Check for GLUT. If GLUT is found, the required compiler and linker flags are included in the output variables GLUT_CFLAGS and GLUT_LIBS, respectively. If GLUT is not found, no_glut is set to yes.

If the header GL/glut.h is found, HAVE_GL_GLUT_H is defined. If the header GLUT/glut.h is found, HAVE_GLUT_GLUT_H is defined. These preprocessor definitions may not be mutually exclusive.