structure and paste them in MS Word and compare the 2 version side by side. I don't know if there is a standard way to illustrate the difference. I simply draw a cross over the removed logical member from the previous version and draw a rectangle around the new logical member of the next version. I know my way is kinda childish. I am wondering how to present them professionally. In addition, You won't believe this, but MS Word doesn't have a shape of CROSS, so I am actually using a multiplication sign that look like a giant monster: This is why I hate myself. Unlike 2 separated lines, this shape is easy to use, draw and resize. I am wondering if MS Word would care about a normal cross.

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  • moving in the wrong direction

    - by Will
    Solution: To move a unit forward: forward = Quaternion(0,0,0,1) rotation.normalize() # ocassionally ... pos += ((rotation * forward) * rotation.conjugated()).xyz().normalized() * speed I think the trouble stemmed from how the Euclid math library was doing Quaternion*Vector3 multiplication, although I can't see it. I have a vec3 position, a quaternion for rotation and a speed. I compute the player position like this: rot *= Quaternion().rotate_euler(0.,roll_speed,pitch_speed) rot.normalize() pos += rot.conjugated() * Vector3(0.,0.,-speed) However, printing the pos to console, I can see that I only ever seem to travel on the x-axis. When I draw the scene using the rot quaternion to rotate my camera, it shows a proper orientation. What am I doing wrong? Here's an example: You start off with rotation being an identity quaternion: w=1,x=0,y=0,z=0 You move forward; the code correctly decrements the Z You then pitch right over to face the other way; if you spin only 175deg it'll go in right direction; you have to spin past 180deg. It doesn't matter which direction you spin in, up or down, though Your quaternion can then be something like: w=0.1,x=0.1,y=0,z=0 And moving forward, you actually move backward?! (I am using the euclid Python module, but its the same as every other conjulate) The code can be tried online at http://williame.github.com/ludum_dare_24_evolution/ The only key that adjusts the speed is W and S. The arrow keys only adjust the pitch/roll. At first you can fly ok, but after a bit of weaving around you end up getting sucked towards one of the sides. The code is https://github.com/williame/ludum_dare_24_evolution/blob/cbacf61a7159d2c83a2187af5f2015b2dde28687/tiny1web.py#L102

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  • Big 0 theta notation

    - by niggersak
    Can some pls help with the solution Use big-O notation to classify the traditional grade school algorithms for addition and multiplication. That is, if asked to add two numbers each having N digits, how many individual additions must be performed? If asked to multiply two N-digit numbers, how many individual multiplications are required? Suppose f is a function that returns the result of reversing the string of symbols given as its input, and g is a function that returns the concatenation of the two strings given as its input. If x is the string hrwa, what is returned by g(f(x),x)? Explain your answer - don't just provide the result!

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