/********************************************************************
  File: curve.cc 
  Draws a circle as a line strip.
  D. Vrajitoru.
********************************************************************/

#include <GL/glut.h>
#include <math.h>
#include <fstream.h>

const int CURVE_ID = 1;

// display a curve as a line strip
void read_file(char *filename)
{
  ifstream fin;
  int nr_points;
  float x, y;
  fin.open(filename);
  fin >> nr_points;
  glNewList(CURVE_ID, GL_COMPILE); 
  glColor3f(1, 0, 0);
  glBegin(GL_LINE_STRIP);
  for (int i=0; i<nr_points; i++) {
    fin >> x >> y;
    glVertex2f(x, y);
  }
  glEnd();
  glEndList();
  fin.close();
}

void display(void)
{
  glClear(GL_COLOR_BUFFER_BIT);
  glCallList(CURVE_ID);
  glFlush();
}

void myinit()
{
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(-1.25, 1.25, -1.25, 1.25);
  glMatrixMode(GL_MODELVIEW);
  glClearColor (1.0, 0.95, 0.9, 1.0);
  glColor3f(1.0,0.0,0.0);
}

void main(int argc, char **argv)
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB );
  glutInitWindowSize(300, 300);
  glutCreateWindow("plot");
  glutDisplayFunc(display);
  myinit();
  glutMainLoop();
}