1. 檢測鼠標的click
glutMouseFunc( (void)(*func) ( int button, int state, int x, int y ) )
button: GLUT_LEFT_BUTTON, GLUT_MIDDLE_BUTTON, BLUT_RIGHT_BUTTON
state: GLUT_DOWN, GLUT_UP
x,y: 左上角爲原點
2. 檢測鼠標的動作
active motion: 鼠標移動並且有一個鼠標鍵按下
passive motion: 鼠標移動並且無鼠標鍵按下
glutMotionFunc( (void)(*func) (int x, int y) )
glutPassiveMotionFunc( (void)(*func) ( int x, int y ) )