Linker Collision

Jeg har ryddet lidt op i min kode og får nu nogle linker collissions, det skulle være ret simplet at undgå, ved bare ikke lige hvordan.

Compiling...
Effekt1.cpp
glInit.cpp
Main.cpp
Music.cpp
Torus.cpp
Linking...
glInit.obj : error LNK2005: \"float  flash\" (?flash@@3MA) already defined in Effekt1.obj
Main.obj : error LNK2005: \"float  flash\" (?flash@@3MA) already defined in Effekt1.obj
Music.obj : error LNK2005: \"float  flash\" (?flash@@3MA) already defined in Effekt1.obj
Torus.obj : error LNK2005: \"float  flash\" (?flash@@3MA) already defined in Effekt1.obj
Effekt1.obj : error LNK2001: unresolved external symbol \"char volatile  KeyHit\" (?KeyHit@@3DC)
glInit.obj : error LNK2001: unresolved external symbol \"char volatile  KeyHit\" (?KeyHit@@3DC)
Main.obj : error LNK2001: unresolved external symbol \"char volatile  KeyHit\" (?KeyHit@@3DC)
Effekt1.obj : error LNK2001: unresolved external symbol \"int  waba_dt\" (?waba_dt@@3HA)
Effekt1.obj : error LNK2001: unresolved external symbol \"struct fXYZ *  detail_torus\" (?detail_torus@@3PAUfXYZ@@A)
Effekt1.obj : error LNK2001: unresolved external symbol \"int  waba_ft\" (?waba_ft@@3HA)
Effekt1.obj : error LNK2001: unresolved external symbol \"struct fXYZ *  four_torus\" (?four_torus@@3PAUfXYZ@@A)
Effekt1.obj : error LNK2001: unresolved external symbol \"float  frameSkip\" (?frameSkip@@3MA)
Main.obj : error LNK2001: unresolved external symbol \"float  frameSkip\" (?frameSkip@@3MA)
Effekt1.obj : error LNK2001: unresolved external symbol \"float  rts\" (?rts@@3MA)
glInit.obj : error LNK2001: unresolved external symbol \"struct HGLRC__ *  glRC\" (?glRC@@3PAUHGLRC__@@A)
glInit.obj : error LNK2001: unresolved external symbol \"struct HDC__ *  hDC\" (?hDC@@3PAUHDC__@@A)
glInit.obj : error LNK2001: unresolved external symbol \"struct HWND__ *  hwnd\" (?hwnd@@3PAUHWND__@@A)
glInit.obj : error LNK2001: unresolved external symbol \"struct HINSTANCE__ *  hInstance\" (?hInstance@@3PAUHINSTANCE__@@A)
Main.obj : error LNK2001: unresolved external symbol \"float  megatime\" (?megatime@@3MA)
Main.obj : error LNK2001: unresolved external symbol \"float  time\" (?time@@3MA)
Main.obj : error LNK2001: unresolved external symbol \"float  startTime\" (?startTime@@3MA)
Main.obj : error LNK2001: unresolved external symbol \"struct FMUSIC_MODULE *  mod\" (?mod@@3PAUFMUSIC_MODULE@@A)
Music.obj : error LNK2001: unresolved external symbol \"struct FMUSIC_MODULE *  mod\" (?mod@@3PAUFMUSIC_MODULE@@A)
Debug/GrugdeDemo.exe : fatal error LNK1120: 15 unresolved externals
Error executing link.exe.

GrugdeDemo.exe - 24 error(s), 0 warning(s)