I have a Qt application which controls 2 Kinects via libfreenect. To access the Kinects, I use one Qt-thread. All works perfectly so far. But I need the program to continue working when one Kinect is disconnected. But if so, the program get stuck in the waitForNewFrame call, even when I specify a timeout parameter. The documentation says, that 'this parameter is ignored if not built with C++11 threading support'.
What must be built with C++11 threading support? Libfreenect or my Qt App?
And how do I build with C++11 threading support?
The Qt App is built with qmake. I have a Global.pri where I can define compiler switches. Compiler is clang but gcc should work too.
Libfreenect is built in an automated build script. It git-clones a fork of libfreenect and executes:
cmake .
make
sudo make install
I found the cause of the problem.
C++11 needs to be enabled during compilation by adding the -DENABLE_CXX11=ON argument to the cmake command.
Related
I am trying to make a C++ application with wxWidgets for raspberry on Visual studio.
I created a blink project from the templates and I only added the library wx.h in order to test the code and when I try to compile it fails because it doesn't find the library.
By the way, the blink project itself works fine. It only fails when I add the wx.h library.
#include <wx-3.1\wx\wx.h>
It's odd, because whe I open the file it has the right path.
Even intellisense detects the path correctly.
But I can't figure out what is causing the error.
I configured a remote connection to the raspberry:
And these are the errors displayed:
There is not enough information to answer your question, e.g. you don't explain how do you build your project at all (e.g. do you use CMake?), but a couple of observations that may be helpful:
wxWidgets headers are included as <wx/wx.h>, you definitely should not have the wx-3.1 component and you must use slashes and not backslashes.
You have to provide the compiler with the appropriate options, which usually happens by running wx-config --cxxflags under Unix systems (which may be hidden from you if you use CMake FindwxWidgets module which uses wx-config internally).
I want to build a dll from all my package dependencies using mtouch. I have tried different options and failed.
Giving the root-assembly as my dll plus all packages gives me MT0052: No command specified
I think mtouch can not do that . From doc of Using mtouch to Bundle Xamarin.iOS Apps , you can see :
The process of turning a .NET executable into an application is mostly driven by the mtouch command, a tool that integrates many of the steps required to turn the application into a bundle. This tool is also used to launch your application in the simulator and to deploy the software to an actual iPhone or iPod Touch device.
It just transfers a existed .NET executable into an application ,can not help you bind library into an application .
You also can see the COMPILATION MODE doc of mtouch , there are four mode :
--abi=ABI
Comma-separated list of ABIs to target. Currently supported: armv6, armv6+llvm, armv7, armv7+llvm, armv7+llvm+thumb2, armv7s, armv7s+llvm, armv7s+llvm+thumb2. Fat binaries are automatically created if more than one ABI is targetted.
To use the LLVM optimizing compiler code generation backend instead of Mono's default code generation backend target one of the llvm ABIs. Build times take considerably longer for native code, but the generated code is shorter and performs better.
You may also instruct the LLVM code generator to produce ARM Thumb instructions by targetting one of the llvm+thumb2 targets. Thumb instructions produce more compact executables.
--cxx
Enables C++ support. This is required if you are linking with some third party libraries that use the C++ runtime. With this flag, mtouch uses the C++ compiler to drive the compilation process instead of the C compiler.
-sim=DIRECTORY
This compiles the program and assemblies passed on the command line into the specified directory for use with the iOS simulator. This generates a standalone program that is entirely driven by the C# or ECMA CIL code.
-dev=DIRECTORY
This compiles the program and assemblies passed on the command line into the specified directory for use on an iPod Touch, iPhone or iPad device. The target directory can be used as the contents of a .app directory This generates a standalone program that is entirely driven by the C# or ECMA CIL code.
mtouch not supports binding library , it just compiles a existed executable which already binded library .
By the way , if want to bind a third party library , official doc recommands you to use Binding iOS Libraries .
In our system, we write the code on C++ without using Qt libraries.Actually, we write the on Windows machine, but finaly, this code must to be rebuilded for Linux Embedded machine. At first stage we did it successfully with Makefile-s, but "old style debugging" with gdb utility killed us. So I want to use Qt Creator to debug the application.
I successfully use Qt Creator to build all libraries and applications for ARM machine(of couse I have an ARM toolchain). But I cannot remotely debug the system.
I do not understand, what I do wrong.
The questions:
1. For system debuging, do I need Qt Libraries buld for ARM machine? (as I wrote above, I do not use Qt Libraries for my applications or for my libraries)
2. Do I need to redefine Mkspec for ARM compiler?
Thanks, Slava
You generally don't need Qt libraries for your system to use Qt Creator as a debugger frontend for your plain C++ program on an embedded device. However, if you use qmake as a build system, the associated Qt version must (roughly) match your target.
I'm trying to build a native ARM GDB for an ARM board to use. Since it lacks a lot of the tools GDB needs for compilation, I'm trying to build it on my x86 machine.
./configure --host=arm-linux-gnueabi --target=arm-linux-gnueabi && make
However, half way through the build process, it complains that "termcap library" is missing. I think it means it couldn't find an ARM version of the library for it to use. So, is there a possible workaround, or should I not bother with this approach and think of another way?
You should be able to do this for your "ARM board". You need to compile GDB library dependencies (e.g. the termcap library) and install them where the cross compiler can find them before you can build GDB. Without a more specific description about the cross compilation toolchain and board it's hard to give more specific advice that will be helpful to you.
I cross build GDB for several Linux targets for my ELLCC cross development tool project (http://ellcc.org). You do need a few libraries built for the target to do a build. In addition to the standard C library, I used libedit, zlib, expat, and ncurses.
I have source code for a linux application. It seems I can compile it on windows with CygWin. My question is, after compilation, can I run it on Windows?
Depends totally on what APIs you use. If you stick to C standard library things, like <stdio.h>, <stdlib.h>, etc. then yes, you can just compile and run on either OS. Or for C++ apps, there is the Standard C++ Library, which any OS / development environment should provide.
If you use any OS-specific APIs, then of course it will not be compatible with another OS. There are libraries however, like APR that try to abstract out the OS-specific bits.
From a casual glance at the code you've linked to, it appears to not use any OS-specific APIs. However:
Note that this code requires the Gnu Scientific Library, http://www.gnu.org/software/gsl/
you'll need to get that library installed as well.
The simple answer is yes; if you can compile a Linux application with Cygwin, then the compiled application will run on windows. Cygwin provides windows implementations of many unix system functions and libraries.
Cygwin/mingw(http://www.mingw.org/) should have most of the tools you need to build the binary. Once the build succeeds, you can run the binary (only) on windows.