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  • Popping a modal view from anywhere in code

    - by ConfusedNoob
    Is it possible to 'pop' a view from any point in an iOS application. For example, I want an event to trigger a view sliding in (modal) and the event can happen at any time, on any screen in the application. Also, we'd like this to be something that can be included in other projects and would prefer them not to have to do anything special to these projects (other than wire in the referenced project).

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  • How do I install a platform into my android device?

    - by Saip
    I downloaded the emulator and followed the steps on the android website on how to install the SDK. i made an AVD and everything showed up on my computer screen perfectly, but now the problem was installing it to my phone. i can't find the instructions the android website on how to install it on my device.

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  • Suspend orientation change

    - by OkyDokyman
    Documentation says: "a configuration change (such as a change in screen orientation, language, input devices, etc) will cause your current activity to be destroyed, going through the normal activity lifecycle process of onPause(), onStop(), and onDestroy()." I would like to suspend the orientation change, since it crashes my app if it was done in the middle of a a loop (of reading a file). How can I do this? Also - looking for some kind of "onOrientationChnage" function :)

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  • iphone view-based app

    - by ms
    I've created a view based application and have connected all of my buttons through Interface Builder (and saved)...however upon launch all I have is a white screen on the simulator. I've uncommented the viewDidLoad, and my header file has IBOutlet UIlabels defined. I'm kind of baffled.

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  • visualizing enter symbol in java (Serif/SansSerif preferred)

    - by Tom
    How can I display the graphical "enter symbol" within java applet using fonts? I want to show "?", which is U+21B5 DOWNWARDS ARROW WITH CORNER LEFTWARDS. – I want to draw this to applet's screen so that it works in WIN, LINUX, MACOSX, etc. Is there a font available that makes this possible or should I draw it manually somehow? g2d.setFont("SymbolFont??which one"); g2d.drawString(myenterSymbolHere,x,Y);

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  • How to create many div's with 100% height?

    - by ChrisBenyamin
    I need a html document, that contains multiple div's with 100% height (screen filling) one below the other. I have tried to apply every element a height of 100%, but that won't work seamless nor clean. Maybe there is a option with JavaScript? I don't have an idea. Please suggest me your solutions. chris

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  • Computer Networks UNISA - Chap 12 &ndash; Networking Security

    - by MarkPearl
    After reading this section you should be able to Identify security risks in LANs and WANs and design security policies that minimize risks Explain how physical security contributes to network security Discuss hardware and design based security techniques Understand methods of encryption such as SSL and IPSec, that can secure data in storage and in transit Describe how popular authentication protocols such as RADIUS< TACACS,Kerberos, PAP, CHAP, and MS-CHAP function Use network operating system techniques to provide basic security Understand wireless security protocols such as WEP, WPA and 802.11i Security Audits Before spending time and money on network security, examine your networks security risks – rate and prioritize risks. Different organizations have different levels of network security requirements. Security Risks Not all security breaches result from a manipulation of network technology – there are human factors that can play a role as well. The following categories are areas of considerations… Risks associated with People Risks associated with Transmission and Hardware Risks associated with Protocols and Software Risks associated with Internet Access An effective security policy A security policy identifies your security goals, risks, levels of authority, designated security coordinator and team members, responsibilities for each team member, and responsibilities for each employee. In addition it specifies how to address security breaches. It should not state exactly which hardware, software, architecture, or protocols will be used to ensure security, nor how hardware or software will be installed and configured. A security policy must address an organizations specific risks. to understand your risks, you should conduct a security audit that identifies vulnerabilities and rates both the severity of each threat and its likelihood of occurring. Security Policy Content Security policy content should… Policies for each category of security Explain to users what they can and cannot do and how these measures protect the networks security Should define what confidential means to the organization Response Policy A security policy should provide for a planned response in the event of a security breach. The response policy should identify the members of a response team, all of whom should clearly understand the the security policy, risks, and measures in place. Some of the roles concerned could include… Dispatcher – the person on call who first notices the breach Manager – the person who coordinates the resources necessary to solve the problem Technical Support Specialist – the person who focuses on solving the problem Public relations specialist – the person who acts as the official spokesperson for the organization Physical Security An important element in network security is restricting physical access to its components. There are various techniques for this including locking doors, security people at access points etc. You should identify the following… Which rooms contain critical systems or data and must be secured Through what means might intruders gain access to these rooms How and to what extent are authorized personnel granted access to these rooms Are authentication methods such as ID cards easy to forge etc. Security in Network Design The optimal way to prevent external security breaches from affecting you LAN is not to connect your LAN to the outside world at all. The next best protection is to restrict access at every point where your LAN connects to the rest of the world. Router Access List – can be used to filter or decline access to a portion of a network for certain devices. Intrusion Detection and Prevention While denying someone access to a section of the network is good, it is better to be able to detect when an attempt has been made and notify security personnel. This can be done using IDS (intrusion detection system) software. One drawback of IDS software is it can detect false positives – i.e. an authorized person who has forgotten his password attempts to logon. Firewalls A firewall is a specialized device, or a computer installed with specialized software, that selectively filters or blocks traffic between networks. A firewall typically involves a combination of hardware and software and may reside between two interconnected private networks. The simplest form of a firewall is a packet filtering firewall, which is a router that examines the header of every packet of data it receives to determine whether that type of packet is authorized to continue to its destination or not. Firewalls can block traffic in and out of a LAN. NOS (Network Operating System) Security Regardless of the operating system, generally every network administrator can implement basic security by restricting what users are authorized to do on a network. Some of the restrictions include things related to Logons – place, time of day, total time logged in, etc Passwords – length, characters used, etc Encryption Encryption is the use of an algorithm to scramble data into a format that can be read only by reversing the algorithm. The purpose of encryption is to keep information private. Many forms of encryption exist and new ways of cracking encryption are continually being invented. The following are some categories of encryption… Key Encryption PGP (Pretty Good Privacy) SSL (Secure Sockets Layer) SSH (Secure Shell) SCP (Secure CoPy) SFTP (Secure File Transfer Protocol) IPSec (Internet Protocol Security) For a detailed explanation on each section refer to pages 596 to 604 of textbook Authentication Protocols Authentication protocols are the rules that computers follow to accomplish authentication. Several types exist and the following are some of the common authentication protocols… RADIUS and TACACS PAP (Password Authentication Protocol) CHAP and MS-CHAP EAP (Extensible Authentication Protocol) 802.1x (EAPoL) Kerberos Wireless Network Security Wireless transmissions are particularly susceptible to eavesdropping. The following are two wireless network security protocols WEP WPA

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  • Geocaching - World wide treasure hunt

    I'm not quite sure how I came across this topic but actually I find it absolutely interesting, challenging and most of all a great fun for the family and friends. The interesting part is for sure that you can follow other peoples treasures and their preferred locations where a cache might be hidden. Of course, it wont be easy to find a cache after all. Sometimes there are even 'mystery caches' which have either riddles, further instructions or little brain games for you in order to find the actual cache - that's the challenge. And last but not least, those caches are hidden outdoor. A great experience to explore nature either on your own, or your family especially with children, or as a treasure hunting pack with a couple of friends. What is geocaching? It's a high-tech outdoor treasure hunting game that's a great way to explore the world with friends, family or on your own. Participants use GPS-enabled devices to locate hidden containers called geocaches. There are over one million geocaches hidden around the world today, waiting for you to find them. Visit Geocaching.com to search for geocaches near you.(Source: Referral Email of geocaching.com) Checkout the Geocaching 101 for further details and information. They also provide a video channel on YouTube. Which equipment do I need? Any GPS-enabled device is sufficient to go onto the hunt. I'm going to start our geocaching experience equipped with my Samsung Galaxy Tab. Additionally, I installed a geocaching.com client called c:geo that hopefully assists me soon. Combined with a map app like Google Maps and a nice Compass app you should be fully equipped and ready to go. I guess, that even a car navigation system is perfect for that task. Later on, with more experience and demand for technology (or precision) it might be interesting to opt-in for a pure GPS device, like a Garmin or any other brand on the market. {loadposition content_adsense} What is a geocache and what does it contain? In its simplest form, a cache always contains a logbook or logsheet for you to log your find. Larger caches may contain a logbook and any number of items. These items turn the adventure into a true treasure hunt. You never know what the cache owner or visitors to the cache may have left for you to enjoy. Remember, if you take something, leave something of equal or greater value in return. It is recommended that items in a cache be individually packaged in a clear, zipped plastic bag to protect them from the elements. Finding your first geocache Well, first you have to have interest to pick up the challenge. Then you have to check out the Geocache directory on geocaching.com. They have recommendations for beginner's caches but you are free to choose any. Actually, we have a Mystery Cache very close to our base, and I guess that we are going for that one on our first trip. Anyway, there is a very informative guide on the website which should answer all your questions about starting your new outdoor adventure. For sure, it's going to be rewarding. Team up with friends and family Especially as a beginner there might be misunderstandings in handling the GPS coordinates, the compass, or the map, and even finding the container at the documented position isn't easy in the first place. Luckily, there are logbook reports online from other hunters, and most of the time there are even 'spoiler' images available. But also bear in mind, that a geocache might have been removed or is lost due to unconscious people or whatever other reasons. Don't be disappointed in case that you can't find anything... There be nothing anymore. A general recommendation in this case would be to replace the missing container with a new one, and give feedback to the original owner about the state of that particular location. After all, it's about fun and active participation in a world-wide community. Geocaches in Mauritius? Yes, there are currently about 45 geocaches spread all over the island, and even a single in Rodriguez - that's gonna be a tough one. Hopefully, we will get increasing numbers as Geocaching.com allows, no better, even encourages you to hide new containers at your locations of choice. I think this is going to be real fun for us during the upcoming weeks and months. Especially, when we are travelling to other countries and transfer so-called trackable items between geocaches. On my first impression, Geocaching.com seems to be very mature, open and community-oriented. There are literally hundreds of thousands geocache 'hunters' all over the world. And usually finding a container remote from your home is very rewarding. I'll keep you updated in these matters during the next months to come...

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  • First time shadow mapping problems

    - by user1294203
    I have implemented basic shadow mapping for the first time in OpenGL using shaders and I'm facing some problems. Below you can see an example of my rendered scene: The process of the shadow mapping I'm following is that I render the scene to the framebuffer using a View Matrix from the light point of view and the projection and model matrices used for normal rendering. In the second pass, I send the above MVP matrix from the light point of view to the vertex shader which transforms the position to light space. The fragment shader does the perspective divide and changes the position to texture coordinates. Here is my vertex shader, #version 150 core uniform mat4 ModelViewMatrix; uniform mat3 NormalMatrix; uniform mat4 MVPMatrix; uniform mat4 lightMVP; uniform float scale; in vec3 in_Position; in vec3 in_Normal; in vec2 in_TexCoord; smooth out vec3 pass_Normal; smooth out vec3 pass_Position; smooth out vec2 TexCoord; smooth out vec4 lightspace_Position; void main(void){ pass_Normal = NormalMatrix * in_Normal; pass_Position = (ModelViewMatrix * vec4(scale * in_Position, 1.0)).xyz; lightspace_Position = lightMVP * vec4(scale * in_Position, 1.0); TexCoord = in_TexCoord; gl_Position = MVPMatrix * vec4(scale * in_Position, 1.0); } And my fragment shader, #version 150 core struct Light{ vec3 direction; }; uniform Light light; uniform sampler2D inSampler; uniform sampler2D inShadowMap; smooth in vec3 pass_Normal; smooth in vec3 pass_Position; smooth in vec2 TexCoord; smooth in vec4 lightspace_Position; out vec4 out_Color; float CalcShadowFactor(vec4 lightspace_Position){ vec3 ProjectionCoords = lightspace_Position.xyz / lightspace_Position.w; vec2 UVCoords; UVCoords.x = 0.5 * ProjectionCoords.x + 0.5; UVCoords.y = 0.5 * ProjectionCoords.y + 0.5; float Depth = texture(inShadowMap, UVCoords).x; if(Depth < (ProjectionCoords.z + 0.001)) return 0.5; else return 1.0; } void main(void){ vec3 Normal = normalize(pass_Normal); vec3 light_Direction = -normalize(light.direction); vec3 camera_Direction = normalize(-pass_Position); vec3 half_vector = normalize(camera_Direction + light_Direction); float diffuse = max(0.2, dot(Normal, light_Direction)); vec3 temp_Color = diffuse * vec3(1.0); float specular = max( 0.0, dot( Normal, half_vector) ); float shadowFactor = CalcShadowFactor(lightspace_Position); if(diffuse != 0 && shadowFactor > 0.5){ float fspecular = pow(specular, 128.0); temp_Color += fspecular; } out_Color = vec4(shadowFactor * texture(inSampler, TexCoord).xyz * temp_Color, 1.0); } One of the problems is self shadowing as you can see in the picture, the crate has its own shadow cast on itself. What I have tried is enabling polygon offset (i.e. glEnable(POLYGON_OFFSET_FILL), glPolygonOffset(GLfloat, GLfloat) ) but it didn't change much. As you see in the fragment shader, I have put a static offset value of 0.001 but I have to change the value depending on the distance of the light to get more desirable effects , which not very handy. I also tried using front face culling when I render to the framebuffer, that didn't change much too. The other problem is that pixels outside the Light's view frustum get shaded. The only object that is supposed to be able to cast shadows is the crate. I guess I should pick more appropriate projection and view matrices, but I'm not sure how to do that. What are some common practices, should I pick an orthographic projection? From googling around a bit, I understand that these issues are not that trivial. Does anyone have any easy to implement solutions to these problems. Could you give me some additional tips? Please ask me if you need more information on my code. Here is a comparison with and without shadow mapping of a close-up of the crate. The self-shadowing is more visible.

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  • Unexpected behaviour with glFramebufferTexture1D

    - by Roshan
    I am using render to texture concept with glFramebufferTexture1D. I am drawing a cube on non-default FBO with all the vertices as -1,1 (maximum) in X Y Z direction. Now i am setting viewport to X while rendering on non default FBO. My background is blue with white color of cube. For default FBO, i have created 1-D texture and attached this texture to above FBO with color attachment. I am setting width of texture equal to width*height of above FBO view-port. Now, when i render this texture to on another cube, i can see continuous white color on start or end of each face of the cube. That means part of the face is white and rest is blue. I am not sure whether this behavior is correct or not. I expect all the texels should be white as i am using -1 and 1 coordinates for cube rendered on non-default FBO. code: #define WIDTH 3 #define HEIGHT 3 GLfloat vertices8[]={ 1.0f,1.0f,1.0f, -1.0f,1.0f,1.0f, -1.0f,-1.0f,1.0f, 1.0f,-1.0f,1.0f,//face 1 1.0f,-1.0f,-1.0f, -1.0f,-1.0f,-1.0f, -1.0f,1.0f,-1.0f, 1.0f,1.0f,-1.0f,//face 2 1.0f,1.0f,1.0f, 1.0f,-1.0f,1.0f, 1.0f,-1.0f,-1.0f, 1.0f,1.0f,-1.0f,//face 3 -1.0f,1.0f,1.0f, -1.0f,1.0f,-1.0f, -1.0f,-1.0f,-1.0f, -1.0f,-1.0f,1.0f,//face 4 1.0f,1.0f,1.0f, 1.0f,1.0f,-1.0f, -1.0f,1.0f,-1.0f, -1.0f,1.0f,1.0f,//face 5 -1.0f,-1.0f,1.0f, -1.0f,-1.0f,-1.0f, 1.0f,-1.0f,-1.0f, 1.0f,-1.0f,1.0f//face 6 }; GLfloat vertices[]= { 0.5f,0.5f,0.5f, -0.5f,0.5f,0.5f, -0.5f,-0.5f,0.5f, 0.5f,-0.5f,0.5f,//face 1 0.5f,-0.5f,-0.5f, -0.5f,-0.5f,-0.5f, -0.5f,0.5f,-0.5f, 0.5f,0.5f,-0.5f,//face 2 0.5f,0.5f,0.5f, 0.5f,-0.5f,0.5f, 0.5f,-0.5f,-0.5f, 0.5f,0.5f,-0.5f,//face 3 -0.5f,0.5f,0.5f, -0.5f,0.5f,-0.5f, -0.5f,-0.5f,-0.5f, -0.5f,-0.5f,0.5f,//face 4 0.5f,0.5f,0.5f, 0.5f,0.5f,-0.5f, -0.5f,0.5f,-0.5f, -0.5f,0.5f,0.5f,//face 5 -0.5f,-0.5f,0.5f, -0.5f,-0.5f,-0.5f, 0.5f,-0.5f,-0.5f, 0.5f,-0.5f,0.5f//face 6 }; GLuint indices[] = { 0, 2, 1, 0, 3, 2, 4, 5, 6, 4, 6, 7, 8, 9, 10, 8, 10, 11, 12, 15, 14, 12, 14, 13, 16, 17, 18, 16, 18, 19, 20, 23, 22, 20, 22, 21 }; GLfloat texcoord[] = { 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0 }; glGenTextures(1, &id1); glBindTexture(GL_TEXTURE_1D, id1); glGenFramebuffers(1, &Fboid); glTexParameterf(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameterf(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameterf(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA, WIDTH*HEIGHT , 0, GL_RGBA, GL_UNSIGNED_BYTE,0); glBindFramebuffer(GL_FRAMEBUFFER, Fboid); glFramebufferTexture1D(GL_DRAW_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_1D,id1,0); draw_cube(); glBindFramebuffer(GL_FRAMEBUFFER, 0); draw(); } draw_cube() { glViewport(0, 0, WIDTH, HEIGHT); glClearColor(0.0f, 0.0f, 0.5f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); glEnableVertexAttribArray(glGetAttribLocation(temp.psId,"position")); glVertexAttribPointer(glGetAttribLocation(temp.psId,"position"), 3, GL_FLOAT, GL_FALSE, 0,vertices8); glDrawArrays (GL_TRIANGLE_FAN, 0, 24); } draw() { glClearColor(1.0f, 0.0f, 0.0f, 1.0f); glClearDepth(1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnableVertexAttribArray(glGetAttribLocation(shader_data.psId,"tk_position")); glVertexAttribPointer(glGetAttribLocation(shader_data.psId,"tk_position"), 3, GL_FLOAT, GL_FALSE, 0,vertices); nResult = GL_ERROR_CHECK((GL_NO_ERROR, "glVertexAttribPointer(position, 3, GL_FLOAT, GL_FALSE, 0,vertices);")); glEnableVertexAttribArray(glGetAttribLocation(shader_data.psId,"inputtexcoord")); glVertexAttribPointer(glGetAttribLocation(shader_data.psId,"inputtexcoord"), 2, GL_FLOAT, GL_FALSE, 0,texcoord); glBindTexture(*target11, id1); glDrawElements ( GL_TRIANGLES, 36,GL_UNSIGNED_INT, indices ); when i change WIDTH=HEIGHT=2, and call a glreadpixels with height, width equal to 4 in draw_cube() i can see first 2 pixels with white color, next two with blue(glclearcolor), next two white and then blue and so on.. Now when i change width parameter in glTeximage1D to 16 then ideally i should see alternate patches of white and blue right? But its not the case here. why so?

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  • Libnoise producing completely random noise

    - by Doodlemeat
    I am using libnoise in C++ taken and I have some problems with getting coherent noise. I mean, the noise produced now are completely random and it doesn't look like a noise. Here's a to the image produced by my game. I am diving the map into several chunks, but I can't seem to find any problem doing that since libnoise supports tileable noise. The code can be found below. Every chunk is 8x8 tiles large. Every tile is 64x64 pixels. I am also providing a link to download the entire project. It was made in Visual Studio 2013. Download link This is the code for generating a chunk Chunk *World::loadChunk(sf::Vector2i pPosition) { sf::Vector2i chunkPos = pPosition; pPosition.x *= mChunkTileSize.x; pPosition.y *= mChunkTileSize.y; sf::FloatRect bounds(static_cast<sf::Vector2f>(pPosition), sf::Vector2f(static_cast<float>(mChunkTileSize.x), static_cast<float>(mChunkTileSize.y))); utils::NoiseMap heightMap; utils::NoiseMapBuilderPlane heightMapBuilder; heightMapBuilder.SetSourceModule(mNoiseModule); heightMapBuilder.SetDestNoiseMap(heightMap); heightMapBuilder.SetDestSize(mChunkTileSize.x, mChunkTileSize.y); heightMapBuilder.SetBounds(bounds.left, bounds.left + bounds.width - 1, bounds.top, bounds.top + bounds.height - 1); heightMapBuilder.Build(); Chunk *chunk = new Chunk(this); chunk->setPosition(chunkPos); chunk->buildChunk(&heightMap); chunk->setTexture(&mTileset); mChunks.push_back(chunk); return chunk; } This is the code for building the chunk void Chunk::buildChunk(utils::NoiseMap *pHeightMap) { // Resize the tiles space mTiles.resize(pHeightMap->GetWidth()); for (int x = 0; x < mTiles.size(); x++) { mTiles[x].resize(pHeightMap->GetHeight()); } // Set vertices type and size mVertices.setPrimitiveType(sf::Quads); mVertices.resize(pHeightMap->GetWidth() * pHeightMap->GetWidth() * 4); // Get the offset position of all tiles position sf::Vector2i tileSize = mWorld->getTileSize(); sf::Vector2i chunkSize = mWorld->getChunkSize(); sf::Vector2f offsetPositon = sf::Vector2f(mPosition); offsetPositon.x *= chunkSize.x; offsetPositon.y *= chunkSize.y; // Build tiles for (int x = 0; x < mTiles.size(); x++) { for (int y = 0; y < mTiles[x].size(); y++) { // Sometimes libnoise can return a value over 1.0, better be sure to cap the top and bottom.. float heightValue = pHeightMap->GetValue(x, y); if (heightValue > 1.f) heightValue = 1.f; if (heightValue < -1.f) heightValue = -1.f; // Instantiate a new Tile object with the noise value, this doesn't do anything yet.. mTiles[x][y] = new Tile(this, pHeightMap->GetValue(x, y)); // Get a pointer to the current tile's quad sf::Vertex *quad = &mVertices[(y + x * pHeightMap->GetWidth()) * 4]; quad[0].position = sf::Vector2f(offsetPositon.x + x * tileSize.x, offsetPositon.y + y * tileSize.y); quad[1].position = sf::Vector2f(offsetPositon.x + (x + 1) * tileSize.x, offsetPositon.y + y * tileSize.y); quad[2].position = sf::Vector2f(offsetPositon.x + (x + 1) * tileSize.x, offsetPositon.y + (y + 1) * tileSize.y); quad[3].position = sf::Vector2f(offsetPositon.x + x * tileSize.x, offsetPositon.y + (y + 1) * tileSize.y); // find out which type of tile to render, atm only air or stone TileStop *tilestop = mWorld->getTileStopAt(heightValue); sf::Vector2i texturePos = tilestop->getTexturePosition(); // define its 4 texture coordinates quad[0].texCoords = sf::Vector2f(texturePos.x, texturePos.y); quad[1].texCoords = sf::Vector2f(texturePos.x + 64, texturePos.y); quad[2].texCoords = sf::Vector2f(texturePos.x + 64, texturePos.y + 64); quad[3].texCoords = sf::Vector2f(texturePos.x, texturePos.y + 64); } } } All the code that uses libnoise in some way are World.cpp, World.h and Chunk.cpp, Chunk.h in the project.

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  • Not getting desired results with SSAO implementation

    - by user1294203
    After having implemented deferred rendering, I tried my luck with a SSAO implementation using this Tutorial. Unfortunately, I'm not getting anything that looks like SSAO, you can see my result below. You can see there is some weird pattern forming and there is no occlusion shading where there needs to be (i.e. in between the objects and on the ground). The shaders I implemented follow: #VS #version 330 core uniform mat4 invProjMatrix; layout(location = 0) in vec3 in_Position; layout(location = 2) in vec2 in_TexCoord; noperspective out vec2 pass_TexCoord; smooth out vec3 viewRay; void main(void){ pass_TexCoord = in_TexCoord; viewRay = (invProjMatrix * vec4(in_Position, 1.0)).xyz; gl_Position = vec4(in_Position, 1.0); } #FS #version 330 core uniform sampler2D DepthMap; uniform sampler2D NormalMap; uniform sampler2D noise; uniform vec2 projAB; uniform ivec3 noiseScale_kernelSize; uniform vec3 kernel[16]; uniform float RADIUS; uniform mat4 projectionMatrix; 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; } mat3 CalcRMatrix(vec3 normal, vec2 texcoord){ ivec2 noiseScale = noiseScale_kernelSize.xy; vec3 rvec = texture(noise, texcoord * noiseScale).xyz; vec3 tangent = normalize(rvec - normal * dot(rvec, normal)); vec3 bitangent = cross(normal, tangent); return mat3(tangent, bitangent, normal); } void main(void){ vec2 TexCoord = pass_TexCoord; vec3 Position = CalcPosition(); vec3 Normal = normalize(texture(NormalMap, TexCoord).xyz); mat3 RotationMatrix = CalcRMatrix(Normal, TexCoord); int kernelSize = noiseScale_kernelSize.z; float occlusion = 0.0; for(int i = 0; i < kernelSize; i++){ // Get sample position vec3 sample = RotationMatrix * kernel[i]; sample = sample * RADIUS + Position; // Project and bias sample position to get its texture coordinates vec4 offset = projectionMatrix * vec4(sample, 1.0); offset.xy /= offset.w; offset.xy = offset.xy * 0.5 + 0.5; // Get sample depth float sample_depth = texture(DepthMap, offset.xy).r; float linearDepth = projAB.y / (sample_depth - projAB.x); if(abs(Position.z - linearDepth ) < RADIUS){ occlusion += (linearDepth <= sample.z) ? 1.0 : 0.0; } } out_AO = 1.0 - (occlusion / kernelSize); } I draw a full screen quad and pass Depth and Normal textures. Normals are in RGBA16F with the alpha channel reserved for the AO factor in the blur pass. I store depth in a non linear Depth buffer (32F) and recover the linear depth using: float linearDepth = projAB.y / (depth - projAB.x); where projAB.y is calculated as: and projAB.x as: These are derived from the glm::perspective(gluperspective) matrix. z_n and z_f are the near and far clip distance. As described in the link I posted on the top, the method creates samples in a hemisphere with higher distribution close to the center. It then uses random vectors from a texture to rotate the hemisphere randomly around the Z direction and finally orients it along the normal at the given pixel. Since the result is noisy, a blur pass follows the SSAO pass. Anyway, my position reconstruction doesn't seem to be wrong since I also tried doing the same but with the position passed from a texture instead of being reconstructed. I also tried playing with the Radius, noise texture size and number of samples and with different kinds of texture formats, with no luck. For some reason when changing the Radius, nothing changes. Does anyone have any suggestions? What could be going wrong?

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  • Trying to detect collision between two polygons using Separating Axis Theorem

    - by Holly
    The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(vertices[0]); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(vertices[i]); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if( other.x <= y || other.y >= x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

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  • Error in my Separating Axis Theorem collision code

    - by Holly
    The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; int x; int y; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } public void update(int xPos, int yPos){ x = xPos; y = yPos; } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(new Vect(vertices[0].x+x, vertices[0].y+y)); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(new Vect(vertices[i].x+x, vertices[i].y+y)); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if(y > other.x && other.y > x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

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  • Creating SparseImages for Pivot

    - by John Conwell
    Learning how to programmatically make collections for Microsoft Live Labs Pivot has been a pretty interesting ride. There are very few examples out there, and the folks at MS Live Labs are often slow on any feedback.  But that is what Reflector is for, right? Well, I was creating these InfoCard images (similar to the Car images in the "New Cars" sample collection that that MS created for Pivot), and wanted to put a Tag Cloud into the info card.  The problem was the size of the tag cloud might vary in order for all the tags to fit into the tag cloud (often times being bigger than the info card itself).  This was because the varying word lengths and calculated font sizes. So, to fix this, I made the tag cloud its own separate image from the info card.  Then, I would create a sparse image out of the two images, where the tag cloud fit into a small section of the info card.  This would allow the user to see the info card, but then zoom into the tag cloud and see all the tags at a normal resolution.  Kind'a cool. But...I couldn't find one code example (not one!) of how to create a sparse image.  There is one page on the SeaDragon site (http://www.seadragon.com/developer/creating-content/deep-zoom-tools/) that gives over the API for creating images and collections, and it sparsely goes over how to create a sparse image, but unless you are familiar with the API already, the documentation doesn't help very much. The key is the Image.ViewportWidth and Image.ViewportOrigin properties of the image that is getting super imposed on the main image.  I'll walk through the code below.  I've setup a couple Point structs to represent the parent and sub image sizes, as well as where on the parent I want to position the sub image.  Next, create the parent image.  This is pretty straight forward.  Then I create the sub image.  Then I calculate several ratios; the height to width ratio of the sub image, the width ratio of the sub image to the parent image, the height ratio of the sub image to the parent image, then the X and Y coordinates on the parent image where I want the sub image to be placed represented as a ratio of the position to the parent image size. After all these ratios have been calculated, I use them to calculate the Image.ViewportWidth and Image.ViewportOrigin values, then pass the image objects into the SparseImageCreator and call Create. The key thing that was really missing from the API documentation page is that when setting up your sub images, everything is expressed in a ratio in relation to the main parent image.  If I had known this, it would have saved me a lot of trial and error time.  And how did I figure this out?  Reflector of course!  There is a tool called Deep Zoom Composer that came from MS Live Labs which can create a sparse image.  I just dug around the tool's code until I found the method that create sparse images.  But seriously...look at the API documentation from the SeaDragon size and look at the code below and tell me if the documentation would have helped you at all.  I don't think so!   public static void WriteDeepZoomSparseImage(string mainImagePath, string subImagePath, string destination) {     Point parentImageSize = new Point(720, 420);     Point subImageSize = new Point(490, 310);     Point subImageLocation = new Point(196, 17);     List<Image> images = new List<Image>();     //create main image     Image mainImage = new Image(mainImagePath);     mainImage.Size = parentImageSize;     images.Add(mainImage);     //create sub image     Image subImage = new Image(subImagePath);     double hwRatio = subImageSize.X/subImageSize.Y;            // height width ratio of the tag cloud     double nodeWidth = subImageSize.X/parentImageSize.X;        // sub image width to parent image width ratio     double nodeHeight = subImageSize.Y / parentImageSize.Y;    // sub image height to parent image height ratio     double nodeX = subImageLocation.X/parentImageSize.X;       //x cordinate position on parent / width of parent     double nodeY = subImageLocation.Y / parentImageSize.Y;     //y cordinate position on parent / height of parent     subImage.ViewportWidth = (nodeWidth < double.Epsilon) ? 1.0 : (1.0 / nodeWidth);     subImage.ViewportOrigin = new Point(         (nodeWidth < double.Epsilon) ? -1.0 : (-nodeX / nodeWidth),         (nodeHeight < double.Epsilon) ? -1.0 : ((-nodeY / nodeHeight) / hwRatio));     images.Add(subImage);     //create sparse image     SparseImageCreator creator = new SparseImageCreator();     creator.Create(images, destination); }

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  • Jersey 2 in GlassFish 4 - First Java EE 7 Implementation Now Integrated (TOTD #182)

    - by arungupta
    The JAX-RS 2.0 specification released their Early Draft 3 recently. One of my earlier blogs explained as the features were first introduced in the very first draft of the JAX-RS 2.0 specification. Last week was another milestone when the first Java EE 7 specification implementation was added to GlassFish 4 builds. Jakub blogged about Jersey 2 integration in GlassFish 4 builds. Most of the basic functionality is working but EJB, CDI, and Validation are still a TBD. Here is a simple Tip Of The Day (TOTD) sample to get you started with using that functionality. Create a Java EE 6-style Maven project mvn archetype:generate -DarchetypeGroupId=org.codehaus.mojo.archetypes -DarchetypeArtifactId=webapp-javaee6 -DgroupId=example -DartifactId=jersey2-helloworld -DarchetypeVersion=1.5 -DinteractiveMode=false Note, this is still a Java EE 6 archetype, at least for now. Open the project in NetBeans IDE as it makes it much easier to edit/add the files. Add the following <respositories> <repositories> <repository> <id>snapshot-repository.java.net</id> <name>Java.net Snapshot Repository for Maven</name> <url>https://maven.java.net/content/repositories/snapshots/</url> <layout>default</layout> </repository></repositories> Add the following <dependency>s <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> <scope>test</scope></dependency><dependency> <groupId>javax.ws.rs</groupId> <artifactId>javax.ws.rs-api</artifactId> <version>2.0-m09</version> <scope>test</scope></dependency><dependency> <groupId>org.glassfish.jersey.core</groupId> <artifactId>jersey-client</artifactId> <version>2.0-m05</version> <scope>test</scope></dependency> The complete list of Maven coordinates for Jersey2 are available here. An up-to-date status of Jersey 2 can always be obtained from here. Here is a simple resource class: @Path("movies")public class MoviesResource { @GET @Path("list") public List<Movie> getMovies() { List<Movie> movies = new ArrayList<Movie>(); movies.add(new Movie("Million Dollar Baby", "Hillary Swank")); movies.add(new Movie("Toy Story", "Buzz Light Year")); movies.add(new Movie("Hunger Games", "Jennifer Lawrence")); return movies; }} This resource publishes a list of movies and is accessible at "movies/list" path with HTTP GET. The project is using the standard JAX-RS APIs. Of course, you need the trivial "Movie" and the "Application" class as well. They are available in the downloadable project anyway. Build the project mvn package And deploy to GlassFish 4.0 promoted build 43 (download, unzip, and start as "bin/asadmin start-domain") as asadmin deploy --force=true target/jersey2-helloworld.war Add a simple test case by right-clicking on the MoviesResource class, select "Tools", "Create Tests", and take defaults. Replace the function "testGetMovies" to @Testpublic void testGetMovies() { System.out.println("getMovies"); Client client = ClientFactory.newClient(); List<Movie> movieList = client.target("http://localhost:8080/jersey2-helloworld/webresources/movies/list") .request() .get(new GenericType<List<Movie>>() {}); assertEquals(3, movieList.size());} This test uses the newly defined JAX-RS 2 client APIs to access the RESTful resource. Run the test by giving the command "mvn test" and see the output as ------------------------------------------------------- T E S T S-------------------------------------------------------Running example.MoviesResourceTestgetMoviesTests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.561 secResults :Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 GlassFish 4 contains Jersey 2 as the JAX-RS implementation. If you want to use Jersey 1.1 functionality, then Martin's blog provide more details on that. All JAX-RS 1.x functionality will be supported using standard APIs anyway. This workaround is only required if Jersey 1.x functionality needs to be accessed. The complete source code explained in this project can be downloaded from here. Here are some pointers to follow JAX-RS 2 Specification Early Draft 3 Latest status on specification (jax-rs-spec.java.net) Latest JAX-RS 2.0 Javadocs Latest status on Jersey (Reference Implementation of JAX-RS 2 - jersey.java.net) Latest Jersey API Javadocs Latest GlassFish 4.0 Promoted Build Follow @gf_jersey Provide feedback on Jersey 2 to [email protected] and JAX-RS specification to [email protected].

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  • The Best BPM Journey: More Exciting Destinations with Process Accelerators

    - by Cesare Rotundo
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Oracle Open World (OOW) earlier this month has been a great occasion to discuss with our BPM customers. It was interesting to hear definite patterns emerging from those conversations: “BPM is a journey”, “experiences to share”, “our organization now understands what BPM is”, and my favorite (with some caveats): “BPM is like wine tasting, once you start, you want to try more”. These customers have started their journey, climbed up the learning curve, and reached a vantage point that allows them to see their next BPM destination. They see the next few processes they are going to tackle and improve with BPM. These processes/destinations target both horizontal processes where BPM replaces or coordinates manual activities, and critical industry processes that the company needs to improve to compete and deliver increasing value. Each new destination generates value, allowing the organization to reduce the cost of manual processes that were not supported by apps/custom development, and increase efficiency of end-to-end processes partially covered by apps/custom dev. The question we wanted to answer is how to help organizations experience deeper success with BPM, by increasing their awareness of the potential for reaching new targets, and equipping them with the right tools. We decided that we needed to identify destinations, and plot routes to show the fastest path to those destinations. In the end we want to enable customers to reach “Process Excellence”: continuously set new targets and consistently and efficiently reach them. The result is Oracle Process Accelerators (PA), solutions built using the rich functionality in Oracle BPM Suite. PAs offers a rapidly expanding list of exciting destinations. Our launch of the latest installment of Process Accelerators at Oracle Open World includes new Industry-focused solutions such as Public Sector Incident Reporting and Financial Services Loan Origination, and improved other horizontal PAs, including Travel Request Management, Document Routing and Approval, and Internal Service Requests. Just before OOW we had extended the Oracle deployment of Travel Request Management, riding the enthusiastic response from early adopters among travelers (employees), management and support (approvers). “Getting there first” means being among the first to extract value from the PA approach, while acquiring deeper insights into the customers’ perspective. This is especially noteworthy when it comes to PAs, a set of solutions designed to be quickly deployed and iteratively improved by customers. The OOW launch has generated immediate feedback from customers, non-customers, analysts, and partners. They all confirmed that both Business and IT at organizations benefit from PAs when it comes to exploring the potential for BPM to improve their business processes. PAs help customers visualize what can be done with BPM, and PAs are made to be extended: you can see your destination, change the path to fit your needs, and deploy. We're discovering new destinations/processes that the market wants us to support, generic enough across industries and within industries. We'll keep on building sets of requirements, deliver functional design, construct solutions using Oracle BPM, and test them not only functionally but for performance, scalability, clustering, making them robust, product-quality. Delivering BPM solutions with product-grade quality is the equivalent of following a tried-and-tested path on a map. Do you know of existing destinations in your industry? If yes, we can draw a path to innovative processes together.

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  • k-d tree implementation [closed]

    - by user466441
    when i run my code and debugged,i got this error - this 0x00093584 {_Myproxy=0x00000000 _Mynextiter=0x00000000 } std::_Iterator_base12 * const - _Myproxy 0x00000000 {_Mycont=??? _Myfirstiter=??? } std::_Container_proxy * _Mycont CXX0017: Error: symbol "" not found _Myfirstiter CXX0030: Error: expression cannot be evaluated + _Mynextiter 0x00000000 {_Myproxy=??? _Mynextiter=??? } std::_Iterator_base12 * but i dont know what does it means,code is this #include<iostream> #include<vector> #include<algorithm> using namespace std; struct point { float x,y; }; vector<point>pointleft(4); vector<point>pointright(4); //we are going to implement two comparison function for x and y coordinates,we need it in calculation of median (we should sort vector //by x or y according to depth informaton,is depth even or odd. bool sortby_X(point &a,point &b) { return a.x<b.x; } bool sortby_Y(point &a,point &b) { return a.y<b.y; } //so i am going to implement to median finding algorithm,one for finding median by x and another find median by y point medianx(vector<point>points) { point temp; sort(points.begin(),points.end(),sortby_X); temp=points[(points.size()/2)]; return temp; } point mediany(vector<point>points) { point temp; sort(points.begin(),points.end(),sortby_Y); temp=points[(points.size()/2)]; return temp; } //now construct basic tree structure struct Tree { float x,y; Tree(point a) { x=a.x; y=a.y; } Tree *left; Tree *right; }; Tree * build_kd( Tree *root,vector<point>points,int depth) { point temp; if(points.size()==1)// that point is as a leaf { if(root==NULL) root=new Tree(points[0]); return root; } if(depth%2==0) { temp=medianx(points); root=new Tree(temp); for(int i=0;i<points.size();i++) { if (points[i].x<temp.x) pointleft[i]=points[i]; else pointright[i]=points[i]; } } else { temp=mediany(points); root=new Tree(temp); for(int i=0;i<points.size();i++) { if(points[i].y<temp.y) pointleft[i]=points[i]; else pointright[i]=points[i]; } } return build_kd(root->left,pointleft,depth+1); return build_kd(root->right,pointright,depth+1); } void print(Tree *root) { while(root!=NULL) { cout<<root->x<<" " <<root->y; print(root->left); print(root->right); } } int main() { int depth=0; Tree *root=NULL; vector<point>points(4); float x,y; int n=4; for(int i=0;i<n;i++) { cin>>x>>y; points[i].x=x; points[i].y=y; } root=build_kd(root,points,depth); print(root); return 0; } i am trying ti implement in c++ this pseudo code tuple function build_kd_tree(int depth, set points): if points contains only one point: return that point as a leaf. if depth is even: Calculate the median x-value. Create a set of points (pointsLeft) that have x-values less than the median. Create a set of points (pointsRight) that have x-values greater than or equal to the median. else: Calculate the median y-value. Create a set of points (pointsLeft) that have y-values less than the median. Create a set of points (pointsRight) that have y-values greater than or equal to the median. treeLeft = build_kd_tree(depth + 1, pointsLeft) treeRight = build_kd_tree(depth + 1, pointsRight) return(median, treeLeft, treeRight) please help me what this error means?

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  • Determining the angle to fire a shot when target and shooter moves, and bullet moves with shooter velocity added in

    - by Azaral
    I saw this question: Predicting enemy position in order to have an object lead its target and followed the link in the answer to stack overflow. In the stack overflow page I used the 2nd answer, the one that is a large mathematical derivation. My situation is a little different though. My first question though is will the answer provided in the stack overflow page even work to begin with, assuming the original circumstances of moving target and stationary shooter. My situation is a little different than that situation. My target moves, the shooter moves, and the bullets from the shooter start off with the velocities in x and y added to the bullets' x and y velocities. If you are sliding to the right, the bullets will remain in front of you as you move so as long as your velocity remains constant. What I'm trying to do is to get the enemy to be able to determine where they need to shoot in order to hit the player. Unless the player and enemy is stationary, the velocity from the ship adding to the velocity of the bullets will cause a miss. I'd rather like to prevent that. I used the formula in the stack overflow answer and did what I thought were the appropriate adjustments. I've been banging at this for the last four hours and I just can't make it click. It is probably something really simple and boneheaded that I am missing (that seems to be a lot of my problems lately). Here is the solution presented from the stack overflow answer: It boils down to solving a quadratic equation of the form: a * sqr(x) + b * x + c == 0 Note that by sqr I mean square, as opposed to square root. Use the following values: a := sqr(target.velocityX) + sqr(target.velocityY) - sqr(projectile_speed) b := 2 * (target.velocityX * (target.startX - cannon.X) + target.velocityY * (target.startY - cannon.Y)) c := sqr(target.startX - cannon.X) + sqr(target.startY - cannon.Y) Now we can look at the discriminant to determine if we have a possible solution. disc := sqr(b) - 4 * a * c If the discriminant is less than 0, forget about hitting your target -- your projectile can never get there in time. Otherwise, look at two candidate solutions: t1 := (-b + sqrt(disc)) / (2 * a) t2 := (-b - sqrt(disc)) / (2 * a) Note that if disc == 0 then t1 and t2 are equal. If there are no other considerations such as intervening obstacles, simply choose the smaller positive value. (Negative t values would require firing backward in time to use!) Substitute the chosen t value back into the target's position equations to get the coordinates of the leading point you should be aiming at: aim.X := t * target.velocityX + target.startX aim.Y := t * target.velocityY + target.startY Here is my code, after being corrected by Sam Hocevar (thank you again for your help!). It still doesn't work. For some reason it never enters the section of code inside the if(disc = 0) (obviously because it is always less than zero but...). However, if I plug the numbers from my game log on the enemy and player positions and velocities it outputs a valid firing solution. I have looked at the code side by side a couple of times now and I can't find any differences. There has got to be something simple I'm missing here. If someone else could look at this code and determine what is going on here I'd appreciate it. I know it's not going through that section because if it were, shouldShoot would become true and the enemy would be blasting away at the player. This section calls the function in question, CalculateShootHeading() if(shouldMove) { UseEngines(); } x += xVelocity; y += yVelocity; CalculateShootHeading(); if(shouldShoot) { ShootWeapons(); } UpdateWeapons(); This is CalculateShootHeading(). This is inside the enemy class so x and y are the enemy's x and y and the same with velocity. One output from my game log gives Player X = 2108, Player Y = -180.956, Player X velocity = 10.9949, Player Y Velocity = -6.26017, Enemy X = 1988.31, Enemy Y = -339.051, Enemy X velocity = 1.81666, Enemy Y velocity = -9.67762, 0 enemy projectiles. The output from the console tester is Bullet position = 2210.49, -239.313 and Player Position = 2210.49, -239.313. This doesn't make any sense. The only thing that could be different is the code or the input into my function in the game and I've checked that and I don't think that it is wrong as it's updated before this and never changed. float const bulletSpeed = 30.f; float const dx = playerX - x; float const dy = playerY - y; float const vx = playerXVelocity - xVelocity; float const vy = playerYVelocity - yVelocity; float const a = vx * vx + vy * vy - bulletSpeed * bulletSpeed; float const b = 2.f * (vx * dx + vy * dy); float const c = dx * dx + dy * dy; float const disc = b * b - 4.f * a * c; shouldShoot = false; if (disc >= 0.f) { float t0 = (-b - std::sqrt(disc)) / (2.f * a); float t1 = (-b + std::sqrt(disc)) / (2.f * a); if (t0 < 0.f || (t1 < t0 && t1 >= 0.f)) { t0 = t1; } if (t0 >= 0.f) { float shootx = vx + dx / t0; float shooty = vy + dy / t0; heading = std::atan2(shooty, shootx) * RAD2DEGREE; } shouldShoot = true; }

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  • Slow login to load-balanced Terminal Server 2008 behind Gateway Server

    - by Frans
    I have a small load-balanced (using Session Broker) Terminal Server 2008 farm behind a Gateway Server which is accessed from the Internet. The problem I have is that there is a delay of 20-30 seconds if the session broker switches the user to another server during login. I think this is related to the fact that I am forcing the security layer to be RDP rather than SSL. The background The Gateway server has a public routeable IP addres and DNS name so it can be accessed from the Internet and all users come in via this route (the system is used to provide access to hosted applications to external customers). The actual terminal servers only have internal IP addresses. This works really well, except that with a Vista or Windows 7 client, the Remote Desktop client will negotiate with the server to use SSL for the security layer. This then exposes the auto-generated certificate that TS1 or TS2 has - but since they are internal, auto-generated certificates, the client will get a stern warning that the certificate is not valid. I can't give the servers a properly authorised certificate as the servers do not have public routeable IP address or DNS name. Instead, I am using Group Policy to force the connections to be over RDP instead of SSL. \Computer Configuration\Policies\Administrative Templates\Windows Components\Terminal Services\Terminal Server\Security\Require use of specific security layer for remote (RDP) connections The Windows 7 user now gets a much less stern warning that "the server's identity cannot be confirmed" which I can live with. I don't have enough control over the end-user's machines to ask them to install a new root certificate either. TS1 and TS2 are also load-balanced using the Session Broker, which is installed on the Gateway Server. I am using round-robin DNS, so the user's initial connection will go via Gateway1 to either TS1 or TS2. TS1/TS2 will then talk to the session broker and may pass the user to the other server. I.e. the user may get connected to TS2, but after talking to the session broker the user may be passed to TS1, which is where they will run their session. When this switching of servers happens, in my setup, the screen sits with the word "Welcome" for 20-30 seconds after which it flickers, Welcome is shown again and then flashing through nthe normal login screens (i.e. "wait for user profile manager" etc). Having done some research, I think what is happening is that the user is being fully logged on to TS2 (while "Welcome" is shown) before being passed to TS1, where they are then logged in again. It is interesting that normally when you see the ""Welcome" word, the little circle to left rotates. However, it does not rotate during this delay - the screen just looks frozen. This blog post leads me to think that this is because CredSSP is not being used, probably because I am disallowing SSL and forcing RDP. What I have tried I enabled SSL again which removes the "Welcome" delay. However, it seems to introduc a new delay much earlier in the process. Specifically, when the RDP client is saying "initialising connection" - this is now much slower. Quite apart from the fact that my certificate problem precludes me using that solution without considerable difficulty. I tried disabling the load balancing (just remove the servers from the session broker farm) and the connections do not have any delay. The problem is also intermittent in the sense that it only happens when the user gets bumped from one server to another. I tested this by trying to connect directly to TS1 (via the Gateway, of course) and then checking which server I actually got connected to. Just to be sure, I also by-passed the round-robin DNS to see if it had any impact and it doesn't. The setup is essentially in line with MS recommendations here: TS Session Broker Load Balancing Step-by-Step Guide I tried changing to using a dedicated redirector. Basically, rather than using a round-robin DNS, I pointed my DNS to the Gateway server and configured it to be a dedicated redirector (disallow logons, add it to the farm). Same problem, alas. Any ideas or suggestions gratefully received.

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