Compiling Chipmunk with Code::Blocks

I seem to be unable to compile chipmunk without compile erro开发者_运维百科rs, can anyone help me? I turned on C99 but I still get errors. Here's a few:

C:\c++\ChipmunkLib\chipmunk.c:70: error: 'M_PI' undeclared (first use in this function) C:\c++\ChipmunkLib\chipmunk.c:70: error: (Each undeclared identifier is reported only once C:\c++\ChipmunkLib\chipmunk.c:70: error: for each function it appears in.) C:\c++\ChipmunkLib\chipmunk.c: In function 'cpAreaForSegment': C:\c++\ChipmunkLib\chipmunk.c:85: error: 'M_PI' undeclared (first use in this function)