Search Results

Search found 38337 results on 1534 pages for 'ubuntu 11 04'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 143/1534 | < Previous Page | 139 140 141 142 143 144 145 146 147 148 149 150  | Next Page >

  • File permission woes on an Ubuntu ec2 instance

    - by Pardoner
    I've set up an amazon ec2 instance and I'm have some file permission issues. I've created myself a new user and added myself to the following groups: adm:x:4:me,ubuntu sudo:x:27:me www-data:x:33:me,www-data ssh:x:108:me admin:x:111:me ubuntu:x:1000:www-data,me me:x:1001:me but when I cd /var/www I can't do simple commands without doing sudo. So I chown -R www-data:www-data /var/www to ensure that I'm in the owning group but I still have to type sudo for everything. If I sudo su www-data it works fine. Since I'm in the www-data group shouldn't I have the same privilages as www-data? One strange thing I'm noticing is that when I ls -l it list the owner but not the group names. Could this possibly be part of the issue? Is is posible for a directory to not be part of a group? drwxr-xr-x 4 www-data 4.0K Oct 24 16:39 . drwxr-xr-x 14 root 4.0K Oct 10 16:58 .. drwxrwxr-x 9 www-data 4.0K Oct 23 04:03 admin.mywebsite.com drwxrwxr-x 2 www-data 4.0K Oct 4 00:29 mywebsite.com drwxrwxr-x 9 www-data 4.0K Oct 23 04:03 staging.mywebsite.com Edit : It appears I had some alias messing with my ls command. By calling \ls -l I can see that all my files are in the correct group.

    Read the article

  • Ubuntu odd mouse and keyboard behavior when window gains inner focus

    - by Scott
    This morning on my Ubuntu 10.10 system when I open a window - for example, system-preferences-about me, if I click in to a field such as "work email", I can no longer close the window with the mouse! Clicking the X on the window will not work. Also, I loose the ability to click on anything else - clicking on the desktop, icons, menus, workspaces, etc. do not work. Even the effect when you hover over a folder on the desktop and that folder highlights - that stops until the window is closed. If I open this same screen but do not click in to a field, everything is fine - I can close the window with the X and everything else works fine. Same thing happens with several other windows I tried. Even calculator - I can open it, everything is fine until I click on a button in the calculator - then no ability to click on anything else. Have to Alt-F4 to close the window. The system is only about a week old from a fresh install (64 bit ubuntu - quad core amd machine). I uninstalled wine, turned off remote desktop/disabled in startup, also in startup disabled visual assistance, bluetooth, dropbox, klipper. Reboot, no difference. The only other thing non-standard I see in startup is nvidia. Using a logitec usb mouse, saitek usb keyboard. Was working fine yesterday. I can not think of anything I did / installed yesterday. I switched themse, then went to update manager and saw two x server / x org related updates and installed them, reboot and NOW IT IS FINE! However, then I re-enabled dropbox, klipper and remote desktop rebooted and the problem is back. Again I disabled and rebooted. Problem is still there!! So somehow I fixed it at least for a few minutes, but now it is back and I am out of ideas.

    Read the article

  • Ubuntu 12.04 Very slow especially with Android Studio

    - by Nada
    I have an old laptop with the following specification: Memory: 485 MiB, Processor: Genuine intel CPU T2300 @ 1.66 GHz ×2, OS Type: 32 bit, Disk: 78.1 GB, I installed on it Ubuntu 12.04 LTS and I noticed that the overall system is very slow in responding. I tried to search about that in the internet and I found some articles talking about how to make Ubuntu 12.04 LTS run fast I applied all what they said including download LXDE desktop environment and then nothing different in the system response time. Then I need to develop some android applications so, I download Android Studio (Beta) 0.8.6. The problem became worse than before whenever I tried to open the Android Studio the screen is frozen for some minutes then it took time to download the projects and initialize the work space also, when I tried to move the cursor he is move very slowly. When I tried to run my first application on the AVD it took three hours and still not run yet. I delete the Android Studio and install it again several times, I was trying to solve the problem but still nothing change. Please if you have any suggestions that may help me make my laptop and Android Studio work faster I will appreciate it for you. Thank you in advance.

    Read the article

  • RAID degraded on Ubuntu server

    - by reano
    We're having a very weird issue at work. Our Ubuntu server has 6 drives, set up with RAID1 as follows: /dev/md0, consisting of: /dev/sda1 /dev/sdb1 /dev/md1, consisting of: /dev/sda2 /dev/sdb2 /dev/md2, consisting of: /dev/sda3 /dev/sdb3 /dev/md3, consisting of: /dev/sdc1 /dev/sdd1 /dev/md4, consisting of: /dev/sde1 /dev/sdf1 As you can see, md0, md1 and md2 all use the same 2 drives (split into 3 partitions). I also have to note that this is done via ubuntu software raid, not hardware raid. Today, the /md0 RAID1 array shows as degraded - it is missing the /dev/sdb1 drive. But since /dev/sdb1 is only a partition (and /dev/sdb2 and /dev/sdb3 are working fine), it's obviously not the drive that's gone AWOL, it seems the partition itself is missing. How is that even possible? And what could we do to fix it? My output of cat /proc/mdstat: Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md1 : active raid1 sda2[0] sdb2[1] 24006528 blocks super 1.2 [2/2] [UU] md2 : active raid1 sda3[0] sdb3[1] 1441268544 blocks super 1.2 [2/2] [UU] md0 : active raid1 sda1[0] 1464710976 blocks super 1.2 [2/1] [U_] md3 : active raid1 sdd1[1] sdc1[0] 2930133824 blocks super 1.2 [2/2] [UU] md4 : active raid1 sdf2[1] sde2[0] 2929939264 blocks super 1.2 [2/2] [UU] unused devices: <none> FYI: I tried the following: mdadm /dev/md0 --add /dev/sdb1 But got this error: mdadm: add new device failed for /dev/sdb1 as 2: Invalid argument Output of mdadm --detail /dev/md0 is: /dev/md0: Version : 1.2 Creation Time : Sat Dec 29 17:09:45 2012 Raid Level : raid1 Array Size : 1464710976 (1396.86 GiB 1499.86 GB) Used Dev Size : 1464710976 (1396.86 GiB 1499.86 GB) Raid Devices : 2 Total Devices : 1 Persistence : Superblock is persistent Update Time : Thu Nov 7 15:55:07 2013 State : clean, degraded Active Devices : 1 Working Devices : 1 Failed Devices : 0 Spare Devices : 0 Name : lia:0 (local to host lia) UUID : eb302d19:ff70c7bf:401d63af:ed042d59 Events : 26216 Number Major Minor RaidDevice State 0 8 1 0 active sync /dev/sda1 1 0 0 1 removed

    Read the article

  • Primary/secondary ethernet interfaces in Ubuntu 9.10

    - by Josh
    I have an Ubuntu 9.10 machine with three ethernet interfaces, eth0, eth1 and eth2. eth2 is connected to a private network. eth0 and eth2 are connected to two different LANs. Either one will provide access to the internet. All three networks have DHCP servers. Using Ubuntu's the default settings (And Gnome), when I boot up all the interfaces are active and my system gets three IP addresses. However any attempt to access the internet results in connection timeouts and other weirdness. I suspect that traffic is going out on one NIC (like eth0) and coming back in on another (like eth1). I'm not sure what's going on. The only way I can access the internet at the moment is to bring two of the devices down with ifdown. How can I configure eth0 as my primary interface so all trafic goes out by default on that interface, while keeping the other two active? Also, I want to make sure Avahi broadcasts properly on all three IPs so that the computers on the LAN of eth1 can still connect to myHostname.local...

    Read the article

  • Getting dwl-g122 to work on ubuntu

    - by User1
    I have a USB WiFi adapter, D-Link dwl-g122. I'm running Ubuntu 10.4. My laptop has a built-in wireless card that is connecting fine to the router. I plug in the usb and it never really connects. Here are some details: iwconfig wlan1 IEEE 802.11bg ESSID:"\x0B\xE1..." Mode:Managed Frequency:2.457 GHz Access Point: Not-Associated Tx-Power=19 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:on lshw -c network: *-network:1 description: Wireless interface physical id: 3 logical name: wlan1 serial: 00:13:46:8b:xx:xx capabilities: ethernet physical wireless configuration: broadcast=yes multicast=yes wireless=IEEE 802.11bg dmesg [ 1096.814176] wlan1: direct probe to AP xxx (try 1) [ 1096.820960] wlan1: direct probe responded [ 1096.820969] wlan1: authenticate with AP xxx (try 1) [ 1096.823790] wlan1: authenticated [ 1096.823869] wlan1: associate with AP xxx (try 1) [ 1096.827667] wlan1: RX AssocResp from xxx (capab=0x411 status=0 aid=1) [ 1096.827674] wlan1: associated [ 1142.590912] wlan1: deauthenticating from xxx by local choice (reason=3) lsmod|rt2 rt2500usb 19643 0 rt2x00usb 11260 1 rt2500usb rt2x00lib 32133 2 rt2500usb,rt2x00usb mac80211 238896 3 ath5k,rt2x00usb,rt2x00lib cfg80211 148725 4 ath5k,ath,rt2x00lib,mac80211 led_class 3764 3 ath5k,rt2x00lib,sdhci It looks like the driver loads but it doesn't feel like connecting. The behavior is identical even if I blacklist the other wifi card (using an ath5k driver). It's almost like it is using the wrong password or something. Does anyone know what is happening? Is anyone using Ubuntu successful?

    Read the article

  • Xamp on ubuntu serves php source for root url only

    - by mazaryk
    Hey, Okay, so installed xamp on my ubuntu machine, started it up and everything worked. Apache ran my php app just fine (including requests to the root url "/"). However, after the first reboot since installing, when I request "http://localhost/" apache serves up the index php page as a phtml source file. All other urls (like "http://localhost/login") work as expected. Backgound: The only modification I made to xamp was to setup a vhost for my app. The app uses an .htaccess file where I define some rewrite rules (the app is an MVC framework and all urls are rewritten to a single entry point php file). I'm using Xamp because I need php = 5.3.0. I know apache will serve up the source of a php file when it doesn't know to process php files. But the config does indeed have "AddType application/x-httpd-php .php" and as I said, the app works for all urls except the root "/" (and only since I've rebooted). The .htaccess file does contain a DirectoryIndex directive. xamp 1.3.7a Ubuntu 9.10 Any ideas?

    Read the article

  • Ubuntu 12.04 can't boot after installing with software RAID 1

    - by Bill
    I've been trying to install Ubuntu with software RAID on my server and there is obviously something that I don't understand about the process. This is the guide that I followed: https://help.ubuntu.com/11.04/serverguide/advanced-installation.html I have two identical 1 TB disks in my server. I went through the initial install process and manually set up my partitions. On each disk I set up: (1) 100 MB partition for EFI boot (I didn't originally have this but added it based on a forum post I found after my original install failed to boot, I ended up with EFIboot since that was what the 'guided partitioning' decided to do) (1) 970 MB partition for / (1) 30 MB partition for swap I then created new RAID 1 disks combining the two partitions, one from each disk, such that each partition is mirrored. I then configured their usage as stated above. After saving the configuration I said yes to boot in a degraded state. The rest of the setup went normally, no errors of any kind. I saw GRUB being installed and again no errors. However, after rebooting the server I get the dreaded 'Insert boot media' and nothing happens. I loaded up the recovery disk and the mdadm configuration looks correct. md0 is my EFIBoot partition md1 is my \ partition using ext4 md2 is my swap partition Running file -s /dev/md0 doesn't indicate that GRUB is there and so I attempted to reinstall GRUB using the recovery disk. I selected the md0 disk and it appeared to install just fine. Running file -s /dev/md1 shows the error needs journal recovery, I'm not sure if that's related or not or how to fix that. Rebooting gives me the same problem, no boot media found. I've searched around the internet but can't figure out what to do next or more importantly how to troubleshoot what exactly is going wrong. Thanks!

    Read the article

  • Ubuntu 9.10 won't reboot after replacing a failed drive

    - by user149041
    Hello Serverfault community. I hope someone can shed light on a peculiar problem I am having with an Ubuntu 9.10 server install. I am not a Linux expert but have the responsibility of fixing the box if something goes wrong. DOH! I have Ubuntu 9.10 server installed on on a desktop platform: Compaq Presario SR5027CL. There are two 1TB SATA drives configured in a RAID 1 array; I use the box as an email backup server for a small group of users. Last week one of the drives failed and was replaced with a new drive of the same type. The problem I have been having is getting the box to reboot after a restart or a shutdown halt. The OS and the RAID 1 array are on the same drives that make up the RAID 1 array. The replacement drive (sda) was added to the box and the partitions were created to match the existing good drive (sdb). The array is made up of sda1 and sdb1. I found an interesting point while checking the BIOS settings: there is a "HDD Boot Group Priority" section, and the new drive was selected as the "1. 3rd master"; the server wouldn't boot configured like that, but when I set the old drive to be "1. 4th master", the box will reboot. I'm checking some more things, but I would certainly appreciate any useful information. Thanks in advance.

    Read the article

  • glm matrix conversion for DirectX

    - by niktehpui
    For on of the coursework specification I need to work with DirectX, so I tried to implement a DirectX Renderer in my small cross-platform framework (to have it optionally available for Windows). Since I want to stick to my dependencies I want use glm for vector/matrix/quaternions math. The vectors seem to be fully compatible with DirectX, but the glm::mat4 is not working properly in DirectX Effects Framework. I assumed the reason is that DirectX uses row majors layouts and OpenGL column majors (although if I remember right internally in HLSL DX uses column major as well), so I transposed the matrix, but I still get no proper results compared to using XNA-Math. XNA-Version of the code (works): XMMATRIX world = XMMatrixIdentity(); XMMATRIX view = XMMatrixLookAtLH(XMVectorSet(5.0, 5.0, 5.0, 1.0f), XMVectorZero(), XMVectorSet(0.0f, 1.0f, 0.0f, 0.0f)); XMMATRIX proj = XMMatrixPerspectiveFovLH(0.25f*3.14f, 1.25f, 1.0f, 1000.0f); XMMATRIX worldViewProj = world*view*proj; m_fxWorldViewProj->SetMatrix(reinterpret_cast<float*>(&worldViewProj)); This works flawlessly and displays the expected colored cube. GLM-Version (does not work): glm::mat4 world(1.0f); glm::mat4 view = glm::lookAt(glm::vec3(5.0f, 5.0f, 5.0f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f)); glm::mat4 proj = glm::perspective(0.25f*3.14f, 1.25f, 1.0f, 1000.0f); glm::mat4 worldViewProj = glm::transpose(world*view*proj); m_fxWorldViewProj->SetMatrix(glm::value_ptr(worldViewProj)); Displays nothing, screen stays black. I really would like to stick to glm on all platforms.

    Read the article

  • soapfault: Couldn't create SOAP message

    - by polarw
    11-23 16:19:30.085: SoapFault - faultcode: 'S:Client' faultstring: 'Couldn't create SOAP message due to exception: Unable to create StAX reader or writer' faultactor: 'null' detail: null 11-23 16:19:30.085: at org.ksoap2.serialization.SoapSerializationEnvelope.parseBody(SoapSerializationEnvelope.java:121) 11-23 16:19:30.085: at org.ksoap2.SoapEnvelope.parse(SoapEnvelope.java:137) 11-23 16:19:30.085: at org.ksoap2.transport.Transport.parseResponse(Transport.java:63) 11-23 16:19:30.085: at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:104) 11-23 16:19:30.085: at com.mobilebox.webservice.CommonWSClient.callWS(CommonWSClient.java:247) 11-23 16:19:30.085: at com.mobilebox.webservice.CommonWSClient.access$1(CommonWSClient.java:217) 11-23 16:19:30.085: at com.mobilebox.webservice.CommonWSClient$WSHandle.run(CommonWSClient.java:201) 11-23 16:19:30.085: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) 11-23 16:19:30.085: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) 11-23 16:19:30.085: at java.lang.Thread.run(Thread.java:1019) My Android application use Soap webservice client to call remote method. Sometimes, it will return the excepion as above. When I call it with SoapUI, it never occours.

    Read the article

  • Trouble move-capturing std::unique_ptr in a lambda using std::bind

    - by user2478832
    I'd like to capture a variable of type std::vector<std::unique_ptr<MyClass>> in a lambda expression (in other words, "capture by move"). I found a solution which uses std::bind to capture unique_ptr (http://stackoverflow.com/a/12744730/2478832) and decided to use it as a starting point. However, the most simplified version of the proposed code I could get doesn't compile (lots of template mistakes, it seems to try to call unique_ptr's copy constructor). #include <functional> #include <memory> std::function<void ()> a(std::unique_ptr<int>&& param) { return std::bind( [] (int* p) {}, std::move(param)); } int main() { a(std::unique_ptr<int>(new int())); } Can anybody point out what is wrong with this code? EDIT: tried changing the lambda to take a reference to unique_ptr, it still doesn't compile. #include <functional> #include <memory> std::function<void ()> a(std::unique_ptr<int>&& param) { return std::bind( [] (std::unique_ptr<int>& p) {}, // also as a const reference std::move(param)); } int main() { a(std::unique_ptr<int>(new int())); }

    Read the article

  • Virtual Inheritance Confusion

    - by alan
    I'm reading about inheritance and I have a major issue that I haven't been able to solve for hours: Given a class Bar is a class with virtual functions, class Bar { virtual void Cook(); } What is the different between: class Foo : public Bar { virtual void Cook(); } and class Foo : public virtual Bar { virtual void Cook(); } ? Hours of Googling and reading came up with lots of information about its uses, but none actually tell me what the difference between the two are, and just confuse me more. Thanks!

    Read the article

  • lmerTest package install failing on Ubuntu 12.04

    - by Alexandra Tyers
    I'm running Ubuntu 12.04.5 LTS precise 32-bit and trying to install the lmerTest package for R version 2.14.1... When I try to install from the CRAN repository or R-forge: install.packages("lmerTest") or install.packages("lmerTest", repos="http://R-Forge.R-project.org"), I get the error: Warning in install.packages : package ‘lmerTest’ is not available (for R version 2.14.1) So I downloaded the Package Archive File from CRAN and tried to install from this Package source: lmerTest_2.0-11.tar.gz ,but get the error: "installation of package /home/.../lmerTest_2.0-11.tar.gz’ had non-zero exit status" I had a similar problem when trying to install lme4, and using the advice from lme4 package install failing on Ubuntu 12.04 was able to download the package using "sudo apt-get install r-cran-lme4" after which it appeared in my R package list and installed fine from there. I tried a similar tactic with lmerTest "sudo apt-get install r-cran-lmerTest" but just get "Unable to locate package r-cran-lmerTest", so really don't know what to do now, bearing in mind that I'm a novice with both Ubuntu and R, any suggestions/help would be much appreciated

    Read the article

  • initializer_list and move semantics

    - by FredOverflow
    Am I allowed to move elements out of a std::initializer_list<T>? #include <initializer_list> #include <utility> template<typename T> void foo(std::initializer_list<T> list) { for (auto it = list.begin(); it != list.end(); ++it) { bar(std::move(*it)); // kosher? } } Since std::intializer_list<T> requires special compiler attention and does not have value semantics like normal containers of the C++ standard library, I'd rather be safe than sorry and ask.

    Read the article

  • Reducing Integer Fractions Algorithm - Solution Explanation?

    - by Andrew Tomazos - Fathomling
    This is a followup to this problem: Reducing Integer Fractions Algorithm Following is a solution to the problem from a grandmaster: #include <cstdio> #include <algorithm> #include <functional> using namespace std; const int MAXN = 100100; const int MAXP = 10001000; int p[MAXP]; void init() { for (int i = 2; i < MAXP; ++i) { if (p[i] == 0) { for (int j = i; j < MAXP; j += i) { p[j] = i; } } } } void f(int n, vector<int>& a, vector<int>& x) { a.resize(n); vector<int>(MAXP, 0).swap(x); for (int i = 0; i < n; ++i) { scanf("%d", &a[i]); for (int j = a[i]; j > 1; j /= p[j]) { ++x[p[j]]; } } } void g(const vector<int>& v, vector<int> w) { for (int i: v) { for (int j = i; j > 1; j /= p[j]) { if (w[p[j]] > 0) { --w[p[j]]; i /= p[j]; } } printf("%d ", i); } puts(""); } int main() { int n, m; vector<int> a, b, x, y, z; init(); scanf("%d%d", &n, &m); f(n, a, x); f(m, b, y); printf("%d %d\n", n, m); transform(x.begin(), x.end(), y.begin(), insert_iterator<vector<int> >(z, z.end()), [](int a, int b) { return min(a, b); }); g(a, z); g(b, z); return 0; } It isn't clear to me how it works. Can anyone explain it? The equivilance is as follows: a is the numerator vector of length n b is the denominator vector of length m

    Read the article

  • Windows secure pinned website tile

    - by Stijn de Voogd
    I'm currently working on a pinned website tile for my website and instead of using a static XML file i'm linking the tile to a web api that returns user specific XML. My question is: Is it possible to secure this tile so that a user needs to be logged in before the data loads? The pinned website livetile doesn't send any security request headers/ cookies: - Http: Request, GET /v1/livetile/firsttile Command: GET + URI: /v1/livetile/firsttile ProtocolVersion: HTTP/1.1 UserAgent: Microsoft-WNS/6.3 Host: 192.168.14.109:2089 Cache-Control: no-cache HeaderEnd: CRLF Sidenote: Notice how it's not even sending an accept header even though it only wants xml. Info: http://msdn.microsoft.com/en-US/library/ie/dn455106 http://msdn.microsoft.com/en-us/library/ie/hh761491.aspx# Thanks in advance!

    Read the article

  • Is there anything exciting in perl 5.11 (to become perl 5.12)?

    - by Ether
    Perl 5.11 is now released! Is there anything really exciting in this release, or is it mostly maintenance patches? (From what I've read so far, it appears to be a rollup of improvements we have already seen in prior releases.) the CHANGES file Jesse Vincent's announcement chromatic's blog post 5.11 is the development release of what will become 5.12. The release process itself is changing to a monthly release model. UPDATE: Perl 5.12 is now released (April 12, 2010). the CHANGES file Jesse Vincent's announcement

    Read the article

  • Impossible to be const-correct when combining data and it's lock?

    - by Graeme
    I've been looking at ways to combine a piece of data which will be accessed by multiple threads alongside the lock provisioned for thread-safety. I think I've got to a point where I don't think its possible to do this whilst maintaining const-correctness. Take the following class for example: template <typename TType, typename TMutex> class basic_lockable_type { public: typedef TMutex lock_type; public: template <typename... TArgs> explicit basic_lockable_type(TArgs&&... args) : TType(std::forward<TArgs...>(args)...) {} TType& data() { return data_; } const TType& data() const { return data_; } void lock() { mutex_.lock(); } void unlock() { mutex_.unlock(); } private: TType data_; mutable TMutex mutex_; }; typedef basic_lockable_type<std::vector<int>, std::mutex> vector_with_lock; In this I try to combine the data and lock, marking mutex_ as mutable. Unfortunately this isn't enough as I see it because when used, vector_with_lock would have to be marked as mutable in order for a read operation to be performed from a const function which isn't entirely correct (data_ should be mutable from a const). void print_values() const { std::lock_guard<vector_with_lock>(values_); for(const int val : values_) { std::cout << val << std::endl; } } vector_with_lock values_; Can anyone see anyway around this such that const-correctness is maintained whilst combining data and lock? Also, have I made any incorrect assumptions here?

    Read the article

  • HSM - cryptoki - opening sessions overhead

    - by Raj
    I am having a query regarding sessions with HSM. I am aware that there is an overhead if you initialise and finalise the cryptoki api for every file you want to encrypt/decrypt. My queries are, Is there an overhead in opening and closing individual sessions for every file, you want to encrypt/decrypt.(C_Initialize/C_Finalize) How many maximum number of sessions can i have for a HSM simultaneously, with out affecting the performance? Is opening and closing the session for processing individual files the best approach or opening a session and processing multiple files and then closing the session the best approach? Thanks

    Read the article

  • Which is faster: creating a detailed mesh before execution or tessellating?

    - by Nick Udell
    For simplicity of the problem let's consider spheres. Let's say I have a sphere, and before execution I know the radius, the position and the triangle count. Let's also say the triangle count is sufficiently large (e.g. ~50k triangles). Would it be faster generally to create this sphere mesh before hand and stream all 50k triangles to the graphics card, or would it be faster to send a single point (representing the centre of the sphere) and use tessellation and geometry shaders to build the sphere on the GPU? Would it still be faster if I had 100 of these spheres in different positions? Can I use hull/geometry shaders to create something which I can then combine with instancing?

    Read the article

  • Output is different for R-value and L-value. Why?

    - by Leonid Volnitsky
    Can someone explain to me why output for R-value is different from L-value? #include <iostream> #include <vector> using namespace std; template<typename Ct> struct ct_wrapper { Ct&& ct; // R or L ref explicit ct_wrapper(Ct&& ct) : ct(std::forward<Ct>(ct)) { std::cout << this->ct[1];}; }; int main() { // L-val vector<int> v{1,2,3}; ct_wrapper<vector<int>&> lv(v); cout << endl << lv.ct[0] << lv.ct[1] << lv.ct[2] << endl; // R-val ct_wrapper<vector<int>&&> rv(vector<int>{1,2,3}); cout << endl << rv.ct[0] << rv.ct[1] << rv.ct[2] << endl; } Output (same for gcc48 and clang32): 2 123 2 003

    Read the article

  • std::conditional compile-time branch evaluation

    - by cmannett85
    Compiling this: template < class T, class Y, class ...Args > struct isSame { static constexpr bool value = std::conditional< sizeof...( Args ), typename std::conditional< std::is_same< T, Y >::value, isSame< Y, Args... >, // Error! std::false_type >::type, std::is_same< T, Y > >::type::value; }; int main() { qDebug() << isSame< double, int >::value; return EXIT_SUCCESS; } Gives me this compiler error: error: wrong number of template arguments (1, should be 2 or more) The issue is that isSame< double, int > has an empty Args parameter pack, so isSame< Y, Args... > effectively becomes isSame< Y > which does not match the signature. But my question is: Why is that branch being evaluated at all? sizeof...( Args ) is false, so the inner std:conditional should not be evaluated. This isn't a runtime piece of code, the compiler knows that sizeof..( Args ) will never be true with the given template types. If you're curious, it's supposed to be a variadic version of std::is_same, not that it works...

    Read the article

  • Cheapest way of binding local variable to closure

    - by mmotorny
    I believe following to be a cheapest way of binding local variable to closure: void ByRValueReference(A&& a) { } std::function<void ()> CreateClosureByRValueReference() { A a; std::function<void ()> f = std::bind(&ByRValueReference, std::move(a)); // !!! return f; } However, it does not compile under Clang 3.1: error: no viable conversion from '__bind<void (*)(A &&), A>' to 'std::function<void ()>' and gcc 4.6.1: /usr/include/c++/4.6/functional:1778:2: error: no match for call to ‘(std::_Bind<void (*(A))(A&&)>) ()’ Am I violating the standard or it's just broken standard libraries?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 139 140 141 142 143 144 145 146 147 148 149 150  | Next Page >