OpenGL tutorial 8

//http://www.youtube.com/user/thecplusplusguy
//Thanks for the typed in code to Tapit85
//you need test.obj file, exported from Blender with normal vectors no texture coorinates (without material)
#include <SDL/SDL.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <cstdlib>
#include <vector>
#include <string>
#include <algorithm>
#include <fstream>
#include <cstdio>
#include <iostream>

struct coordinate{
    float x,y,z;
    coordinate(float a, float b, float c) : x(a),y(b),z(c) {};
};

struct face{
    int facenum;
    bool four;
    int faces[4];
    face(int facen, int f1, int f2, int f3) : facenum(facen) {
        faces[0] = f1;
        faces[1] = f2;
        faces[2] = f3;
        four = false;
    }
    face(int facen, int f1, int f2, int f3, int f4) : facenum(facen) {
        faces[0] = f1;
        faces[1] = f2;
        faces[2] = f3;
        faces[3] = f4;
        four = true;
    }
};

float angle = 0.0;

int loadObject(const char* filename)
{
    std::vector<std::string*> coord;
    std::vector<coordinate*> vertex;
    std::vector<face*> faces;
    std::vector<coordinate*> normals;
    std::ifstream in(filename);
    if(!in.is_open())
    {
        std::cout << "Not Opened" << std::endl;
        return -1;
    }
    char buf[256];
    while(!in.eof())
    {
        in.getline(buf, 256);
        coord.push_back(new std::string(buf));
    }

    for(int i = 0; i < coord.size(); i += 1)
    {
        if((*coord[i])[0] == '#')
            continue;
        else if((*coord[i])[0] == 'v' && (*coord[i])[1] == ' ')
        {
            float tmpx, tmpy, tmpz;
            sscanf(coord[i]->c_str(), "v %f %f %f",&tmpx,&tmpy,&tmpz);
            vertex.push_back(new coordinate(tmpx,tmpy,tmpz));
        }
        else if((*coord[i])[0]=='v' && (*coord[i])[1]=='n')
        {
            float tmpx,tmpy,tmpz;
            sscanf(coord[i]->c_str(), "vn %f %f %f",&tmpx,&tmpy,&tmpz);
            normals.push_back(new coordinate(tmpx,tmpy,tmpz));
        }
        else if((*coord[i])[0] == 'f')
        {
            int a,b,c,d,e;
            if(count(coord[i]->begin(), coord[i]->end(), ' ') == 3)
            {
                sscanf(coord[i]->c_str(), "f %d//%d %d//%d %d//%d",&a,&b,&c,&b,&d,&b);
                faces.push_back(new face(b,a,c,d));
            }
            else
            {
                sscanf(coord[i]->c_str(), "f %d//%d %d//%d %d//%d %d//%d",&a,&b,&c,&b,&d,&b,&e,&b);
                faces.push_back(new face(b,a,c,d,e));
            }
        }
    }
    // draw
    int num;
    num = glGenLists(1);
    glNewList(num, GL_COMPILE);
    for(int i = 0; i < faces.size(); i += 1)
    {
        if(faces[i]->four)
        {
            glBegin(GL_QUADS);
                glNormal3f(normals[faces[i]->facenum-1]->x,normals[faces[i]->facenum-1]->y,normals[faces[i]->facenum-1]->z);
                glVertex3f(vertex[faces[i]->faces[0]-1]->x,vertex[faces[i]->faces[0]-1]->y,vertex[faces[i]->faces[0]-1]->z);
                glVertex3f(vertex[faces[i]->faces[1]-1]->x,vertex[faces[i]->faces[1]-1]->y,vertex[faces[i]->faces[1]-1]->z);
                glVertex3f(vertex[faces[i]->faces[2]-1]->x,vertex[faces[i]->faces[2]-1]->y,vertex[faces[i]->faces[2]-1]->z);
                glVertex3f(vertex[faces[i]->faces[3]-1]->x,vertex[faces[i]->faces[3]-1]->y,vertex[faces[i]->faces[3]-1]->z);
            glEnd();
        }
        else
        {
            glBegin(GL_TRIANGLES);
                glNormal3f(normals[faces[i]->facenum-1]->x,normals[faces[i]->facenum-1]->y,normals[faces[i]->facenum-1]->z);
                glVertex3f(vertex[faces[i]->faces[0]-1]->x,vertex[faces[i]->faces[0]-1]->y,vertex[faces[i]->faces[0]-1]->z);
                glVertex3f(vertex[faces[i]->faces[1]-1]->x,vertex[faces[i]->faces[1]-1]->y,vertex[faces[i]->faces[1]-1]->z);
                glVertex3f(vertex[faces[i]->faces[2]-1]->x,vertex[faces[i]->faces[2]-1]->y,vertex[faces[i]->faces[2]-1]->z);
            glEnd();
        }
    }

    glEndList();

    for(int i = 0; i < coord.size(); i += 1)
        delete coord[i];
    for(int i = 0; i < faces.size(); i += 1)
        delete faces[i];
    for(int i = 0; i < normals.size(); i += 1)
        delete normals[i];
    for(int i = 0; i < vertex.size(); i += 1)
        delete vertex[i];

    return num;
}

int cube;

void init()
{
    glClearColor(0.0,0.0,0.0,1.0);  //background color and alpha
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45,640.0/480.0,1.0,500.0);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_DEPTH_TEST);
    cube = loadObject("test.obj");
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    float col[] = {1.0, 1.0, 1.0, 1.0};
    glLightfv(GL_LIGHT0, GL_DIFFUSE, col);
}

void display()
{
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    float pos[] = {-1.0, 1.0, -2.0, 1.0};
    glLightfv(GL_LIGHT0, GL_POSITION, pos);
    glTranslatef(0.0,0.0,-5.0);
    glRotatef(angle,0.0,1.0,0.0);   // angle, x-axis, y-axis, z-axis
    glCallList(cube);
}

int main(int argc, char** argv)
{
    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_Surface *screen;
    screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE|SDL_OPENGL);
//  screen = SDL_SetVideoMode(1024, 768, 32, SDL_SWSURFACE|SDL_OPENGL|SDL_FULLSCREEN);
    bool running = true;
    const int FPS = 30;
    Uint32 start;
    SDL_Event event;
    init();
    while(running) {
        start = SDL_GetTicks();
        while(SDL_PollEvent(&event)) {
            switch(event.type) {
                case SDL_QUIT:
                    running = false;
                    break;
                case SDL_KEYDOWN:
                    switch(event.key.keysym.sym)
                    {
                        case SDLK_ESCAPE:
                            running = false;
                            break;
                    }
                    break;
            }
        }

        display();
        SDL_GL_SwapBuffers();
        angle += 0.5;
        if(angle > 360)
            angle -= 360;
        if(1000/FPS > SDL_GetTicks()-start)
            SDL_Delay(1000/FPS-(SDL_GetTicks()-start));
    }
    SDL_Quit();
    return 0;
}