Fails to compile on Windows 32 bit

[qno]

Error is

[6/9] Building CXX object libs\clap-imgui-support\CMakeFiles\imgui-clap-support.dir\__\imgui\backends\imgui_impl_dx12.cpp.obj
FAILED: libs/clap-imgui-support/CMakeFiles/imgui-clap-support.dir/__/imgui/backends/imgui_impl_dx12.cpp.obj 
C:\PROGRA~2\MICROS~2\2022\BUILDT~1\VC\Tools\MSVC\1434~1.319\bin\Hostx86\x86\cl.exe  /nologo /TP  -IC:\Users\Silvio\Desktop\test\clap-saw-demo-imgui\libs\clap-imgui-support\include -IC:\Users\Silvio\Desktop\test\clap-saw-demo-imgui\libs\imgui -IC:\Users\Silvio\Desktop\test\clap-saw-demo-imgui\libs\clap\include /DWIN32 /D_WINDOWS /GR /EHsc /Zi /Ob0 /Od /RTC1 -MTd -std:c++17 /showIncludes /Folibs\clap-imgui-support\CMakeFiles\imgui-clap-support.dir\__\imgui\backends\imgui_impl_dx12.cpp.obj /Fdlibs\clap-imgui-support\CMakeFiles\imgui-clap-support.dir\imgui-clap-support.pdb /FS -c C:\Users\Silvio\Desktop\test\clap-saw-demo-imgui\libs\imgui\backends\imgui_impl_dx12.cpp
C:\Users\Silvio\Desktop\test\clap-saw-demo-imgui\libs\imgui\backends\imgui_impl_dx12.cpp(435): error C2338: static_assert failed: 'Can't pack descriptor handle into TexID, 32-bit not supported yet.'
[7/9] Building CXX object libs\clap-imgui-support\CMakeFiles\imgui-clap-support.dir\src\win-dx12.cpp.obj

To compile this on Windows with Visual Studio you have to add the definition ImTextureID=ImU64.

...
if(WIN32)
   target_sources(${PROJECT_NAME} PRIVATE
            src/win-dx12.cpp
            ${IMGUI_SOURCE_DIR}/backends/imgui_impl_win32.cpp
            ${IMGUI_SOURCE_DIR}/backends/imgui_impl_dx12.cpp
            )
   target_compile_definitions(${PROJECT_NAME} PRIVATE ImTextureID=ImU64)
endif()

[qno]

I figured out what is going on here, so basically it was my fault because I use Clion and used the CMake Ninja Generator.
This seems to set the platform to Win32 per default. Using Visual Studio Generator it works.

Now I'm not sure if this should be fixed, but if it could look like this

   if (NOT CMAKE_VS_PLATFORM_NAME STREQUAL "x64")
      target_compile_definitions(${PROJECT_NAME} PRIVATE ImTextureID=ImU64)
   endif ()

Or throw an CMake error that Win32 is not supported?

[baconpaul]

I don’t understand why CLion does thst and it trips me up all the time

I think the intent is indeed to not support 32 bit windows. There’s other ways I think to get to 32 bit so I use a size of void check using the cmake_sizeof_voidp variable but we should see which frank prefers

[qno]

It looks like it is more a problem of Ninja. I just switched to native Visual Studio Generator, which has x64 as default platform set. Clion supports also Visual Studio projects and doesn't requiere Ninja for this, so it works.

I would say that you probalby just check if target platform is not Win x64 and exit CMake with error.

[u-he-frank]

Thanks for the report. I only tested x64 builds. I see no reason to exclude 32 bit builds, as long as it doesn't make things too complicated. But what is the best way? I would prefer a positive test like

 if (CMAKE_VS_PLATFORM_NAME STREQUAL "Win32")
     target_compile_definitions(${PROJECT_NAME} PRIVATE ImTextureID=ImU64)
 endif()

or

 if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "4")
     target_compile_definitions(${PROJECT_NAME} PRIVATE ImTextureID=ImU64)
 endif()

I am not sure which will work best?

[qno]

I know that this doesn't really belong here, but as the repo free-audio/clap-saw-demo-imgui has no issue tracker setup, I just wanted also to mention here, that you have an issue there for the Linux build at the https://github.com/free-audio/clap-saw-demo-imgui/blob/96da3ab3ed9bc9cc26eecae691db8104bd2d2f79/CMakeLists.txt#L75.

The line target_sources(${PROJECT_NAME} PRIVATE src/linux-vstgui-adapter.cpp) should be removed.