c++ - FreeGLUT linking option -

i started project ubuntu 12.04 lts (64bit machine), , installed freeglut3 , freeglut3-dev. , other gl libraries installed using nvidia's driver installer (it must 32 bit libraries). when compile code, , option -lglut , -lglew. however, turns out

at preprocessor 26 #include <gl/glew.h> 27 #include <gl/glut.h>  ...   :~/downloads/homework/src$ gcc main.cpp -o homework -lglew -lfreeglut main.cpp: in function ‘void calculatefps()’: main.cpp:296:43: error: ‘glut_elapsed_time’ not declared in scope main.cpp: in function ‘void mouse(int, int, int, int)’: main.cpp:381:14: error: ‘glut_down’ not declared in scope main.cpp:381:37: error: ‘glut_left_button’ not declared in scope main.cpp:397:14: error: ‘glut_up’ not declared in scope main.cpp:397:35: error: ‘glut_left_button’ not declared in scope main.cpp: in function ‘void keyselect(unsigned char, int, int)’: main.cpp:442:49: error: ‘glutclosefunc’ not declared in scope main.cpp:448:93: error: ‘glprogramuniform1i’ not declared in scope main.cpp: in function ‘int main(int, char**)’: main.cpp:489:25: error: ‘glut_rgba’ not declared in scope main.cpp:489:37: error: ‘glut_double’ not declared in scope main.cpp:489:51: error: ‘glut_depth’ not declared in scope main.cpp:489:64: error: ‘glut_multisample’ not declared in scope main.cpp:493:20: error: ‘glut_action_on_window_close’ not declared in scope main.cpp:493:49: error: ‘glut_action_glutmainloop_returns’ not declared in scope main.cpp:493:82: error: ‘glutsetoption’ not declared in scope main.cpp:494:28: error: ‘glutclosefunc’ not declared in scope main.cpp:496:32: error: ‘glutinitcontextversion’ not declared in scope main.cpp:497:25: error: ‘glut_forward_compatible’ not declared in scope main.cpp:497:49: error: ‘glutinitcontextflags’ not declared in scope main.cpp:498:27: error: ‘glut_core_profile’ not declared in scope main.cpp:498:45: error: ‘glutinitcontextprofile’ not declared in scope 

i don't know why happened, , attached gl folder