Removes unused Windows-specific headers and adds arguments to specify
source and output directories, which is necessary for out-of-tree
builds, which are necessary to avoid name collisions on platforms where
executables have no file extension (so, basically everything except
Windows).
Also add stddef.h include to GpRenderedGlyphMetrics.h to make size_t
visible. Does MSVC provide size_t by default, or via stdint.h? This
prevents compilation and I can't see how this would have compiled on
Windows otherwise.
- Adds missing includes, removes some unused ones.
- Removes unused Windows.h and shellapi.h includes.
- Uses / as path separator. This is portable and should still work fine
on Windows.
Downgrades c++11-narrowing to a warning when compiling with Clang. A
better solution would be to fix the error, but this at least brings
Clang in line with the more permissive GCC, which treats this as a
warning by default.
The BUILD_INTERFACE generator expression isn't actually useful as we
don't use export(). CMAKE_CURRENT_SOURCE_DIR is also unnecessary as
CMake treats relative paths as relative to the current source directory
(or the current binary directory for outputs).
