I'm trying to compile Godot to use doubles for vectors and math functions internally and found I can do this by setting the preprocessor macro REAL_T_IS_DOUBLE but I don't know how to set this using the scons build environment.
All I've been able to find so far is this snippet of code from stackoverflow that will add the macro to the environment variables:
env = Environment()
env.Append(CPPDEFINES=["REAL_T_IS_DOUBLE"])
Looking through the SConstruct file in the root folder of the source code seems to confirm that this will work as it is used to set other macros to control the build process. However, I can't find any mechanism in there to set user defined macros.
I figure I could just edit the file directly but this seems like a hack. What's the recommended way to set preprocessor macros when compiling Godot?