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  • Create a class that inherets DrawableGameComponent in XNA as a CLASS with custom functions

    - by user3675013
    using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Media; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Content; namespace TileEngine { class Renderer : DrawableGameComponent { public Renderer(Game game) : base(game) { } SpriteBatch spriteBatch ; protected override void LoadContent() { base.LoadContent(); } public override void Draw(GameTime gameTime) { base.Draw(gameTime); } public override void Update(GameTime gameTime) { base.Update(gameTime); } public override void Initialize() { base.Initialize(); } public RenderTarget2D new_texture(int width, int height) { Texture2D TEX = new Texture2D(GraphicsDevice, width, height); //create the texture to render to RenderTarget2D Mine = new RenderTarget2D(GraphicsDevice, width, height); GraphicsDevice.SetRenderTarget(Mine); //set the render device to the reference provided //maybe base.draw can be used with spritebatch. Idk. We'll see if the order of operation //works out. Wish I could call base.draw here. return Mine; //I'm hoping that this returns the same instance and not a copy. } public void draw_texture(int width, int height, RenderTarget2D Mine) { GraphicsDevice.SetRenderTarget(null); //Set the renderer to render to the backbuffer again Rectangle drawrect = new Rectangle(0, 0, width, height); //Set the rendering size to what we want spriteBatch.Begin(); //This uses spritebatch to draw the texture directly to the screen spriteBatch.Draw(Mine, drawrect, Color.White); //This uses the color white spriteBatch.End(); //ends the spritebatch //Call base.draw after this since it doesn't seem to recognize inside the function //maybe base.draw can be used with spritebatch. Idk. We'll see if the order of operation //works out. Wish I could call base.draw here. } } } I solved a previous issue where I wasn't allowed to access GraphicsDevice outside the main Default 'main' class Ie "Game" or "Game1" etc. Now I have a new issue. FYi no one told me that it would be possible to use GraphicsDevice References to cause it to not be null by using the drawable class. (hopefully after this last bug is solved it doesn't still return null) Anyways at present the problem is that I can't seem to get it to initialize as an instance in my main program. Ie Renderer tileClipping; and I'm unable to use it such as it is to be noted i haven't even gotten to testing these two steps below but before it compiled but when those functions of this class were called it complained that it can't render to a null device. Which meant that the device wasn't being initialized. I had no idea why. It took me hours to google this. I finally figured out the words I needed.. which were "do my rendering in XNA in a seperate class" now I haven't used the addcomponent function because I don't want it to only run these functions automatically and I want to be able to call the custom ones. In a nutshell what I want is: *access to rendering targets and graphics device OUTSIDE default class *passing of Rendertarget2D (which contain textures and textures should automatically be passed with a rendering target? ) *the device should be passed to this function as well OR the device should be passed to this function as a byproduct of passing the rendertarget (which is automatically associated with the render device it was given originally) *I'm assuming I'm dealing with abstracted pointers here so when I pass a class object or instance, I should be recieving the SAME object , I referenced, and not a copy that has only the lifespan of the function running. *the purpose for all these options: I want to initialize new 2d textures on the fly to customize tileclipping and even the X , y Offsets of where a WHOLE texture will be rendered, and the X and Y offsets of where tiles will be rendered ON that surface. This is why. And I'll be doing region based lighting effects per tile or even per 8X8 pixel spaces.. we'll see I'll also be doing sprite rotations on the whole texture then copying it again to a circular masked texture, and then doing a second copy for only solid tiles for masked rotated collisions on sprites. I'll be checking the masked pixels for my collision, and using raycasting possibly to check for collisions on those areas. The sprite will stay in the center, when this rotation happens. Here is a detailed diagram: http://i.stack.imgur.com/INf9K.gif I'll be using texture2D for steps 4-6 I suppose for steps 1 as well. Now ontop of that, the clipping size (IE the sqaure rendered) will be able to be shrunk or increased, on a per frame basis Therefore I can't use the same static size for my main texture2d and I can't use just the backbuffer Or we get the annoying flicker. Also I will have multiple instances of the renderer class so that I can freely pass textures around as if they are playing cards (in a sense) layering them ontop of eachother, cropping them how i want and such. and then using spritebatch to simply draw them at the locations I want. Hopefully this makes sense, and yes I will be planning on using alpha blending but only after all tiles have been drawn.. The masked collision is important and Yes I am avoiding using math on the tile rendering and instead resorting to image manipulation in video memory which is WHY I need this to work the way I'm intending it to work and not in the default way that XNA seems to handle graphics. Thanks to anyone willing to help. I hate the code form offered, because then I have to rely on static presence of an update function. What if I want to kill that update function or that object, but have it in memory, but just have it temporarily inactive? I'm making the assumption here the update function of one of these gamecomponents is automatic ? Anyways this is as detailed as I can make this post hopefully someone can help me solve the issue. Instead of tell me "derrr don't do it this wayyy" which is what a few people told me (but they don't understand the actual goal I have in mind) I'm trying to create basically a library where I can copy images freely no matter the size, i just have to specify the size in the function then as long as a reference to that object exists it should be kept alive? right? :/ anyways.. Anything else? I Don't know. I understand object oriented coding but I don't understand this XNA It's beggining to feel impossible to do anything custom in it without putting ALL my rendering code into the draw function of the main class tileClipping.new_texture(GraphicsDevice, width, height) tileClipping.Draw_texture(...)

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  • Get the layout mode (landscape or portrait) of a pdf from php/linux

    - by Jonathan Hendler
    Given a PDF, how can one get the layout mode of a PDF (or relative width/height) using a PHP lib or linux command line tool? Using http://www.tecnick.com/public/code/cp%5Fdpage.php?aiocp%5Fdp=tcpdf which can set this variable on new PDFs, but for existing pdfs from adobe. Thought of converting pdfs to ps, or using gs in some other way - like converting it to an image first, and getting the width and height of that. Is this the best way?

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  • Vetical and Horizontally Align an image in a box

    - by Rhyso
    The problem: I have a set width and height image Lets say height:160px; width:200px; with an image in each box. The image can vary in size but I need a solution that will always center the image vertically and horizontally within the box no matter what it's size. Horizontal doesn't seem to be a problem by using margin: 0 auto but vertical is proving difficult. I have tried vertical align: center but this doesnt appear to work either Any help is appriciated Thanks

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  • Too Many ESTABLISHED connection from a single IP address in Apache

    - by ananthan
    netstat -ntp |grep 80 shows too many ESTABLISHED connection from single IP address. Around 300 of them and it is not an attack and user is using a 2G connection to access Apache. This is the case with other 2G connections also. As a result of this Apache is running out of children. Earlier it was showing too many close_wait and after enabling tcp_tw_reuse and tcp_tw-recycle there is not much close_wait but the number of ESTABLISHED connections increased. We are using Ubuntu 11.04 having 48 GB ram keepalive On keepalive timeout 10 max clients 800 max-request-perchild 4000 timeout 300 I have set syn_ack to 1 and syn_retries to 2. On wifi there is no such issue. Connections are closing properly, but with 2G connections Apache is running out of children and too many ESTABLISHED connection. also i have tried setting timeout from default 300 to 30,but since our project is image hosting for mobile phones,clients couldn't upload images properly as they are getting frequent time out.Also there were a lot of 408 messages so changed it to the default 300

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  • Can you get the size of the Flash object in Actionscript?

    - by futuraprime
    I'm working with a Flash movie and I'm trying to get the size of the player itself (i.e. the height and width Flash has to work with from the object/embed tag). As far as I can tell, Flash doesn't make this available to ActionScript. I'm able to use this.root.loaderInfo.width and this.root.loaderInfo.height to get the "intended" size of the flash movie (what's specified on export), but if the dimensions are different on the page, this isn't helpful.

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  • is it possible to store server returned json data in jqgrid to display columnnames models data dynamically for every request?

    - by user1768246
    is it possible to store server returned json data in jqgrid to display columnnames models data dynamically for every request ? $("#grid").jqGrid({ type: "GET", url: "", var columnNames = $("#grid")[0].p.colNames, var columnModel = $("#grid")[0].p.colNames, var columnData = $("#grid")[0].p.colNames, datatype: 'jsonstring', datastr: columnData, colModel: columnModel, jsonReader: { root: 'innerWrapper.rows', page: "result.gridData.outerWrapper.page", total: "result.gridData.outerWrapper.total", records: "result.gridData.outerWrapper.total", repeatitems: false, }, gridview: true, pager: "pager", height: "auto", rowNum: 10, width:"auto", height:"auto", rowList: [10, 20, 30,40], viewrecords: true, caption:"Graph Data", rownumbers: true, });

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  • WPF Style Triggers: can I apply the one style for a variety of Properties?

    - by Matt H.
    It seems like there has to be a way to do this: I am applying an ItemContainerStyle in my Listbox, based on two property triggers. As you can see, I'm using the exact same set of trigger enter/exit actions, simply applied on two different properties. Is there something equivalent to a <Trigger Property="prop1" OR Property="prop2" ??? (Obviously wouldn't look like that, but that probably gets the point across.) <Style x:Key="ListBoxItemStyle" TargetType="ListBoxItem"> <Style.Triggers> <Trigger Property="IsKeyboardFocusWithin" Value="True"> <Trigger.EnterActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Storyboard.TargetProperty="Height" To="50" Duration="0:0:.3"></DoubleAnimation> </Storyboard> </BeginStoryboard> </Trigger.EnterActions> <Trigger.ExitActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Storyboard.TargetProperty="Height" To="25" Duration="0:0:.3" /> </Storyboard> </BeginStoryboard> </Trigger.ExitActions> </Trigger> </Style.Triggers> </Style> <Style x:Key="ListBoxItemStyle" TargetType="ListBoxItem"> <Style.Triggers> <Trigger Property="IsMouseOver" Value="True"> <Trigger.EnterActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Storyboard.TargetProperty="Height" To="50" Duration="0:0:.3"></DoubleAnimation> </Storyboard> </BeginStoryboard> </Trigger.EnterActions> <Trigger.ExitActions> <BeginStoryboard> <Storyboard> <DoubleAnimation Storyboard.TargetProperty="Height" To="25" Duration="0:0:.3" /> </Storyboard> </BeginStoryboard> </Trigger.ExitActions> </Trigger> </Style.Triggers> </Style>

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  • I am making a maze type of game using javascript and HTML and need some questions answered [on hold]

    - by Timothy Bilodeau
    First off, i am a noob to JavaScript but am willing to learn. :) I found a simple JavaScript moment engine created by another member on this site. Using that i made it so my character can walk around within a rectangle/square shaped room. I want to make it so the character can walk through a "doorway" within a wall to the next room. Either that or make it so if the character moves over a certain image within the room it will take the player to another webpage in which the character "spawns" into the room and so on and so fourth. Here is a link to what i have made so far as to get an idea. http://bit.ly/1fSMesA Any help would be much appreciated. Here is the javascript code for the character movement and boundaries. <script type='text/javascript'> // movement vars var xpos = 100; var ypos = 100; var xspeed = 1; var yspeed = 0; var maxSpeed = 5; // boundary var minx = 37; var miny = 41; var maxx = 187; // 10 pixels for character's width var maxy = 178; // 10 pixels for character's width // controller vars var upPressed = 0; var downPressed = 0; var leftPressed = 0; var rightPressed = 0; function slowDownX() { if (xspeed > 0) xspeed = xspeed - 1; if (xspeed < 0) xspeed = xspeed + 1; } function slowDownY() { if (yspeed > 0) yspeed = yspeed - 1; if (yspeed < 0) yspeed = yspeed + 1; } function gameLoop() { // change position based on speed xpos = Math.min(Math.max(xpos + xspeed,minx),maxx); ypos = Math.min(Math.max(ypos + yspeed,miny),maxy); // or, without boundaries: // xpos = xpos + xspeed; // ypos = ypos + yspeed; // change actual position document.getElementById('character').style.left = xpos; document.getElementById('character').style.top = ypos; // change speed based on keyboard events if (upPressed == 1) yspeed = Math.max(yspeed - 1,-1*maxSpeed); if (downPressed == 1) yspeed = Math.min(yspeed + 1,1*maxSpeed) if (rightPressed == 1) xspeed = Math.min(xspeed + 1,1*maxSpeed); if (leftPressed == 1) xspeed = Math.max(xspeed - 1,-1*maxSpeed); // deceleration if (upPressed == 0 && downPressed == 0) slowDownY(); if (leftPressed == 0 && rightPressed == 0) slowDownX(); // loop setTimeout("gameLoop()",10); } function keyDown(e) { var code = e.keyCode ? e.keyCode : e.which; if (code == 38) upPressed = 1; if (code == 40) downPressed = 1; if (code == 37) leftPressed = 1; if (code == 39) rightPressed = 1; } function keyUp(e) { var code = e.keyCode ? e.keyCode : e.which; if (code == 38) upPressed = 0; if (code == 40) downPressed = 0; if (code == 37) leftPressed = 0; if (code == 39) rightPressed = 0; } </script> here is the HTML code to follow <!-- The Level --> <img src="room1.png" /> <!-- The Character --> <img id='character' src='../texture packs/characters/snazgel.png' style='position:absolute;left:100;top:100;height:40;width:26;'/>

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  • I need objective syntax for calculating bmi

    - by Umaid
    Actually I am working on bmi calculator. Where I would like to calculate bmi for height in inches and weight in lbs and also in need of correct formula for height in cm and weight in kgs. I have tried but couldn't calculate actual value coming withing the range as below. It exceeds the range. BMI Categories: * Underweight = <18.5 * Normal weight = 18.5-24.9 * Overweight = 25-29.9 * Obesity = BMI of 30 or greater

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  • Endless scroll paging in jquery Safari

    - by socheata
    I'm using : $(window).scroll(function () { if ($(window).scrollTop() + 10 >= ($(document).height() - $(window).height())) { loadContent(); } } It works fine with Chrome, IE, Firefox but except in Safari. In function loadContent, I used JSON to load data, as this tutorial. But while I test in Safari, It takes the content twice from JSON. If the other takes 9 items, then Safari takes 18 items. Does anyone know how to solve this problem? Thanks.

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  • This is a valid C code but not a valid C++ code?

    - by claws
    In some library I'm using (written in C) its StorePGM(image, width, height, filename) char *image; int width, height; char *filename; { // something something } All functions are defined this way. I never seen such function definitions in my life. They seem to be valid to MSVC but when I compile it as C++ it gives errors. What is it? some kind of old version C?

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  • Iframe size manipulation

    - by portoalet
    Is there a way to make the Iframe request an external website as if it is a mobile device, so the content returned will have a small dimension etc? I am displaying external websites in iframes, using width and height attributes <iframe src="http://marketwatch.com" width="300px" height="300px" ></iframe> but because the browser is not a mobile browser, the content returned is tailored to normal browser, and I end up having scrollbars. If the content returned is that for a mobile device, then no more scrollbars etc.

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  • Sorry, Parameter is not valid.

    - by maruthikumar
    Hello All, I'm exporting some data to PDF. The data contains one or more bitmaps. Unfortunately I'm getting the following error during the export. Sorry, Parameter is not valid. Source: at System.Drawing.Bitmap..ctor(Int32 width, Int32 height, PixelFormat format) at System.Drawing.Bitmap..ctor(Image original, Int32 width, Int32 height) Type: System.ArgumentException Any help will be highly appreciable. Regards, Maruthi Kumar

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  • Java: If I overwrite the .equals method, can I still test for reference equality with ==?

    - by shots fired
    I have the following situation: I need to sort trees based by height, so I made the Tree's comparable using the height attribute. However, I was also told to overwrite the equals and hashCode methods to avoid unpredictable behaviour. Still, sometimes I may want to compare the references of the roots or something along those lines using ==. Is that still possible or does the == comparison call the equals method?

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  • Fastest Memory (within reason) for a MotherBoard [on hold]

    - by sampson
    I was wondering if it would be OK to use DDR3 3000 memory with Asus Maximus VI Impact MotherBoard, Intel® Core™ i3-4130T Processor and Steamcom's FC8 case The purpose of this machine is for a HTPC (Home Theater Personal Computer) system, only, no gaming. The case is fan less as is the CPU cooling system. Also, would it be worth it, heat wise, to go past the 1600 memory type? I mean, would DDR 3000 make the box that much faster to make it worthwhile? The Processor has a TDP rating of 35 W. The memory specifications for the processor are: Memory Specifications Max Memory Size (dependent on memory type) 32 GB Memory Types DDR3-1333/1600 # of Memory Channels 2 Max Memory Bandwidth 25.6 GB/s ECC Memory Supported ‡ Yes The FC8 case's heat displacement system is rated at 95 W TDP

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  • borders are not visible in ie7

    - by S.Rangaraj
    i want a border on bottom of a td.i got that using border:dotted 1px black;.but it is not visible in ie7.the td height is 10px.if i use &nbsp it is visible in ie7.but i dont need that much height.can anyone help me?

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  • Calculate needed size for a TLabel

    - by Tom
    Ok, here's the problem. I have a label component in a panel. The label is aligned as alClient and has wordwrap enabled. The text can vary from one line to several lines. I would like to re-size the height of the the panel (and the label) to fit all the text. How do I get the necessary height of a label when I know the text and the width of the panel?

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  • make it simpliest

    - by gcc
    input 000 000 000 000 255 000 000 000 000 000 000 000 purpose instead of 000 write 0 and 255 write 2 take input { char A[800][600]; scanf("%d",&height); for(i=0;i<height;++i) scanf("%s",A[i]); then what output 0 0 0 0 2 0 0 0 0 0 0 0

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  • How to design database for tests in online test application

    - by Kien Thanh
    I'm building an online test application, the purpose of app is, it can allow teacher create courses, topics of course, and questions (every question has mark), and they can create tests for students and students can do tests online. To create tests of any courses for students, first teacher need to create a test pattern for that course, test pattern actually is a general test includes the number of questions teacher want it has, then from that test pattern, teacher will generate number of tests corresponding with number of students will take tests of that course, and every test for student will has different number of questions, although the max mark of test in every test are the same. Example if teacher generate tests for two students, the max mark of test will be 20, like this: Student A take test with 20 questions, student B take test only has 10 questions, it means maybe every question in test of student A only has mark is 1, but questions in student B has mark is 2. So 20 = 10 x 2, sorry for my bad English but I don't know how to explain it better. I have designed tables for: - User (include students and teachers account) - Course - Topic - Question - Answer But I don't know how to define associations between user and test pattern, test, question. Currently I only can think these: Test pattern table: name, description, dateStart, dateFinish, numberOfMinutes, maxMarkOfTest Test table: test_pattern_id And when user (is Student) take tests, I think i will have one more table: Result: user_id, test_id, mark but I can't set up associations among test pattern and test and question. How to define associations?

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  • Rendering shadow sprites in cocos2d-x

    - by lukeluke
    I am writing a 2D game with cocos2d-x. I want to put a "shadow" sprite on a background sprite using the equation: MAX(0, Cd*1 - Cs*S) where Cd is the destination color (that is, a background pixel), Cs is the source color (the shadow pixel) , S is the scale factor (between 0 and 1). The MAX() function is used to avoid negative results. This is a lighting effect: when the shadow sprite pixel is 0, there is no effect on the background pixel, otherwise, the background pixel becomes darker. Now, the only way that comes to my mind is to change the blending equation to GL_FUNC_SUBTRACT, but it doesn't compile with cocos2d-x (can't found it)... I would subclass the CCSprite class in order to implement the draw() method in order to change, when needed, the blending equation, call the original draw() method and restore the blending equation to its previous state at the end of the method. So my questions are two: how to use glBlendEquation() with cocos2d-x? Keep in mind that i am writing a game for iphone/android/windows. are shadows handled this way in 2D games? Thx

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  • Silverlight Cream for April 06, 2010 -- #832

    - by Dave Campbell
    In this Issue: Alex van Beek, Gill Cleeren, SilverlightShow, Michael Sync, Rénald Nollet, Charles Petzold, The-Oliver, and Max Paulousky. Shoutouts: Denislav Savkov of SilverlightShow ported his Slider control to WP7: Windows Phone 7 Series Sample Image Viewer SilverlightShow interview: The Silverlight Tour - what, where and why. Interview with one of the Tour organizers Laurent Duveau From SilverlightCream.com: Silverlight 4: using the VisualStateManager for state animations with MVVM Alex van Beek has an approach to resolving the MVVM issue of Animations without keeping a reference to the ViewModel by way of VisualStateManager Leveraging the ASP.NET Membership in Silverlight Gill Cleeren's post at SilverlightShow talks about using ASP.NET authentication inside your Silverlight making membership not only something you know and understand, but now the transition from your ASP.NET apps to Silverlight is simple as well. Windows Phone 7 Series RSS reader SilverlightShow has a demo RSS Reader for WP7 up... no text, but the code is there. Step by Step Tutorial : Installing Multi-Touch Simulator for Silverlight Phone 7 Michael Sync actually has a multi-touch simulator working for WP7 ... it involves a bunch of moving parts and one of the requirements is Windows 7, but if that works for you, this will too :) Element Property Binding Improvements in Blend 4 Beta and Visual Studio 2010 RC Rénald Nollet demonstrates new Blend and VS2010 features that assists you in Element Property binding with real examples. Projection Transforms Sans Math Charles Petzold is writing about Silverlight and 3D and specifically in this post 3D without math which becomes PlaneProjection... good long tutorial on it and code to back it all up. Daily Demo: Silverlight Install out of browser & Check for Update Behaviors The-Oliver has a post up about OOB and checking for updates using behaviors with only a slight change to your xaml... cool! Wizards. Prototype of sketching Wizard for WPF – 2 Max Paulousky has part 2 of his tutorial on a sketchflow Wizard for WPF ... yes WPF, but check it out... source too. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • Optimizing Solaris 11 SHA-1 on Intel Processors

    - by danx
    SHA-1 is a "hash" or "digest" operation that produces a 160 bit (20 byte) checksum value on arbitrary data, such as a file. It is intended to uniquely identify text and to verify it hasn't been modified. Max Locktyukhin and others at Intel have improved the performance of the SHA-1 digest algorithm using multiple techniques. This code has been incorporated into Solaris 11 and is available in the Solaris Crypto Framework via the libmd(3LIB), the industry-standard libpkcs11(3LIB) library, and Solaris kernel module sha1. The optimized code is used automatically on systems with a x86 CPU supporting SSSE3 (Intel Supplemental SSSE3). Intel microprocessor architectures that support SSSE3 include Nehalem, Westmere, Sandy Bridge microprocessor families. Further optimizations are available for microprocessors that support AVX (such as Sandy Bridge). Although SHA-1 is considered obsolete because of weaknesses found in the SHA-1 algorithm—NIST recommends using at least SHA-256, SHA-1 is still widely used and will be with us for awhile more. Collisions (the same SHA-1 result for two different inputs) can be found with moderate effort. SHA-1 is used heavily though in SSL/TLS, for example. And SHA-1 is stronger than the older MD5 digest algorithm, another digest option defined in SSL/TLS. Optimizations Review SHA-1 operates by reading an arbitrary amount of data. The data is read in 512 bit (64 byte) blocks (the last block is padded in a specific way to ensure it's a full 64 bytes). Each 64 byte block has 80 "rounds" of calculations (consisting of a mixture of "ROTATE-LEFT", "AND", and "XOR") applied to the block. Each round produces a 32-bit intermediate result, called W[i]. Here's what each round operates: The first 16 rounds, rounds 0 to 15, read the 512 bit block 32 bits at-a-time. These 32 bits is used as input to the round. The remaining rounds, rounds 16 to 79, use the results from the previous rounds as input. Specifically for round i it XORs the results of rounds i-3, i-8, i-14, and i-16 and rotates the result left 1 bit. The remaining calculations for the round is a series of AND, XOR, and ROTATE-LEFT operators on the 32-bit input and some constants. The 32-bit result is saved as W[i] for round i. The 32-bit result of the final round, W[79], is the SHA-1 checksum. Optimization: Vectorization The first 16 rounds can be vectorized (computed in parallel) because they don't depend on the output of a previous round. As for the remaining rounds, because of step 2 above, computing round i depends on the results of round i-3, W[i-3], one can vectorize 3 rounds at-a-time. Max Locktyukhin found through simple factoring, explained in detail in his article referenced below, that the dependencies of round i on the results of rounds i-3, i-8, i-14, and i-16 can be replaced instead with dependencies on the results of rounds i-6, i-16, i-28, and i-32. That is, instead of initializing intermediate result W[i] with: W[i] = (W[i-3] XOR W[i-8] XOR W[i-14] XOR W[i-16]) ROTATE-LEFT 1 Initialize W[i] as follows: W[i] = (W[i-6] XOR W[i-16] XOR W[i-28] XOR W[i-32]) ROTATE-LEFT 2 That means that 6 rounds could be vectorized at once, with no additional calculations, instead of just 3! This optimization is independent of Intel or any other microprocessor architecture, although the microprocessor has to support vectorization to use it, and exploits one of the weaknesses of SHA-1. Optimization: SSSE3 Intel SSSE3 makes use of 16 %xmm registers, each 128 bits wide. The 4 32-bit inputs to a round, W[i-6], W[i-16], W[i-28], W[i-32], all fit in one %xmm register. The following code snippet, from Max Locktyukhin's article, converted to ATT assembly syntax, computes 4 rounds in parallel with just a dozen or so SSSE3 instructions: movdqa W_minus_04, W_TMP pxor W_minus_28, W // W equals W[i-32:i-29] before XOR // W = W[i-32:i-29] ^ W[i-28:i-25] palignr $8, W_minus_08, W_TMP // W_TMP = W[i-6:i-3], combined from // W[i-4:i-1] and W[i-8:i-5] vectors pxor W_minus_16, W // W = (W[i-32:i-29] ^ W[i-28:i-25]) ^ W[i-16:i-13] pxor W_TMP, W // W = (W[i-32:i-29] ^ W[i-28:i-25] ^ W[i-16:i-13]) ^ W[i-6:i-3]) movdqa W, W_TMP // 4 dwords in W are rotated left by 2 psrld $30, W // rotate left by 2 W = (W >> 30) | (W << 2) pslld $2, W_TMP por W, W_TMP movdqa W_TMP, W // four new W values W[i:i+3] are now calculated paddd (K_XMM), W_TMP // adding 4 current round's values of K movdqa W_TMP, (WK(i)) // storing for downstream GPR instructions to read A window of the 32 previous results, W[i-1] to W[i-32] is saved in memory on the stack. This is best illustrated with a chart. Without vectorization, computing the rounds is like this (each "R" represents 1 round of SHA-1 computation): RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR With vectorization, 4 rounds can be computed in parallel: RRRRRRRRRRRRRRRRRRRR RRRRRRRRRRRRRRRRRRRR RRRRRRRRRRRRRRRRRRRR RRRRRRRRRRRRRRRRRRRR Optimization: AVX The new "Sandy Bridge" microprocessor architecture, which supports AVX, allows another interesting optimization. SSSE3 instructions have two operands, a input and an output. AVX allows three operands, two inputs and an output. In many cases two SSSE3 instructions can be combined into one AVX instruction. The difference is best illustrated with an example. Consider these two instructions from the snippet above: pxor W_minus_16, W // W = (W[i-32:i-29] ^ W[i-28:i-25]) ^ W[i-16:i-13] pxor W_TMP, W // W = (W[i-32:i-29] ^ W[i-28:i-25] ^ W[i-16:i-13]) ^ W[i-6:i-3]) With AVX they can be combined in one instruction: vpxor W_minus_16, W, W_TMP // W = (W[i-32:i-29] ^ W[i-28:i-25] ^ W[i-16:i-13]) ^ W[i-6:i-3]) This optimization is also in Solaris, although Sandy Bridge-based systems aren't widely available yet. As an exercise for the reader, AVX also has 256-bit media registers, %ymm0 - %ymm15 (a superset of 128-bit %xmm0 - %xmm15). Can %ymm registers be used to parallelize the code even more? Optimization: Solaris-specific In addition to using the Intel code described above, I performed other minor optimizations to the Solaris SHA-1 code: Increased the digest(1) and mac(1) command's buffer size from 4K to 64K, as previously done for decrypt(1) and encrypt(1). This size is well suited for ZFS file systems, but helps for other file systems as well. Optimized encode functions, which byte swap the input and output data, to copy/byte-swap 4 or 8 bytes at-a-time instead of 1 byte-at-a-time. Enhanced the Solaris mdb(1) and kmdb(1) debuggers to display all 16 %xmm and %ymm registers (mdb "$x" command). Previously they only displayed the first 8 that are available in 32-bit mode. Can't optimize if you can't debug :-). Changed the SHA-1 code to allow processing in "chunks" greater than 2 Gigabytes (64-bits) Performance I measured performance on a Sun Ultra 27 (which has a Nehalem-class Xeon 5500 Intel W3570 microprocessor @3.2GHz). Turbo mode is disabled for consistent performance measurement. Graphs are better than words and numbers, so here they are: The first graph shows the Solaris digest(1) command before and after the optimizations discussed here, contained in libmd(3LIB). I ran the digest command on a half GByte file in swapfs (/tmp) and execution time decreased from 1.35 seconds to 0.98 seconds. The second graph shows the the results of an internal microbenchmark that uses the Solaris libpkcs11(3LIB) library. The operations are on a 128 byte buffer with 10,000 iterations. The results show operations increased from 320,000 to 416,000 operations per second. Finally the third graph shows the results of an internal kernel microbenchmark that uses the Solaris /kernel/crypto/amd64/sha1 module. The operations are on a 64Kbyte buffer with 100 iterations. third graph shows the results of an internal kernel microbenchmark that uses the Solaris /kernel/crypto/amd64/sha1 module. The operations are on a 64Kbyte buffer with 100 iterations. The results show for 1 kernel thread, operations increased from 410 to 600 MBytes/second. For 8 kernel threads, operations increase from 1540 to 1940 MBytes/second. Availability This code is in Solaris 11 FCS. It is available in the 64-bit libmd(3LIB) library for 64-bit programs and is in the Solaris kernel. You must be running hardware that supports Intel's SSSE3 instructions (for example, Intel Nehalem, Westmere, or Sandy Bridge microprocessor architectures). The easiest way to determine if SSSE3 is available is with the isainfo(1) command. For example, nehalem $ isainfo -v $ isainfo -v 64-bit amd64 applications sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu 32-bit i386 applications sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov sep cx8 tsc fpu If the output also shows "avx", the Solaris executes the even-more optimized 3-operand AVX instructions for SHA-1 mentioned above: sandybridge $ isainfo -v 64-bit amd64 applications avx xsave pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu 32-bit i386 applications avx xsave pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov sep cx8 tsc fpu No special configuration or setup is needed to take advantage of this code. Solaris libraries and kernel automatically determine if it's running on SSSE3 or AVX-capable machines and execute the correctly-tuned code for that microprocessor. Summary The Solaris 11 Crypto Framework, via the sha1 kernel module and libmd(3LIB) and libpkcs11(3LIB) libraries, incorporated a useful SHA-1 optimization from Intel for SSSE3-capable microprocessors. As with other Solaris optimizations, they come automatically "under the hood" with the current Solaris release. References "Improving the Performance of the Secure Hash Algorithm (SHA-1)" by Max Locktyukhin (Intel, March 2010). The source for these SHA-1 optimizations used in Solaris "SHA-1", Wikipedia Good overview of SHA-1 FIPS 180-1 SHA-1 standard (FIPS, 1995) NIST Comments on Cryptanalytic Attacks on SHA-1 (2005, revised 2006)

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  • SQL SERVER – Relationship with Parallelism with Locks and Query Wait – Question for You

    - by Pinal Dave
    Today, I have one very simple question based on following image. A full disclaimer is that I have no idea why it is like that. I tried to reach out to few of my friends who know a lot about SQL Server but no one has any answer. Here is the question: If you go to server properties and click on Advanced you will see the following screen. Under the Parallelism section if you noticed there are four options: Cost Threshold for Parallelism Locks Max Degree of Parallelism Query Wait I can clearly understand why Cost Threshold for Parallelism and Max Degree of Parallelism belongs to Parallelism but I am not sure why we have two other options Locks and Query Wait belongs to Parallelism section. I can see that the options are ordered alphabetically but I do not understand the reason for locks and query wait to list under Parallelism. Here is the question for you – Why Locks and Query Wait options are listed under Parallelism section in SQL Server Advanced Properties? Please leave a comment with your explanation. I will publish valid answers on this blog with due credit. Reference: Pinal Dave (http://blog.sqlauthority.com)   Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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