"Professional CMake" book suggest the following:
"Targets should build successfully with or without compiler support for precompiled headers. It
should be considered an optimization, not a requirement. In particular, do not explicitly include a
precompile header (e.g. stdafx.h) in the source code, let CMake force-include an automatically
generated precompile header on the compiler command line instead. This is more portable across
the major compilers and is likely to be easier to maintain. It will also avoid warnings being
generated from certain code checking tools like iwyu (include what you use)."
Therefore, removed the "#include <PreCompiled.h>" from sources, also
there is no need for the "#ifdef _PreComp_" anymore
Before the change the compiler raised the warning: 'Gui::ViewProviderDatum::getRoot' hides overloaded virtual function [-Werror,-Woverloaded-virtual]
In the base class the method getRoot() is declared as const while in ViewProviderDatum it's not and that's why it's considered as an overloaded method.
However, this signature causes two problems:
1. In the client code it's not always clear which version of getRoot() should be called
2. It violates const-correctness
So, trying to declare the method ViewProviderDatum::getRoot() as const it now overrides the method of the base class (and fixes the warning) but
this doesn't lead to the expected result: See https://forum.freecad.org/viewtopic.php?p=796064#p796064
The other option is to rename the method. And this gives the expected result now.
Most of App::Origin is moved into this sub class of App::Origin.
Add App::Point. Change graphics of the planes/axis.
Remove scale-by-content behavior and make it fixed size on screen.
