This will make the template easier to use for Windows users who often struggle to understand how DLLs work.

It's common that Ubuntu users are missing some packages they need to install. Let's put that all in a simple shell script so they don't have to dig into the CI script or ask on Discord about it. The CI pipeline can use this script too to ensure it's continuously up to date.

In the future we could extend this to work on Fedora or other Linux distros as well.

It's kind of a common problem with FetchContent that it also pulls in all the install instructions from the fetched content.
There some workarounds with manual add_subdirectory and EXCLUDE_FROM_ALL, not sure what's the best solution.

I am new to SFML and have started with following instruction on this page https://www.sfml-dev.org/tutorials/2.6/start-cmake.php. I was able to get all the setup done except running the last build command fails.

When I run the build command I get this error

cmake --build build

[ 14%] Built target sfml-system
[ 48%] Built target sfml-window
[ 49%] Building CXX object _deps/sfml-build/src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/Font.cpp.o
In file included from /Users/subham/Desktop/code/SFML/cmake-sfml-project/build/_deps/sfml-src/src/SFML/Graphics/Font.cpp:35:
/Library/Frameworks/Mono.framework/Headers/ft2build.h:56:10: fatal error: 'freetype/config/ftheader.h' file not found
#include <freetype/config/ftheader.h>
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Library/Frameworks/Mono.framework/Headers/ft2build.h:56:10: note: did not find header 'config/ftheader.h' in framework 'freetype' (loaded from '/Users/subham/Desktop/code/SFML/cmake-sfml-project/build/_deps/sfml-src/extlibs/libs-osx/Frameworks')
1 error generated.
make[2]: *** [_deps/sfml-build/src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/Font.cpp.o] Error 1
make[1]: *** [_deps/sfml-build/src/SFML/Graphics/CMakeFiles/sfml-graphics.dir/all] Error 2
make: *** [all] Error 2

Anyone using the Audio module on Windows is going to run into this problem. Because there is no corresponding CMake target for that DLL, CMake can't know to automatically copy it like it does all other DLLs. An upstream fix to SFML/SFML would be preferred but maybe for now we automatically copy that DLL whenever someone is using Windows.

I tried using this template for building my school assignment using CMake, which works great on either MacOS or Linux.
However, when using it on Windows, I just keep getting this error. I've tried it with several devices. Everything builds correctly, and I can find the .dll in the _deps folder. Am I missing something?

The default installation includes all of the SFML development information. I'm

git clone https://github.com/SFML/cmake-sfml-project.git
cd cmake-sfml-project/
mkdir build && cd build
cmake ..
make -j
make install

On ubuntu this gives me

[100%] Built target sfml-audio
Install the project...
-- Install configuration: ""
CMake Error at _deps/sfml-build/cmake_install.cmake:54 (file):
  file cannot create directory: /usr/local/lib/pkgconfig.  Maybe need
  administrative privileges.
Call Stack (most recent call first):
  cmake_install.cmake:47 (include)


make: *** [Makefile:120: install] Error 1

Which, yes, with admin privileges would work. But also that would be installing SFML and not the binary. You can make this go away by specifying an install prefix cmake -DCMAKE_INSTALL_PREFIX=install .. but then you're still installing the SFML stuff.

Is that expected? If not, how can I prevent that from happening?

Specify what directory to run CMake commands from

I never mentioned that you have to run those CMake commands from the same directory as the repo. It's fair to assume someone may assume you can run those from anywhere.

Explicitly mention that users must clone the repo they made

This is never explicitly mentioned and I can understand why someone new to GitHub may think they just need to copy a few files to their computer.

I keep literally getting this annoying error

Error.txt

It takes another ~10 lines of CMake to incorporate those two projects plus some tweaks to main.cpp to demonstrate basic usage. It may be worth adding a branch that demonstrates that so those who want to use ImGui have something to reference. The build instructions would be the same.

The CMakeList includes the sfml-graphics library, but not the others, such as sfml-audio. A new user would not understand that these are different libraries that need to be specified independently.

Suggestion 1: Add the rest of the libraries to the CMakeList.txt
Suggestion 2: Add instructions to the README.md for how to change CMakeList.txt to link to these libraries

I'm using the CMakeLists.txt template from the master branch with this only relevant modification:

target_link_libraries(CMakeSFMLProject PRIVATE sfml-graphics sfml-audio)
file(GLOB DATA
  "${PROJECT_SOURCE_DIR}/data/*"
)
file(COPY ${DATA} DESTINATION "${PROJECT_BINARY_DIR}")

In main.cpp I have this relevant code:

sf::SoundBuffer buf;
if (!buf.loadFromFile("sound.wav"))
  return -1;
sf::Sound sound;
sound.setBuffer(buf);
sound.play();

Compiling it on WIndows 10 with MSVC on x64 Native Tools Command Prompt for VS 2022:

cmake -S . -B build
cmake --build build --config Release
.\build\bin\Release\CMakeSFMLProject.exe

The exe is built, but when I try to run it, Windows gives me the helpful error message: "The app could not be initialized correctly (0xc000007b)".
Running it in Visual Studio, the debug output yields (in portuguese):

"CMakeSFMLProject.exe" (Win32): Carregado "C:\Users\<long_path>\SFML\out\build\x64-release-windows\bin\openal32.dll". O módulo foi criado sem símbolos.
"CMakeSFMLProject.exe" (Win32): Não carregado "C:\Users\<long_path>\SFML\out\build\x64-release-windows\bin\openal32.dll"

Which translates to something like:

"CMakeSFMLProject.exe" (Win32): Loaded "C:\Users\<long_path>\SFML\out\build\x64-release-windows\bin\openal32.dll". The module was created without symbols.
"CMakeSFMLProject.exe" (Win32): Not loaded "C:\Users\<long_path>\SFML\out\build\x64-release-windows\bin\openal32.dll"

The error does not occur if I don't use/link sfml-audio.

I was able to make OpenAL32 work with the following script:

# Add OpenAL32 (required by sfml-audio on Windows)
if(WIN32)
    set(OPENAL32_URL "https://openal-soft.org/openal-binaries/openal-soft-1.23.1-bin.zip")
    set(OPENAL32_ZIP_PATH "${CMAKE_BINARY_DIR}/openal-soft.zip")
    set(OPENAL32_DIR "${CMAKE_BINARY_DIR}/OpenAL32")
    set(OPENAL32_PATH "${OPENAL32_DIR}/openal-soft-1.23.1-bin")
    if(NOT EXISTS ${OPENAL32_DIR})
        file(DOWNLOAD ${OPENAL32_URL} ${OPENAL32_ZIP_PATH})
        execute_process(COMMAND powershell -Command "Expand-Archive \"${OPENAL32_ZIP_PATH}\" -DestinationPath \"${OPENAL32_DIR}\"")
        file(RENAME "${OPENAL32_PATH}/bin/Win64/soft_oal.dll" "${OPENAL32_PATH}/bin/Win64/OpenAL32.dll")
        file(REMOVE ${OPENAL32_ZIP_PATH})
    endif()
    add_library(OpenAL32 SHARED IMPORTED)
    set_target_properties(OpenAL32 PROPERTIES
        IMPORTED_LOCATION "${OPENAL32_PATH}/bin/Win64/OpenAL32.dll"
        IMPORTED_IMPLIB "${OPENAL32_PATH}/libs/Win64/OpenAL32.lib"
    )
    target_link_libraries(CMakeSFMLProject PRIVATE OpenAL32)
endif()
if (WIN32 AND BUILD_SHARED_LIBS)
    add_custom_command(TARGET CMakeSFMLProject POST_BUILD
        COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_RUNTIME_DLLS:CMakeSFMLProject> $<TARGET_FILE_DIR:CMakeSFMLProject> COMMAND_EXPAND_LISTS)
endif()

But it requires fetching from openal-soft.org, which is slow and I don't know if it would violate any licenses.
Since the dll from openal-soft works, I think the openal binary in ${SFML_SOURCE_DIR}/extlibs/bin/$<IF:$<BOOL:${ARCH_64BITS}>,x64,x86>/openal32.dll might be the problem.

SFML/SFML#2464

STB Image 2.28 included some new code that triggers an MSVC warning related to lossy conversions. When using CMake 3.24 or newer, CMake has the ability to tell MSVC to ignore warnings in 3rd party code. However anyone using an older version does not get that fix and thus MSVC emits a warning about this 3rd party code which due to the default of WARNINGS_AS_ERRORS get promoted to a error that breaks the build.

This was never caught in SFML's CI pipeline because GitHub Actions CI runners always use the latest CMake release which means they've been using CMake 3.24 or newer for many months now. Users on VS 2019 have an older release of CMake and thus are prone to encounter this problem.

All we need is set(WARNINGS_AS_ERRORS OFF) before the FetchContent call unless we're willing to fix this upstream in SFML itself.