Reading and storing values from .OBJ files using C++

Question

First, sorry for bad english. Well, I'm trying read the values of a .OBJ file (see here) and storing them in variables using this program:

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
using namespace std;

int main()
{
string line;
string v, valuesX[8], valuesY[8], valuesZ[8];
int n = 0;

ifstream myfile ("cubo.obj");
while(!myfile.eof())
{
    getline (myfile,line);
    if (line[0] == 'v')
    {
        myfile >> v >> valuesX[n]>> valuesY[n]>> valuesZ[n];
        cout << valuesX[n] << "\t" << valuesY[n] << "\t" << valuesZ[n] << endl;
        n++;
    }
}
return 0;
}

The file it's only a simple cube, exported by Blender. I expected him to show me all lines beginning with "v", but the result presents only the odd "v" lines. When I read directly the value of the variable "line", the result is the same. However, when I remove the line that assigns values ​​to variables "value" and read the variable "line" directly, the program works perfectly. Anyone know explain to me what is happening? Why the program is ignoring the even lines?

Answer 1

You're reading 2 lines per loop:

First time:

getline(myfile, line);

Second time:

myfile >> v >> valuesX[n] >> valuesY[n] >> valuesZ[n];

So you're discarding half your data.

Solution: Try using the ifstream::peek function to see if a line begins with a 'v', then you would read all the values into your variables.