/tmp/cc2TBu9g.o: In function `display()':
main.cpp:(.text+0xa): undefined reference to `glClear'
main.cpp:(.text+0xf): undefined reference to `glutSwapBuffers'
/tmp/cc2TBu9g.o: In function `main':
main.cpp:(.text+0x33): undefined reference to `glutInit'
main.cpp:(.text+0x3d): undefined reference to `glutInitDisplayMode'
main.cpp:(.text+0x4c): undefined reference to `glutInitWindowPosition'
main.cpp:(.text+0x5b): undefined reference to `glutInitWindowSize'
main.cpp:(.text+0x65): undefined reference to `glutCreateWindow'
main.cpp:(.text+0x6f): undefined reference to `glutDisplayFunc'
main.cpp:(.text+0x8f): undefined reference to `glClearColor'
main.cpp:(.text+0x94): undefined reference to `glutMainLoop'
collect2: error: ld returned 1 exit status
main.cpp:(.text+0xa): undefined reference to `glClear'
main.cpp:(.text+0xf): undefined reference to `glutSwapBuffers'
/tmp/cc2TBu9g.o: In function `main':
main.cpp:(.text+0x33): undefined reference to `glutInit'
main.cpp:(.text+0x3d): undefined reference to `glutInitDisplayMode'
main.cpp:(.text+0x4c): undefined reference to `glutInitWindowPosition'
main.cpp:(.text+0x5b): undefined reference to `glutInitWindowSize'
main.cpp:(.text+0x65): undefined reference to `glutCreateWindow'
main.cpp:(.text+0x6f): undefined reference to `glutDisplayFunc'
main.cpp:(.text+0x8f): undefined reference to `glClearColor'
main.cpp:(.text+0x94): undefined reference to `glutMainLoop'
collect2: error: ld returned 1 exit status