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  • Glenn Fiedler's fixed timestep with fake threads

    - by kaoD
    I've implemented Glenn Fiedler's Fix Your Timestep! quite a few times in single-threaded games. Now I'm facing a different situation: I'm trying to do this in JavaScript. I know JS is single-threaded, but I plan on using requestAnimationFrame for the rendering part. This leaves me with two independent fake threads: simulation and rendering (I suppose requestAnimationFrame isn't really threaded, is it? I don't think so, it would BREAK JS.) Timing in these threads is independent too: dt for simulation and render is not the same. If I'm not mistaken, simulation should be up to Fiedler's while loop end. After the while loop, accumulator < dt so I'm left with some unspent time (dt) in the simulation thread. The problem comes in the draw/interpolation phase: const double alpha = accumulator / dt; State state = currentState*alpha + previousState * ( 1.0 - alpha ); render( state ); In my render callback, I have the current timestamp to which I can subtract the last-simulated-in-physics-timestamp to have a dt for the current frame. Should I just forget about this dt and draw using the physics thread's dt? It seems weird, since, well, I want to interpolate for the unspent time between simulation and render too, right? Of course, I want simulation and rendering to be completely independent, but I can't get around the fact that in Glenn's implementation the renderer produces time and the simulation consumes it in discrete dt sized chunks. A similar question was asked in Semi Fixed-timestep ported to javascript but the question doesn't really get to the point, and answers there point to removing physics from the render thread (which is what I'm trying to do) or just keeping physics in the render callback too (which is what I'm trying to avoid.)

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  • links for 2010-03-31

    - by Bob Rhubart
    Andy Mulholland: Rethinking the narrow and deep expertise model "We increasingly realise that we have to read requirements in a more open way to decide what techniques can be used, what business experience can be added, etc, so the whole idea of encouraging ‘cross’ discipline understanding seems to look increasingly necessary as we look at how technology touches every part of business, and/or any other aspect of life. It is time to rethink the narrow and deep expertise model and consider T-shaped approaches where the depth is complimented by the width to understand how it might be used and how it fits with other capabilities and disciplines too." -- Andy Mulholland (tags: enterprisearchitecture) @vambenepe: Smoothing a discrete world "For the short term (until we sell one) there are three cars in my household. A manual transmission, an automatic and a CVT (continuous variable transmission). This makes me uniquely qualified to write about Cloud Computing." -- William Vambenepe (tags: otn oracle cloud) @fteter: The Price of Progress "I wonder about the price of progress on the business world. Do some of us get attached to old business models or software applications? Do we resist change for the better for emotional reasons? Are we sometimes impediments to progress just because we don't want things to change?" -- Oracle ACE Director Floyd Teter (tags: otn oracle oracleace progress innovation) Pat Shepherd: Enterprise Architecture should not be Arbitrary "If done properly the Business, Application and Information architectures are nailed down BEFORE any technological direction (SOA or otherwise) is set. Those 3 layers and Governance (people and processes), IMHO, are layers that should not vary much as they have everything to do with understanding the business -- from which technological conclusions can later be drawn." - Pat Shepherd, responding to a post by Jordan Braunstein. (tags: oracle otn enterprisearchitecture soa)

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  • How to re-configure graphics from Intel integrated to Intel / ATI switchable?

    - by Bucic
    There are lots of 'how to get switchable graphics to work' guides but I found none on how to configure a system for switchable graphics operation on Ubuntu from the ground up, nor explaining the current driver situation for particular computer models (integrated+discrete combinations). Example: https://help.ubuntu.com/community/HybridGraphics My system being mature and on Intel integrated card also makes things complicated. System information: Ubuntu 12.04 amd64, installed clean with system configured to use only the integrated Intel card Lenovo Thinkpad T500 Intel GMA 4500MHD / ATI Mobility Radeon HD 3650 Current situation: Mature and up-to-date system with no configuration changes to what's given above. I've made a backup image of the system (Clonezilla) so regardless of what's written below let's assume it's our starting point. If something in What I have already tried is not clear you may as well diregard it. What I have already tried: Configuring BIOS to switchable graphics and: Installing Additional Hardware drivers - returned an error. Installing proprietary amd-driver-installer-12.6-legacy-x86.x86_64.run automatically - system starts to 'low-graphics mode'. Tried fixing as per https://help.ubuntu.com/community/BinaryDriverHowto/ATI#Manually_installing_Catalyst_12.6.2C_special_case_for_Intel.2BAC8-ATI_hybrid_graphics Got lost, gave up. Please note that while configuring BIOS for integrated graphics only is pretty straightforward, configuring for switchable graphics is not.

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  • The dreaded Brightness issue (Fn keys + Max brightness)

    - by Adam
    I'm trying to get some control over the brightness of my Samsung QX411 (Integrated Intel and discrete Nvidia, though Ubuntu doesn't see the latter yet, I'll play around with Bumblebee later) Using the FN+up/down lowers the screen brightness from max to one peg down or back up. If I try to bring the brightness down any more, it just flickers and stays the same. I can lower the brightness in Settings, but that's delicate and gets reverted to max if I open up the brightness settings again, or log out. The closest I got was adding acpi_backlight=vendor to a line in /etc/default/grub, (source) I could consequently lower the brightness a couple of pegs down to the minimum with FN+down, but then it's as if the problem got inversed, and I'd get stuck in the bottom tier, I could only increase the brightness by one peg and back down. Rebooting would revert to max brightness. acpi_osi=, acpi_osi=Linux, acpi_osi=vendor, acpi_osi='!Windows 2012', acpi_backlight=Linux, acpi_backlight='!Windows 2012' don't do anything for me. I've also tried adding echo 2000 > /sys/class/backlight/intel_backlight/brightness to /etc/rc.local, where my max value from cat /sys/class/backlight/intel_backlight/brightness is 4648, which didn't do anything. (same result with echo 2000 > /sys/class/backlight/acpi_video0/brightness) source Samsung tools also didn't help in this regard. I've spent hours on this, it's getting quite frustrating. Any help would be greatly appreciated.

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  • GRE subject Computer science

    - by Maddy.Shik
    How do I prepare for the GRE Computer Science subject test? Are there any standard text books I should follow? Agree that its under graduation level and one doesn't need to dig to deep for it. I have done my computer engineering from a college who ranks in top 20 in India. So may be my curriculum has not been that good as compared to international students. Since now i want to get admission in to world renowned university's Ph. D. program. I want to enhance my basic skills up to a level to beat other international students in competition. I want to know good book references which are recommended by professors in international school like CMU, MIT, Standford etc. Like for Algorithms Coreman is considered very good. Good books builds concepts from very basic so that one doesn't need to mug up even a basic concepts. Coreman is just too good with good blend of Mathematics and programming concepts. Definitely Test paper are must but that can be practiced once one has read text books thoroughly. Besides its been 2 years i passed out from college so its is essential for me to revise all concepts from text books. Please tell me standard text books for each subject like Computer Architecture, Database Design, Operating Systems, Discrete Maths etc.

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  • Extreme Optimization Numerical Libraries for .NET – Part 1 of n

    - by JoshReuben
    While many of my colleagues are fascinated in constructing the ultimate ViewModel or ServiceBus, I feel that this kind of plumbing code is re-invented far too many times – at some point in the near future, it will be out of the box standard infra. How many times have you been to a customer site and built a different variation of the same kind of code frameworks? How many times can you abstract Prism or reliable and discoverable WCF communication? As the bar is raised for whats bundled with the framework and more tasks become declarative, automated and configurable, Information Systems will expose a higher level of abstraction, forcing software engineers to focus on more advanced computer science and algorithmic tasks. I've spent the better half of the past decade building skills in .NET and expanding my mathematical horizons by working through the Schaums guides. In this series I am going to examine how these skillsets come together in the implementation provided by ExtremeOptimization. Download the trial version here: http://www.extremeoptimization.com/downloads.aspx Overview The library implements a set of algorithms for: linear algebra, complex numbers, numerical integration and differentiation, solving equations, optimization, random numbers, regression, ANOVA, statistical distributions, hypothesis tests. EONumLib combines three libraries in one - organized in a consistent namespace hierarchy. Mathematics Library - Extreme.Mathematics namespace Vector and Matrix Library - Extreme.Mathematics.LinearAlgebra namespace Statistics Library - Extreme.Statistics namespace System Requirements -.NET framework 4.0  Mathematics Library The classes are organized into the following namespace hierarchy: Extreme.Mathematics – common data types, exception types, and delegates. Extreme.Mathematics.Calculus - numerical integration and differentiation of functions. Extreme.Mathematics.Curves - points, lines and curves, including polynomials and Chebyshev approximations. curve fitting and interpolation. Extreme.Mathematics.Generic - generic arithmetic & linear algebra. Extreme.Mathematics.EquationSolvers - root finding algorithms. Extreme.Mathematics.LinearAlgebra - vectors , matrices , matrix decompositions, solvers for simultaneous linear equations and least squares. Extreme.Mathematics.Optimization – multi-d function optimization + linear programming. Extreme.Mathematics.SignalProcessing - one and two-dimensional discrete Fourier transforms. Extreme.Mathematics.SpecialFunctions

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  • Why doesn't Bumblebee work with Nvidia GT640M?

    - by Dickson Wong
    I've done a clean install of Ubuntu 12.04 from a liveCD on a Samsung Series 7 Chronos with a 3rd Gen i7 and the Nvidia GeForce GT 640M. I've followed this: (https://wiki.ubuntu.com/Bumblebee#Installation) to install bumblebee so I can switch to my discrete GPU. I have not used ironhide, or preivous bumblee since it's a clean install. When I use optirun, optirun says it can't initialize the GPU: [ERROR]Cannot access secondary GPU - error: [XORG] (EE) NVIDIA(0): Failed to initialize the NVIDIA GPU at PCI:1:0:0. Please [ERROR]Aborting because fallback start is disabled. I've looked at the troubleshooting page for bumblebee and I have the correct driver and do not think I have aspci disabled. Also, my keyboard becomes very unresponsive and my mouse skips and isn't smooth after optirun crashes. The only thing to fix this is a reboot. Here's my lspci | grep VGA output: 00:02.0 VGA compatible controller: Intel Corporation Ivy Bridge Graphics Controller (rev 09) 01:00.0 VGA compatible controller: NVIDIA Corporation Device 0fd2 (rev ff) It seems Ubuntu can see my graphics card. I don't really know what's going on.

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  • Can One Get a Solid Programming Foundation Without Going To College/University?

    - by Daniel
    First, I have already searched the site and read all the previous "self-taught vs. college" topics. The majority of the answers defended that going to college was the best choice, for two main reasons: Going to college gives you the paper, which is essential to landing jobs, especially in tough economic times. Going to college gives you a solid programming base, teaching you the principles that will be essential regardless of the language/path you take after. Here comes my question: I am not worried about reason 1 at all, because I already have my own company (I build websites/ do affiliate marketing) and a stable financial situation, so I am pretty sure I won't need to look around for a job. I am worried about reason 2 though. That is, I want to make sure I'll have as solid a programming foundation as anyone else out there, and I am wondering if that is possible with self-learning. Suppose I take my time to study the very basics, like discrete maths, algorithm design, programming logic, computer architecture, Assembly, C programming, databases and data structures - mostly using books,online resources and lots of coding. Say I spend 1-2 years covering those basics. Do you think my foundation would be solid, or still lack in comparison to someone who went to college?

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  • How can I perform 2D side-scroller collision checks in a tile-based map?

    - by bill
    I am trying to create a game where you have a player that can move horizontally and jump. It's kind of like Mario but it isn't a side scroller. I'm using a 2D array to implement a tile map. My problem is that I don't understand how to check for collisions using this implementation. After spending about two weeks thinking about it, I've got two possible solutions, but both of them have some problems. Let's say that my map is defined by the following tiles: 0 = sky 1 = player 2 = ground The data for the map itself might look like: 00000 10002 22022 For solution 1, I'd move the player (the 1) a complete tile and update the map directly. This make the collision easy because you can check if the player is touching the ground simply by looking at the tile directly below the player: // x and y are the tile coordinates of the player. The tile origin is the upper-left. if (grid[x][y+1] == 2){ // The player is standing on top of a ground tile. } The problem with this approach is that the player moves in discrete tile steps, so the animation isn't smooth. For solution 2, I thought about moving the player via pixel coordinates and not updating the tile map. This will make the animation much smoother because I have a smaller movement unit per frame. However, this means I can't really accurately store the player in the tile map because sometimes he would logically be between two tiles. But the bigger problem here is that I think the only way to check for collision is to use Java's intersection method, which means the player would need to be at least a single pixel "into" the ground to register collision, and that won't look good. How can I solve this problem?

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  • Installing nvidia drivers causes computer to boot to command prompt.

    - by levesque
    Hi, I have an Asus u30jc laptop, which comes with the Optimus prime graphics card switching technology that is now supported under 2.6.35, so I decided to give it a try. First I made sure the discrete graphics card was activated and then I installed the drivers proposed by the ubuntu software repository (nvidia-current). However, after rebooting all I got was a command prompt. My graphics card is a nvidia 310M. This is on Ubuntu 10.10 64 bits. What can I do to diagnose/identify the source of this problem? UPDATE: The messsages in my syslog tell me to check the xorg log: Oct 11 12:42:59 u30jc-test gdm-binary[1095]: WARNING: GdmDisplay: display lasted 0.053144 seconds Oct 11 12:42:59 u30jc-test gdm-simple-slave[1450]: WARNING: Unable to load file '/etc/gdm/custom.conf': No such file or directory Oct 11 12:42:59 u30jc-test gdm-binary[1095]: WARNING: GdmDisplay: display lasted 0.038176 seconds Oct 11 12:42:59 u30jc-test gdm-binary[1095]: WARNING: GdmLocalDisplayFactory: maximum number of X display failures reached: check X server log for errors Which I did. I found this message in my /var/log/Xorg.0.log : Fatal server error: [ 113.540] no screens found [ 113.540] What does that mean?

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  • CUDA & MSI GT60 with Optimus enabled GTX670M?

    - by user1076693
    I have a MSI GT60 Laptop with an Optimus enabled GTX 670M GPU, and I have been trying to get CUDA going in Ubuntu 12.04 environment. I realize that Optimus is not supported in Linux, but I have read the following post suggesting that CUDA works for hybrid GPUs. How can I get nVidia CUDA or OpenCL working on a laptop with nVidia discrete card/Intel Integrated Graphics? I installed the NVIDIA driver via sudo add-apt-repository ppa:ubuntu-x-swat/x-updates sudo apt-get update sudo apt-get install nvidia-current The resulting driver version is 302.17, and supposedly GTX 670M is supported since 295.59. I also downloaded CUDA 4.2 from the NVIDIA site, and compiled it against nvidia-current libraries. Unfortunately, when I run deviceQuery in the CUDA SDK, I get the following output cudaGetDeviceCount returned 38 -> no CUDA-capable device is detected Checking /proc/driver/nvidia/gpus/0/information gives the following Model: GeForce GTX 670M IRQ: 16 GPU UUID: GPU-????????-????-????-????-???????????? Video BIOS: ??.??.??.??.?? Bus Type: PCI-E DMA Size: 32 bits DMA Mask: 0xffffffffff Bus Location: 0000:01.00.0 Here is the output of "lspci | grep VGA" 00:02.0 VGA compatible controller: Intel Corporation Ivy Bridge Graphics Controller (rev 09) 01:00.0 VGA compatible controller: NVIDIA Corporation Device 1213 (rev ff) So... what am I doing wrong? Thanks!

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  • Pathfinding with MicroPather : costs calculations with sectors and portals

    - by Adan
    Hello, I'm considering using micropather to help me with pathfinding. I'm not using a discrete map : I'm working in 2d with sectors and portales. However, I'm just wondering what is the best way to compute costs with this library in this context. Just to be more clear about geometrical shapes I'm using : sectors are basically convex polygons, and portals are segments that lies on sector's edge. Micropather exposes a pure virtual Graph class that you must inherate and overrides 3 functions. I understand how pathfinding works, so there's no problem in overriding those functions. Right now, my implementation give me results, i.e I'm able to find a path in my map, but I'm not sure I'm using an optimal solution. For the AdjacentCost method : I just take the distance between sector's centers as the cost. I think a better solution should be to use the portal between the two sectors, compute its center, and then the cost should be : distance( sector A center, portal center ) + distance ( sector B center, portal center ). I'm pretty sure the approximation I'm using with just sector's center is enough for most cases, but maybe with thin and long sectors that are perpendicular, this approximation could mislead the A* algorithm. For the LeastCostEstimate method : I just take the midpoint of the two sectors. So, as you understand, I'm always working with sectors' centers, and it's working fine. And I'm pretty sure there's a better way to work. Any suggestions or feedbacks? Thanks in advance!

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  • Naming a class that processes orders

    - by p.campbell
    I'm in the midst of refactoring a project. I've recently read Clean Code, and want to heed some of the advice within, with particular interest in Single Responsibility Principle (SRP). Currently, there's a class called OrderProcessor in the context of a manufacturing product order system. This class is currently performs the following routine every n minutes: check database for newly submitted + unprocessed orders (via a Data Layer class already, phew!) gather all the details of the orders mark them as in-process iterate through each to: perform some integrity checking call a web service on a 3rd party system to place the order check status return value of the web service for success/fail email somebody if web service returns fail constantly log to a text file on each operation or possible fail point I've started by breaking out this class into new classes like: OrderService - poor name. This is the one that wakes up every n minutes OrderGatherer - calls the DL to get the order from the database OrderIterator (? seems too forced or poorly named) - OrderPlacer - calls web service to place the order EmailSender Logger I'm struggling to find good names for each class, and implementing SRP in a reasonable way. How could this class be separated into new class with discrete responsibilities?

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  • OpenJDK In The News: AMD and Oracle to Collaborate in the OpenJDK Community [..]

    - by $utils.escapeXML($entry.author)
    During the JavaOne™ 2012 Strategy Keynote, AMD (NYSE: AMD) announced its participation in OpenJDK™ Project “Sumatra” in collaboration with Oracle and other members of the OpenJDK community to help bring heterogeneous computing capabilities to Java™ for server and cloud environments. The OpenJDK Project “Sumatra” will explore how the Java Virtual Machine (JVM), as well as the Java language and APIs, might be enhanced to allow applications to take advantage of graphics processing unit (GPU) acceleration, either in discrete graphics cards or in high-performance graphics processor cores such as those found in AMD accelerated processing units (APUs).“Affirming our plans to contribute to the OpenJDK Project represents the next step towards bringing heterogeneous computing to millions of Java developers and can potentially lead to future developments of new hardware models, as well as server and cloud programming paradigms,” said Manju Hegde, corporate vice president, Heterogeneous Applications and Developer Solutions at AMD. “AMD has an established track record of collaboration with open-software development communities from OpenCL™ to the Heterogeneous System Architecture (HSA) Foundation, and with this initiative we will help further the development of graphics acceleration within the Java community.”“We expect our work with AMD and other OpenJDK participants in Project “Sumatra” will eventually help provide Java developers with the ability to quickly leverage GPU acceleration for better performance,” said Georges Saab, vice president, Software Development, Java Platform Group at Oracle. "We hope individuals and other organizations interested in this exciting development will follow AMD's lead by joining us in Project “Sumatra."Quotes taken from the first press release from AMD mentioning OpenJDK, titled "AMD and Oracle to Collaborate in the OpenJDK Community to Explore Heterogeneous Computing for Java ".

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  • No MAU required on a T4

    - by jsavit
    Cryptic background One of the powerful features of the T-series servers is its hardware crypto acceleration, which dramatically speeds up the compute intensive algorithms needed to encrypt and decrypt data. Previously, administrators setting up logical domains on older T-series servers had to explicitly assign crypto resources (called "MAU" for historical reasons from the T1 chip that had "modular arithmetic units") to domains that had a significant crypto workload (say, an SSL based web server). This could be an administrative burden, as you had to choose which domains got the crypto units, and issue the appropriate ldm set-mau N mydomain commands. The T4 changes things The T4 is fast. Really fast. Its clock rate and out-of-order (OOO) execution that provides the single-thread performance that T-series machines previously did not have. If you have any preconceptions about T-series performance, or SPARC in general, based on the older servers (which, it must be said, were absolutely outstanding for multi-threaded applications), those assumptions are now obsolete. The T4 provides outstanding. performance for all kinds of workload, as illustrated at https://blogs.oracle.com/bestperf. While we all focused on this (did I mention the T4 is fast?), another feature of the T4 went largely unnoticed: The T4 servers have crypto acceleration "just built in" so administrators no longer have to assign crypto accelerator units to domains - it "just happens". This is way way better since you have crypto everywhere by default without having to manage it like a discrete and limited resource. It's a feature of the processor, like doing an integer add. With T4, there is no management necessary, you just have HW crypto everywhere all the time seamlessly. This change hasn't been widely advertised, and some administrators have wondered why there were unable to assign a MAU to a domain as they did with T2 and T3 machines. The answer is that there is no longer any separate MAU, so you don't have to take any action at all - just leave the default of 0. Summary Besides being much faster than its predecessors, the T4 also integrates hardware crypto acceleration so its seamlessly available to applications, whether domains are being used or not. Administrators no longer have to control how they are allocated - it "just happens"

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  • How do I simplify a 2D game grid for level management while keeping its by-pixel features?

    - by Eric Thoma
    (I cross-posted this from StackOverflow as this seems to be a more appropriate forum. I've looked around a little here and I did not find an answer, so I hope this is not a recurring question.) This is a question dealing with 2D world design. I am playing around by creating a 2D bird's eye view shooter game, and I am looking to make the game sleek and advanced. I hope to be able to write physics so projectiles have momentum and knock-down properties. I am immediately running into the problem of world design. I need a way to have level files that store everything there is about a game. This is easiest by just having a grid of objects. But there are thin-walls and other objects that don't seem to fit into a traditional cell of a grid. I want to be able to fit all these together so I can streamline level design; so I don't have to put in the exact pixel-specific start and end of a wall. There doesn't seem to be an obvious translation from level file to game without forcing myself into a pacman-life scenario, meaning a scenario where the game feels boxy and discrete. There is a contrast between the smoothly (relatively) moving characters and finite jumps in a grid. I would appreciate an answer that would describe implementation options or point me to resources that do. I would also appreciate references to sites that teach game design. The language I am using is Java (although I would love to use C or C++, but I can never find convenient resources in those languages). Thank you for any answers. Please leave any questions in the space below; I will be able to answer them later tonight (28th Nov).

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  • Impossible quandrary involving UCK, graphics card, and Nvidia drivers

    - by InkBlend
    I have a computer that I want to install Ubuntu on. It is an older gaming computer with a Nvidia graphics card. When I attempt to boot any unmodified Linux distribution onto it, I get a "Boot error" message, which I assume is because the computer uses a discrete graphics card, which the Linux kernel does not have support for. Ordinarily, that would not be a problem, as I would just plug the monitor into the VGA port built in to the motherboard. However, this particular model of motherboard does not have an on-board graphics connector, so I am stuck with using the graphics card connection. That further would not be a problem; all I would have to do would be to use UCK to create a customized Ubuntu image that included the graphics drivers. Except for the fact that the Nvidia Linux drivers must be installed on a computer with a Nvidia graphics card present. So while using UCK, the driver installer fails with a message stating that there is no Nvidia graphics card present. How do I get Ubuntu on my desktop computer?

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  • Cheap ways to do scaling ops in shader?

    - by Nick Wiggill
    I've got an extensive world terrain that uses vec3 for the vertex position attribute. That's good, because the terrain has endless gradations due to the use of floating point. But I'm thinking about how to reduce the amount of data uploaded to the GPU. For my terrain, which uses discrete / grid-based vertex positions in x and z, it's pretty clear that I can replace my vec3s (floats, really) with shorts, halving the per-vertex position attribute cost from 12 bytes each to 6 bytes. Considering I've got little enough other vertex data, and an enormous amount of terrain data to push into the world, it's a major gain. Currently in my code, one unit in GLSL shaders is equal to 1m in the world. I like that scale. If I move over to using shorts, though, I won't be able to use the same scale, as I would then have a very blocky world where every step in height is an entire metre. So I see these potential solutions to scale the positional data correctly once it arrives at the vertex shader stage: Use 10:1 scaling, i.e. 1 short unit = 1 decimetre in CPU-side code. Do a division by 10 in the vertex shader to scale incoming decimetre values back to metres. Arbirary (non-PoT) divisions tend to be slow, however. Use (some-power-of-two):1 scaling (eg. 8:1), which enables the use of a bitshift (eg. val >> 3) to do the division... not sure how performant this is in shaders, though. Not as intuitive to read values, but possibly quite a bit faster than div by a non-PoT value. Use a texture as lookup table. I've heard that this is really fast. Or whatever solutions others can offer to achieve the same results -- minimal vertex data with sensible scaling.

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  • How to get Nvidia 555M working on Ubuntu 12.10 (drivers, optimus, cuda)?

    - by bluudz
    I'm trying for few days to get my GPU working properly on Alienware M14x with GPU NVidia 555M, but I have no luck at all. After fresh ubuntu install I did follow the guide here NVIDIA Optimus and Ubuntu 12.10 and istalled Bumblebee without problems. Tested glxspheres/optirun glxspheres both working fine. Now I was continuing to install CUDA as is said here How can I get nVidia CUDA or OpenCL working on a laptop with nVidia discrete card/Intel Integrated Graphics? but I'm getting: Driver: Not Selected Toolkit: Installation Failed. Using unsupported Compiler. Samples: Installation Failed. Missing required libraries. I did not select the driver as I though Bumblebee installed driver already. How should I proceed? And also at what point is the NVidia driver being installed and how can I try its working? Bumblebee seems to be installing the driver, CUDA wants to do the same, its all a bit confusing really. Sorry if its lame question, but I would really want to at least get graphic card and second screen working.. Thank you for any help.

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  • Will I be able to get programming interviews at good software companies with a non-CS degree?

    - by friend
    I'll be graduating in a year, but I'll have a degree in Economics. I'm pretty much done with my Economics coursework, and by the time next year comes around I will have devoted 1.5 years to learning CS. I will have almost finished the requirements to graduate with a degree in CS, but unfortunately my school requires a science series that would add another 6-9 months of study if I were to try and get the degree (not to mention a max unit cap). I have or will have taken: Objected Oriented Programming Discrete Math Data structures Calculus through multivariable (doubt this matters at all) Linear Algebra (same) Computer Organization Operating Systems Computational Statistics (many data mining projects in R) Parallel Programming Programming Languages Databases Algorithms Compilers Artificial Intelligence I've done well in the ones I've taken, and I hope to do well in the rest, but will that matter if I can't say to the HR people that I have a CS degree? I'd be happy to get an internship at first too, so should I just apply as if I'm an intern and not looking for fulltime, and then try and parlay that into something? Sidenote if you have time -- Is a computer networks or theory of computation class important? Would it be worth taking either of those in lieu of a class on my list? edit -- I know this isn't AskReddit or College Confidential; I know there will be some outrage at posting a question like this. I'm merely looking for insight into a situation that I've been struggling with, and I think this is the absolute best place to find an answer to this question. Thanks.

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  • Garage Sale Code &ndash; Everything must go!

    - by mbcrump
    Garage Sale Code     The term “Garage Sale Code” came from a post by Scott Hanselman. He defines Garage Sale Code as: Complete – It’s a whole library or application. Concise – It does one discrete thing. Clear – It’ll work when you get it. Cheap – It’s free or < 25 cents. (Quite Possibly) Crap – As with a Garage Sale, you’ll never know until you get it home if it’s useless. With the code I’ve posted here, you’ll get all 5 of those things (with an emphasis on crap). All of the projects listed below are available on CodePlex with full source code and executables (for those that just want to run it).  I plan on keeping this page updated when I complete projects that benefit the community.  You can always find this page again by swinging by http://garagesale.michaelcrump.net or you can keep on driving and find another sale. Name Description Language/Technology Used WPF Alphabet WPF Alphabet is a application that I created to help my child learn the alphabet. It displays each letter and pronounces it using speech synthesis. It was developed using WPF and c# in about 3 hours (so its kinda rough). C#, WPF Windows 7 Playlist Generator This program allows you to quickly create wvx video playlist for Windows Media Center. This functionality is not included in WMC and is useful if you want to play video files back to back without selecting the next file. It is also useful to queue up video files to keep children occupied! C#, WinForms Windows 7 Automatic Playlist Creator This application is designed to create W7MC playlist automatically whenever you want. You can select if you want the playlist sorted Alphabetical, by Creation Date or Random. C#, WinForms, Console Generator Twitter Message for Live Writer This is a plug-in for Windows Live Writer that generates a twitter message with your blog post name and a TinyUrl link to the blog post. It will do all of this automatically after you publish your post. C#, LiveWriter API

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  • OIM 11g notification framework

    - by Rajesh G Kumar
    OIM 11g has introduced an improved and template based Notifications framework. New release has removed the limitation of sending text based emails (out-of-the-box emails) and enhanced to support html features. New release provides in-built out-of-the-box templates for events like 'Reset Password', 'Create User Self Service' , ‘User Deleted' etc. Also provides new APIs to support custom templates to send notifications out of OIM. OIM notification framework supports notification mechanism based on events, notification templates and template resolver. They are defined as follows: Ø Events are defined as XML file and imported as part of MDS database in order to make notification event available for use. Ø Notification templates are created using OIM advance administration console. The template contains the text and the substitution 'variables' which will be replaced with the data provided by the template resolver. Templates support internationalization and can be defined as HTML or in form of simple text. Ø Template resolver is a Java class that is responsible to provide attributes and data to be used at runtime and design time. It must be deployed following the OIM plug-in framework. Resolver data provided at design time is to be used by end user to design notification template with available entity variables and it also provides data at runtime to replace the designed variable with value to be displayed to recipients. Steps to define custom notifications in OIM 11g are: Steps# Steps 1. Define the Notification Event 2. Create the Custom Template Resolver class 3. Create Template with notification contents to be sent to recipients 4. Create Event triggering spots in OIM 1. Notification Event metadata The Notification Event is defined as XML file which need to be imported into MDS database. An event file must be compliant with the schema defined by the notification engine, which is NotificationEvent.xsd. The event file contains basic information about the event.XSD location in MDS database: “/metadata/iam-features-notification/NotificationEvent.xsd”Schema file can be viewed by exporting file from MDS using weblogicExportMetadata.sh script.Sample Notification event metadata definition: 1: <?xml version="1.0" encoding="UTF-8"?> 2: <Events xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xsi:noNamespaceSchemaLocation="../../../metadata/NotificationEvent.xsd"> 3: <EventType name="Sample Notification"> 4: <StaticData> 5: <Attribute DataType="X2-Entity" EntityName="User" Name="Granted User"/> 6: </StaticData> 7: <Resolver class="com.iam.oim.demo.notification.DemoNotificationResolver"> 8: <Param DataType="91-Entity" EntityName="Resource" Name="ResourceInfo"/> 9: </Resolver> 10: </EventType> 11: </Events> Line# Description 1. XML file notation tag 2. Events is root tag 3. EventType tag is to declare a unique event name which will be available for template designing 4. The StaticData element lists a set of parameters which allow user to add parameters that are not data dependent. In other words, this element defines the static data to be displayed when notification is to be configured. An example of static data is the User entity, which is not dependent on any other data and has the same set of attributes for all event instances and notification templates. Available attributes are used to be defined as substitution tokens in the template. 5. Attribute tag is child tag for StaticData to declare the entity and its data type with unique reference name. User entity is most commonly used Entity as StaticData. 6. StaticData closing tag 7. Resolver tag defines the resolver class. The Resolver class must be defined for each notification. It defines what parameters are available in the notification creation screen and how those parameters are replaced when the notification is to be sent. Resolver class resolves the data dynamically at run time and displays the attributes in the UI. 8. The Param DataType element lists a set of parameters which allow user to add parameters that are data dependent. An example of the data dependent or a dynamic entity is a resource object which user can select at run time. A notification template is to be configured for the resource object. Corresponding to the resource object field, a lookup is displayed on the UI. When a user selects the event the call goes to the Resolver class provided to fetch the fields that are displayed in the Available Data list, from which user can select the attribute to be used on the template. Param tag is child tag to declare the entity and its data type with unique reference name. 9. Resolver closing tag 10 EventType closing tag 11. Events closing tag Note: - DataType needs to be declared as “X2-Entity” for User entity and “91-Entity” for Resource or Organization entities. The dynamic entities supported for lookup are user, resource, and organization. Once notification event metadata is defined, need to be imported into MDS database. Fully qualified resolver class name need to be define for XML but do not need to load the class in OIM yet (it can be loaded later). 2. Coding the notification resolver All event owners have to provide a resolver class which would resolve the data dynamically at run time. Custom resolver class must implement the interface oracle.iam.notification.impl.NotificationEventResolver and override the implemented methods with actual implementation. It has 2 methods: S# Methods Descriptions 1. public List<NotificationAttribute> getAvailableData(String eventType, Map<String, Object> params); This API will return the list of available data variables. These variables will be available on the UI while creating/modifying the Templates and would let user select the variables so that they can be embedded as a token as part of the Messages on the template. These tokens are replaced by the value passed by the resolver class at run time. Available data is displayed in a list. The parameter "eventType" specifies the event Name for which template is to be read.The parameter "params" is the map which has the entity name and the corresponding value for which available data is to be fetched. Sample code snippet: List<NotificationAttribute> list = new ArrayList<NotificationAttribute>(); long objKey = (Long) params.get("resource"); //Form Field details based on Resource object key HashMap<String, Object> formFieldDetail = getObjectFormName(objKey); for (Iterator<?> itrd = formFieldDetail.entrySet().iterator(); itrd.hasNext(); ) { NotificationAttribute availableData = new NotificationAttribute(); Map.Entry formDetailEntrySet = (Entry<?, ?>)itrd.next(); String fieldLabel = (String)formDetailEntrySet.getValue(); availableData.setName(fieldLabel); list.add(availableData); } return list; 2. Public HashMap<String, Object> getReplacedData(String eventType, Map<String, Object> params); This API would return the resolved value of the variables present on the template at the runtime when notification is being sent. The parameter "eventType" specifies the event Name for which template is to be read.The parameter "params" is the map which has the base values such as usr_key, obj_key etc required by the resolver implementation to resolve the rest of the variables in the template. Sample code snippet: HashMap<String, Object> resolvedData = new HashMap<String, Object>();String firstName = getUserFirstname(params.get("usr_key"));resolvedData.put("fname", firstName); String lastName = getUserLastName(params.get("usr_key"));resolvedData.put("lname", lastname);resolvedData.put("count", "1 million");return resolvedData; This code must be deployed as per OIM 11g plug-in framework. The XML file defining the plug-in is as below: <?xml version="1.0" encoding="UTF-8"?> <oimplugins xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <plugins pluginpoint="oracle.iam.notification.impl.NotificationEventResolver"> <plugin pluginclass= " com.iam.oim.demo.notification.DemoNotificationResolver" version="1.0" name="Sample Notification Resolver"/> </plugins> </oimplugins> 3. Defining the template To create a notification template: Log in to the Oracle Identity Administration Click the System Management tab and then click the Notification tab From the Actions list on the left pane, select Create On the Create page, enter values for the following fields under the Template Information section: Template Name: Demo template Description Text: Demo template Under the Event Details section, perform the following: From the Available Event list, select the event for which the notification template is to be created from a list of available events. Depending on your selection, other fields are displayed in the Event Details section. Note that the template Sample Notification Event created in the previous step being used as the notification event. The contents of the Available Data drop down are based on the event XML StaticData tag, the drop down basically lists all the attributes of the entities defined in that tag. Once you select an element in the drop down, it will show up in the Selected Data text field and then you can just copy it and paste it into either the message subject or the message body fields prefixing $ symbol. Example if list has attribute like First_Name then message body will contains this as $First_Name which resolver will parse and replace it with actual value at runtime. In the Resource field, select a resource from the lookup. This is the dynamic data defined by the Param DataType element in the XML definition. Based on selected resource getAvailableData method of resolver will be called to fetch the resource object attribute detail, if method is overridden with required implementation. For current scenario, Map<String, Object> params will get populated with object key as value and key as “resource” in the map. This is the only input will be provided to resolver at design time. You need to implement the further logic to fetch the object attributes detail to populate the available Data list. List string should not have space in between, if object attributes has space for attribute name then implement logic to replace the space with ‘_’ before populating the list. Example if attribute name is “First Name” then make it “First_Name” and populate the list. Space is not supported while you try to parse and replace the token at run time with real value. Make a note that the Available Data and Selected Data are used in the substitution tokens definition only, they do not define the final data that will be sent in the notification. OIM will invoke the resolver class to get the data and make the substitutions. Under the Locale Information section, enter values in the following fields: To specify a form of encoding, select either UTF-8 or ASCII. In the Message Subject field, enter a subject for the notification. From the Type options, select the data type in which you want to send the message. You can choose between HTML and Text/Plain. In the Short Message field, enter a gist of the message in very few words. In the Long Message field, enter the message that will be sent as the notification with Available data token which need to be replaced by resolver at runtime. After you have entered the required values in all the fields, click Save. A message is displayed confirming the creation of the notification template. Click OK 4. Triggering the event A notification event can be triggered from different places in OIM. The logic behind the triggering must be coded and plugged into OIM. Examples of triggering points for notifications: Event handlers: post process notifications for specific data updates in OIM users Process tasks: to notify the users that a provisioning task was executed by OIM Scheduled tasks: to notify something related to the task The scheduled job has two parameters: Template Name: defines the notification template to be sent User Login: defines the user record that will provide the data to be sent in the notification Sample Code Snippet: public void execute(String templateName , String userId) { try { NotificationService notService = Platform.getService(NotificationService.class); NotificationEvent eventToSend=this.createNotificationEvent(templateName,userId); notService.notify(eventToSend); } catch (Exception e) { e.printStackTrace(); } } private NotificationEvent createNotificationEvent(String poTemplateName, String poUserId) { NotificationEvent event = new NotificationEvent(); String[] receiverUserIds= { poUserId }; event.setUserIds(receiverUserIds); event.setTemplateName(poTemplateName); event.setSender(null); HashMap<String, Object> templateParams = new HashMap<String, Object>(); templateParams.put("USER_LOGIN",poUserId); event.setParams(templateParams); return event; } public HashMap getAttributes() { return null; } public void setAttributes() {} }

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  • Simplex Noise Help

    - by Alex Larsen
    Im Making A Minecraft Like Gae In XNA C# And I Need To Generate Land With Caves This Is The Code For Simplex I Have /// <summary> /// 1D simplex noise /// </summary> /// <param name="x"></param> /// <returns></returns> public static float Generate(float x) { int i0 = FastFloor(x); int i1 = i0 + 1; float x0 = x - i0; float x1 = x0 - 1.0f; float n0, n1; float t0 = 1.0f - x0 * x0; t0 *= t0; n0 = t0 * t0 * grad(perm[i0 & 0xff], x0); float t1 = 1.0f - x1 * x1; t1 *= t1; n1 = t1 * t1 * grad(perm[i1 & 0xff], x1); // The maximum value of this noise is 8*(3/4)^4 = 2.53125 // A factor of 0.395 scales to fit exactly within [-1,1] return 0.395f * (n0 + n1); } /// <summary> /// 2D simplex noise /// </summary> /// <param name="x"></param> /// <param name="y"></param> /// <returns></returns> public static float Generate(float x, float y) { const float F2 = 0.366025403f; // F2 = 0.5*(sqrt(3.0)-1.0) const float G2 = 0.211324865f; // G2 = (3.0-Math.sqrt(3.0))/6.0 float n0, n1, n2; // Noise contributions from the three corners // Skew the input space to determine which simplex cell we're in float s = (x + y) * F2; // Hairy factor for 2D float xs = x + s; float ys = y + s; int i = FastFloor(xs); int j = FastFloor(ys); float t = (float)(i + j) * G2; float X0 = i - t; // Unskew the cell origin back to (x,y) space float Y0 = j - t; float x0 = x - X0; // The x,y distances from the cell origin float y0 = y - Y0; // For the 2D case, the simplex shape is an equilateral triangle. // Determine which simplex we are in. int i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords if (x0 > y0) { i1 = 1; j1 = 0; } // lower triangle, XY order: (0,0)->(1,0)->(1,1) else { i1 = 0; j1 = 1; } // upper triangle, YX order: (0,0)->(0,1)->(1,1) // A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and // a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where // c = (3-sqrt(3))/6 float x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords float y1 = y0 - j1 + G2; float x2 = x0 - 1.0f + 2.0f * G2; // Offsets for last corner in (x,y) unskewed coords float y2 = y0 - 1.0f + 2.0f * G2; // Wrap the integer indices at 256, to avoid indexing perm[] out of bounds int ii = i % 256; int jj = j % 256; // Calculate the contribution from the three corners float t0 = 0.5f - x0 * x0 - y0 * y0; if (t0 < 0.0f) n0 = 0.0f; else { t0 *= t0; n0 = t0 * t0 * grad(perm[ii + perm[jj]], x0, y0); } float t1 = 0.5f - x1 * x1 - y1 * y1; if (t1 < 0.0f) n1 = 0.0f; else { t1 *= t1; n1 = t1 * t1 * grad(perm[ii + i1 + perm[jj + j1]], x1, y1); } float t2 = 0.5f - x2 * x2 - y2 * y2; if (t2 < 0.0f) n2 = 0.0f; else { t2 *= t2; n2 = t2 * t2 * grad(perm[ii + 1 + perm[jj + 1]], x2, y2); } // Add contributions from each corner to get the final noise value. // The result is scaled to return values in the interval [-1,1]. return 40.0f * (n0 + n1 + n2); // TODO: The scale factor is preliminary! } public static float Generate(float x, float y, float z) { // Simple skewing factors for the 3D case const float F3 = 0.333333333f; const float G3 = 0.166666667f; float n0, n1, n2, n3; // Noise contributions from the four corners // Skew the input space to determine which simplex cell we're in float s = (x + y + z) * F3; // Very nice and simple skew factor for 3D float xs = x + s; float ys = y + s; float zs = z + s; int i = FastFloor(xs); int j = FastFloor(ys); int k = FastFloor(zs); float t = (float)(i + j + k) * G3; float X0 = i - t; // Unskew the cell origin back to (x,y,z) space float Y0 = j - t; float Z0 = k - t; float x0 = x - X0; // The x,y,z distances from the cell origin float y0 = y - Y0; float z0 = z - Z0; // For the 3D case, the simplex shape is a slightly irregular tetrahedron. // Determine which simplex we are in. int i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords int i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords /* This code would benefit from a backport from the GLSL version! */ if (x0 >= y0) { if (y0 >= z0) { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // X Y Z order else if (x0 >= z0) { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 0; k2 = 1; } // X Z Y order else { i1 = 0; j1 = 0; k1 = 1; i2 = 1; j2 = 0; k2 = 1; } // Z X Y order } else { // x0<y0 if (y0 < z0) { i1 = 0; j1 = 0; k1 = 1; i2 = 0; j2 = 1; k2 = 1; } // Z Y X order else if (x0 < z0) { i1 = 0; j1 = 1; k1 = 0; i2 = 0; j2 = 1; k2 = 1; } // Y Z X order else { i1 = 0; j1 = 1; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // Y X Z order } // A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z), // a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and // a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where // c = 1/6. float x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords float y1 = y0 - j1 + G3; float z1 = z0 - k1 + G3; float x2 = x0 - i2 + 2.0f * G3; // Offsets for third corner in (x,y,z) coords float y2 = y0 - j2 + 2.0f * G3; float z2 = z0 - k2 + 2.0f * G3; float x3 = x0 - 1.0f + 3.0f * G3; // Offsets for last corner in (x,y,z) coords float y3 = y0 - 1.0f + 3.0f * G3; float z3 = z0 - 1.0f + 3.0f * G3; // Wrap the integer indices at 256, to avoid indexing perm[] out of bounds int ii = i % 256; int jj = j % 256; int kk = k % 256; // Calculate the contribution from the four corners float t0 = 0.6f - x0 * x0 - y0 * y0 - z0 * z0; if (t0 < 0.0f) n0 = 0.0f; else { t0 *= t0; n0 = t0 * t0 * grad(perm[ii + perm[jj + perm[kk]]], x0, y0, z0); } float t1 = 0.6f - x1 * x1 - y1 * y1 - z1 * z1; if (t1 < 0.0f) n1 = 0.0f; else { t1 *= t1; n1 = t1 * t1 * grad(perm[ii + i1 + perm[jj + j1 + perm[kk + k1]]], x1, y1, z1); } float t2 = 0.6f - x2 * x2 - y2 * y2 - z2 * z2; if (t2 < 0.0f) n2 = 0.0f; else { t2 *= t2; n2 = t2 * t2 * grad(perm[ii + i2 + perm[jj + j2 + perm[kk + k2]]], x2, y2, z2); } float t3 = 0.6f - x3 * x3 - y3 * y3 - z3 * z3; if (t3 < 0.0f) n3 = 0.0f; else { t3 *= t3; n3 = t3 * t3 * grad(perm[ii + 1 + perm[jj + 1 + perm[kk + 1]]], x3, y3, z3); } // Add contributions from each corner to get the final noise value. // The result is scaled to stay just inside [-1,1] return 32.0f * (n0 + n1 + n2 + n3); // TODO: The scale factor is preliminary! } private static byte[] perm = new byte[512] { 151,160,137,91,90,15, 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180, 151,160,137,91,90,15, 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180 }; private static int FastFloor(float x) { return (x > 0) ? ((int)x) : (((int)x) - 1); } private static float grad(int hash, float x) { int h = hash & 15; float grad = 1.0f + (h & 7); // Gradient value 1.0, 2.0, ..., 8.0 if ((h & 8) != 0) grad = -grad; // Set a random sign for the gradient return (grad * x); // Multiply the gradient with the distance } private static float grad(int hash, float x, float y) { int h = hash & 7; // Convert low 3 bits of hash code float u = h < 4 ? x : y; // into 8 simple gradient directions, float v = h < 4 ? y : x; // and compute the dot product with (x,y). return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -2.0f * v : 2.0f * v); } private static float grad(int hash, float x, float y, float z) { int h = hash & 15; // Convert low 4 bits of hash code into 12 simple float u = h < 8 ? x : y; // gradient directions, and compute dot product. float v = h < 4 ? y : h == 12 || h == 14 ? x : z; // Fix repeats at h = 12 to 15 return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -v : v); } private static float grad(int hash, float x, float y, float z, float t) { int h = hash & 31; // Convert low 5 bits of hash code into 32 simple float u = h < 24 ? x : y; // gradient directions, and compute dot product. float v = h < 16 ? y : z; float w = h < 8 ? z : t; return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -v : v) + ((h & 4) != 0 ? -w : w); } This Is My World Generation Code Block[,] BlocksInMap = new Block[1024, 256]; public bool IsWorldGenerated = false; Random r = new Random(); private void RunThread() { for (int BH = 0; BH <= 256; BH++) { for (int BW = 0; BW <= 1024; BW++) { Block b = new Block(); if (BH >= 192) { } BlocksInMap[BW, BH] = b; } } IsWorldGenerated = true; } public void GenWorld() { new Thread(new ThreadStart(RunThread)).Start(); } And This Is A Example Of How I Set Blocks Block b = new Block(); b.BlockType = = Block.BlockTypes.Air; This Is A Example Of How I Set Models foreach (Block b in MyWorld) { switch(b.BlockType) { case Block.BlockTypes.Dirt: b.Model = DirtModel; break; ect. } } How Would I Use These To Generate To World (The Block Array) And If Possible Thread It More? btw It's 1024 Wide And 256 Tall

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  • XNA 3D model collision is inaccurate

    - by Daniel Lopez
    I am creating a classic game in 3d that deals with asteriods and you have to shoot them and avoid being hit from them. I can generate the asteroids just fine and the ship can shoot bullets just fine. But the asteroids always hit the ship even it doesn't look they are even close. I know 2D collision very well but not 3D so can someone please shed some light to my problem. Thanks in advance. Code For ModelRenderer: using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace _3D_Asteroids { class ModelRenderer { private float aspectratio; private Model model; private Vector3 camerapos; private Vector3 modelpos; private Matrix rotationy; float radiansy = 0; private bool isalive; public ModelRenderer(Model m, float AspectRatio, Vector3 initial_pos, Vector3 initialcamerapos) { isalive = true; model = m; if (model.Meshes.Count == 0) { throw new Exception("Invalid model because it contains zero meshes!"); } modelpos = initial_pos; camerapos = initialcamerapos; aspectratio = AspectRatio; return; } public float RadiusOfSphere { get { return model.Meshes[0].BoundingSphere.Radius; } } public BoundingBox BoxBounds { get { return BoundingBox.CreateFromSphere(model.Meshes[0].BoundingSphere); } } public BoundingSphere SphereBounds { get { return model.Meshes[0].BoundingSphere; } } public Vector3 CameraPosition { set { camerapos = value; } get { return camerapos; } } public bool IsAlive { get { return isalive; } } public Vector3 ModelPosition { set { modelpos = value; } get { return modelpos; } } public void RotateY(float radians) { radiansy += radians; rotationy = Matrix.CreateRotationY(radiansy); } public Matrix RotationY { set { rotationy = value; } get { return rotationy; } } public float AspectRatio { set { aspectratio = value; } get { return aspectratio; } } public void Kill() { isalive = false; } public void Draw(float scale) { Matrix world; if (rotationy == new Matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)) { world = Matrix.CreateScale(scale) * Matrix.CreateTranslation(modelpos); } else { world = rotationy * Matrix.CreateScale(scale) * Matrix.CreateTranslation(modelpos); } Matrix view = Matrix.CreateLookAt(camerapos, Vector3.Zero, Vector3.Up); Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f), this.AspectRatio, 1f, 100000f); foreach (ModelMesh mesh in model.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.World = world; effect.View = view; effect.Projection = projection; } mesh.Draw(); } } public void Draw() { Matrix world; if (rotationy == new Matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)) { world = Matrix.CreateTranslation(modelpos); } else { world = rotationy * Matrix.CreateTranslation(modelpos); } Matrix view = Matrix.CreateLookAt(camerapos, Vector3.Zero, Vector3.Up); Matrix projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f), this.AspectRatio, 1f, 100000f); foreach (ModelMesh mesh in model.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.World = world; effect.View = view; effect.Projection = projection; } mesh.Draw(); } } } Code For Game1: using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; namespace _3D_Asteroids { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; int score = 0, lives = 5; SpriteBatch spriteBatch; GameState gstate = GameState.OnMenuScreen; Menu menu = new Menu(Color.Yellow, Color.White); SpriteFont font; Texture2D background; ModelRenderer ship; Model b, a; List<ModelRenderer> bullets = new List<ModelRenderer>(); List<ModelRenderer> asteriods = new List<ModelRenderer>(); float time = 0.0f; int framecount = 0; SoundEffect effect; public Game1() { graphics = new GraphicsDeviceManager(this); graphics.PreferredBackBufferWidth = 1280; graphics.PreferredBackBufferHeight = 796; graphics.ApplyChanges(); Content.RootDirectory = "Content"; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here base.Initialize(); } /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); font = Content.Load<SpriteFont>("Fonts\\Lucida Console"); background = Content.Load<Texture2D>("Textures\\B1_stars"); Model p1 = Content.Load<Model>("Models\\p1_wedge"); b = Content.Load<Model>("Models\\pea_proj"); a = Content.Load<Model>("Models\\asteroid1"); effect = Content.Load<SoundEffect>("Audio\\tx0_fire1"); ship = new ModelRenderer(p1, GraphicsDevice.Viewport.AspectRatio, new Vector3(0, 0, 0), new Vector3(0, 0, 9000)); } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { KeyboardState state = Keyboard.GetState(PlayerIndex.One); switch (gstate) { case GameState.OnMenuScreen: { if (state.IsKeyDown(Keys.Enter)) { switch (menu.SelectedChoice) { case MenuChoices.Play: { gstate = GameState.GameStarted; break; } case MenuChoices.Exit: { this.Exit(); break; } } } if (state.IsKeyDown(Keys.Down)) { menu.MoveSelectedMenuChoiceDown(gameTime); } else if(state.IsKeyDown(Keys.Up)) { menu.MoveSelectedMenuChoiceUp(gameTime); } else { menu.KeysReleased(); } break; } case GameState.GameStarted: { foreach (ModelRenderer bullet in bullets) { if (bullet.ModelPosition.X < (ship.ModelPosition.X + 4000) && bullet.ModelPosition.Z < (ship.ModelPosition.X + 4000) && bullet.ModelPosition.X > (ship.ModelPosition.Z - 4000) && bullet.ModelPosition.Z > (ship.ModelPosition.Z - 4000)) { bullet.ModelPosition += (bullet.RotationY.Forward * 120); } else if (collidedwithasteriod(bullet)) { bullet.Kill(); } else { bullet.Kill(); } } foreach (ModelRenderer asteroid in asteriods) { if (ship.SphereBounds.Intersects(asteroid.BoxBounds)) { lives -= 1; asteroid.Kill(); // This always hits no matter where the ship goes. } else { asteroid.ModelPosition -= (asteroid.RotationY.Forward * 50); } } for (int index = 0; index < asteriods.Count; index++) { if (asteriods[index].IsAlive == false) { asteriods.RemoveAt(index); } } for (int index = 0; index < bullets.Count; index++) { if (bullets[index].IsAlive == false) { bullets.RemoveAt(index); } } if (state.IsKeyDown(Keys.Left)) { ship.RotateY(0.1f); if (state.IsKeyDown(Keys.Space)) { if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0; } } else if (state.IsKeyDown(Keys.Right)) { ship.RotateY(-0.1f); if (state.IsKeyDown(Keys.Space)) { if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0; } } else if (state.IsKeyDown(Keys.Up)) { ship.ModelPosition += (ship.RotationY.Forward * 50); if (state.IsKeyDown(Keys.Space)) { if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0; } } else if (state.IsKeyDown(Keys.Space)) { time += gameTime.ElapsedGameTime.Milliseconds; if (time < 17) { firebullet(); //effect.Play(); } } else { time = 0.0f; } if ((framecount % 60) == 0) { createasteroid(); framecount = 0; } framecount++; break; } } base.Update(gameTime); } void firebullet() { if (bullets.Count < 3) { ModelRenderer bullet = new ModelRenderer(b, GraphicsDevice.Viewport.AspectRatio, ship.ModelPosition, new Vector3(0, 0, 9000)); bullet.RotationY = ship.RotationY; bullets.Add(bullet); } } void createasteroid() { if (asteriods.Count < 2) { Random random = new Random(); float z = random.Next(-13000, -11000); float x = random.Next(-9000, -8000); Random random2 = new Random(); int degrees = random.Next(0, 45); float radians = MathHelper.ToRadians(degrees); ModelRenderer asteroid = new ModelRenderer(a, GraphicsDevice.Viewport.AspectRatio, new Vector3(x, 0, z), new Vector3(0,0, 9000)); asteroid.RotateY(radians); asteriods.Add(asteroid); } } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); switch (gstate) { case GameState.OnMenuScreen: { spriteBatch.Begin(); spriteBatch.Draw(background, Vector2.Zero, Color.White); menu.DrawMenu(ref spriteBatch, font, new Vector2(GraphicsDevice.Viewport.Width / 2, GraphicsDevice.Viewport.Height / 2) - new Vector2(50f), 100f); spriteBatch.End(); break; } case GameState.GameStarted: { spriteBatch.Begin(); spriteBatch.Draw(background, Vector2.Zero, Color.White); spriteBatch.DrawString(font, "Score: " + score.ToString() + "\nLives: " + lives.ToString(), Vector2.Zero, Color.White); spriteBatch.End(); ship.Draw(); foreach (ModelRenderer bullet in bullets) { bullet.Draw(); } foreach (ModelRenderer asteroid in asteriods) { asteroid.Draw(0.1f); } break; } } base.Draw(gameTime); } bool collidedwithasteriod(ModelRenderer bullet) { foreach (ModelRenderer asteroid in asteriods) { if (bullet.SphereBounds.Intersects(asteroid.BoxBounds)) { score += 10; asteroid.Kill(); return true; } } return false; } } } }

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  • AIX Checklist for stable obiee deployment

    - by user554629
    Common AIX configuration issues     ( last updated 27 Aug 2012 ) OBIEE is a complicated system with many moving parts and connection points.The purpose of this article is to provide a checklist to discuss OBIEE deployment with your systems administrators. The information in this article is time sensitive, and updated as I discover new  issues or details. What makes OBIEE different? When Tech Support suggests AIX component upgrades to a stable, locked-down production AIX environment, it is common to get "push back".  "Why is this necessary?  We aren't we seeing issues with other software?"It's a fair question that I have often struggled to answer; here are the talking points: OBIEE is memory intensive.  It is the entire purpose of the software to trade memory for repetitive, more expensive database requests across a network. OBIEE is implemented in C++ and is very dependent on the C++ runtime to behave correctly. OBIEE is aggressively thread efficient;  if atomic operations on a particular architecture do not work correctly, the software crashes. OBIEE dynamically loads third-party database client libraries directly into the nqsserver process.  If the library is not thread-safe, or corrupts process memory the OBIEE crash happens in an unrelated part of the code.  These are extremely difficult bugs to find. OBIEE software uses 99% common source across multiple platforms:  Windows, Linux, AIX, Solaris and HPUX.  If a crash happens on only one platform, we begin to suspect other factors.  load intensity, system differences, configuration choices, hardware failures.  It is rare to have a single product require so many diverse technical skills.   My role in support is to understand system configurations, performance issues, and crashes.   An analyst trained in Business Analytics can't be expected to know AIX internals in the depth required to make configuration choices.  Here are some guidelines. AIX C++ Runtime must be at  version 11.1.0.4$ lslpp -L | grep xlC.aixobiee software will crash if xlC.aix.rte is downlevel;  this is not a "try it" suggestion.Nov 2011 11.1.0.4 version  is appropriate for all AIX versions ( 5, 6, 7 )Download from here:https://www-304.ibm.com/support/docview.wss?uid=swg24031426 No reboot is necessary to install, it can even be installed while applications are using the current version.Restart the apps, and they will pick up the latest version. AIX 5.3 Technology Level 12 is required when running on Power5,6,7 processorsAIX 6.1 was introduced with the newer Power chips, and we have seen no issues with 6.1 or 7.1 versions.Customers with an unstable deployment, dozens of unexplained crashes, became stable after the upgrade.If your AIX system is 5.3, the minimum TL level should be at or higher than this:$ oslevel -s  5300-12-03-1107IBM typically supports only the two latest versions of AIX ( 6.1 and 7.1, for example).  AIX 5.3 is still supported and popular running in an LPAR. obiee userid limits$ ulimit -Ha  ( hard limits )$ ulimit -a   ( default limits )core file size (blocks)     unlimiteddata seg size (kbytes)      unlimitedfile size (blocks)          unlimitedmax memory size (kbytes)    unlimitedopen files                  10240 cpu time (seconds)          unlimitedvirtual memory (kbytes)     unlimitedIt is best to establish the values in /etc/security/limitsroot user is needed to observe and modify this file.If you modify a limit, you will need to relog in to change it again.  For example,$ ulimit -c 0$ ulimit -c 2097151cannot modify limit: Operation not permitted$ ulimit -c unlimited$ ulimit -c0There are only two meaningful values for ulimit -c ; zero or unlimited.Anything else is likely to produce a truncated core file that cannot be analyzed. Deploy 32-bit or 64-bit ?Early versions of OBIEE offered 32-bit or 64-bit choice to AIX customers.The 32-bit choice was needed if a database vendor did not supply a 64-bit client library.That's no longer an issue and beginning with OBIEE 11, 32-bit code is no longer shipped.A common error that leads to "out of memory" conditions to to accept the 32-bit memory configuration choices on 64-bit deployments.  The significant configuration choices are: Maximum process data (heap) size is in an AIX environment variableLDR_CNTRL=IGNOREUNLOAD@LOADPUBLIC@PREREAD_SHLIB@MAXDATA=0x... Two thread stack sizes are made in obiee NQSConfig.INI[ SERVER ]SERVER_THREAD_STACK_SIZE = 0;DB_GATEWAY_THREAD_STACK_SIZE = 0; Sort memory in NQSConfig.INI[ GENERAL ]SORT_MEMORY_SIZE = 4 MB ;SORT_BUFFER_INCREMENT_SIZE = 256 KB ; Choosing a value for MAXDATA:0x080000000  2GB Default maximum 32-bit heap size ( 8 with 7 zeros )0x100000000  4GB 64-bit breaking even with 32-bit ( 1 with 8 zeros )0x200000000  8GB 64-bit double 32-bit max0x400000000 16GB 64-bit safetyUsing 2GB heap size for a 64-bit process will almost certainly lead to an out-of-memory situation.Registers are twice as big ... consume twice as much memory in the heap.Upgrading to a 4GB heap for a 64-bit process is just "breaking even" with 32-bit.A 32-bit process is constrained by the 32-bit virtual addressing limits.  Heap memory is used for dynamic requirements of obiee software, thread stacks for each of the configured threads, and sometimes for shared libraries. 64-bit processes are not constrained in this way;  extra heap space can be configured for safety against a query that might create a sudden requirement for excessive storage.  If the storage is not available, this query might crash the whole server and disrupt existing users.There is no performance penalty on AIX for configuring more memory than required;  extra memory can be configured for safety.  If there are no other considerations, start with 8GB.Choosing a value for Thread Stack size:zero is the value documented to select an appropriate default for thread stack size.  My preference is to change this to an absolute value, even if you intend to use the documented default;  it provides better documentation and removes the "surprise" factor.There are two thread types that can be configured. GATEWAY is used by a thread pool to call a database client library to establish a DB connection.The default size is 256KB;  many customers raise this to 512KB ( no performance penalty for over-configuring ). This value must be set to 1 MB if Teradata connections are used. SERVER threads are used to run queries.  OBIEE uses recursive algorithms during the analysis of query structures which can consume significant thread stack storage.  It's difficult to provide guidance on a value that depends on data and complexity.  The general notion is to provide more space than you think you need,  "double down" and increase the value if you run out, otherwise inspect the query to understand why it is too complex for the thread stack.  There are protections built into the software to abort a single user query that is too complex, but the algorithms don't cover all situations.256 KB  The default 32-bit stack size.  Many customers increased this to 512KB on 32-bit.  A 64-bit server is very likely to crash with this value;  the stack contains mostly register values, which are twice as big.512 KB  The documented 64-bit default.  Some early releases of obiee didn't set this correctly, resulting in 256KB stacks.1 MB  The recommended 64-bit setting.  If your system only ever uses 512KB of stack space, there is no performance penalty for using 1MB stack size.2 MB  Many large customers use this value for safety.  No performance penalty.nqscheduler does not use the NQSConfig.INI file to set thread stack size.If this process crashes because the thread stack is too small, use this to set 2MB:export OBI_BACKGROUND_STACK_SIZE=2048 Shared libraries are not (shared) When application libraries are loaded at run-time, AIX makes a decision on whether to load the libraries in a "public" memory segment.  If the filesystem library permissions do not have the "Read-Other" permission bit, AIX loads the library into private process memory with two significant side-effects:* The libraries reduce the heap storage available.      Might be significant in 32-bit processes;  irrelevant in 64-bit processes.* Library code is loaded into multiple real pages for execution;  one copy for each process.Multiple execution images is a significant issue for both 32- and 64-bit processes.The "real memory pages" saved by using public memory segments is a minor concern.  Today's machines typically have plenty of real memory.The real problem with private copies of libraries is that they consume processor cache blocks, which are limited.   The same library instructions executing in different real pages will cause memory delays as the i-cache ( instruction cache 128KB blocks) are refreshed from real memory.   Performance loss because instructions are delayed is something that is difficult to measure without access to low-level cache fault data.   The machine just appears to be running slowly for no observable reason.This is an easy problem to detect, and an easy problem to correct.Detection:  "genld -l" AIX command produces a list of the libraries used by each process and the AIX memory address where they are loaded.32-bit public segment is 13 ( "dxxxxxxx" ).   private segments are 2-a.64-bit public segment is 9 ( "9xxxxxxxxxxxxxxx") ; private segment is 8.genld -l | grep -v ' d| 9' | sort +2provides a list of privately loaded libraries. Repair: chmod o+r <libname>AIX shared libraries will have a suffix of ".so" or ".a".Another technique is to change all libraries in a selected directory to repair those that might not be currently loaded.   The usual directories that need repair are obiee code, httpd code and plugins, database client libraries and java.chmod o+r /shr/dir/*.a /shr/dir/*.so Configure your system for diagnosticsProduction systems shouldn't crash, and yet bad things happen to good software.If obiee software crashes and produces a core, you should configure your system for reliable transfer of the failing conditions to Oracle Tech Support.  Here's what we need to be able to diagnose a core file from your system.* fullcore enabled. chdev -lsys0 -a fullcore=true* core naming enabled. chcore -n on -d* ulimit must not truncate core. see item 3.* pstack.sh is used to capture core documentation.* obidoc is used to capture current AIX configuration.* snapcore  AIX utility captures core and libraries. Use the proper syntax. $ snapcore -r corename executable-fullpath   /tmp/snapcore will contain the .pax.Z output file.  It is compressed.* If cores are directed to a common directory, ensure obiee userid can write to the directory.  ( chcore -p /cores -d ; chmod 777 /cores )The filesystem must have sufficient space to hold a crashing obiee application.Use:  df -k  Check the "Free" column ( not "% Used" )  8388608 is 8GB. Disable Oracle Client Library signal handlingThe Oracle DB Client Library is frequently distributed with the sqlplus development kit.By default, the library enables a signal handler, which will document a call stack if the application crashes.   The signal handler is not needed, and definitely disruptive to obiee diagnostics.   It needs to be disabled.   sqlnet.ora is typically located at:   $ORACLE_HOME/network/admin/sqlnet.oraAdd this line at the top of the file:   DIAG_SIGHANDLER_ENABLED=FALSE Disable async query in the RPD connection pool.This might be an obiee 10.1.3.4 issue only ( still checking  )."async query" must be disabled in the connection pools.It was designed to enable query cancellation to a database, and turned out to have too many edge conditions in normal communication that produced random corruption of data and crashes.  Please ensure it is turned off in the RPD. Check AIX error report (errpt).Errors external to obiee applications can trigger crashes.  $ /bin/errpt -aHardware errors ( firmware, adapters, disks ) should be reported to IBM support.All application core files are recorded by AIX;  the most recent ones are listed first. Reserved for something important to say.

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