Add linux gomp and post link to screened poisson

[bartoszek]

The project file for screened poisson is lacking linux linker flag -lgomp and post link filter_screened_poisson.xml copying script.
The libfilter_screened_poisson.xml link is somehow needed for plugin manager to work correctly on linux (help>about_plugins menu is empty for screened_poisson plugin without it)
mutualinfo, measure, and sketchfab plugins share this problem too

[eboudrand]

I recompiled meshlab with your patch and run it. When I apply Screened poisson plugin, Meshlab crashes with error "undefined symbol: omp_get_num_procs". I am using Ubuntu 16.04 64bit. Do you met this issue ?

[bartoszek]

Yes, this is the issue I got when building bare meshlab repository on Arch Linux.
This patch fixes the issue for me.
Already include it in my AUR meshlab package

[eboudrand]

I added test -h "lib"$$TARGET".xml" in QMAKE_POST_LINK before ln -s "$$TARGET".xml lib"$$TARGET".xml" because I had an error (file already exists). My QMAKE_POST_LINK line is :

linux:QMAKE_POST_LINK = "cp "$$_PRO_FILE_PWD_/$$TARGET".xml ../../distrib/plugins/"$$TARGET".xml; cd ../../distrib/plugins/ ; test -h "lib"$$TARGET".xml" || ln -s "$$TARGET".xml lib"$$TARGET".xml"

[bartoszek]

I recompiled meshlab with your patch and run it. When I apply Screened poisson plugin, Meshlab crashes with error "undefined symbol: omp_get_num_procs"

Have the same error on Ubuntu 16.10 despite correct flags passed to linker invocation

g++ -m64 -lgomp -Wl,-O1 -shared -o libfilter_screened_poisson.so filter_screened_poisson.o MarchingCubes.o PlyFile.o Factor.o Geometry.o moc_filter_screened_poisson.o -L/usr/X11R6/lib64 -L../../distrib -lcommon -lGLU -lQt5OpenGL -lQt5Widgets -lQt5Gui -lQt5Xml -lQt5XmlPatterns -lQt5Network -lQt5Script -lQt5Core -lGL -lpthread

[bartoszek]

Solution was to add -fopenmp linker flag.