I downloaded a plugin called Warp, and it came as a *.c file.  I compiled it using gcc, but it is giving me an error message because it cannot find the gimp.h header file that is called in the preprocessor directive.  I looked at the source code, and from the bits and pieces I know about programming, I saw that gimp.h was enclosed in double-quotes, meaning that it is looking for that header file in the current directory.  What directory must you compile this in? Where is gimp.h located?