#include <windows.h>   // use as needed for your system
#include <gl/Gl.h>
#include <gl/glu.h>
#include <gl/glut.h>
#include <math.h>

#define PI 3.14159265

GLfloat light_diffuse[] = {1.0, 1.0, 1.0, 1.0};  /* White diffuse light. */
GLfloat light_position[] = {10.0, 10.0, 10.0, 1.0};  /* Light location. */
GLfloat cylinder_mat[] = {0.f, .5f, 1.f, 1.f}; /* Material for the dome. */

/* This program demonstrates how to use quad strips to make a shape.
In this case, a cylinder made up of strips. */

void cylinder(float r,int steps) 
{
  /* Set material properties for the cylinder. */
  glMaterialfv(GL_FRONT, GL_DIFFUSE, cylinder_mat);

  glBegin(GL_QUAD_STRIP);
  GLfloat u = -PI;
  GLfloat h = 2*PI/steps;
  for(int n = 0;n <= steps;n++) {
	glNormal3f(r*cos(u),r*sin(u),0.0);
	glVertex3f(r*cos(u),r*sin(u),1.0);
	glVertex3f(r*cos(u),r*sin(u),-1.0);
	u += h;
	}
  glEnd();
}

void
resize(int w,int h)
{
  glViewport(0,0,(GLsizei) w,(GLsizei) h);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective( /* field of view in degree */ 40.0,
    /* aspect ratio */ (float) w/(float) h,
    /* Z near */ 5.0, /* Z far */ 50.0);
  glutPostRedisplay();
}

void
display(void)
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  /* Be sure to set the matrix mode before drawing. */
  glMatrixMode(GL_MODELVIEW);

  /* Draw two copies of the cylinder. */
   glPushMatrix();
   glTranslatef(-2.0, 0.0, 0.0);
   glScalef(1.0,1.0,1.5);
   cylinder(0.5,20);
   glPopMatrix();

   glPushMatrix();
   glTranslatef(2.0, 0.0, 0.0);
   glRotatef(90,1.0, 0.0, 0.0);
   glScalef(1.0,1.0,1.5);
   cylinder(0.5,20);
   glPopMatrix();

  glutSwapBuffers();
}

void
init(void)
{
  /* Enable a single OpenGL light. */
  glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHTING);

  /* Turn on automatic normalization. */
  glEnable(GL_NORMALIZE);

  /* Use depth buffering for hidden surface elimination. */
  glEnable(GL_DEPTH_TEST);

  /* Make sure smooth shading is turned on. */
  glShadeModel(GL_SMOOTH);

  /* Set the clear color to white. */
  glClearColor(1.0, 1.0, 1.0, 1.0);

  /* Setup the view of the cube. */
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective( /* field of view in degree */ 40.0,
    /* aspect ratio */ 1.0,
    /* Z near */ 5.0, /* Z far */ 50.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  gluLookAt(0.0, 2.0, 10.0,  /* eye is at (0,2,10) */
    0.0, 0.0, 0.0,      /* center is at (0,0,0) */
    0.0, 1.0, 0.);      /* up is in positive Y direction */

}

int
main(int argc, char **argv)
{
  glutInit(&argc, argv);
  glutInitWindowSize(512, 512);
  glutInitWindowPosition(100,100);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutCreateWindow("Cylinders");
  glutDisplayFunc(display);
  glutReshapeFunc(resize);
  
  init();
  glutMainLoop();
  return 0;             /* ANSI C requires main to return int. */
}