#include <GL/glut.h>

void init(void)
{
  glClearColor(1.0, 1.0, 1.0, 0.0);

  glMatrixMode(GL_PROJECTION);
  gluOrtho2D(0.0, 200.0, 0.0, 200.0);
}

void drawPrimitives(void)
{
  glClear(GL_COLOR_BUFFER_BIT);

  glEnable(GL_POINT_SMOOTH);
  glPointSize(40.0);

  glBegin(GL_POINTS);
   glColor3f(0.0, 1.0, 0.0);
   glVertex2i(180, 105);
  glEnd();

  glDisable(GL_POINT_SMOOTH);
  glPointSize(50.0);

  glBegin(GL_POINTS);
   glVertex2i(100, 105);
  glEnd();

  glLineWidth(5.0);

  glBegin(GL_LINES);
   glColor3f(1.0, 0.0, 0.0);
   glVertex2i(5, 50);
   glVertex2i(25, 50);
   glVertex2i(15, 50);
   glVertex2i(15, 15);
   
   glColor3f(0.0, 1.0, 0.0);
   glVertex2i(35, 50);
   glVertex2i(55, 50);
   glVertex2i(35, 15);
   glVertex2i(55, 15);
   glVertex2i(35, 50);
   glVertex2i(35, 15);
   glVertex2i(55, 50);
   glVertex2i(55, 15);

   glColor3f(0.0, 0.0, 1.0);
   glVertex2i(65, 50);
   glVertex2i(65, 15);
   glVertex2i(65, 50);
   glVertex2i(85, 15);
   glVertex2i(85, 15);
   glVertex2i(85, 50);

   glColor3f(0.0, 0.0, 0.0);
   glVertex2i(95, 50);
   glVertex2i(105, 40);
   glVertex2i(115, 50);
   glVertex2i(105, 40);
   glVertex2i(105, 40);
   glVertex2i(105, 15);
  glEnd();

  glFlush();
}

int main(int argc, char** argv)
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
  glutInitWindowPosition(0, 0);
  glutInitWindowSize(500, 500);
  glutCreateWindow("An Example OpenGL Program");

  init();
  glutDisplayFunc(drawPrimitives);

  glutMainLoop();

  return 1;
}