opengl_code

#include <SFML/Graphics.hpp>
#include <SFML/OpenGL.hpp>
#include <cstdio>
#include <vector>
#include <array>
#include <cstring>

using namespace sf;
using namespace std;

vector<array<float, 3> > vertices;
vector<array<float, 3> > normals;
vector<array<int, 2> > triangles;


int main (int, char** argv)
{
  vertices.push_back({0,0,0});
  normals.push_back({0,0,0});
  
  
  FILE * file = fopen(argv[1], "r");
  char header[128];
  float x, y, z;
  int a, b, c, d, e, f;
  while (fscanf(file, "%s ", header)!=EOF)
  {
    if (strcmp(header, "v")==0)
    {
      fscanf(file, "%f %f %f\n", &x, &y, &z);
      vertices.push_back({x, y, z});
    }
    else if (strcmp(header, "vn")==0)
    {
      fscanf(file, "%f %f %f\n", &x, &y, &z);
      normals.push_back({x, y, z});
    }
    else if (strcmp(header, "f")==0)
    {
      fscanf(file, "%d//%d %d//%d %d//%d\n", &a, &b, &c, &d, &e, &f);
      triangles.push_back({a, b});
      triangles.push_back({c, d});
      triangles.push_back({e, f});
    }
  }
  
  RenderWindow window(VideoMode(640,640), "OpenGL");
  
  glDepthFunc(GL_LEQUAL);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_LIGHTING);
  glEnable(GL_NORMALIZE);
  
  GLfloat ambientColor[] = {0.2f, 0.2f, 0.2f, 1.0f};
  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientColor);
  glEnable(GL_LIGHT0);
  
  GLfloat lightColor1[] = {0.5f, 0.2f, 0.2f, 1.0f};
  GLfloat lightPos1[] = {-1.0f, 0.5f, 0.5f, 0.0f};
  glLightfv(GL_LIGHT1, GL_DIFFUSE, lightColor1);
  glLightfv(GL_LIGHT1, GL_POSITION, lightPos1);
  glEnable(GL_LIGHT1);
  
  
  
  while(window.isOpen())
  {
    Event ev;
    while(window.pollEvent(ev))
    {
      if (ev.type==Event::Closed)
      {
        window.close();
        break;
      }
    }
    
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glClearColor(0,0,0.1,1);
    glColor3f(1, 1, 0.7);
    glRotatef(0.7, 0, 1, 0);

    glBegin(GL_TRIANGLES);
    for (auto q : triangles)
    {
      a=q[0];
      b=q[1];
      glNormal3f(normals[b][0], normals[b][1], normals[b][2]);
      glVertex3f(vertices[a][0], vertices[a][1], vertices[a][2]);
    }
    glEnd();
    
    window.display();
  }
  return 0;
}