Open_GL program please help!!

In the following opengl program I am trying to make octagone column with startpoint (0,0,0). Although my program compiles, I am unable to find why my column is not visible. I would be greateful if somebody could have a look at it and let me know! :-) #include <stdio.h> #include <math.h> /* in case math.h dose not define PI */ #ifndef PI #define PI 3.141593 #endif /* include openGL, glUtility and utility toolkit headers*/ #include <GL/gl.h> #include <GL/glu.h> #include <GL/glut.h> /* define values for the view flag */ #define FIXED 0 #define ROBOT 1 #define PLAN 2 /* declare the function prototypes */ void display(void); void reshape(int, int); void init_ground(void); void init_lights(void); void special(int, int, int); void menu(int); /* declare the global variables holding display lists*/ GLuint ground; /* a flag for the viewing state */ GLuint look_flag=FIXED; int main(int argc, char **argv){ glutInit(&argc, argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH); /******************************** CREATING THE WINDOW ********************************/ glutInitWindowSize(500, 500); glutCreateWindow("Sat Sales"); glClearColor (1.0, 1.0, 1.0, 0.0); glEnable(GL_DEPTH_TEST); glutReshapeFunc(reshape); glutDisplayFunc(display); glutSpecialFunc(special); init_ground(); init_lights(); glutCreateMenu(menu); glutAddMenuEntry("Fixed View", FIXED); // glutAddMenuEntry("Front View", FRONT); glutAddMenuEntry("Plan View", PLAN); glutAddMenuEntry("Exit", -1); glutAttachMenu(GLUT_MIDDLE_BUTTON); glutMainLoop(); return 0; } void reshape(int w, int h){ glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); /********************************************************* The plan view is an orthographic projection it must project the project squares as squares not rectangles. So when the width is greater than the height the bottom' and top' values are scaled. This adds white space at the top and bottom of the image but ensures the geometry is correct. The opposite applies when h > w. ***********************************************************/ if(look_flag==PLAN){ if(w <= h) glOrtho(-110, 110, -110*(GLfloat)h/(GLfloat)w, 110*(GLfloat)h/(GLfloat)w, 10, 200); else glOrtho(-110*(GLfloat)w/(GLfloat)h, 110*(GLfloat)w/(GLfloat)h, -110, 110, 10, 200); }else gluPerspective(120.0, ((GLfloat) w)/((GLfloat)h), 1.0, 1000.0); glMatrixMode(GL_MODELVIEW); glutPostRedisplay(); return; } void display(){ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); if(look_flag==FIXED){ gluLookAt(-65.0, 15.0, 70.0, 70.0, 10.0, -70.0, 0.0, 1.0, 0.0); }else{ gluLookAt(0.0, 100.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0); } init_lights(); glCallList(ground); glFlush(); glutSwapBuffers(); return; } void init_lights(){ GLfloat light0_position[]={70.0, 50.0, -90.0, 1.0}; GLfloat light1_position[]={-110.0, 60.0, 120.0, 1.0}; GLfloat light2_position[]={0.0, 40, 0.0, 1.0}; GLfloat amb_and_diff[]={0.8, 0.4, 0.5, 1.0}; GLfloat global_abm[]={0.2, 0.2, 0.2, 1.0}; GLfloat specular[] = {0.3, 0.3, 0.3, 1.0}; glEnable(GL_LIGHTING); glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, GL_TRUE); glLightModelfv(GL_LIGHT_MODEL_AMBIENT, global_abm); /********************************** Part 2: your code goes here **********************************/ return; } void init_ground(){ GLfloat amb_and_diffuse[]= {0.1, 0.7, 0.1, 1.0}; GLfloat emission[]= {0.0, 0.2, 0.0, 1.0}; ground = glGenLists(1); if(ground!=0){ glNewList(ground, GL_COMPILE); glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, amb_and_diffuse); glMaterialfv(GL_FRONT, GL_EMISSION, emission); glBegin(GL_QUADS); glNormal3f(0.0, 1.0, 0.0); glVertex3f(-100.0, 0.0, -100.0); glVertex3f(100.0, 0.0,-100.0); glVertex3f(100.0, 0.0, 100.0); glVertex3f(-100.0, 0.0, 100.0); glEnd(); glEndList(); }else fprintf(stderr, "Error: OpenGL could not obtain a list for the ground\n"); return; } /************************************** THIS FUNCTION UTILISES THE ARROW KEYS ***************************************/ void special(int key, int x, int y){ float X, Z; /********************************************** The robot moves forward and backward in its current attitude. This requires a bit of trig to find the X and Z increments and more complicated guards on the motion. ************************************************/ /* switch(key){ case GLUT_KEY_DOWN: X = sin(robot_angle*PI/180); Z = cos(robot_angle*PI/180); if((X>0.0 && robotX<=-95) || (X<0.0 && robotX>=95) || (Z>0.0 && robotZ<=-95) || (Z<0.0 && robotZ>=95)) break; robotX -= X; robotZ -= Z; break; case GLUT_KEY_UP: X = sin(robot_angle*PI/180); Z = cos(robot_angle*PI/180); if((X>0.0 && robotX>=95) || (X<0.0 && robotX<=-95) || (Z>0.0 && robotZ>=95) || (Z<0.0 && robotZ<=-95)) break; robotX += X; robotZ += Z; break; case GLUT_KEY_RIGHT: robot_angle-=5; break; case GLUT_KEY_LEFT: robot_angle+=5; break; default: fprintf(stdout, "No function attached to key.\n"); }*/ glutPostRedisplay(); return; } /********************************************* The menue is used to set the view it must therefor change the projection matrices when entering or leaving the PLAN state. This requires the use of `glutGet' to find the current window size. *********************************************/ void menu(int id){ float w, h; if(id==look_flag) return; if(id<0) exit(0); if(id==PLAN){ w = (float) glutGet(GLUT_WINDOW_WIDTH ); h = (float) glutGet(GLUT_WINDOW_HEIGHT ); glMatrixMode(GL_PROJECTION); glLoadIdentity(); if(w <= h) glOrtho(-110, 110, -110*(GLfloat)h/(GLfloat)w, 110*(GLfloat)h/(GLfloat)w, 10, 200); else glOrtho(-110*(GLfloat)w/(GLfloat)h, 110*(GLfloat)w/(GLfloat)h, -110, 110, 10, 200); glMatrixMode(GL_MODELVIEW); }else if(look_flag==PLAN){ w = (float) glutGet(GLUT_WINDOW_WIDTH ); h = (float) glutGet(GLUT_WINDOW_HEIGHT ); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(120.0, ((GLfloat) w)/((GLfloat)h), 1.0, 1000.0); glMatrixMode(GL_MODELVIEW); } look_flag=id; glutPostRedisplay(); return; }