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  • SQL SERVER – Performance Tuning Resolution

    - by pinaldave
    This blog post is written in response to T-SQL Tuesday hosted by MidnightDBAs. Taking resolutions is such an interesting subject. I think just like records, these are broken way more often. I find this is the funniest thing as we all take resolutions every year but not every year, we can manage to keep them. Well, does it mean we should not take resolutions? In fact I support resolutions. Every year, I take a resolution that I will strive reduce my body weight and I usually manage to keep eating healthy till the end of January. When February begins, I begin to loose focus from my goal and as March starts, the “As usual” eating habits begin. Looking at the positive side, what would happen if every year I do not eat healthy in January, I think that might cause terrible consequences to my health in the long run. So keeping resolutions is a good practise and following them to the extent one can is commendable. Let us come back to the world of SQL Server. What is my resolution for year 2011 for SQL Server? There are many, I am going to list three of very important resolutions that I have taken this new year over here. To understand SQL Server Performance Tuning at a deeper Level I think I am already half way through. I have been being very much busy during any given month doing hands-on performance tuning for at least 12 days on an average. That means, I am doing this activity for almost doing 2 weeks a month. I believe that I have a good understanding of the subject. Note that the word that I have used is “good,” and not “best.” There are often cases when I am stumped, and I have no clue of what to do next. Then, I usually go for my “trial and error” method - whichever method works, I make sure to keep a note on my blog. My goal is that I should never ever go for the trial and error method again to achieve the same solution. I should know the solution right away when I see the problem. I do understand that Performance Tuning can be a strange animal at times and one cannot guess the right step every time. However, aiming a high goal never hurts and I am going to learn more and more in this focused area. Going further from Basic BI understanding I do fairly decent with BI concepts. I know the nbasics of SSIS, SSRS, SSAS, PowerPivot and SharePoint (and few other things MDS, StreamInsight, etc). However, I still consider myself as a beginner. I do not have hands-on experience like many other BI Gurus around. I think I want to take my learning further in this direction. I do not want to be a BI expert as the first step but the goal is to move ahead from basic level towards an advanced level. I am going to start presenting in User Group Sessions and other places on this subject. When I have to prepare new subject for presentations, I think I force myself to learn more. I am committed to learn a bit more in this direction. Learning new features SQL Server 2011 Denali This is new thing from “Microsoft” for all the SQL Geeks. I am eagerly waiting for final product later this year and I am planning to learn it well. I think if I follow my above two goals, I think this goal will be automatically covered. I am eager and excited for this new offering from Microsoft. I guess, these are my resolutions; may be next year about the same time, I must revisit this post and see how much successful I am in following my goal. On a lighter note, I am particularly fan of following cartoon strip (Courtesy: Calvin and Hobbes). I think when we cannot resolve our resolutions, we tend to act like Calvin. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Help me get my 3D camera to look like the ones in RTS

    - by rFactor
    I am a newbie in 3D game development and I am trying to make a real-time strategy game. I am struggling with the camera currently as I am unable to make it look like they do in RTS games. Here is my Camera.cs class using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Input; namespace BB { public class Camera : Microsoft.Xna.Framework.GameComponent { public Matrix view; public Matrix projection; protected Game game; KeyboardState currentKeyboardState; Vector3 cameraPosition = new Vector3(600.0f, 0.0f, 600.0f); Vector3 cameraForward = new Vector3(0, -0.4472136f, -0.8944272f); BoundingFrustum cameraFrustum = new BoundingFrustum(Matrix.Identity); // Light direction Vector3 lightDir = new Vector3(-0.3333333f, 0.6666667f, 0.6666667f); public Camera(Game game) : base(game) { this.game = game; } public override void Initialize() { this.view = Matrix.CreateLookAt(this.cameraPosition, this.cameraPosition + this.cameraForward, Vector3.Up); this.projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, this.game.renderer.aspectRatio, 1, 10000); base.Initialize(); } /* Handles the user input * @ param GameTime gameTime */ private void HandleInput(GameTime gameTime) { float time = (float)gameTime.ElapsedGameTime.TotalMilliseconds; currentKeyboardState = Keyboard.GetState(); } void UpdateCamera(GameTime gameTime) { float time = (float)gameTime.ElapsedGameTime.TotalMilliseconds; // Check for input to rotate the camera. float pitch = 0.0f; float turn = 0.0f; if (currentKeyboardState.IsKeyDown(Keys.Up)) pitch += time * 0.001f; if (currentKeyboardState.IsKeyDown(Keys.Down)) pitch -= time * 0.001f; if (currentKeyboardState.IsKeyDown(Keys.Left)) turn += time * 0.001f; if (currentKeyboardState.IsKeyDown(Keys.Right)) turn -= time * 0.001f; Vector3 cameraRight = Vector3.Cross(Vector3.Up, cameraForward); Vector3 flatFront = Vector3.Cross(cameraRight, Vector3.Up); Matrix pitchMatrix = Matrix.CreateFromAxisAngle(cameraRight, pitch); Matrix turnMatrix = Matrix.CreateFromAxisAngle(Vector3.Up, turn); Vector3 tiltedFront = Vector3.TransformNormal(cameraForward, pitchMatrix * turnMatrix); // Check angle so we cant flip over if (Vector3.Dot(tiltedFront, flatFront) > 0.001f) { cameraForward = Vector3.Normalize(tiltedFront); } // Check for input to move the camera around. if (currentKeyboardState.IsKeyDown(Keys.W)) cameraPosition += cameraForward * time * 0.4f; if (currentKeyboardState.IsKeyDown(Keys.S)) cameraPosition -= cameraForward * time * 0.4f; if (currentKeyboardState.IsKeyDown(Keys.A)) cameraPosition += cameraRight * time * 0.4f; if (currentKeyboardState.IsKeyDown(Keys.D)) cameraPosition -= cameraRight * time * 0.4f; if (currentKeyboardState.IsKeyDown(Keys.R)) { cameraPosition = new Vector3(0, 50, 50); cameraForward = new Vector3(0, 0, -1); } cameraForward.Normalize(); // Create the new view matrix view = Matrix.CreateLookAt(cameraPosition, cameraPosition + cameraForward, Vector3.Up); // Set the new frustum value cameraFrustum.Matrix = view * projection; } public override void Update(Microsoft.Xna.Framework.GameTime gameTime) { HandleInput(gameTime); UpdateCamera(gameTime); } } } The problem is that the initial view is looking in a horizontal direction. I would like to have an RTS like top down view (but with a slight pitch). Can you help me out?

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  • Best of OTN - Week of Oct 21st

    - by CassandraClark-OTN
    This week's Best of OTN, for you, the best devs, dba's, sysadmins and architects out there!  In these weekly posts the OTN team will highlight the top content from each community; Architect, Database, Systems and Java.  Since we'll be publishing this on Fridays, we'll also mix in a little fun! Architect Community Top Content- The Road Ahead for WebLogic 12c | Edwin BiemondOracle ACE Edwin Biemond shares his thoughts on announced new features in Oracle WebLogic 12.1.3 & 12.1.4 and compares those upcoming releases to Oracle WebLogic 12.1.2. A Roadmap for SOA Development and Delivery | Mark NelsonDo you know the way to S-O-A? Mark Nelson does. His latest blog post, part of an ongoing series, will help to keep you from getting lost along the way. Updated ODI Statement of Direction | Robert SchweighardtHeads up Oracle Data Integrator fans! A new statement of product direction document is available, offering an overview of the strategic product plans for Oracle’s data integration products for bulk data movement and transformation, specifically Oracle Data Integrator (ODI) and Oracle Warehouse Builder (OWB). Bob Rhubart, Architect Community Manager Friday Funny - "Some people approach every problem with an open mouth." — Adlai E. Stevenson (October 23, 1835 – June 14, 1914) 23rd Vice President of the United States Database Community Top Content - Pre-Built Developer VMs (for Oracle VM VirtualBox)Heard all the chatter about Oracle VirtualBox? Over 1 million downloads per week and look: pre-built virtual appliances designed specifically for developers. Video: Big Data, or BIG DATA?Oracle Ace Director Ben Prusinski explains the differences.?? Webcast Series - Developing Applications in Oracle's Public CloudTime to get started on developing and deploying cloud applications by moving to the cloud. Good friend Gene Eun from Oracle's Cloud team posted this two-part Webcast series that has an overview and demonstration of the Oracle Database Cloud Service. Check out the demos on how to migrate your data to the cloud, extend your application with interactive reporting, and create and access RESTful Web services. Registration required, but so worth it! Laura Ramsey, Database Community Manager Friday Funny - Systems Community Top Content - Video: What Kind of Scalability is Better, Horizontal or Vertical?Rick Ramsey asks the question "Is Oracle's approach to large vertically scaled servers at odds with today's trend of combining lots and lots of small, low-cost servers systems with networking to build a cloud, or is it a better approach?" Michael Palmeter, Director of Solaris Product Management, and Renato Ribeiro, Director Product Management for SPARC Servers, discuss.Video: An Engineer Takes a Minute to Explain CloudBart Smaalders, long-time Oracle Solaris core engineer, takes a minute to explain cloud from a sysadmin point of view. ?Hands-On Lab: How to Deploy and Manage a Private IaaS Cloud Soup to nuts. This lab shows you how to set up and manage a private cloud with Oracle Enterprise Manager Cloud Control 12c in an Infrastructure as a service (IaaS) model. You will first configure the IaaS cloud as the cloud administrator and then deploy guest virtual machines (VMs) as a self-service user. Rick Ramsey, Systems Community Manager Friday Funny - Video: Drunk Airline Pilot - Dean Martin - Foster Brooks Java Community Top Content - Video: NightHacking Interview with James GoslingJames Gosling, the Father of Java, discusses robotics, Java and how to keep his autonomous WaveGliders in the ocean for weeks at a time. Live from Hawaii.  Video: Raspberry Pi Developer Challenge: Remote Controller A developer who knew nothing about Java Embedded or Raspberry Pi shows how he can now control a robot with his phone. The project was built during the Java Embedded Challenge for Raspberry Pi at JavaOne 2013.Java EE 7 Certification Survey - Participants NeededHelp us define how to server your training and certification needs for Java EE 7. Tori Wieldt, Java Community Manager Friday Funny - Programmers have a strong sensitivity to Yak's pheromone. Causes irresistible desire to shave said Yak. Thanks, @rickasaurus! To follow and take part in the conversation follow/like etc. at one or all of the resources below -  OTN TechBlog The Java Source Blog The OTN Garage Blog The OTN ArchBeat Blog @oracletechnet @java @OTN_Garage @OTNArchBeat @OracleDBDev OTN I Love Java OTN Garage OTN ArchBeat Oracle DB Dev OTN Java

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  • Blueprints for Oracle NoSQL Database

    - by dan.mcclary
    I think that some of the most interesting analytic problems are graph problems.  I'm always interested in new ways to store and access graphs.  As such, I really like the work being done by Tinkerpop to create Open Source Software to make property graphs more accessible over a wide variety of datastores.  Since key-value stores like Oracle NoSQL Database are well-suited to storing property graphs, I decided to extend the Blueprints API to work with it.  Below I'll discuss some of the implementation details, but you can check out the finished product here: http://github.com/dwmclary/blueprints-oracle-nosqldb.  What's in a Property Graph?  In the most general sense, a graph is just a collection of vertices and edges.  Vertices and edges can have properties: weights, names, or any number of other traits.  In an undirected graph, edges connect vertices without direction.  A directed graph specifies that all edges have a head and a tail --- a direction.  A multi-graph allows multiple edges to connect two vertices.  A "property graph" encompasses all of these traits. Key-Value Stores for Property Graphs Key-Value stores like Oracle NoSQL Database tend to be ideal for implementing property graphs.  First, if any vertex or edge can have any number of traits, we can treat it as a hash map.  For example: Vertex["name"] = "Mary" Vertex["age"] = 28 Vertex["ID"] = 12345  and so on.  This is a natural key-value relationship: the key "name" maps to the value "Mary."  Moreover if we maintain two hash maps, one for vertex objects and one for edge objects, we've essentially captured the graph.  As such, any scalable key-value store is fertile ground for planting graphs. Oracle NoSQL Database as a Scalable Graph Database While Oracle NoSQL Database offers useful features like tunable consistency, what lends it to storing property graphs is the storage guarantees around its key structure.  Keys in Oracle NoSQL Database are divided into two parts: a major key and a minor key.  The storage guarantee is simple.  Major keys will be distributed across storage nodes, which could encompass a large number of servers.  However, all minor keys which are children of a given major key are guaranteed to be stored on the same storage node.  For example, the vertices: /Personnel/Vertex/1  and /Personnel/Vertex/2 May be stored on different servers, but /Personnel/Vertex/1-/name and  /Personnel/Vertex/1-/age will always be on the same server.  This means that we can structure our graph database such that retrieving all the properties for a vertex or edge requires I/O from only a single storage node.  Moreover, Oracle NoSQL Database provides a storeIterator which allows us to store a huge number of vertices and edges in a scalable fashion.  By storing the vertices and edges as major keys, we guarantee that they are distributed evenly across all storage nodes.  At the same time we can use a partial major key to iterate over all the vertices or edges (e.g. we search over /Personnel/Vertex to iterate over all vertices). Fork It! The Blueprints API and Oracle NoSQL Database present a great way to get started using a scalable key-value database to store and access graph data.  However, a graph store isn't useful without a good graph to work on.  I encourage you to fork or pull the repository, store some data, and try using Gremlin or any other language to explore.

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  • Cocos2d Box2d how to shoot an object inside the screen

    - by Ahoura Ghotbi
    I have the code below : - (id) initWithGame:(mainGame*)game { if ((self = [super init])) { isTouchEnabled_ = YES; self.game = game; CGSize size = [[CCDirector sharedDirector] winSize]; screenH = size.height; screenW = size.width; character = [CCSprite spriteWithFile:@"o.png"]; character.position = ccp( size.width /2 , size.height/2 ); character.contentSize = CGSizeMake(72, 79); [self addChild:character z:10 tag:1]; _body = NULL; _radius = 14.0f; // Create ball body and shape b2BodyDef ballBodyDef; ballBodyDef.type = b2_dynamicBody; ballBodyDef.position.Set(100/PTM_RATIO, 100/PTM_RATIO); ballBodyDef.userData = character; _body = _game.world->CreateBody(&ballBodyDef); b2CircleShape circle; circle.m_radius = 26.0/PTM_RATIO; b2FixtureDef ballShapeDef; ballShapeDef.shape = &circle; ballShapeDef.density = 1.0f; ballShapeDef.friction = 0.2f; ballShapeDef.restitution = 0.8f; _body->CreateFixture(&ballShapeDef); [self schedule:@selector(gameChecker:)]; [self schedule:@selector(tick:)]; } return self; } - (void)gameChecker:(ccTime) dt{ if(character.position.y > 200){ [self unschedule:@selector(tick:)]; [self schedule:@selector(dropObject:)]; } } - (void)tick:(ccTime) dt { b2Vec2 force; force.Set(_body->GetLinearVelocity().x, _body->GetLinearVelocity().y+1.0f); for (b2Body* b = _game.world->GetBodyList(); b; b = b->GetNext()) { if (b->GetUserData() == character) { b->SetLinearVelocity(force); } } _game.world->Step(dt, 10, 10); for(b2Body *b = _game.world->GetBodyList(); b; b=b->GetNext()) { if (b->GetUserData() != NULL) { CCSprite *ballData = (CCSprite *)b->GetUserData(); ballData.position = ccp(b->GetPosition().x * PTM_RATIO, b->GetPosition().y * PTM_RATIO); ballData.rotation = -1 * CC_RADIANS_TO_DEGREES(b->GetAngle()); } } } -(void)dropObject:(ccTime) dt{ b2Vec2 force; force.Set(_body->GetLinearVelocity().x, _body->GetLinearVelocity().y-1.0f); for (b2Body* b = _game.world->GetBodyList(); b; b = b->GetNext()) { if (b->GetUserData() == character) { b->SetLinearVelocity(force); } } _game.world->Step(dt, 10, 10); for(b2Body *b = _game.world->GetBodyList(); b; b=b->GetNext()) { if (b->GetUserData() != NULL) { CCSprite *ballData = (CCSprite *)b->GetUserData(); ballData.position = ccp(b->GetPosition().x * PTM_RATIO, b->GetPosition().y * PTM_RATIO); ballData.rotation = -1 * CC_RADIANS_TO_DEGREES(b->GetAngle()); } } } I have been trying to get the effect that fruit ninja has when shooting the fruits. but it seems like its hard to get such animation so I was wondering if anyone can point me to the right direction and/or give me a sample code for a single object that gets thrown into the screen with a direction.

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  • RPi and Java Embedded GPIO: Sensor Reading using Java Code

    - by hinkmond
    And, now to program the Java code for reading the fancy-schmancy static electricity sensor connected to your Raspberry Pi, here is the source code we'll use: First, we need to initialize ourselves... /* * Java Embedded Raspberry Pi GPIO Input app */ package jerpigpioinput; import java.io.FileWriter; import java.io.RandomAccessFile; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Calendar; /** * * @author hinkmond */ public class JerpiGPIOInput { static final String GPIO_IN = "in"; // Add which GPIO ports to read here static String[] GpioChannels = { "7" }; /** * @param args the command line arguments */ public static void main(String[] args) { try { /*** Init GPIO port(s) for input ***/ // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); for (String gpioChannel : GpioChannels) { System.out.println(gpioChannel); // Reset the port unexportFile.write(gpioChannel); unexportFile.flush(); // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write(GPIO_IN); directionFile.flush(); } And, next we will open up a RandomAccessFile pointer to the GPIO port. /*** Read data from each GPIO port ***/ RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; int sleepPeriod = 10; final int MAXBUF = 256; byte[] inBytes = new byte[MAXBUF]; String inLine; int zeroCounter = 0; // Get current timestamp with Calendar() Calendar cal; DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS"); String dateStr; // Open RandomAccessFile handle to each GPIO port for (int channum=0; channum Then, loop forever to read in the values to the console. // Loop forever while (true) { // Get current timestamp for latest event cal = Calendar.getInstance(); dateStr = dateFormat.format(cal.getTime()); // Use RandomAccessFile handle to read in GPIO port value for (int channum=0; channum Rinse, lather, and repeat... Compile this Java code on your host PC or Mac with javac from the JDK. Copy over the JAR or class file to your Raspberry Pi, "sudo -i" to become root, then start up this Java app in a shell on your RPi. That's it! You should see a "1" value get logged each time you bring a statically charged item (like a balloon you rub on the cat) near the antenna of the sensor. There you go. You've just seen how Java Embedded technology on the Raspberry Pi is an easy way to access sensors. Hinkmond

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  • Problems implementing a screen space shadow ray tracing shader

    - by Grieverheart
    Here I previously asked for the possibility of ray tracing shadows in screen space in a deferred shader. Several problems were pointed out. One of the most important problem is that only visible objects can cast shadows and objects between the camera and the shadow caster can interfere. Still I thought it'd be a fun experiment. The idea is to calculate the view coordinates of pixels and cast a ray to the light. The ray is then traced pixel by pixel to the light and its depth is compared with the depth at the pixel. If a pixel is in front of the ray, a shadow is casted at the original pixel. At first I thought that I could use the DDA algorithm in 2D to calculate the distance 't' (in p = o + t d, where o origin, d direction) to the next pixel and use it in the 3D ray equation to find the ray's z coordinate at that pixel's position. For the 2D ray, I would use the projected and biased 3D ray direction and origin. The idea was that 't' would be the same in both 2D and 3D equations. Unfortunately, this is not the case since the projection matrix is 4D. Thus, some tweak needs to be done to make this work this way. I would like to ask if someone knows of a way to do what I described above, i.e. from a 2D ray in texture coordinate space to get the 3D ray in screen space. I did implement a simple version of the idea which you can see in the following video: video here Shadows may seem a bit pixelated, but that's mostly because of the size of the step in 't' I chose. And here is the shader: #version 330 core uniform sampler2D DepthMap; uniform vec2 projAB; uniform mat4 projectionMatrix; const vec3 light_p = vec3(-30.0, 30.0, -10.0); noperspective in vec2 pass_TexCoord; smooth in vec3 viewRay; layout(location = 0) out float out_AO; vec3 CalcPosition(void){ float depth = texture(DepthMap, pass_TexCoord).r; float linearDepth = projAB.y / (depth - projAB.x); vec3 ray = normalize(viewRay); ray = ray / ray.z; return linearDepth * ray; } void main(void){ vec3 origin = CalcPosition(); if(origin.z < -60) discard; vec2 pixOrigin = pass_TexCoord; //tex coords vec3 dir = normalize(light_p - origin); vec2 texel_size = vec2(1.0 / 600.0); float t = 0.1; ivec2 pixIndex = ivec2(pixOrigin / texel_size); out_AO = 1.0; while(true){ vec3 ray = origin + t * dir; vec4 temp = projectionMatrix * vec4(ray, 1.0); vec2 texCoord = (temp.xy / temp.w) * 0.5 + 0.5; ivec2 newIndex = ivec2(texCoord / texel_size); if(newIndex != pixIndex){ float depth = texture(DepthMap, texCoord).r; float linearDepth = projAB.y / (depth - projAB.x); if(linearDepth > ray.z + 0.1){ out_AO = 0.2; break; } pixIndex = newIndex; } t += 0.5; if(texCoord.x < 0 || texCoord.x > 1.0 || texCoord.y < 0 || texCoord.y > 1.0) break; } } As you can see, here I just increment 't' by some arbitrary factor, calculate the 3D ray and project it to get the pixel coordinates, which is not really optimal. Hopefully, I would like to optimize the code as much as possible and compare it with shadow mapping and how it scales with the number of lights. PS: Keep in mind that I reconstruct position from depth by interpolating rays through a full screen quad.

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  • Shadows shimmer when camera moves

    - by Chad Layton
    I've implemented shadow maps in my simple block engine as an exercise. I'm using one directional light and using the view volume to create the shadow matrices. I'm experiencing some problems with the shadows shimmering when the camera moves and I'd like to know if it's an issue with my implementation or just an issue with basic/naive shadow mapping itself. Here's a video: http://www.youtube.com/watch?v=vyprATt5BBg&feature=youtu.be Here's the code I use to create the shadow matrices. The commented out code is my original attempt to perfectly fit the view frustum. You can also see my attempt to try clamping movement to texels in the shadow map which didn't seem to make any difference. Then I tried using a bounding sphere instead, also to no apparent effect. public void CreateViewProjectionTransformsToFit(Camera camera, out Matrix viewTransform, out Matrix projectionTransform, out Vector3 position) { BoundingSphere cameraViewFrustumBoundingSphere = BoundingSphere.CreateFromFrustum(camera.ViewFrustum); float lightNearPlaneDistance = 1.0f; Vector3 lookAt = cameraViewFrustumBoundingSphere.Center; float distanceFromLookAt = cameraViewFrustumBoundingSphere.Radius + lightNearPlaneDistance; Vector3 directionFromLookAt = -Direction * distanceFromLookAt; position = lookAt + directionFromLookAt; viewTransform = Matrix.CreateLookAt(position, lookAt, Vector3.Up); float lightFarPlaneDistance = distanceFromLookAt + cameraViewFrustumBoundingSphere.Radius; float diameter = cameraViewFrustumBoundingSphere.Radius * 2.0f; Matrix.CreateOrthographic(diameter, diameter, lightNearPlaneDistance, lightFarPlaneDistance, out projectionTransform); //Vector3 cameraViewFrustumCentroid = camera.ViewFrustum.GetCentroid(); //position = cameraViewFrustumCentroid - (Direction * (camera.FarPlaneDistance - camera.NearPlaneDistance)); //viewTransform = Matrix.CreateLookAt(position, cameraViewFrustumCentroid, Up); //Vector3[] cameraViewFrustumCornersWS = camera.ViewFrustum.GetCorners(); //Vector3[] cameraViewFrustumCornersLS = new Vector3[8]; //Vector3.Transform(cameraViewFrustumCornersWS, ref viewTransform, cameraViewFrustumCornersLS); //Vector3 min = cameraViewFrustumCornersLS[0]; //Vector3 max = cameraViewFrustumCornersLS[0]; //for (int i = 1; i < 8; i++) //{ // min = Vector3.Min(min, cameraViewFrustumCornersLS[i]); // max = Vector3.Max(max, cameraViewFrustumCornersLS[i]); //} //// Clamp to nearest texel //float texelSize = 1.0f / Renderer.ShadowMapSize; //min.X -= min.X % texelSize; //min.Y -= min.Y % texelSize; //min.Z -= min.Z % texelSize; //max.X -= max.X % texelSize; //max.Y -= max.Y % texelSize; //max.Z -= max.Z % texelSize; //// We just use an orthographic projection matrix. The sun is so far away that it's rays are essentially parallel. //Matrix.CreateOrthographicOffCenter(min.X, max.X, min.Y, max.Y, -max.Z, -min.Z, out projectionTransform); } And here's the relevant part of the shader: if (CastShadows) { float4 positionLightCS = mul(float4(position, 1.0f), LightViewProj); float2 texCoord = clipSpaceToScreen(positionLightCS) + 0.5f / ShadowMapSize; float shadowMapDepth = tex2D(ShadowMapSampler, texCoord).r; float distanceToLight = length(LightPosition - position); float bias = 0.2f; if (shadowMapDepth < (distanceToLight - bias)) { return float4(0.0f, 0.0f, 0.0f, 0.0f); } } The shimmer is slightly better if I drastically reduce the view volume but I think that's mostly just because the texels become smaller and it's harder to notice them flickering back and forth. I'd appreciate any insight, I'd very much like to understand what's going on before I try other techniques.

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  • Simple OpenGL program major slow down at high resolution

    - by Grieverheart
    I have created a small OpenGL 3.3 (Core) program using freeglut. The whole geometry is two boxes and one plane with some textures. I can move around like in an FPS and that's it. The problem is I face a big slow down of fps when I make my window large (i.e. above 1920x1080). I have monitors GPU usage when in full-screen and it shows GPU load of nearly 100% and Memory Controller load of ~85%. When at 600x600, these numbers are at about 45%, my CPU is also at full load. I use deferred rendering at the moment but even when forward rendering, the slow down was nearly as severe. I can't imagine my GPU is not powerful enough for something this simple when I play many games at 1080p (I have a GeForce GT 120M btw). Below are my shaders, First Pass #VS #version 330 core uniform mat4 ModelViewMatrix; uniform mat3 NormalMatrix; uniform mat4 MVPMatrix; uniform float scale; layout(location = 0) in vec3 in_Position; layout(location = 1) in vec3 in_Normal; layout(location = 2) in vec2 in_TexCoord; smooth out vec3 pass_Normal; smooth out vec3 pass_Position; smooth out vec2 TexCoord; void main(void){ pass_Position = (ModelViewMatrix * vec4(scale * in_Position, 1.0)).xyz; pass_Normal = NormalMatrix * in_Normal; TexCoord = in_TexCoord; gl_Position = MVPMatrix * vec4(scale * in_Position, 1.0); } #FS #version 330 core uniform sampler2D inSampler; smooth in vec3 pass_Normal; smooth in vec3 pass_Position; smooth in vec2 TexCoord; layout(location = 0) out vec3 outPosition; layout(location = 1) out vec3 outDiffuse; layout(location = 2) out vec3 outNormal; void main(void){ outPosition = pass_Position; outDiffuse = texture(inSampler, TexCoord).xyz; outNormal = pass_Normal; } Second Pass #VS #version 330 core uniform float scale; layout(location = 0) in vec3 in_Position; void main(void){ gl_Position = mat4(1.0) * vec4(scale * in_Position, 1.0); } #FS #version 330 core struct Light{ vec3 direction; }; uniform ivec2 ScreenSize; uniform Light light; uniform sampler2D PositionMap; uniform sampler2D ColorMap; uniform sampler2D NormalMap; out vec4 out_Color; vec2 CalcTexCoord(void){ return gl_FragCoord.xy / ScreenSize; } vec4 CalcLight(vec3 position, vec3 normal){ vec4 DiffuseColor = vec4(0.0); vec4 SpecularColor = vec4(0.0); vec3 light_Direction = -normalize(light.direction); float diffuse = max(0.0, dot(normal, light_Direction)); if(diffuse 0.0){ DiffuseColor = diffuse * vec4(1.0); vec3 camera_Direction = normalize(-position); vec3 half_vector = normalize(camera_Direction + light_Direction); float specular = max(0.0, dot(normal, half_vector)); float fspecular = pow(specular, 128.0); SpecularColor = fspecular * vec4(1.0); } return DiffuseColor + SpecularColor + vec4(0.1); } void main(void){ vec2 TexCoord = CalcTexCoord(); vec3 Position = texture(PositionMap, TexCoord).xyz; vec3 Color = texture(ColorMap, TexCoord).xyz; vec3 Normal = normalize(texture(NormalMap, TexCoord).xyz); out_Color = vec4(Color, 1.0) * CalcLight(Position, Normal); } Is it normal for the GPU to be used that much under the described circumstances? Is it due to poor performance of freeglut? I understand that the problem could be specific to my code, but I can't paste the whole code here, if you need more info, please tell me.

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  • Calculating for leap year [migrated]

    - by Bradley Bauer
    I've written this program using Java in Eclipse. I was able to utilize a formula I found that I explained in the commented out section. Using the for loop I can iterate through each month of the year, which I feel good about in that code, it seems clean and smooth to me. Maybe I could give the variables full names to make everything more readable but I'm just using the formula in its basic essence :) Well my problem is it doesn't calculate correctly for years like 2008... Leap Years. I know that if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) then we have a leap year. Maybe if the year is a leap year I need to subtract a certain amount of days from a certain month. Any solutions, or some direction would be great thanks :) package exercises; public class E28 { /* * Display the first days of each month * Enter the year * Enter first day of the year * * h = (q + (26 * (m + 1)) / 10 + k + k/4 + j/4 + 5j) % 7 * * h is the day of the week (0: Saturday, 1: Sunday ......) * q is the day of the month * m is the month (3: March 4: April.... January and Feburary are 13 and 14) * j is the century (year / 100) * k is the year of the century (year %100) * */ public static void main(String[] args) { java.util.Scanner input = new java.util.Scanner(System.in); System.out.print("Enter the year: "); int year = input.nextInt(); int j = year / 100; // Find century for formula int k = year % 100; // Find year of century for formula // Loop iterates 12 times. Guess why. for (int i = 1, m = i; i <= 12; i++) { // Make m = i. So loop processes formula once for each month if (m == 1 || m == 2) m += 12; // Formula requires that Jan and Feb are represented as 13 and 14 else m = i; // if not jan or feb, then set m to i int h = (1 + (26 * (m + 1)) / 10 + k + k/4 + j/4 + 5 * j) % 7; // Formula created by a really smart man somewhere // I let the control variable i steer the direction of the formual's m value String day; if (h == 0) day = "Saturday"; else if (h == 1) day = "Sunday"; else if (h == 2) day = "Monday"; else if (h == 3) day = "Tuesday"; else if (h == 4) day = "Wednesday"; else if (h == 5) day = "Thursday"; else day = "Friday"; switch (m) { case 13: System.out.println("January 1, " + year + " is " + day); break; case 14: System.out.println("Feburary 1, " + year + " is " + day); break; case 3: System.out.println("March 1, " + year + " is " + day); break; case 4: System.out.println("April 1, " + year + " is " + day); break; case 5: System.out.println("May 1, " + year + " is " + day); break; case 6: System.out.println("June 1, " + year + " is " + day); break; case 7: System.out.println("July 1, " + year + " is " + day); break; case 8: System.out.println("August 1, " + year + " is " + day); break; case 9: System.out.println("September 1, " + year + " is " + day); break; case 10: System.out.println("October 1, " + year + " is " + day); break; case 11: System.out.println("November 1, " + year + " is " + day); break; case 12: System.out.println("December 1, " + year + " is " + day); break; } } } }

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  • Incorrect lighting results with deferred rendering

    - by Lasse
    I am trying to render a light-pass to a texture which I will later apply on the scene. But I seem to calculate the light position wrong. I am working on view-space. In the image above, I am outputting the attenuation of a point light which is currently covering the whole screen. The light is at 0,10,0 position, and I transform it to view-space first: Vector4 pos; Vector4 tmp = new Vector4 (light.Position, 1); // Transform light position for shader Vector4.Transform (ref tmp, ref Camera.ViewMatrix, out pos); shader.SendUniform ("LightViewPosition", ref pos); Now to me that does not look as it should. What I think it should look like is that the white area should be on the center of the scene. The camera is at the corner of the scene, and it seems as if the light would move along with the camera. Here's the fragment shader code: void main(){ // default black color vec3 color = vec3(0); // Pixel coordinates on screen without depth vec2 PixelCoordinates = gl_FragCoord.xy / ScreenSize; // Get pixel position using depth from texture vec4 depthtexel = texture( DepthTexture, PixelCoordinates ); float depthSample = unpack_depth(depthtexel); // Get pixel coordinates on camera-space by multiplying the // coordinate on screen-space by inverse projection matrix vec4 world = (ImP * RemapMatrix * vec4(PixelCoordinates, depthSample, 1.0)); // Undo the perspective calculations vec3 pixelPosition = (world.xyz / world.w) * 3; // How far the light should reach from it's point of origin float lightReach = LightColor.a / 2; // Vector in between light and pixel vec3 lightDir = (LightViewPosition.xyz - pixelPosition); float lightDistance = length(lightDir); vec3 lightDirN = normalize(lightDir); // Discard pixels too far from light source //if(lightReach < lightDistance) discard; // Get normal from texture vec3 normal = normalize((texture( NormalTexture, PixelCoordinates ).xyz * 2) - 1); // Half vector between the light direction and eye, used for specular component vec3 halfVector = normalize(lightDirN + normalize(-pixelPosition)); // Dot product of normal and light direction float NdotL = dot(normal, lightDirN); float attenuation = pow(lightReach / lightDistance, LightFalloff); // If pixel is lit by the light if(NdotL > 0) { // I have moved stuff from here to above so I can debug them. // Diffuse light color color += LightColor.rgb * NdotL * attenuation; // Specular light color color += LightColor.xyz * pow(max(dot(halfVector, normal), 0.0), 4.0) * attenuation; } RT0 = vec4(color, 1); //RT0 = vec4(pixelPosition, 1); //RT0 = vec4(depthSample, depthSample, depthSample, 1); //RT0 = vec4(NdotL, NdotL, NdotL, 1); RT0 = vec4(attenuation, attenuation, attenuation, 1); //RT0 = vec4(lightReach, lightReach, lightReach, 1); //RT0 = depthtexel; //RT0 = 100 / vec4(lightDistance, lightDistance, lightDistance, 1); //RT0 = vec4(lightDirN, 1); //RT0 = vec4(halfVector, 1); //RT0 = vec4(LightColor.xyz,1); //RT0 = vec4(LightViewPosition.xyz/100, 1); //RT0 = vec4(LightPosition.xyz, 1); //RT0 = vec4(normal,1); } What am I doing wrong here?

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  • Numerically stable(ish) method of getting Y-intercept of mouse position?

    - by Fraser
    I'm trying to unproject the mouse position to get the position on the X-Z plane of a ray cast from the mouse. The camera is fully controllable by the user. Right now, the algorithm I'm using is... Unproject the mouse into the camera to get the ray: Vector3 p1 = Vector3.Unproject(new Vector3(x, y, 0), 0, 0, width, height, nearPlane, farPlane, viewProj; Vector3 p2 = Vector3.Unproject(new Vector3(x, y, 1), 0, 0, width, height, nearPlane, farPlane, viewProj); Vector3 dir = p2 - p1; dir.Normalize(); Ray ray = Ray(p1, dir); Then get the Y-intercept by using algebra: float t = -ray.Position.Y / ray.Direction.Y; Vector3 p = ray.Position + t * ray.Direction; The problem is that the projected position is "jumpy". As I make small adjustments to the mouse position, the projected point moves in strange ways. For example, if I move the mouse one pixel up, it will sometimes move the projected position down, but when I move it a second pixel, the project position will jump back to the mouse's location. The projected location is always close to where it should be, but it does not smoothly follow a moving mouse. The problem intensifies as I zoom the camera out. I believe the problem is caused by numeric instability. I can make minor improvements to this by doing some computations at double precision, and possibly abusing the fact that floating point calculations are done at 80-bit precision on x86, however before I start micro-optimizing this and getting deep into how the CLR handles floating point, I was wondering if there's an algorithmic change I can do to improve this? EDIT: A little snooping around in .NET Reflector on SlimDX.dll: public static Vector3 Unproject(Vector3 vector, float x, float y, float width, float height, float minZ, float maxZ, Matrix worldViewProjection) { Vector3 coordinate = new Vector3(); Matrix result = new Matrix(); Matrix.Invert(ref worldViewProjection, out result); coordinate.X = (float) ((((vector.X - x) / ((double) width)) * 2.0) - 1.0); coordinate.Y = (float) -((((vector.Y - y) / ((double) height)) * 2.0) - 1.0); coordinate.Z = (vector.Z - minZ) / (maxZ - minZ); TransformCoordinate(ref coordinate, ref result, out coordinate); return coordinate; } // ... public static void TransformCoordinate(ref Vector3 coordinate, ref Matrix transformation, out Vector3 result) { Vector3 vector; Vector4 vector2 = new Vector4 { X = (((coordinate.Y * transformation.M21) + (coordinate.X * transformation.M11)) + (coordinate.Z * transformation.M31)) + transformation.M41, Y = (((coordinate.Y * transformation.M22) + (coordinate.X * transformation.M12)) + (coordinate.Z * transformation.M32)) + transformation.M42, Z = (((coordinate.Y * transformation.M23) + (coordinate.X * transformation.M13)) + (coordinate.Z * transformation.M33)) + transformation.M43 }; float num = (float) (1.0 / ((((transformation.M24 * coordinate.Y) + (transformation.M14 * coordinate.X)) + (coordinate.Z * transformation.M34)) + transformation.M44)); vector2.W = num; vector.X = vector2.X * num; vector.Y = vector2.Y * num; vector.Z = vector2.Z * num; result = vector; } ...which seems to be a pretty standard method of unprojecting a point from a projection matrix, however this serves to introduce another point of possible instability. Still, I'd like to stick with the SlimDX Unproject routine rather than writing my own unless it's really necessary.

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  • Approach for packing 2D shapes while minimizing total enclosing area

    - by Dennis
    Not sure on my tags for this question, but in short .... I need to solve a problem of packing industrial parts into crates while minimizing total containing area. These parts are motors, or pumps, or custom-made components, and they have quite unusual shapes. For some, it may be possible to assume that a part === rectangular cuboid, but some are not so simple, i.e. they assume a shape more of that of a hammer or letter T. With those, (assuming 2D shape), by alternating direction of top & bottom, one can pack more objects into the same space, than if all tops were in the same direction. Crude example below with letter "T"-shaped parts: ***** xxxxx ***** x ***** *** ooo * x vs * x vs * x vs * x o * x * xxxxx * x * x o xxxxx xxx Right now we are solving the problem by something like this: using CAD software, make actual models of how things fit in crate boxes make estimates of actual crate dimensions & write them into Excel file (1) is crazy amount of work and as the result we have just a limited amount of possible entries in (2), the Excel file. The good things is that programming this is relatively easy. Given a combination of products to go into crates, we do a lookup, and if entry exists in the Excel (or Database), we bring it out. If it doesn't, we say "sorry, no data!". I don't necessarily want to go full force on making up some crazy algorithm that given geometrical part description can align, rotate, and figure out best part packing into a crate, given its shape, but maybe I do.. Question Well, here is my question: assuming that I can represent my parts as 2D (to be determined how), and that some parts look like letter T, and some parts look like rectangles, which algorithm can I use to give me a good estimate on the dimensions of the encompassing area, while ensuring that the parts are packed in a minimal possible area, to minimize crating/shipping costs? Are there approximation algorithms? Seeing how this can get complex, is there an existing library I could use? My thought / Approach My naive approach would be to define a way to describe position of parts, and place the first part, compute total enclosing area & dimensions. Then place 2nd part in 0 degree orientation, repeat, place it at 180 degree orientation, repeat (for my case I don't think 90 degree rotations will be meaningful due to long lengths of parts). Proceed using brute force "tacking on" other parts to the enclosing area until all parts are processed. I may have to shift some parts a tad (see 3rd pictorial example above with letters T). This adds a layer of 2D complexity rather than 1D. I am not sure how to approach this. One idea I have is genetic algorithms, but I think those will take up too much processing power and time. I will need to look out for shape collisions, as well as adding extra padding space, since we are talking about real parts with irregularities rather than perfect imaginary blocks. I'm afraid this can get geometrically messy fairly fast, and I'd rather keep things simple, if I can. But what if the best (practical) solution is to pack things into different crate boxes rather than just one? This can get a bit more tricky. There is human element involved as well, i.e. like parts can go into same box and are thus a constraint to be considered. Some parts that are not the same are sometimes grouped together for shipping and can be considered as a common grouped item. Sometimes customers want things shipped their way, which adds human element to constraints. so there will have to be some customization.

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  • Bounding Box Collision Glitching Problem (Pygame)

    - by Ericson Willians
    So far the "Bounding Box" method is the only one that I know. It's efficient enough to deal with simple games. Nevertheless, the game I'm developing is not that simple anymore and for that reason, I've made a simplified example of the problem. (It's worth noticing that I don't have rotating sprites on my game or anything like that. After showing the code, I'll explain better). Here's the whole code: from pygame import * DONE = False screen = display.set_mode((1024,768)) class Thing(): def __init__(self,x,y,w,h,s,c): self.x = x self.y = y self.w = w self.h = h self.s = s self.sur = Surface((64,48)) draw.rect(self.sur,c,(self.x,self.y,w,h),1) self.sur.fill(c) def draw(self): screen.blit(self.sur,(self.x,self.y)) def move(self,x): if key.get_pressed()[K_w] or key.get_pressed()[K_UP]: if x == 1: self.y -= self.s else: self.y += self.s if key.get_pressed()[K_s] or key.get_pressed()[K_DOWN]: if x == 1: self.y += self.s else: self.y -= self.s if key.get_pressed()[K_a] or key.get_pressed()[K_LEFT]: if x == 1: self.x -= self.s else: self.x += self.s if key.get_pressed()[K_d] or key.get_pressed()[K_RIGHT]: if x == 1: self.x += self.s else: self.x -= self.s def warp(self): if self.y < -48: self.y = 768 if self.y > 768 + 48: self.y = 0 if self.x < -64: self.x = 1024 + 64 if self.x > 1024 + 64: self.x = -64 r1 = Thing(0,0,64,48,1,(0,255,0)) r2 = Thing(6*64,6*48,64,48,1,(255,0,0)) while not DONE: screen.fill((0,0,0)) r2.draw() r1.draw() # If not intersecting, then moves, else, it moves in the opposite direction. if not ((((r1.x + r1.w) > (r2.x - r1.s)) and (r1.x < ((r2.x + r2.w) + r1.s))) and (((r1.y + r1.h) > (r2.y - r1.s)) and (r1.y < ((r2.y + r2.h) + r1.s)))): r1.move(1) else: r1.move(0) r1.warp() if key.get_pressed()[K_ESCAPE]: DONE = True for ev in event.get(): if ev.type == QUIT: DONE = True display.update() quit() The problem: In my actual game, the grid is fixed and each tile has 64 by 48 pixels. I know how to deal with collision perfectly if I moved by that size. Nevertheless, obviously, the player moves really fast. In the example, the collision is detected pretty well (Just as I see in many examples throughout the internet). The problem is that if I put the player to move WHEN IS NOT intersecting, then, when it touches the obstacle, it does not move anymore. Giving that problem, I began switching the directions, but then, when it touches and I press the opposite key, it "glitches through". My actual game has many walls, and the player will touch them many times, and I can't afford letting the player go through them. The code-problem illustrated: When the player goes towards the wall (Fine). When the player goes towards the wall and press the opposite direction. (It glitches through). Here is the logic I've designed before implementing it: I don't know any other method, and I really just want to have walls fixed in a grid, but move by 1 or 2 or 3 pixels (Slowly) and have perfect collision without glitching-possibilities. What do you suggest?

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  • XNA - 3D AABB collision detection and response

    - by fastinvsqrt
    I've been fiddling around with 3D AABB collision in my voxel engine for the last couple of days, and every method I've come up with thus far has been almost correct, but each one never quite worked exactly the way I hoped it would. Currently what I do is get two bounding boxes for my entity, one modified by the X translation component and the other by the Z component, and check if each collides with any of the surrounding chunks (chunks have their own octrees that are populated only with blocks that support collision). If there is a collision, then I cast out rays into that chunk to get the shortest collision distance, and set the translation component to that distance if the component is greater than the distance. The problem is that sometimes collisions aren't even registered. Here's a video on YouTube that I created showing what I mean. I suspect the problem may be with the rays that I cast to get the collision distance not being where I think they are, but I'm not entirely sure what would be wrong with them if they are indeed the problem. Here is my code for collision detection and response in the X direction (the Z direction is basically the same): // create the XZ offset vector Vector3 offsXZ = new Vector3( ( _translation.X > 0.0f ) ? SizeX / 2.0f : ( _translation.X < 0.0f ) ? -SizeX / 2.0f : 0.0f, 0.0f, ( _translation.Z > 0.0f ) ? SizeZ / 2.0f : ( _translation.Z < 0.0f ) ? -SizeZ / 2.0f : 0.0f ); // X physics BoundingBox boxx = GetBounds( _translation.X, 0.0f, 0.0f ); if ( _translation.X > 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Right, offsXZ ) - 0.0001f; if ( dist < _translation.X ) { _translation.X = dist; } } } } else if ( _translation.X < 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Left, offsXZ ) - 0.0001f; if ( dist < -_translation.X ) { _translation.X = -dist; } } } } And here is my implementation for GetShortestCollisionDistance: private float GetShortestCollisionDistance( Chunk chunk, Vector3 rayDir, Vector3 offs ) { int startY = (int)( -SizeY / 2.0f ); int endY = (int)( SizeY / 2.0f ); int incY = (int)Cube.Size; float dist = Chunk.Size; for ( int y = startY; y <= endY; y += incY ) { // Position is the center of the entity's bounding box Ray ray = new Ray( new Vector3( Position.X + offs.X, Position.Y + offs.Y + y, Position.Z + offs.Z ), rayDir ); // Chunk.GetIntersections(Ray) returns Dictionary<Block, float?> foreach ( var pair in chunk.GetIntersections( ray ) ) { if ( pair.Value.HasValue && pair.Value.Value < dist ) { dist = pair.Value.Value; } } } return dist; } I realize some of this code can be consolidated to help with speed, but my main concern right now is to get this bit of physics programming to actually work.

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  • I need help with 2D collision response (of stacking rotating polygons, with friction and gravity, for a game)

    - by Register Sole
    Hi I am looking for suggestions on how to write a collision response for game programming purpose (so not a scientific simulation). I am dealing with 2D polygons that are rotating, and I want them to be able to stack. I also want friction and gravity. I have a detection mechanism that returns the separating axis, how long the polygons are overlapping, and up to 2 points of contact. For the response, I am currently using an impulse-based response, which main idea is: find the separating axis, length of overlap, and the point of contact (if there are two, pick a random point between to simulate averaged force. i believe there are better ways than this) separate the object (modifying their positions, taking into account of their masses. i do not separate them completely though, to keep track that they are colliding to reduce jitter) calculate normal force based on the coefficient of restitution as if there is no friction. calculate friction, as if there is no normal force. I also assume that the direction of the friction is the same throughout the collision. apply the two forces (which result in a rather inaccurate result, since each force is calculated as if the other is not present. for non-rotating bodies though, this method is exact) I am aware that this method requires the coefficient of friction to be sufficiently small due to the assumption that the direction of friction stays the same in a collision. Also, the result is visually satisfying if gravity is not present. However, when there is gravity, objects on ground jitter and drift (even with zero coefficient of restitution)! It also happens for stacking objects. Larger coefficient of restitution and gravity increase the jittering. I hope you can help me with this. Some things i would like to know more about is how to handle collision with two point of contacts (how to end up having an object sitting still on the ground?), how to reduce, and prevent if possible, jitter and drift (do people use the most accurate method possible, or is there a trick to overcome this?), and how to handle multiple objects collision (for example, in the case of stacking objects, how do I check collisions between all of them and keep them all stable at every frame so they don't jitter?). A total reformulation of my algorithm is also welcomed, as long as it works. Another thing to note is that I am not making a Physics game, so I only need a visually satisfying response (though a realistic response is preferable, if it is not performance-heavy). But surely jittering and drifting objects on flat ground are not at all acceptable. In addition, I am a Physics student, so feel free to talk about impulse and whatever needed. Finally, I'm sorry for the long post. I tried to be as concise as I can. Thank you for reading it! EDIT It seems what I didn't manage to come up all this time is to separate resting contact as a class of its own and how to solve them. Currently reading the paper suggested by Jedediah. More suggestions on the topic are welcome :) CASE CLOSED After reading various papers referenced in the paper, successfully implemented simultaneous impulse method (referring to the original paper by Erin Catto, [Catt05]). Thanks maaaan!! The paper is wonderful. The current system is visibly much better than the previous. Still haven't separated resting contact as a class of its own though, which brings me to my next question. Love you all! Haha (sorry, I'm just so happy thanks to you).

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  • The data reader returned by the store data provider does not have enough columns

    - by molgan
    Hello I get the following error when I try to execute a stored procedure: "The data reader returned by the store data provider does not have enough columns" When I in the sql-manager execute it like this: DECLARE @return_value int, @EndDate datetime EXEC @return_value = [dbo].[GetSomeDate] @SomeID = 91, @EndDate = @EndDate OUTPUT SELECT @EndDate as N'@EndDate' SELECT 'Return Value' = @return_value GO It returns the value properly.... @SomeDate = '2010-03-24 09:00' And in my app I have: if (_entities.Connection.State == System.Data.ConnectionState.Closed) _entities.Connection.Open(); using (EntityCommand c = new EntityCommand("MyAppEntities.GetSomeDate", (EntityConnection)this._entities.Connection)) { c.CommandType = System.Data.CommandType.StoredProcedure; EntityParameter paramSomeID = new EntityParameter("SomeID", System.Data.DbType.Int32); paramSomeID.Direction = System.Data.ParameterDirection.Input; paramSomeID.Value = someID; c.Parameters.Add(paramSomeID); EntityParameter paramSomeDate = new EntityParameter("SomeDate", System.Data.DbType.DateTime); SomeDate.Direction = System.Data.ParameterDirection.Output; c.Parameters.Add(paramSomeDate); int retval = c.ExecuteNonQuery(); return (DateTime?)c.Parameters["SomeDate"].Value; Why does it complain about columns? I googled on error and someone said something about removing RETURN in sp, but I dont have any RETURN there. last like is like SELECT @SomeDate = D.SomeDate FROM .... /M

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  • Javascript or CSS hover not working in Safari and Chrome

    - by PAZtech
    I have a problem with a script for a image gallery. The problem seems to only occur on Safari and Chrome, but if I refresh the page I get it to work correctly - weird! Correct function: The gallery has a top bar, which if you hover over it, it will display a caption. Below sits the main image. At the bottom there is another bar that is a reversal of the top bar. When you hover over it, it will display thumbnails of the gallery. The problem: In Safari and Chrome, the thumbnail holder will not display. In fact, it doesn't even show it as an active item (or a rollover). But oddly enough, if you manually refresh the page it begins to work correctly for the rest of the time you view the page. Once you have left the page and return the same error occurs again and you have to go through the same process. Here's one of the pages to look at: link text Here's the CSS: #ThumbsGutter { background: url(../Images/1x1.gif); background: url(/Images/1x1.gif); height: 105px; left: 0px; position: absolute; top: 0px; width: 754px; z-index: 2; } #ThumbsHolder { display: none; } #ThumbsTable { left: 1px; } #Thumbs { background-color: #000; width: 703px; } #Thumbs ul { list-style: none; margin: 0; padding: 0; } #Thumbs ul li { display: inline; } .Thumbs ul li a { border-right: 1px solid #fff; border-top: 1px solid #fff; float: left; left: 1px; } .Thumbs ul li a img { filter: alpha(opacity=50); height: 104px; opacity: .5; width: 140px; } .Thumbs ul li a img.Hot { filter: alpha(opacity=100); opacity: 1; } Here is the javascript: //Variables var globalPath = ""; var imgMain; var gutter; var holder; var thumbs; var loadingImage; var holderState; var imgCount; var imgLoaded; var captionHolder; var captionState = 0; var captionHideTimer; var captionHideTime = 500; var thumbsHideTimer; var thumbsHideTime = 500; $(document).ready(function() { //Load Variables imgMain = $("#MainImage"); captionHolder = $("#CaptionHolder"); gutter = $("#ThumbsGutter"); holder = $("#ThumbsHolder"); thumbs = $("#Thumbs"); loadingImage = $("#LoadingImageHolder"); //Position Loading Image loadingImage.centerOnObject(imgMain); //Caption Tab Event Handlers $("#CaptionTab").mouseover(function() { clearCaptionHideTimer(); showCaption(); }).mouseout(function() { setCaptionHideTimer(); }); //Caption Holder Event Handlers captionHolder.mouseenter(function() { clearCaptionHideTimer(); }).mouseleave(function() { setCaptionHideTimer(); }); //Position Gutter if (jQuery.browser.safari) { gutter.css("left", imgMain.position().left + "px").css("top", ((imgMain.offset().top + imgMain.height()) - 89) + "px"); } else { gutter.css("left", imgMain.position().left + "px").css("top", ((imgMain.offset().top + imgMain.height()) - 105) + "px"); } //gutter.css("left", imgMain.position().left + "px").css("top", ((imgMain.offset().top + imgMain.height()) - 105) + "px"); //gutter.css("left", imgMain.offset().left + "px").css("top", ((imgMain.offset().top + imgMain.height()) - gutter.height()) + "px"); //Thumb Tab Event Handlers $("#ThumbTab").mouseover(function() { clearThumbsHideTimer(); showThumbs(); }).mouseout(function() { setThumbsHideTimer(); }); //Gutter Event Handlers gutter.mouseenter(function() { //showThumbs(); clearThumbsHideTimer(); }).mouseleave(function() { //hideThumbs(); setThumbsHideTimer(); }); //Next/Prev Button Event Handlers $("#btnPrev").mouseover(function() { $(this).attr("src", globalPath + "/Images/GalleryLeftButtonHot.jpg"); }).mouseout(function() { $(this).attr("src", globalPath + "/Images/GalleryLeftButton.jpg"); }); $("#btnNext").mouseover(function() { $(this).attr("src", globalPath + "/Images/GalleryRightButtonHot.jpg"); }).mouseout(function() { $(this).attr("src", globalPath + "/Images/GalleryRightButton.jpg"); }); //Load Gallery //loadGallery(1); }); function loadGallery(galleryID) { //Hide Holder holderState = 0; holder.css("display", "none"); //Hide Empty Gallery Text $("#EmptyGalleryText").css("display", "none"); //Show Loading Message $("#LoadingGalleryOverlay").css("display", "inline").centerOnObject(imgMain); $("#LoadingGalleryText").css("display", "inline").centerOnObject(imgMain); //Load Thumbs thumbs.load(globalPath + "/GetGallery.aspx", { GID: galleryID }, function() { $("#TitleHolder").html($("#TitleContainer").html()); $("#DescriptionHolder").html($("#DescriptionContainer").html()); imgCount = $("#Thumbs img").length; imgLoaded = 0; if (imgCount == 0) { $("#LoadingGalleryText").css("display", "none"); $("#EmptyGalleryText").css("display", "inline").centerOnObject(imgMain); } else { $("#Thumbs img").load(function() { imgLoaded++; if (imgLoaded == imgCount) { holder.css("display", "inline"); //Carousel Thumbs thumbs.jCarouselLite({ btnNext: "#btnNext", btnPrev: "#btnPrev", mouseWheel: true, scroll: 1, visible: 5 }); //Small Image Event Handlers $("#Thumbs img").each(function(i) { $(this).mouseover(function() { $(this).addClass("Hot"); }).mouseout(function() { $(this).removeClass("Hot"); }).click(function() { //Load Big Image setImage($(this)); }); }); holder.css("display", "none"); //Load First Image var img = new Image(); img.onload = function() { imgMain.attr("src", img.src); setCaption($("#Image1").attr("alt")); //Hide Loading Message $("#LoadingGalleryText").css("display", "none"); $("#LoadingGalleryOverlay").css("display", "none"); } img.src = $("#Image1").attr("bigimg"); } }); } }); } function showCaption() { if (captionState == 0) { $("#CaptionTab").attr("src", globalPath + "/Images/CaptionTabHot.jpg"); captionHolder.css("display", "inline").css("left", imgMain.position().left + "px").css("top", imgMain.position().top + "px").css("width", imgMain.width() + "px").effect("slide", { "direction": "up" }, 500, function() { captionState = 1; }); } } function hideCaption() { if (captionState == 1) { captionHolder.toggle("slide", { "direction": "up" }, 500, function() { $("#CaptionTab").attr("src", globalPath + "/Images/CaptionTab.jpg"); captionState = 0; }); } } function setCaptionHideTimer() { captionHideTimer = window.setTimeout(hideCaption,captionHideTime); } function clearCaptionHideTimer() { if(captionHideTimer) { window.clearTimeout(captionHideTimer); captionHideTimer = null; } } function showThumbs() { if (holderState == 0) { $("#ThumbTab").attr("src", globalPath + "/Images/ThumbTabHot.jpg"); holder.effect("slide", { "direction": "down" }, 500, function() { holderState = 1; }); } } function hideThumbs() { if (holderState == 1) { if (jQuery.browser.safari) { holder.css("display", "none"); $("#ThumbTab").attr("src", globalPath + "/Images/ThumbTab.jpg"); holderState = 0; } else { holder.toggle("slide", { "direction": "down" }, 500, function() { $("#ThumbTab").attr("src", globalPath + "/Images/ThumbTab.jpg"); holderState = 0; }); } } } function setThumbsHideTimer() { thumbsHideTimer = window.setTimeout(hideThumbs,thumbsHideTime); } function clearThumbsHideTimer() { if(thumbsHideTimer) { window.clearTimeout(thumbsHideTimer); thumbsHideTimer = null; } } function setImage(image) { //Show Loading Image loadingImage.css("display", "inline"); var img = new Image(); img.onload = function() { //imgMain.css("background","url(" + img.src + ")").css("display","none").fadeIn(250); imgMain.attr("src", img.src).css("display", "none").fadeIn(250); setCaption(image.attr("alt")); //Hide Loading Image loadingImage.css("display", "none"); }; img.src = image.attr("bigimg"); } function setCaption(caption) { $("#CaptionText").html(caption); //alert($("#CaptionText").html()); /* if (caption.length 0) { $("#CaptionText") .css("display", "inline") .css("left", imgMain.position().left + "px") .css("top", imgMain.position().top + "px") .css("width", imgMain.width() + "px") .html(caption); $("#CaptionOverlay").css("display", "inline") .css("height", $("#CaptionText").height() + 36 + "px") .css("left", imgMain.position().left + "px") .css("top", imgMain.position().top + "px") .css("width", imgMain.width() + "px"); } else { $("#CaptionText").css("display", "none"); $("#CaptionOverlay").css("display", "none"); } */ } Please if anyone could help, it would be greatly appreciated! Thanks in advance. Justin

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  • Android ViewFlipper + homescreen animation

    - by Tim
    I am trying to use a ViewFlipper and make it act like the home screen(The layout will move with your finger). Check out this for an example. I want to do this with a ViewFlipper that only contains two children so the opposite view should be shown on either side of the current view depending on which way the user moves their finger. This code works but only for 1 direction at a time. This is in onTouchEvent. case MotionEvent.ACTION_MOVE: leftView.setVisibility(View.VISIBLE); rightView.setVisibility(View.VISIBLE); // move the current view to the left or right. currentView.layout((int) (touchEvent.getX() - oldTouchValue), currentView.getTop(), (int) (touchEvent.getX() - oldTouchValue) + 320, currentView.getBottom()); // place this view just left of the currentView leftView.layout(currentView.getLeft() - 320, leftView.getTop(), currentView.getLeft(), leftView.getBottom()); // place this view just right of the currentView rightView.layout(currentView.getRight(), rightView.getTop(), currentView.getRight() + 320, rightView.getBottom()); Which ever of the bottom two lines I put last that direction will work correctly but the other will not. Here is how I set the leftView and rightView: final View currentView = myFlipper.getCurrentView(); final View leftView, rightView; if (currentView == meView) { Log.d("current layout: ", "me"); leftView = youView; rightView = youView; } else if (currentView == youView) { Log.d("current layout: ", "you"); leftView = meView; rightView = meView; }else { leftView = null; rightView = null; } Is it going to be possible to set it up so that the same view is shown on both sides of the current view?

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  • ICollectionView.SortDescriptions sort does not work if underlying DataTable has zero rows

    - by BigBlondeViking
    We have a WPF app that has a DataGrid inside a ListView. private DataTable table_; We do a bunch or dynamic column generation ( depending on the report we are showing ) We then do the a query and fill the DataTable row by row, this query may or may not have data.( not the problem, an empty grid is expected ) We set the ListView's ItemsSource to the DefaultView of the DataTable. lv.ItemsSource = table_.DefaultView; We then (looking at the user's pass usage of the app, set the sort on the column) Sort Method below: private void Sort(string sortBy, ListSortDirection direction) { ICollectionView dataView = CollectionViewSource.GetDefaultView(lv.ItemsSource); dataView.SortDescriptions.Clear(); var sd = new SortDescription(sortBy, direction); dataView.SortDescriptions.Add(sd); dataView.Refresh(); } In the Zero DataTable rows scenario, the sort does not "hold"? and if we dynamically add rows they will not be in sorted order. If the DataTable has at-least 1 row when the sort is applied, and we dynamically add rows to the DataTable, the rows com in sorted correctly. I have built a standalone app that replicate this... It is an annoyance and I can add a check to see if the DataTable was empty, and re-apply the sort... Anyone know whats going on here, and am I doing something wrong? FYI: What we based this off if comes from the MSDN as well: http://msdn.microsoft.com/en-us/library/ms745786.aspx

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  • Need to replace 3rd party WinForm controls, what's the closet WPF equivalent?

    - by Refracted Paladin
    I am tired of Windows Forms...I just am. I am not trying to start a debate on it I am just bored with it. Unfortunately we have become dependent on 4 controls in DevExpress XtraEditors. I have had nothing but difficulties with them and I want to move on. What I need now is what the closet replacement would be for the 4 controls I am using. Here they are: LookUpEdit - this is a dropdown that filters the dropdown list as you type. MemoExEdit - this is a textbox that 'pops up' a bigger area when it has focus CheckedComboBoxEdit - this is a dropdown of checkboxes. CheckedListBoxControl - this is a nicely columned list box of checkboxes This is a LOB app that has tons of data entry. In reality, the first two are nice but not essential. The second two are essential in that I would either need to replicate the functionality or change the way the users are interacting with that particular data. I am looking for help in replicating these in a WPF environment with existing controls(codeplex etc) or in straight XAML. Any code or direction would be greatly appreciated but mostly I am hoping to avoid any commercial 3rd party WPF and would instead like to focus on building them myself(but I need direction) or using Codeplex

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  • Android: Creating a Scrollable Layout

    - by MD
    I'm trying to create a "scrollable" layout in Android. Even using developers.android.com, though, I feel a little bit lost at the moment. I'm somewhat new to Java, but not so much that I feel I should be having these issues--being new to Android is the bigger problem right now. The layout I'm trying to create should scroll in a sort of a "grid". I THINK what I'm looking for is the Gallery view, but I'm really lost as to how to implement it at the moment. I want it to "snap" to center the frame, like in the actual Gallery application. Essentially, if I had a photo gallery of 9 pictures, the idea is to scroll between them up/down AND side to side, in a 3x3 manner. Doesn't need to dynamically adjust, or anything like that, I just want a grid I can scroll through. I'm also not asking for anyone to give me explicit code for it--I'm trying to learn, more than anything. But pointing me in the right direction for helpful layout programming resources would be greatly appreciated, and confirming if it's a Gallery view I'm looking for would also be really helpful. EDIT: To clarify, the goal is to have ONE item on screen at a time. If you scroll between one item and the next, the previous one leaves the screen, and the new one snaps into place. So if it were a photo gallery, each spot on the grid would take up the entire screen size, approximately, and would be flung out of the viewable area when you slide across to the next photo, in either direction. (Photos are just an example for illustration purposes)

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  • SDL_image/C++ OpenGL Program: IMG_Load() produces fuzzy images

    - by Kami
    I'm trying to load an image file and use it as a texture for a cube. I'm using SDL_image to do that. I used this image because I've found it in various file formats (tga, tif, jpg, png, bmp) The code : SDL_Surface * texture; //load an image to an SDL surface (i.e. a buffer) texture = IMG_Load("/Users/Foo/Code/xcode/test/lena.bmp"); if(texture == NULL){ printf("bad image\n"); exit(1); } //create an OpenGL texture object glGenTextures(1, &textureObjOpenGLlogo); //select the texture object you need glBindTexture(GL_TEXTURE_2D, textureObjOpenGLlogo); //define the parameters of that texture object //how the texture should wrap in s direction glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); //how the texture should wrap in t direction glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); //how the texture lookup should be interpolated when the face is smaller than the texture glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); //how the texture lookup should be interpolated when the face is bigger than the texture glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); //send the texture image to the graphic card glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture->w, texture->h, 0, GL_RGB, GL_UNSIGNED_BYTE, texture-> pixels); //clean the SDL surface SDL_FreeSurface(texture); The code compiles without errors or warnings ! I've tired all the files formats but this always produces that ugly result : I'm using : SDL_image 1.2.9 & SDL 1.2.14 with XCode 3.2 under 10.6.2 Does anyone knows how to fix this ?

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  • Collision detection of huge number of circles

    - by Tomek Tarczynski
    What is the best way to check collision of huge number of circles? It's very easy to detect collision between two circles, but if we check every combination then it is O(n^2) which definitely not an optimal solution. We can assume that circle object has following properties: -Coordinates -Radius -Velocity -Direction Velocity is constant, but direction can change. I've come up with two solutions, but maybe there are some better solutions. Solution 1 Divide whole space into overlapping squares and check for collision only with circles that are in the same square. Squares needs to overlap so there won't be a problem when circle moves from one square to another. Solution 2 At the beginning distances between every pair of circles need to be calculated. If the distance is small then these pair is stored in some list, and we need to check for collision in every update. If the distance is big then we store after which update there can be a collision (it can be calculated because we know the distance and velocitites). It needs to be stored in some kind of priority queue. After previously calculated number of updates distance needs to be checked again and then we do the same procedure - put it on the list or again in the priority queue.

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  • Javascript: Collision detection

    - by jack moore
    Hello, could someone please help me to understand how collision detection works in JS? I can't use jQuery or gameQuery - already using prototype - so, I'm looking for something very simple. Not asking for complete solution, just point me to the right direction. Let's say there's: <div id="ball"></div> and <div id="someobject0"></div> Now the ball is moving (any direction). "Someobject"(0-X) is already pre-defined and there's 20-60 of them randomly positioned like this: #someobject {position: absolute; top: RNDpx; left: RNDpx;} I can create an array with "someobject(X)" positions and test collision while the "ball" is moving... Something like: for(var c=0; c<objposArray.length; c++){ ........ and code to check ball's current position vs all objects one by one.... } But I guess this would be a "noob" solution and it looks pretty slow. Is there anything better?

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