Compiling grx11.o

Hello,
First, sorry for delay, I am studying for my final exams that will held beginning of June.
I am playing with graph/grx11 at the same time.

Those I what I did so far:
-Research for X11
-Compiled all the demos and runned them
-Studied build process of graph apps

I wanted to compile grx11.c by itself to see the output application well
so deleted
> #ifdef TEST
> #if 0
>
> #endif
> #endif
lines to compile it with its main function. but that time i got huge amount of errors such as
> /freetype-demos/graph/x11/grx11.c:1529:5: error: call to undeclared function 'grInit'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>     grInit();

I need to link it with the graph  but getting complicated.

I wanted inform you about the progress and ask if I am on the right path.

Best,
Goksu
goksu.in