gistfile1.c

#include <GL/glut.h>
#define font GLUT_BITMAP_HELVETICA_18
#define tx "Hello, world."

void text(void)
{
  char *p, tex[] = tx;
  p = tex;
  glColor3d(1.0, 1.0, 0.0);
  glRasterPos2d(-.5, 0.);
  while(*p) glutBitmapCharacter(font, *p++);
}

void display()
{
  glClear(GL_COLOR_BUFFER_BIT);
  text();
  glFlush();
}

void reshape(int width, int height)
{
  glViewport(0, 0, width, height);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(-1, 1, -1, 1, -1, 1);
  glMatrixMode(GL_MODELVIEW);
  display();
}

int main(int argc, char **argv)
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
  glutInitWindowPosition(50, 50);
  glutInitWindowSize(500, 500);
  glutCreateWindow("Hello World OpenGL");
  glClearColor(0,0,0,0);
  glutDisplayFunc(display);
  glutReshapeFunc(reshape);
  glutMainLoop();
  return 0;
}