I am trying to DllImport a DLL into a Windows .Net/C# application that has a dependency on OpenCV. It is my own DLL; I build it from source and implicitly link to the OpenCV "world" DLL, where OpenCV is built into a single DLL including all of its dependencies. This works when I use the prebuilt binaries from here.
However I need to build an x86 version of this application as well as x64, and OpenCV does not provide prebuilt binaries for x86. Instead of trying to build OpenCV from source myself I decided to try to get it as a vcpkg package. I executed the following vcpkg commands:
.\vcpkg.exe install opencv[world]:x86-windows
and
.\vcpkg.exe install opencv[world]:x64-windows
This does give me opencv_world4.dll and opencv_world4d.dll and associated .lib files but when I attempt to DllImport my DLL with the OpenCV dependency and opencv_world4.dll next to my DLL in the working directory, this version of the DLL fails to load with a "not found" exception. If I directly try to LoadLibrary this DLL it returns NULL and GetLastError returns 126.
I am wondering if this DLL from vcpkg has not really been built with all the dependencies statically linked in or if this is some issue with the runtime library switch, /MT vs /MD or whatever? Any help appreciated.
Edit: looking at this with Dependency Walker it is clear that the DLL that vcpkg built has dependencies on various DLLs
whereas the prebuilt DLL does not. My question thus reduces to Is there a way to get vcpkg to make a real opencv_world.dll. To be clear the vcpkg documentation on the world features states as follows:
Feature Name: world Description: Compile to a single package support for opencv Build-Depends: [object Object]