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  • Why won't my vertex buffer render in GLFW3?

    - by sm81095
    I have started to try to learn OpenGL, and I decided to use GLFW to assist in window creation. The problem is, since GLFW3 is so new, there are no tutorials on it or how to use it with modern OpenGL (3.3, specifically). Using the GLFW3 tutorial found on the website, which uses older OpenGL rendering (glBegin(GL_TRIANGLES), glVertex3f(), and such), I can get a triangle to render to the screen. The problem is, using new OpenGL, I can't get the same triangle to render to the screen. I am new to OpenGL, and GLFW3 is new to most people, so I may be completely missing something obvious, but here is my code: static const GLuint g_vertex_buffer_data[] = { -1.0f, -1.0f, 0.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f }; int main(void) { GLFWwindow* window; if(!glfwInit()) { fprintf(stderr, "Failed to initialize GLFW."); return -1; } glfwWindowHint(GLFW_SAMPLES, 4); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); window = glfwCreateWindow(800, 600, "Test Window", NULL, NULL); if(!window) { glfwTerminate(); fprintf(stderr, "Failed to create a GLFW window"); return -1; } glfwMakeContextCurrent(window); glewExperimental = GL_TRUE; GLenum err = glewInit(); if(err != GLEW_OK) { glfwTerminate(); fprintf(stderr, "Failed to initialize GLEW"); fprintf(stderr, (char*)glewGetErrorString(err)); return -1; } GLuint VertexArrayID; glGenVertexArrays(1, &VertexArrayID); glBindVertexArray(VertexArrayID); GLuint programID = LoadShaders("SimpleVertexShader.glsl", "SimpleFragmentShader.glsl"); GLuint vertexBuffer; glGenBuffers(1, &vertexBuffer); glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW); while(!glfwWindowShouldClose(window)) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glUseProgram(programID); glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0); glDrawArrays(GL_TRIANGLES, 0, 3); glDisableVertexAttribArray(0); glfwSwapBuffers(window); glfwPollEvents(); } glDeleteBuffers(1, &vertexBuffer); glDeleteProgram(programID); glfwDestroyWindow(window); glfwTerminate(); exit(EXIT_SUCCESS); } I know it is not my shaders, they are super simple and I've checked them against GLFW 2.7 so I know that they work. I'm assuming that I've missed something crucial to using the OpenGL context with GLFW3, so any help locating the problem would be greatly appreciated.

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  • mongoDB Management Studio

    - by Liam McLennan
    This weekend I have been in Sydney at the MS Web Camp, learning about web application development. At the end of the first day we came up with application ideas and pitched them. My idea was to build a web management application for mongoDB. mongoDB I pitched my idea, put down the microphone, and then someone asked, “what’s mongo?”. Good question. MongoDB is a document database that stores JSON style documents. This is a JSON document for a tweet from twitter: db.tweets.find()[0] { "_id" : ObjectId("4bfe4946cfbfb01420000001"), "created_at" : "Thu, 27 May 2010 10:25:46 +0000", "profile_image_url" : "http://a3.twimg.com/profile_images/600304197/Snapshot_2009-07-26_13-12-43_normal.jpg", "from_user" : "drearyclocks", "text" : "Does anyone know who has better coverage, Optus or Vodafone? Telstra is still too expensive.", "to_user_id" : null, "metadata" : { "result_type" : "recent" }, "id" : { "floatApprox" : 14825648892 }, "geo" : null, "from_user_id" : 6825770, "search_term" : "telstra", "iso_language_code" : "en", "source" : "&lt;a href=&quot;http://www.tweetdeck.com&quot; rel=&quot;nofollow&quot;&gt;TweetDeck&lt;/a&gt;" } A mongodb server can have many databases, each database has many collections (instead of tables) and a collection has many documents (instead of rows). Development Day 2 of the Sydney MS Web Camp was allocated to building our applications. First thing in the morning I identified the stories that I wanted to implement: Scenario: View databases Scenario: View Collections in a database Scenario: View Documents in a Collection Scenario: Delete a Collection Scenario: Delete a Database Scenario: Delete Documents Over the course of the day the team (3.5 developers) implemented all of the planned stories (except ‘delete a database’) and also implemented the following: Scenario: Create Database Scenario: Create Collection Lessons Learned I’m new to MongoDB and in the past I have only accessed it from Ruby (for my hare-brained scheme). When it came to implementing our MongoDB management studio we discovered that their is no official MongoDB driver for .NET. We chose to use NoRM, honestly just because it was the only one I had heard of. NoRM was a challenge. I think it is a fine library but it is focused on mapping strongly typed objects to MongoDB. For our application we had no prior knowledge of the types that would be in the MongoDB database so NoRM was probably a poor choice. Here are some screens (click to enlarge):

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  • Ray Intersecting Plane Formula in C++/DirectX

    - by user4585
    I'm developing a picking system that will use rays that intersect volumes and I'm having trouble with ray intersection versus a plane. I was able to figure out spheres fairly easily, but planes are giving me trouble. I've tried to understand various sources and get hung up on some of the variables used within their explanations. Here is a snippet of my code: bool Picking() { D3DXVECTOR3 vec; D3DXVECTOR3 vRayDir; D3DXVECTOR3 vRayOrig; D3DXVECTOR3 vROO, vROD; // vect ray obj orig, vec ray obj dir D3DXMATRIX m; D3DXMATRIX mInverse; D3DXMATRIX worldMat; // Obtain project matrix D3DXMATRIX pMatProj = CDirectXRenderer::GetInstance()->Director()->Proj(); // Obtain mouse position D3DXVECTOR3 pos = CGUIManager::GetInstance()->GUIObjectList.front().pos; // Get window width & height float w = CDirectXRenderer::GetInstance()->GetWidth(); float h = CDirectXRenderer::GetInstance()->GetHeight(); // Transform vector from screen to 3D space vec.x = (((2.0f * pos.x) / w) - 1.0f) / pMatProj._11; vec.y = -(((2.0f * pos.y) / h) - 1.0f) / pMatProj._22; vec.z = 1.0f; // Create a view inverse matrix D3DXMatrixInverse(&m, NULL, &CDirectXRenderer::GetInstance()->Director()->View()); // Determine our ray's direction vRayDir.x = vec.x * m._11 + vec.y * m._21 + vec.z * m._31; vRayDir.y = vec.x * m._12 + vec.y * m._22 + vec.z * m._32; vRayDir.z = vec.x * m._13 + vec.y * m._23 + vec.z * m._33; // Determine our ray's origin vRayOrig.x = m._41; vRayOrig.y = m._42; vRayOrig.z = m._43; D3DXMatrixIdentity(&worldMat); //worldMat = aliveActors[0]->GetTrans(); D3DXMatrixInverse(&mInverse, NULL, &worldMat); D3DXVec3TransformCoord(&vROO, &vRayOrig, &mInverse); D3DXVec3TransformNormal(&vROD, &vRayDir, &mInverse); D3DXVec3Normalize(&vROD, &vROD); When using this code I'm able to detect a ray intersection via a sphere, but I have questions when determining an intersection via a plane. First off should I be using my vRayOrig & vRayDir variables for the plane intersection tests or should I be using the new vectors that are created for use in object space? When looking at a site like this for example: http://www.tar.hu/gamealgorithms/ch22lev1sec2.html I'm curious as to what D is in the equation AX + BY + CZ + D = 0 and how does it factor in to determining a plane intersection? Any help will be appreciated, thanks.

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  • xubuntu 12.04 slow boot

    - by user76390
    my xubuntu 12.04 fresh installed boots in more than 30 seconds, here the first big gap in dmesg: [ 1.984795] firewire_core: created device fw0: GUID 000ae4060034203a, S400 [ 2.336568] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null) [ 15.465275] ADDRCONF(NETDEV_UP): eth0: link is not ready [ 15.503348] udevd[331]: starting version 175 once booted everything works fine (networks included) thanks for help!

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  • algorithm for project euler problem no 18

    - by Valentino Ru
    Problem number 18 from Project Euler's site is as follows: By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum total from top to bottom is 23. 3 7 4 2 4 6 8 5 9 3 That is, 3 + 7 + 4 + 9 = 23. Find the maximum total from top to bottom of the triangle below: 75 95 64 17 47 82 18 35 87 10 20 04 82 47 65 19 01 23 75 03 34 88 02 77 73 07 63 67 99 65 04 28 06 16 70 92 41 41 26 56 83 40 80 70 33 41 48 72 33 47 32 37 16 94 29 53 71 44 65 25 43 91 52 97 51 14 70 11 33 28 77 73 17 78 39 68 17 57 91 71 52 38 17 14 91 43 58 50 27 29 48 63 66 04 68 89 53 67 30 73 16 69 87 40 31 04 62 98 27 23 09 70 98 73 93 38 53 60 04 23 NOTE: As there are only 16384 routes, it is possible to solve this problem by trying every route. However, Problem 67, is the same challenge with a triangle containing one-hundred rows; it cannot be solved by brute force, and requires a clever method! ;o) The formulation of this problems does not make clear if the "Traversor" is greedy, meaning that he always choosed the child with be higher value the maximum of every single walkthrough is asked The NOTE says, that it is possible to solve this problem by trying every route. This means to me, that is is also possible without! This leads to my actual question: Assumed that not the greedy one is the max, is there any algorithm that finds the max walkthrough value without trying every route and that doesn't act like the greedy algorithm? I implemented an algorithm in Java, putting the values first in a node structure, then applying the greedy algorithm. The result, however, is cosidered as wrong by Project Euler. sum = 0; void findWay(Node node){ sum += node.value; if(node.nodeLeft != null && node.nodeRight != null){ if(node.nodeLeft.value > node.nodeRight.value){ findWay(node.nodeLeft); }else{ findWay(node.nodeRight); } } }

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  • how to dbkg-preconfigure login manager

    - by Josh
    I've written a script that installs several desktops with a menu loop. I have also redirecteed the output to /dev/null, Now every Time when it comes to dpk login manager selection the script doesn't continue. What could I du to preconfigure the login mangager that should be choosen. How do the lines for dpkg preconfigure look for lightdm gdm Kdm mdm debconf-set-selections <<< ' ' would be grate, too. Thank you folks!

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  • OpenGL VertexBuffer won'e render in GLFW3

    - by sm81095
    So I have started to try to learn OpenGL, and I decided to use GLFW to assist in window creation. The problem is, since GLFW3 is so new, there are no tutorials on it yet and how to use it with modern OpenGL (3.3, specifically). Using the GLFW3 tutorial found on the website, which uses older OpenGL rendering (glBegin(GL_TRIANGLES), glVertex3f()), and such, I can get a triangle to render to the screen. The problem is, using new OpenGL, I can't get the same triangle to render to the screen. I am new to OpenGL, and GLFW3 is new to most people, so I may be completely missing something obvious, but here is my code: static const GLuint g_vertex_buffer_data[] = { -1.0f, -1.0f, 0.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f }; int main(void) { GLFWwindow* window; if(!glfwInit()) { fprintf(stderr, "Failed to initialize GLFW."); return -1; } glfwWindowHint(GLFW_SAMPLES, 4); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); window = glfwCreateWindow(800, 600, "Test Window", NULL, NULL); if(!window) { glfwTerminate(); fprintf(stderr, "Failed to create a GLFW window"); return -1; } glfwMakeContextCurrent(window); glewExperimental = GL_TRUE; GLenum err = glewInit(); if(err != GLEW_OK) { glfwTerminate(); fprintf(stderr, "Failed to initialize GLEW"); fprintf(stderr, (char*)glewGetErrorString(err)); return -1; } GLuint VertexArrayID; glGenVertexArrays(1, &VertexArrayID); glBindVertexArray(VertexArrayID); GLuint programID = LoadShaders("SimpleVertexShader.glsl", "SimpleFragmentShader.glsl"); GLuint vertexBuffer; glGenBuffers(1, &vertexBuffer); glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW); while(!glfwWindowShouldClose(window)) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glUseProgram(programID); glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0); glDrawArrays(GL_TRIANGLES, 0, 3); glDisableVertexAttribArray(0); glfwSwapBuffers(window); glfwPollEvents(); } glDeleteBuffers(1, &vertexBuffer); glDeleteProgram(programID); glfwDestroyWindow(window); glfwTerminate(); exit(EXIT_SUCCESS); } I know it is not my shaders, they are super simple and I've checked them against GLFW 2.7 so I know that they work. I'm assuming that I've missed something crucial to using the OpenGL context with GLFW3, so any help locating the problem would be greatly appreciated.

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  • WebLogic Server internal server error [migrated]

    - by Abhinav Pandey
    When I deployed a project in Apache Tomcat 6.0 it is working fine. When I deployed a same project in WebLogic Server 10.3 it's showing an error: Error 500--Internal Server Error javax.servlet.ServletException: [HTTP:101249][weblogic.servlet.internal.WebAppServletContext@ae43b8 - appName: '_appsdir_ab_dir', name: 'ab', context-path: '/ab', spec-version: 'null']: Servlet class FirstServlet for servlet FirstServlet could not be loaded because the requested class was not found in the classpath . java.lang.UnsupportedClassVersionError: FirstServlet : Unsupported major.minor version 51.0.

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  • Oracle HRMS API – Update Employee Assignment

    - by PRajkumar
    To Update Supervisor, Manager Flag, Bargaining Unit, Labour Union Member Flag, Gre, Time Card, Work Schedule, Normal Hours, Frequency, Time Normal Finish, Time Normal Start, Default Code Combination, Set of Books Id API -- hr_assignment_api.update_emp_asg   To Update Grade, Location, Job, Payroll, Organization, Employee Category, People Group API -- hr_assignment_api.update_emp_asg_criteria   Example --   DECLARE    -- Local Variables    -- -----------------------    lc_dt_ud_mode           VARCHAR2(100)    := NULL;    ln_assignment_id       NUMBER                  := 33561;    ln_supervisor_id        NUMBER                  := 2;    ln_object_number       NUMBER                  := 1;    ln_people_group_id  NUMBER                  := 1;      -- Out Variables for Find Date Track Mode API    -- -----------------------------------------------------------------    lb_correction                           BOOLEAN;    lb_update                                 BOOLEAN;    lb_update_override              BOOLEAN;    lb_update_change_insert   BOOLEAN;       -- Out Variables for Update Employee Assignment API    -- ----------------------------------------------------------------------------    ln_soft_coding_keyflex_id       HR_SOFT_CODING_KEYFLEX.SOFT_CODING_KEYFLEX_ID%TYPE;    lc_concatenated_segments       VARCHAR2(2000);    ln_comment_id                             PER_ALL_ASSIGNMENTS_F.COMMENT_ID%TYPE;    lb_no_managers_warning        BOOLEAN;  -- Out Variables for Update Employee Assgment Criteria  -- -------------------------------------------------------------------------------  ln_special_ceiling_step_id                    PER_ALL_ASSIGNMENTS_F.SPECIAL_CEILING_STEP_ID%TYPE;  lc_group_name                                          VARCHAR2(30);  ld_effective_start_date                             PER_ALL_ASSIGNMENTS_F.EFFECTIVE_START_DATE%TYPE;  ld_effective_end_date                              PER_ALL_ASSIGNMENTS_F.EFFECTIVE_END_DATE%TYPE;  lb_org_now_no_manager_warning   BOOLEAN;  lb_other_manager_warning                  BOOLEAN;  lb_spp_delete_warning                          BOOLEAN;  lc_entries_changed_warning                VARCHAR2(30);  lb_tax_district_changed_warn             BOOLEAN;   BEGIN    -- Find Date Track Mode    -- --------------------------------    dt_api.find_dt_upd_modes    (    p_effective_date                  => TO_DATE('12-JUN-2011'),         p_base_table_name            => 'PER_ALL_ASSIGNMENTS_F',         p_base_key_column           => 'ASSIGNMENT_ID',         p_base_key_value               => ln_assignment_id,          -- Output data elements          -- --------------------------------          p_correction                          => lb_correction,          p_update                                => lb_update,          p_update_override              => lb_update_override,          p_update_change_insert   => lb_update_change_insert      );      IF ( lb_update_override = TRUE OR lb_update_change_insert = TRUE )    THEN        -- UPDATE_OVERRIDE        -- ---------------------------------        lc_dt_ud_mode := 'UPDATE_OVERRIDE';    END IF;     IF ( lb_correction = TRUE )   THEN       -- CORRECTION       -- ----------------------      lc_dt_ud_mode := 'CORRECTION';   END IF;     IF ( lb_update = TRUE )   THEN       -- UPDATE       -- --------------       lc_dt_ud_mode := 'UPDATE';    END IF;     -- Update Employee Assignment   -- ---------------------------------------------  hr_assignment_api.update_emp_asg  ( -- Input data elements   -- ------------------------------   p_effective_date                              => TO_DATE('12-JUN-2011'),   p_datetrack_update_mode         => lc_dt_ud_mode,   p_assignment_id                            => ln_assignment_id,   p_supervisor_id                              => NULL,   p_change_reason                           => NULL,   p_manager_flag                              => 'N',   p_bargaining_unit_code              => NULL,   p_labour_union_member_flag   => NULL,   p_segment1                                       => 204,   p_segment3                                       => 'N',   p_normal_hours                              => 10,   p_frequency                                       => 'W',   -- Output data elements   -- -------------------------------   p_object_version_number             => ln_object_number,   p_soft_coding_keyflex_id              => ln_soft_coding_keyflex_id,   p_concatenated_segments             => lc_concatenated_segments,   p_comment_id                                   => ln_comment_id,   p_effective_start_date                      => ld_effective_start_date,   p_effective_end_date                        => ld_effective_end_date,   p_no_managers_warning               => lb_no_managers_warning,   p_other_manager_warning            => lb_other_manager_warning  );    -- Find Date Track Mode for Second API   -- ------------------------------------------------------   dt_api.find_dt_upd_modes   (  p_effective_date                   => TO_DATE('12-JUN-2011'),      p_base_table_name            => 'PER_ALL_ASSIGNMENTS_F',      p_base_key_column           => 'ASSIGNMENT_ID',      p_base_key_value               => ln_assignment_id,      -- Output data elements      -- -------------------------------      p_correction                           => lb_correction,      p_update                                 => lb_update,      p_update_override               => lb_update_override,      p_update_change_insert    => lb_update_change_insert   );     IF ( lb_update_override = TRUE OR lb_update_change_insert = TRUE )   THEN     -- UPDATE_OVERRIDE     -- --------------------------------     lc_dt_ud_mode := 'UPDATE_OVERRIDE';   END IF;      IF ( lb_correction = TRUE )    THEN      -- CORRECTION      -- ----------------------      lc_dt_ud_mode := 'CORRECTION';   END IF;      IF ( lb_update = TRUE )    THEN      -- UPDATE      -- --------------      lc_dt_ud_mode := 'UPDATE';    END IF;    -- Update Employee Assgment Criteria  -- -----------------------------------------------------  hr_assignment_api.update_emp_asg_criteria  ( -- Input data elements   -- ------------------------------   p_effective_date                                   => TO_DATE('12-JUN-2011'),   p_datetrack_update_mode               => lc_dt_ud_mode,   p_assignment_id                                 => ln_assignment_id,   p_location_id                                        => 204,   p_grade_id                                             => 29,   p_job_id                                                  => 16,   p_payroll_id                                          => 52,   p_organization_id                               => 239,   p_employment_category                    => 'FR',   -- Output data elements   -- -------------------------------   p_people_group_id                              => ln_people_group_id,   p_object_version_number                   => ln_object_number,   p_special_ceiling_step_id                  => ln_special_ceiling_step_id,   p_group_name                                        => lc_group_name,   p_effective_start_date                           => ld_effective_start_date,   p_effective_end_date                             => ld_effective_end_date,   p_org_now_no_manager_warning  => lb_org_now_no_manager_warning,   p_other_manager_warning                 => lb_other_manager_warning,   p_spp_delete_warning                         => lb_spp_delete_warning,   p_entries_changed_warning              => lc_entries_changed_warning,   p_tax_district_changed_warning     => lb_tax_district_changed_warn  );    COMMIT; EXCEPTION          WHEN OTHERS THEN                       ROLLBACK;                       dbms_output.put_line(SQLERRM); END; / SHOW ERR;    

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  • Why is my arrow texture being drawn in odd places?

    - by tyjkenn
    This is a script I wrote that places an arrow on the screen, pointing to an enemy off-screen, or, if the enemy is on-screen, it places an arrow hovering above the enemy. Everything seems to work, except for some odd reason, I see random arrows floating around, often skewed and resized (which I really don't understand, because I only rotate and place in this script). Even when I only have one enemy in the scene, I still see these random arrows. It should only be drawing one per enemy. Note: when all enemies are removed, no arrows appear. var arrow : Texture; var cam : Camera; var dim : int = 30; function OnGUI() { var objects = GameObject.FindGameObjectsWithTag("Enemy"); for(var ob : GameObject in objects) { var pos = cam.WorldToViewportPoint(ob.transform.position); if(gameObject.GetComponent(FollowCamera).target != null){ var tar = gameObject.GetComponent(FollowCamera).target.parent; } if(pos.z>1 && ob.transform != tar){ var xDiff = (pos.x*cam.pixelWidth)-(cam.pixelWidth/2); var yDiff = (pos.y*cam.pixelHeight)-(cam.pixelHeight/2); var angle = Mathf.Rad2Deg*Mathf.Atan(yDiff/xDiff)+180; if(xDiff>0) angle += 180; var dist = Mathf.Sqrt(xDiff*xDiff + yDiff*yDiff); var slope = yDiff/xDiff; var camSlope = cam.pixelHeight/cam.pixelWidth; var theX = -1000.0; var theY = -1000.0; var mult = 0; var temp; if(Mathf.Abs(xDiff)>(cam.pixelWidth/2)||Mathf.Abs(yDiff)>(cam.pixelHeight/2)){ //touching right if(slope<camSlope && slope>-camSlope) { if(xDiff>(cam.pixelWidth/2)) { theX = cam.pixelWidth - (dim/2); mult = -1; }else if(xDiff<-(cam.pixelWidth/2)) { theX = (dim/2); mult = 1; } temp = ((cam.pixelWidth/2)*yDiff)/xDiff; theY =(cam.pixelHeight/2)+(mult*temp); } else{ if(yDiff>(cam.pixelHeight/2)) { theY = (dim/2); mult = 1; }else if(yDiff<-(cam.pixelHeight/2)) { theY = cam.pixelHeight - (dim/2); mult = -1; } temp = ((cam.pixelHeight/2)*xDiff)/yDiff; theX =(cam.pixelWidth/2)+(mult*temp); } } else { angle = -90; theX = (cam.pixelWidth/2)+xDiff; theY = (cam.pixelHeight/2)-yDiff-dim; } GUIUtility.RotateAroundPivot(-angle, Vector2(theX, theY)); Graphics.DrawTexture(Rect(theX-(dim/2),theY-(dim/2),dim,dim),arrow,null); GUIUtility.RotateAroundPivot(angle, Vector2(theX, theY)); } } }

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  • Unknown C# keywords: params

    - by Chris Skardon
    Often overlooked, and (some may say) unloved, is the params keyword, but it’s an awesome keyword, and one you should definitely check out. What does it do? Well, it lets you specify a single parameter that can have a variable number of arguments. You what? Best shown with an example, let’s say we write an add method: public int Add(int first, int second) { return first + second; } meh, it’s alright, does what it says on the tin, but it’s not exactly awe-inspiring… Oh noes! You need to add 3 things together??? public int Add(int first, int second, int third) { return first + second + third; } oh yes, you code master you! Overloading a-plenty! Now a fourth… Ok, this is starting to get a bit ridiculous, if only there was some way… public int Add(int first, int second, params int[] others) { return first + second + others.Sum(); } So now I can call this with any number of int arguments? – well, any number > 2..? Yes! int ret = Add(1, 2, 3); Is as valid as: int ret = Add(1, 2, 3, 4); Of course you probably won’t really need to ever do that method, so what could you use it for? How about adding strings together? What about a logging method? We all know ToString can be an expensive method to call, it might traverse every node on a class hierarchy, or may just be the name of the type… either way, we don’t really want to call it if we can avoid it, so how about a logging method like so: public void Log(LogLevel level, params object[] objs) { if(LoggingLevel < level) return; StringBuilder output = new StringBuilder(); foreach(var obj in objs) output.Append((obj == null) ? "null" : obj.ToString()); return output; } Now we only call ‘ToString’ when we want to, and because we’re passing in just objects we don’t have to call ToString if the Logging Level isn’t what we want… Of course, there are a multitude of things to use params for…

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  • My co-worker has not been doing such a good job for the past decade. What do I do? [closed]

    - by stijn
    Possible Duplicate: How do I approach a coworker about his or her code quality? I started working with him almost a decade ago and back then I had never really programmed before, being a young hardware engineer. Right now however I have made quite some progress in all areas being part of software design and i am much, much more skilled than my co-worker who is 15 years older and has been programming more than twice as long. He is super nice and definitely smart enough, but lately his lack of skill and performance are starting to drag me down because we're more and more working on the same codebase. And soon we are going to do a quite ambitious start from scratch creating a whole new hard/software system. I feel it is time to address all issues now, but i do not know how to start. Here are some of the things that I would like to see him improve on: no consistent usage of style, spaces nor tabs (eg if(something ) a =b ) adds newlines around pieces of code to make it easier to read, then commits those with messages like 'no changes made' overall commit messages are useless and so are most of the comments, if there are any (eg 'remove solves for bug Rik' if Rik reported a bug). There is no function/class documentation. lots of spelling errors, in both English and native language, which sometimes are mixed 6/7/8 level deep deep nesting is no exception, a lot of functions start with one level already like if(ptr!=Null){ even when ptr is the result of allocation via new in the constructor numerous source files have over 10k lines of those lines, a major part is simply a result of copy-pasting functionality instead of using a function. This includes copying comments so we end up with 50 occurrences of var=NULL; //TODO TEST this!!!!!!! another part is hundreds of lines of dead code knows what versioning does, yet comments out old code and places new code underneath it when making changes coding skills are below par, especially for the type of rather high precision applications we do. Yet somehow, after a lot of trying and testing, stuff starts to work. But then breaks again some time later because every change casues a waterfall effect. violates every single item in the C++ FAQ lite, practices every bad practice I can think of still doesn't know how to properly use the debugger, but spends hours inspecting messy logfiles in notepad on a tiny laptop screen. Does not make any adjustments to the settings of the software he uses. Never uses keyboard shortcuts. does not seem to progress or learn new things at all. Work rather slow, mostly due to the lack of planning and incorrect usage of tools. How does one deal with this? For starters, how do I make him aware of all these problems? Should I tell the staff about it? And the next step, how to get him to learn new things and adopt another way of working?

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  • How to Plug a Small Hole in NetBeans JSF (Join Table) Code Generation

    - by MarkH
    I was asked recently to provide an assist with designing and building a small-but-vital application that had at its heart some basic CRUD (Create, Read, Update, & Delete) functionality, built upon an Oracle database, to be accessible from various locations. Working from the stated requirements, I fleshed out the basic application and database designs and, once validated, set out to complete the first iteration for review. Using SQL Developer, I created the requisite tables, indices, and sequences for our first run. One of the tables was a many-to-many join table with three fields: one a primary key for that table, the other two being primary keys for the other tables, represented as foreign keys in the join table. Here is a simplified example of the trio of tables: Once the database was in decent shape, I fired up NetBeans to let it have first shot at the code. NetBeans does a great job of generating a mountain of essential code, saving developers what must be millions of hours of effort each year by building a basic foundation with a few clicks and keystrokes. Lest you think it (or any tool) can do everything for you, however, occasionally something tosses a paper clip into the delicate machinery and makes you open things up to fix them. Join tables apparently qualify.  :-) In the case above, the entity class generated for the join table (New Entity Classes from Database) included an embedded object consisting solely of the two foreign key fields as attributes, in addition to an object referencing each one of the "component" tables. The Create page generated (New JSF Pages from Entity Classes) worked well to a point, but when trying to save, we were greeted with an error: Transaction aborted. Hmm. A quick debugger session later and I'd identified the issue: when trying to persist the new join-table object, the embedded "foreign-keys-only" object still had null values for its two (required value) attributes...even though the embedded table objects had populated key attributes. Here's the simple fix: In the join-table controller class, find the public String create() method. It will look something like this:     public String create() {        try {            getFacade().create(current);            JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("JoinEntityCreated"));            return prepareCreate();        } catch (Exception e) {            JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));            return null;        }    } To restore balance to the force, modify the create() method as follows (changes in red):     public String create() {         try {            // Add the next two lines to resolve:            current.getJoinEntityPK().setTbl1id(current.getTbl1().getId().toBigInteger());            current.getJoinEntityPK().setTbl2id(current.getTbl2().getId().toBigInteger());            getFacade().create(current);            JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("JoinEntityCreated"));            return prepareCreate();        } catch (Exception e) {            JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));            return null;        }    } I'll be refactoring this code shortly, but for now, it works. Iteration one is complete and being reviewed, and we've met the milestone. Here's to happy endings (and customers)! All the best,Mark

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  • Mounting Nexus 7 on Ubuntu 12.04 through

    - by Pomario
    I would like to transfer files between my Ubuntu 12.04 and Nexus 7 (Android 4.2) I have followed another post precisely. BUT upon... mount /mnt/nexus7 I get... Android device detected, assigning default bug flags.Listing File Information on Device with name: (NULL) and even doing an "ls" in "/mnt" generates... ls: cannot access nexus7: Transport endpoint is not connected Ideas why that is happening???

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  • Rhythmbox is not launching

    - by Somogyi László
    I'm using Rhythmbox 2.99 in Ubuntu 13.10, and when I first launch the application it searches for music and works like a charm, but if I try to launch it later again nothing happens. When I run it in terminal I get this: $ rhythmbox (rhythmbox:8860): GLib-GObject-CRITICAL **: Custom constructor for class SoupServer returned NULL (which is invalid). Unable to remove object from construction_objects list, so memory was probably just leaked. Please use GInitable instead. Segmentation fault Any ideas how to make it work again?

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  • Selling Federal Enterprise Architecture (EA)

    - by TedMcLaughlan
    Selling Federal Enterprise Architecture A taxonomy of subject areas, from which to develop a prioritized marketing and communications plan to evangelize EA activities within and among US Federal Government organizations and constituents. Any and all feedback is appreciated, particularly in developing and extending this discussion as a tool for use – more information and details are also available. "Selling" the discipline of Enterprise Architecture (EA) in the Federal Government (particularly in non-DoD agencies) is difficult, notwithstanding the general availability and use of the Federal Enterprise Architecture Framework (FEAF) for some time now, and the relatively mature use of the reference models in the OMB Capital Planning and Investment (CPIC) cycles. EA in the Federal Government also tends to be a very esoteric and hard to decipher conversation – early apologies to those who agree to continue reading this somewhat lengthy article. Alignment to the FEAF and OMB compliance mandates is long underway across the Federal Departments and Agencies (and visible via tools like PortfolioStat and ITDashboard.gov – but there is still a gap between the top-down compliance directives and enablement programs, and the bottom-up awareness and effective use of EA for either IT investment management or actual mission effectiveness. "EA isn't getting deep enough penetration into programs, components, sub-agencies, etc.", verified a panelist at the most recent EA Government Conference in DC. Newer guidance from OMB may be especially difficult to handle, where bottom-up input can't be accurately aligned, analyzed and reported via standardized EA discipline at the Agency level – for example in addressing the new (for FY13) Exhibit 53D "Agency IT Reductions and Reinvestments" and the information required for "Cloud Computing Alternatives Evaluation" (supporting the new Exhibit 53C, "Agency Cloud Computing Portfolio"). Therefore, EA must be "sold" directly to the communities that matter, from a coordinated, proactive messaging perspective that takes BOTH the Program-level value drivers AND the broader Agency mission and IT maturity context into consideration. Selling EA means persuading others to take additional time and possibly assign additional resources, for a mix of direct and indirect benefits – many of which aren't likely to be realized in the short-term. This means there's probably little current, allocated budget to work with; ergo the challenge of trying to sell an "unfunded mandate". Also, the concept of "Enterprise" in large Departments like Homeland Security tends to cross all kinds of organizational boundaries – as Richard Spires recently indicated by commenting that "...organizational boundaries still trump functional similarities. Most people understand what we're trying to do internally, and at a high level they get it. The problem, of course, is when you get down to them and their system and the fact that you're going to be touching them...there's always that fear factor," Spires said. It is quite clear to the Federal IT Investment community that for EA to meet its objective, understandable, relevant value must be measured and reported using a repeatable method – as described by GAO's recent report "Enterprise Architecture Value Needs To Be Measured and Reported". What's not clear is the method or guidance to sell this value. In fact, the current GAO "Framework for Assessing and Improving Enterprise Architecture Management (Version 2.0)", a.k.a. the "EAMMF", does not include words like "sell", "persuade", "market", etc., except in reference ("within Core Element 19: Organization business owner and CXO representatives are actively engaged in architecture development") to a brief section in the CIO Council's 2001 "Practical Guide to Federal Enterprise Architecture", entitled "3.3.1. Develop an EA Marketing Strategy and Communications Plan." Furthermore, Core Element 19 of the EAMMF is advised to be applied in "Stage 3: Developing Initial EA Versions". This kind of EA sales campaign truly should start much earlier in the maturity progress, i.e. in Stages 0 or 1. So, what are the understandable, relevant benefits (or value) to sell, that can find an agreeable, participatory audience, and can pave the way towards success of a longer-term, funded set of EA mechanisms that can be methodically measured and reported? Pragmatic benefits from a useful EA that can help overcome the fear of change? And how should they be sold? Following is a brief taxonomy (it's a taxonomy, to help organize SME support) of benefit-related subjects that might make the most sense, in creating the messages and organizing an initial "engagement plan" for evangelizing EA "from within". An EA "Sales Taxonomy" of sorts. We're not boiling the ocean here; the subjects that are included are ones that currently appear to be urgently relevant to the current Federal IT Investment landscape. Note that successful dialogue in these topics is directly usable as input or guidance for actually developing early-stage, "Fit-for-Purpose" (a DoDAF term) Enterprise Architecture artifacts, as prescribed by common methods found in most EA methodologies, including FEAF, TOGAF, DoDAF and our own Oracle Enterprise Architecture Framework (OEAF). The taxonomy below is organized by (1) Target Community, (2) Benefit or Value, and (3) EA Program Facet - as in: "Let's talk to (1: Community Member) about how and why (3: EA Facet) the EA program can help with (2: Benefit/Value)". Once the initial discussion targets and subjects are approved (that can be measured and reported), a "marketing and communications plan" can be created. A working example follows the Taxonomy. Enterprise Architecture Sales Taxonomy Draft, Summary Version 1. Community 1.1. Budgeted Programs or Portfolios Communities of Purpose (CoPR) 1.1.1. Program/System Owners (Senior Execs) Creating or Executing Acquisition Plans 1.1.2. Program/System Owners Facing Strategic Change 1.1.2.1. Mandated 1.1.2.2. Expected/Anticipated 1.1.3. Program Managers - Creating Employee Performance Plans 1.1.4. CO/COTRs – Creating Contractor Performance Plans, or evaluating Value Engineering Change Proposals (VECP) 1.2. Governance & Communications Communities of Practice (CoP) 1.2.1. Policy Owners 1.2.1.1. OCFO 1.2.1.1.1. Budget/Procurement Office 1.2.1.1.2. Strategic Planning 1.2.1.2. OCIO 1.2.1.2.1. IT Management 1.2.1.2.2. IT Operations 1.2.1.2.3. Information Assurance (Cyber Security) 1.2.1.2.4. IT Innovation 1.2.1.3. Information-Sharing/ Process Collaboration (i.e. policies and procedures regarding Partners, Agreements) 1.2.2. Governing IT Council/SME Peers (i.e. an "Architects Council") 1.2.2.1. Enterprise Architects (assumes others exist; also assumes EA participants aren't buried solely within the CIO shop) 1.2.2.2. Domain, Enclave, Segment Architects – i.e. the right affinity group for a "shared services" EA structure (per the EAMMF), which may be classified as Federated, Segmented, Service-Oriented, or Extended 1.2.2.3. External Oversight/Constraints 1.2.2.3.1. GAO/OIG & Legal 1.2.2.3.2. Industry Standards 1.2.2.3.3. Official public notification, response 1.2.3. Mission Constituents Participant & Analyst Community of Interest (CoI) 1.2.3.1. Mission Operators/Users 1.2.3.2. Public Constituents 1.2.3.3. Industry Advisory Groups, Stakeholders 1.2.3.4. Media 2. Benefit/Value (Note the actual benefits may not be discretely attributable to EA alone; EA is a very collaborative, cross-cutting discipline.) 2.1. Program Costs – EA enables sound decisions regarding... 2.1.1. Cost Avoidance – a TCO theme 2.1.2. Sequencing – alignment of capability delivery 2.1.3. Budget Instability – a Federal reality 2.2. Investment Capital – EA illuminates new investment resources via... 2.2.1. Value Engineering – contractor-driven cost savings on existing budgets, direct or collateral 2.2.2. Reuse – reuse of investments between programs can result in savings, chargeback models; avoiding duplication 2.2.3. License Refactoring – IT license & support models may not reflect actual or intended usage 2.3. Contextual Knowledge – EA enables informed decisions by revealing... 2.3.1. Common Operating Picture (COP) – i.e. cross-program impacts and synergy, relative to context 2.3.2. Expertise & Skill – who truly should be involved in architectural decisions, both business and IT 2.3.3. Influence – the impact of politics and relationships can be examined 2.3.4. Disruptive Technologies – new technologies may reduce costs or mitigate risk in unanticipated ways 2.3.5. What-If Scenarios – can become much more refined, current, verifiable; basis for Target Architectures 2.4. Mission Performance – EA enables beneficial decision results regarding... 2.4.1. IT Performance and Optimization – towards 100% effective, available resource utilization 2.4.2. IT Stability – towards 100%, real-time uptime 2.4.3. Agility – responding to rapid changes in mission 2.4.4. Outcomes –measures of mission success, KPIs – vs. only "Outputs" 2.4.5. Constraints – appropriate response to constraints 2.4.6. Personnel Performance – better line-of-sight through performance plans to mission outcome 2.5. Mission Risk Mitigation – EA mitigates decision risks in terms of... 2.5.1. Compliance – all the right boxes are checked 2.5.2. Dependencies –cross-agency, segment, government 2.5.3. Transparency – risks, impact and resource utilization are illuminated quickly, comprehensively 2.5.4. Threats and Vulnerabilities – current, realistic awareness and profiles 2.5.5. Consequences – realization of risk can be mapped as a series of consequences, from earlier decisions or new decisions required for current issues 2.5.5.1. Unanticipated – illuminating signals of future or non-symmetric risk; helping to "future-proof" 2.5.5.2. Anticipated – discovering the level of impact that matters 3. EA Program Facet (What parts of the EA can and should be communicated, using business or mission terms?) 3.1. Architecture Models – the visual tools to be created and used 3.1.1. Operating Architecture – the Business Operating Model/Architecture elements of the EA truly drive all other elements, plus expose communication channels 3.1.2. Use Of – how can the EA models be used, and how are they populated, from a reasonable, pragmatic yet compliant perspective? What are the core/minimal models required? What's the relationship of these models, with existing system models? 3.1.3. Scope – what level of granularity within the models, and what level of abstraction across the models, is likely to be most effective and useful? 3.2. Traceability – the maturity, status, completeness of the tools 3.2.1. Status – what in fact is the degree of maturity across the integrated EA model and other relevant governance models, and who may already be benefiting from it? 3.2.2. Visibility – how does the EA visibly and effectively prove IT investment performance goals are being reached, with positive mission outcome? 3.3. Governance – what's the interaction, participation method; how are the tools used? 3.3.1. Contributions – how is the EA program informed, accept submissions, collect data? Who are the experts? 3.3.2. Review – how is the EA validated, against what criteria?  Taxonomy Usage Example:   1. To speak with: a. ...a particular set of System Owners Facing Strategic Change, via mandate (like the "Cloud First" mandate); about... b. ...how the EA program's visible and easily accessible Infrastructure Reference Model (i.e. "IRM" or "TRM"), if updated more completely with current system data, can... c. ...help shed light on ways to mitigate risks and avoid future costs associated with NOT leveraging potentially-available shared services across the enterprise... 2. ....the following Marketing & Communications (Sales) Plan can be constructed: a. Create an easy-to-read "Consequence Model" that illustrates how adoption of a cloud capability (like elastic operational storage) can enable rapid and durable compliance with the mandate – using EA traceability. Traceability might be from the IRM to the ARM (that identifies reusable services invoking the elastic storage), and then to the PRM with performance measures (such as % utilization of purchased storage allocation) included in the OMB Exhibits; and b. Schedule a meeting with the Program Owners, timed during their Acquisition Strategy meetings in response to the mandate, to use the "Consequence Model" for advising them to organize a rapid and relevant RFI solicitation for this cloud capability (regarding alternatives for sourcing elastic operational storage); and c. Schedule a series of short "Discovery" meetings with the system architecture leads (as agreed by the Program Owners), to further populate/validate the "As-Is" models and frame the "To Be" models (via scenarios), to better inform the RFI, obtain the best feedback from the vendor community, and provide potential value for and avoid impact to all other programs and systems. --end example -- Note that communications with the intended audience should take a page out of the standard "Search Engine Optimization" (SEO) playbook, using keywords and phrases relating to "value" and "outcome" vs. "compliance" and "output". Searches in email boxes, internal and external search engines for phrases like "cost avoidance strategies", "mission performance metrics" and "innovation funding" should yield messages and content from the EA team. This targeted, informed, practical sales approach should result in additional buy-in and participation, additional EA information contribution and model validation, development of more SMEs and quick "proof points" (with real-life testing) to bolster the case for EA. The proof point here is a successful, timely procurement that satisfies not only the external mandate and external oversight review, but also meets internal EA compliance/conformance goals and therefore is more transparently useful across the community. In short, if sold effectively, the EA will perform and be recognized. EA won’t therefore be used only for compliance, but also (according to a validated, stated purpose) to directly influence decisions and outcomes. The opinions, views and analysis expressed in this document are those of the author and do not necessarily reflect the views of Oracle.

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  • Using Dynamic LINQ to get a filter for my Web API

    - by Espo
    We are considering using the Dynamic.CS linq-sample included in the "Samples" directory of visual studio 2008 for our WebAPI project to allow clients to query our data. The interface would be something like this (In addition to the normal GET-methods): public HttpResponseMessage List(string filter = null); The plan is to use the dynamic library to parse the "filter"-variable and then execute the query agains the DB. Any thoughts if this is a good idea? Is it a security problem?

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  • IEnumerator.Current property and IEnumerator.MoveNext method

    - by nmarun
    Here’s a question: What happens to the Current property of an IEnumerator before and after the MoveNext() call? When I say ‘after the MoveNext() call’, I mean after MoveNext() returns a false indicating an end of the collection. I was going through the MSDN for IEnumerator.Current and the first paragraph basically boils down to: If MoveNext() method has never been called on an IEnumerator, the Current property is undefined. I wanted to know what ‘undefined’ means – is it null? If so, what if the...(read more)

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  • Mounting Nexus 7 on Ubuntu 12.04 through USB?

    - by Pomario
    I would like to transfer files between my Ubuntu 12.04 and Nexus 7 (Android 4.2) I have followed another post carefully. BUT upon... mount /mnt/nexus7 I get... Android device detected, assigning default bug flags.Listing File Information on Device with name: (NULL) and even doing an "ls" in "/mnt" generates... ls: cannot access nexus7: Transport endpoint is not connected Ideas why that is happening???

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  • Looking for a code Plugin !!

    - by GrumpyOldDBA
    SET ANSI_NULLS ON SET QUOTED_IDENTIFIER ON GO IF NOT EXISTS( SELECT 1 FROM INFORMATION_SCHEMA . TABLES WHERE TABLE_SCHEMA = 'dbo' AND TABLE_NAME = 'MSPaymentForExtraction' ) BEGIN CREATE TABLE [dbo] . [MSPaymentForExtraction] ( [MSPaymentID] [int] NOT NULL IDENTITY ( 1 , 1 ) NOT FOR REPLICATION ) ON [PRIMARY] END GO...(read more)

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  • ResolveUrl() from WCF service

    - by Michael Freidgeim
    I wanted to ResolveUrl() from WCF service and foundhttp://www.west-wind.com/weblog/posts/2007/Sep/18/ResolveUrl-without-Page .However the function assumes that the call is synchronous, in asynchronous call (e.g called from TPL task) HttpContext.Current==null.I had to split my asynchronous method into two-a long asynchronous one, invoked as task and generating relative URL and a post-task, that is calling wwWebUtils.ResolveServerUrl(relativeUrL)The http://www.codeproject.com/Articles/205425/ASP-NET-ResolveUrl-Without-Page  article suggests to useSystem.Web.VirtualPathUtility.ToAbsolute("~/default.aspx");but i expect, it wouldn’t work from asynchronous thread as well.

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  • CVE-2014-0191 Denial of Service(DOS) vulnerability in Libxml2

    - by Ritwik Ghoshal
    CVE DescriptionCVSSv2 Base ScoreComponentProduct and Resolution CVE-2014-0191 Denial of Service(DOS) vulnerability null Libxml2 Solaris 11.2 11.2.1.5.0 This notification describes vulnerabilities fixed in third-party components that are included in Oracle's product distributions.Information about vulnerabilities affecting Oracle products can be found on Oracle Critical Patch Updates and Security Alerts page.

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  • Position sprite at center of screen

    - by Wellie
    I am trying to get a sprite to position itself at the center of the screen but nothing seems to be working for me. I'm trying Viewport viewport = graphics.GraphicsDevice.Viewport; logoPosition = new Vector2((viewport.Width - towerImage.Width) / 2, (viewport.Height - towerImage.Height) / 2); and spriteBatch.Draw(towerImage, centre, null, Color.White, 0, baseOrigin, 1.0f, SpriteEffects.None, 0); This is my first time using XNA and I don't really have a clue what I'm doing.

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  • What is the abstract name for Drive, Directory and file?

    - by Omkar panhalkar
    I want to give nice name to my function while returns drive, directory and file. Can you please suggest a good abstract name for this trio? This is the function. static IEnumerable<string> GetDriveDirectoriesAndFile(string path) { if (path.Contains('/')) { path = path.Replace('/', '\\'); } if (path.Contains('\\')) { return path.Split('\\'); } return null; } Thanks, Omkar

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  • A Simple Entity Tagger

    - by Elton Stoneman
    In the REST world, ETags are your gateway to performance boosts by letting clients cache responses. In the non-REST world, you may also want to add an ETag to an entity definition inside a traditional service contract – think of a scenario where a consumer persists its own representation of your entity, and wants to keep it in sync. Rather than load every entity by ID and check for changes, the consumer can send in a set of linked IDs and ETags, and you can return only the entities where the current ETag is different from the consumer’s version.  If your entity is a projection from various sources, you may not have a persistent ETag, so you need an efficient way to generate an ETag which is deterministic, so an entity with the same state always generates the same ETag. I have an implementation for a generic ETag generator on GitHub here: EntityTagger code sample. The essence is simple - we get the entity, serialize it and build a hash from the serialized value. Any changes to either the state or the structure of the entity will result in a different hash. To use it, just call SetETag, passing your populated object and a Func<> which acts as an accessor to the ETag property: EntityTagger.SetETag(user, x => x.ETag); The implementation is all in at 80 lines of code, which is all pretty straightforward: var eTagProperty = AsPropertyInfo(eTagPropertyAccessor); var originalETag = eTagProperty.GetValue(entity, null); try { ResetETag(entity, eTagPropertyAccessor); string json; var serializer = new DataContractJsonSerializer(entity.GetType()); using (var stream = new MemoryStream()) { serializer.WriteObject(stream, entity); json = Encoding.UTF8.GetString(stream.GetBuffer(), 0, (int)stream.Length); } var guid = GetDeterministicGuid(json); eTagProperty.SetValue(entity, guid.ToString(), null); //... There are a couple of helper methods to check if the object has changed since the ETag value was last set, and to reset the ETag. This implementation uses JSON to do the serializing rather than XML. Benefit - should be marginally more efficient as your hashing a much smaller serialized string; downside, JSON doesn't include namespaces or class names at the root level, so if you have two classes with the exact same structure but different names, then instances which have the same content will have the same ETag. You may want that behaviour, but change to use the XML DataContractSerializer if you think that will be an issue. If you can persist the ETag somewhere, it will save you server processing to load up the entity, but that will only apply to scenarios where you can reliably invalidate your ETag (e.g. if you control all the entry points where entity contents can be updated, then you can calculate and persist the new ETag with each update).

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