I'm working on a C++ project that requires libpng. So far I've worked on Linux and everything is smooth. I installed libpng, CMAKE picks it up and everything is alright. Now move to Windows.
Here I first installed zlib (required by libpng) and libpng. When I say install, I mean I downloaded the source files, and then built them and install them using msbuild.
I noticed that by doing so, I got new folders under c:\program files (x86):
c:\program files (x86)\zlib
c:\program files (x86)\libpng
Seemed all right to me. Now when I configure my project with CMAKE zlib is picked up:
-- Found ZLIB: C:/Program Files (x86)/zlib/lib/zlib.lib (found version "1.2.13")
but there's no way CMAKE finds the PNG library:
Could NOT find PNG (missing: PNG_LIBRARY PNG_PNG_INCLUDE_DIR)
Now I tried to have a look at the FindPNG and I noticed this line:
find_path(PNG_PNG_INCLUDE_DIR png.h PATH_SUFFIXES include/libpng)
Does this mean that CMAKE expects the file png.h to be in a directory ending in include/libpng? If so, then it will never find it because in my case png.h is placed in libpng/include. But this is also the "official" installation from the source code just downloaded from http://www.libpng.org/pub/png/libpng.html.
So now I am superconfused. How things are supposed to work in Windows? Should I "create" a folder structure with the correct files for every library so that CMAKE is happy? In a way I hoped things in Windows were similar to what happens in Linux: libraries go in a standard folder, they are detected by CMAKE.. everything is ok. But apparently this is not the case. So my question in general is: how do you ship a package like this to a Windows user so that he can builds it without having to go through all this?
Thanks so much
Fabrizio
This would be the right one to use:
find_package(PNG)
You can tell CMake to look in the location where you installed it by adding the libpng base install location to CMAKE_PREFIX_PATH. Without this, CMake doesn't know where you put it.
cmake "-DCMAKE_PREFIX_PATH=C:/Program Files (x86)/libpng" ...
Note that FindPNG first looks for zlib and will fail if zlib could not be found.
I am new to programming and I am trying to use SDL library with Code::Blocks on Windows. I downloaded the Library from : https://www.libsdl.org/download-2.0.php.
I downloaded the files, decompressed and then copied SDL.dll file in
C:\Program Files (x86)\CodeBlocks\MinGW\bin
and then the include and lib files in
C:\Program Files (x86)\CodeBlocks\SDL,
which is a new file I created. However, when I open Code::Blocks, new SDL project and arrive at the step where I am supposed to give the directory where the include and lib files are, once I hit next I get the following error :
The path you entered seems valid but the wizard can't locate the following SDL's library file: SDLmain in it.
Any idea why this might be happening and how I can fix it?
I am trying to install mingw-w64 onto Windows. However I receive an error, "the file has been downloaded incorrectly". Redownloading the setup file again from sourceforge does not fix the problem. Is there an alternative way to install it or am I doing something wrong?
Old post but same problem, the installer doesn't seem to work.
I give the solution which works for me
You can directly download the archive of MinGW64 with your chosen configuration :
https://sourceforge.net/projects/mingw-w64/files/mingw-w64/
Once the compressed file downloaded, you have just to extract and copy/paste the MinGW64 folder( with the pre-compiled librairies) to your chosen folder ( in my case : C:\mingw64)
I got same error and solved it, after struggling a few hours. You should download MinGW64 via https://winlibs.com/#download-release.
After downloading, You should unzip mingw64 file to a folder(in my case I unzipped it to c disk; C:\mingw64)
And then you have to set up path. for that follow below steps;
open settings.
Search for Edit environment variables for your
account.
choose path variable and then select edit.
Select New and add the Mingw-w64 folder path(bin folder). In my case, I added (C:\mingw64\bin).
Select OK to save the updated path.
And reopen your cmd, then check if everything is good by typing; gcc --version
Long story short, the official installer is broken and not been fixed for years, so we have to install it manually.
The official download link above would bring you to sourceforge: https://sourceforge.net/projects/mingw-w64/files/Toolchains targetting Win32/Personal Builds/mingw-builds/installer/mingw-w64-install.exe
And in the same folder that contains the installer, there's a repository.txt. (about this file)
Take a look at it, the installer basically just download and unzip the build from one of these urls within repository.txt. Choose the url you want and download/upzip it manually. (In my case, I use 8.1.0|x86_64|posix|seh|rev0 setup)
Last, setup the Path environment variable pointing to your unzipped bin folder, let say C:\mingw64\bin, and this should do the trick.
Finally, I solved this problem by downloading this:http://winlibs.com/
GCC 10.1.0 + LLVM/Clang/LLD/LLDB 10.0.0 + MinGW-w64 7.0.0 - release 3 (LATEST)
Win32: 7-Zip archive* | Zip archive
Win64: 7-Zip archive* | Zip archive
and set the %path%
After that, I still can't execute gcc correctly, but then I solved the problem by adding this environment variable:
"CGO_ENABLED=1"
I encountered the problem when using this golang package: https://github.com/mattn/go-sqlite3
I received the same error. When I re-ran the installer as an adminstrator it was installed successfully.
I also made sure not to add any spaces to the installation path.
Following this tutorial helped me manually install MinGW for windows : youtube
So the problem for me was that when I tried to use the .exe installer, it either showed me that,
"the file has been downloaded incorrectly" , or , the /.../bin folder did not have any files in it.
In the link above, the MinGW files (including the /bin files) were manually downloaded and identified properly by the Environment Variables.
The problem is with your internet connection and/or ISP. I'm not great at networking so I'll let others be more specific. I tried installing/downloading it using my mobile's data as wifi hotspot and it worked. Hope it helps
I am trying to run this code that should open the webcam and take frames.
However, I am getting this error. Cannot open source file "opencv2/highgui/highgui.hpp"
I download opencv and VS15, I followed online guides on how to install opencv 3.1 on VS15 using CMAKE.
However, It gives the error I mentioned above along side some more errors
Cannot open source file "opencv2/highgui/highgui.hpp"
Cannot open source file "opencv2/imgproc/imgproc.hpp"
I am really new to this and it got me frustrated. Any help will be apreciated. Thanks in advance!
I copied the files into the project folder and just included the file names rather than the filepath, then I used tools -> NuGet package manager -> NuGet Package Console and entered
PM > Install-Package opencvdefault
If you use OpenCV on Windows, VS, I think you had better download opencv.exe and extract and compile automatically.
Add this dll and header file to the VS path. And add opencv path to the system environment, then restart Windows
I am currently working on a program that will have to be able to read and save PNG files. I've decided to use libpng so I've downloaded it's source files. I unpacked them and here is where my problem started.
There are very many files in the unpacked folder and I don't know which of them I should compile to get proper.o files that I will be able to link to my program.
There are makefiles in the libpng "scripts" directory. Most of those contain a list of the files that need to be compiled (namely, all of png*.c in the main libpng directory except for pngtest.c).
You'll also need pnglibconf.h which you can create by copying scripts/pnglibconf.h_prebuilt.