When I attempt to compile a MFC project I get told I need to include this file. What and where is it? Why do I need it?
It's a rather important Windows SDK header file, the very first one that gets #included in <windows.h>. It declares Windows version numbers, the kind you should use in your program that states what version of Windows you want to be compatible with. The MSDN Library article is here.
If this file is actually missing on your machine (it isn't clear from the question) then you've either got a very old SDK version and are mixing headers (very bad) or you've got some disk damage (very very bad). It is the kind of problem you'd get when you are stuck on an ancient version of Visual Studio and are trying to use modern Windows api functions. Do not mix and match, it won't come to a good end.
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I've got a problem for which I would very much like a solution please:
All I'm trying to do is use wxWidgets in Visual Studio 2012 (in C++), and make it accessible to my code project. That shouldn't be so hard, should it? But as usual, even though there are programming tutorials for it, wxWidgets is evidently one of those things that has no proper documentation just to simply get it running, or if it does then I sure can't find it.
I downloaded the installer for Windows and installed it. When it finished, it gave me a message that said:
wxWidgets was installed successfully!
Please note: before using wxWidgets in your application,
you must build the library using the same compiler you
use for building your program.
Please see docs/msw/install.md file in the installation
directory for the detailed instructions about how to build
wxWidgets and use it from your application.
It should be noted that I think I remember something on the website or somewhere saying that I can just include a header file into my project and forego the DLL altogether (which is what I'd prefer to do, if possible), though I may possibly be misremembering that or confusing it with something else.
Anyway, when I opened the docs/msw/install.md file, I found (amongst other things) these instructions:
--- From the IDE
Ready to use project files are provided for VC++ versions 8, 9,
10, 11, 12, 14, 15, 16 and 17 (also known as MSVS 2005, 2008, 2010, 2012,
2013, 2015, 2017, 2019 and 2022 respectively).
Simply open wx_vcN.sln (for N=8, 9, 10, 11, 12, 14, 15, 16 or 17) file,
select the appropriate configuration (Debug or Release, static or DLL)
and build the solution. Notice that when building a DLL configuration,
you may need to perform the build several times because the projects
are not always built in the correct order, and this may result in link
errors. Simply do the build again, up to 3 times, to fix this.
Of course, it doesn't even say WHERE the "wx_vcN.sln" files are, but I ran a file search and found them in C:\wxWidgets-3.1.6\build\msw and I opened the one called wx_vc11.sln, because that seems to be the one that corresponds to VS2012, right?
Anyway, it took a LONG time to load, because it had to keep scanning through thousands of files and so forth, but when it was finally finished, I did the "Rebuild All" command thrice in a row, like it says to do (which also took a while).
But I'm not sure where it even put the actual DLL file. It says that it's in C:\wxWidgets-3.1.6\build\msw....\lib\vc_lib\wxmsw31ud_xrc.lib, but where the hell is "...."? It doesn't even bother to specify the entire path! What kind of nonsense is that?! I just want the file so that I can put it into my project! Or better yet, just a .h file that takes care of everything would be great. Supposedly there's one to include called "wx/wx.h", which then includes everything else, I think, but I don't know if that one indirectly also requires a DLL.
I always have problems with DLLs, anyway, though I'll use one if I absolutely have to. You'd think it would be the easiest thing to import a DLL into a project, but for some reason, I've never been able to find any sort of tutorial that explains a specific, step-by-step way to do it which is guaranteed to work, so on the rare occasion that I actually need to use a DLL (99% of the time I can just rely on my own code and the .h files included with Visual Studio), I always end up muddling through it until it FINALLY works by sheer accident (if I'm lucky). Mostly, it just reports errors for one reason or another, that it's not properly included or compatible, or that the header files that I'm using which reference it keep showing the same errors, as though I hadn't even imported the DLL file at all! I've been programming for about 30 years, and I work on things like AI and compression and cryptographic algorithms. I don't say this to brag, but to point out that if someone as experienced as me has trouble getting a DLL to attach properly to a roject, then there's something severely wrong with the whole process, or the documentation for it! I HATE using DLLS, because it's always a HUGE chore, but I'll do it if there's absolutely no other way (though I'd appreciate step-by-step instructions, if you don't mind).
But enough about that. In any case, I have an example project in which wxWidgets is being used in conjunction with Vulkan, and though it has compilation errors (because Vulkan didn't properly install on my machine (when I try to run the sample programs it says they're missing DLLs - big surprise) and as it turns out, I don't think it's compatible with my video card, anyway (which might possibly be why it didn't install properly), so I think I'll have to resort to OpenGL instead - PLEASE tell me that's compatible with wxWidgets!), but even in that example project, it has errors where it's trying to include and use wxWidgets stuff (like "wx/wx.h"), even though that's supposed to be a complete and already working project! I can't find any DLL files or the header files in question anywhere in the project directories!
So anyway, there's got to be an easier way to get this all set up, just to the point that I can make a simple test program using wxWidgets, and compile it. I'd REALLY like to be able to get at least that much working sometime tomorrow morning, so I'd greatly appreciate any help you can give me! Thank you.
#ThisIsMe,
First of all you need to educate yourself on properly using C++.
When you acquire the C++ code it contains of 2 portion - header file and source code.
Header file is what you call a declaration you declare you classes there - class name, member variable and method.
In the source files You define what you declared and you put an actual code there.
Now with that in mind:
wxWidgets contains both header and source files. When you downloaded the installer and did the installation it just copied the "text file" (headers and sources) into the folder of you choice.
Now as you can imagine text files are not executable - you need to compile them into the binary files And that is exactly what you did. (I don't know why you did it 3 times though - I guess you got an errors after building 1st and 2nd time).
Now, you said you have a project that (either uses wxWidgets or you want to incorporate wxWidgets into - which one is it, BTW?). The answer to this question will help direct you to a proper solution.
Now, you said that you tried the Vulkan and it fails to run the demo. How did it fails? Did it produce an error? What was it? Did it even run?
Now wxWidgets does support OpenGL as can be seen by looking at the documentation and checking the different samples that comes with the library, but I'm just curious if what you are seeing from Vulkan is really an incompatibility with the Video Card.
So, we need you to answer the questions I put and so we can help you further. Just keep in mind - C++ is not for the beginner programmers and if you are struggling with understanding the difference between compilation, installation , headers and sources - it will be very hard for you.
Maybe you should start with something simpler - like wxPython and forget about C++ for now.
Question:
Once my code is working how should I prepare my files so that a stranger on a different computer can compile it without difficulty?
Additional Details:
I am sending a code sample to a company as part of an application so obviously an elegant solution would be better (i.e. minimise number of files required etc) and no work should be necessary by the stranger at the other end.
Although I am only using one simple library, even so I need to set include directories, include lib files, images, dll files etc so that it all compiles correctly.
If it matters, I am using Visual Studio 2015 and the simple library is SDL.
Sorry if this is a duplicate, I was sure that this question would have been asked before but if it exists I just don't know the correct terminology to find it amongst the noise.
Apologies if this is overly simplistic, but you might want to bound the scope of your project by deciding which computers you want to support, and build your code yourself on those platforms, in advance, just to be sure.
List the supported platforms in your release notes, including any platform-specific instructions or information (which VC++ versions, which C++ versions, which OS versions, which DLLs, directory structure, etc.).
You may have to stick some "#ifdef"s and such in your code, but only by building on a particular platform/configuration will you really know for sure.
You can use properties/props files in your VS solution which sets the paths to includes and precompiled libs, then reference the build variables in your project files.
To compile on another machine, you just need to change the values in the properties files.
I'm trying to write my first game in c++, and I want it to dynamically load everything from files. This includes the enemies, and I was wondering if there was a way to dynamically include their code at runtime, instead of linking the on compile, so that the levels are easily interchangeable. Lua might be an option but I have no clue where to start, and dll seems to be Windows-only (and I wouldn't know where to start there anyway). Can anyone help with this?
tl;dr I want to link in code to my c++ game at runtime.
For the Lua approach you first need to choose the version first. Right now there is the major version 5.1 and 5.2. My previous work was using 5.1 and for my new project I decided to update to 5.2, however I found that my favorite script wrapping tool (SWIG) does not work with 5.2. Just something to decide at the beginning, because you do not want to get a version working and then have to change it.
Lua comes with makefile build environment. My first experience of trying to build on Windows was a bit of a nightmare, did not appear to just run out-of-the-box, so I opted to create my own Visual Studio project at the time, and just include all the .C files in the project. There are two files which need to selectively included/excluded depending on how you intend to compile: lua.c and luac.c. If you are planning to embed Lua in your app, then exclude both of these files; they both contain a main() function and are designed to build console apps. Include all the rest of the C files in your project.
You should be able to compile easy from this point.
When you include the headers of Lua, keep in mind that the functions are C functions so if you are including them from C++ you need to wrap the file inclusion inside of: extern "C" {} - example: C++ Lua 5.1 Issue
Wrapping your interfaces in another topic and there are lots of resources available. My favorite is SWIG but there are lots of options, including hand coding the conversion of your C/C++ -> LUA -> C/C++ code. Would recommend just focusing on getting the first part working first, get the interpreter embedded so that you can run a "hello, world!" script from Lua inside your app.
So going by your requirement of crossplatform use and dynamic linking, what you're probably looking for is an environment like QT which has QLibrary: https://stackoverflow.com/a/9675063/453673
But https://softwareengineering.stackexchange.com/questions/88685/why-arent-more-desktop-apps-written-with-qt
MingW is the open-source equivalent for Visual C++, so it can help you writing code for Windows (though if I had a choice, I'd directly use Visual C++). The way dll's are loaded in Windows is somewhat similar to the way they're loaded in Linux, so you'll be able to write code with #ifdef's to do conditional compilation. I've written one such program a couple of years back.
To load a shared library(always with .so as suffix) under Linux, you could use dlopen(), dlsym() and dlclose()
I want to use simple plotting functions in my C++ code. Presently I am using Qt5 with VS2010 c++ compiler. I came across this library called koolplot. But I cannot buid it with VS2010 from its source files. I am opening vs2010 cmd and running nmake...It shows winbgim.h missing..I copied that header in MinGW include folder and ran it ...now it shows "Plotdata.h:warning: 'typedef' was ignored in this declaration" Please help...if any one knows a simple plotting library running with VS2010 please suggest..
According to its website, Koolplot is designed for the MinGW/gcc toolchain - you'll have to do a bit of leg work to get it to compile on Visual Studio, though I don't know specifically what you'd have to do without taking a closer look.
Also, the library seems to do its own window management and the like, so I'm not sure how well you'll be able to integrate it with Qt.
koolplot needs WinBGI library (BGI = Borland Graphics Interface?).
I have changed it to use native Win32 using VS2008:
http://www.tu-chemnitz.de/~heha/hs/koolplot-heha.zip/
It's still incomplete as a good Win32 implementation would implement koolplot in a DLL which self-registers a Window class, and has both C and C++ interface. Moreover, koolplot as-is doesn't support multiple scales, finer plotting options, GDIplus, and fast data update, so it's not the right thing to write an oscilloscope program.
It's C++ code is also outdated as there are lambda functions available now.
However, good integrating into Qt is another task.
So, I am trying to deal with small differences in the various versions of the Windows SDK but am having trouble determining during compilation precisely what version of the Windows SDK I am building against in C++.
As of version 6.1 of the Windows SDK, there is a WinSDKVer.h file that contains some version information that I could use to determine what version of the SDK is being used even though it does not contain a direct version number for the SDK. However, 6.0A does not include this header file, so simply inserting #include and then using something like #ifdef will not work since there is no WinSDKVer.h in the environment.
A colleague of mine had a vague recollection of a way to include a header on Windows if and only if it exists, but could not remember any details and I have so far failed to find any information on doing so either on stackoverflow or the internet.
I've already done what I can to our make process to try to force the use of a 6.1 or greater SDK if installed on the developer's machine, but I'm also interested if others have run into this general kind of issue before and if/how they solved it.
Any ideas?
(ugly) create your own empty version of the header file and place it on a folder. Then add this folder last in your include directories. if the file exists in the SDK it will be included; otherwise your file will be used.
You cannot do it on C++ level. You can do it on build system level — e.g. in SCons see "Checking for the Existence of Header Files". The basic idea is to compile a little program that just includes the file, and see whether compilation succeeds or fails. Then you can set a macro that says if you have the header, or not, and do
#ifdef HAVE_WINSDKVER_H
# include <winsdkver.h>
#endif
or whatever.
Do some spelunking through historic versions of the SDK headers, looking for a header file that has existed in all versions of the SDK but contains subtle variation in its #defines in different SDK versions. You can test these with #ifdef to distinguish the SDKs.
Obviously it'll have to be some file other than WinSDKVer.h, and in some cases you may need a combination of several files.
I did something similar for Palm OS SDKs many years ago.