OVRhead set cmake build issues for Windows and solution

[mebbaid]

The following should be noted when dealing with overhead set dependencies:

• LibOVR and LibOVRKerenel: If you are using the newer versions of both libraries, make sure to go to yarp/cmake/ycm-0.6.0/find-modules/FindLibOVR.cmake and add the following to your _arch variable definition loop: if(MSVC) set(_arch "VS2015") endif()
  (I am using VS2017 to build a 2015 LibOVRKernel.lib, if you are building a 2017 LibOVRKernel.lib, then replace VS2015 in the code snippet above with VS2017 as that would be the folder generated. I can/will modify/patch the FindLibOVR cmake file).
• GLEW: cmake uses it's own standard FindGLEW module, however, if you installed GLEW in a non-standard directory, make sure to set CMAKE_PREFIX_PATH user env variable to point to that directory, so cmake can find it.
• GLFW: The FindGLFW cmake uses (among the at least 3-5 versions you have on your computer, depending on if you built yarp using the robotology-superbuild or not) is located in yarp/cmake/ycm-0.6.0/find-modules/, any editing needed should be done there.

After configuring and generating the solution, depending on the OculusSDK version you are using, you might face the following error:

SeverityCodeDescriptionProjectFileLineSuppression State
ErrorC2039'HmdToEyeOffset': is not a member of
'ovrEyeRenderDesc_'yarp_ovrheadsetC:\Users\Alex\robotology\yarp\src\devices\ovrheadset\OVRHeadset.cpp896

SeverityCodeDescriptionProjectFileLineSuppression State
ErrorC2664'void ovr_CalcEyePoses2(ovrPosef,const ovrPosef [],ovrPosef
[])': cannot convert argument 2 from 'ovrVector3f [2]' to 'const
ovrPosef
[]'yarp_ovrheadsetC:\Users\Alex\robotology\yarp\src\devices\ovrheadset\OVRHeadset.cpp898 

This is due to the breaking changes in the OculusSDK reported here, this also will be patched.

[traversaro]

Some small comments:

• I think we should track the changes necessary in Find<...>.cmake in a separate issue in the robotology/ycm repository, as those files are mantained there and just imported in YARP for convenience.
• What changes are necessary in FindGLFW.cmake file?
• CMAKE_PREFIX_PATH, both the environmental variable and the CMake variable, is always written as all uppercase, not as cmake_prefix_path.

[mebbaid]

@traversaro : regarding your question: if GLFW3 was installed using vcpkg install --triplet x64-windows glfw3 then this current FindGLFW3.cmake will not return GLFW3_INCLUDE_DIRS and GLFW3_LIBRARIES variables, and when building the generated solution , Visual studio throws LNK1181 error. Agreed regarding moving to YCM, didn't know which is the most relevant repo to put the issue. As for the variable name, yeah, my mistake, a typo.

Edited to add: in case of using vcpkg as above, a way to return the variables is to change the line if(NOT GLFW3_FOUND) in the find module to if( GLFW3_FOUND) and it compiles, however, i am not sure if that has unforeseen implications, since i trust Daniele's work more.

[traversaro]

I see. Spawning a new issue for replying on the FindGLFW3.cmake .