I wanted to use FTGL library, and I downloaded freetype2 because the compiler said
/usr/include/FTGL/ftgl.h:32:10: fatal error: ft2build.h: No such file or directory #include ^~~~~~~~~~~~ compilation teminated.
So, I put freetype-2.9.1 folder in /usr/include/FTGL, confirmed ft2build.h is in freetype-2.9.1/devel. Then I tried to compile, but the compiler still gives the same error. How can I fix this? I run Ubuntu 18.04 on Virtualbox. Any help will be appreciated.