Reading Values Object wise from data file in c++

Question

I am Beginner and trying to read data from a file and store data into object.

Below are my file structure:

 #mat 4    //count of mat type of objects
 #lit 1
 #obj 4     //count of objects in scene

mat                     //mat object
ka   0.5 0.5 0.5
kd   1 0 0
ks   1 1 1
sh   10 

lit                    //lit object
color    1 0.7 0.7
pos -10 10 10

triangle                //scene object
v1   1 0 0
v2   0 1 0
v3   0 0 1
mat 0

And Below are my class mat class structure

class Mat {
public:
    Mat();
    Mat(Color& r, Color& g, Color& b, int s);
private:
    Color r;
    Color g; 
    Color b; 
    int n;

I tried to do like this.

vector<Mat> mat; // list of available 
Mat temp;
string line;


 if (file.is_open())
            {
                while (getline(file, line))
                {
                    file >> mat >> matCount;
                    file >> lit>> litCount;
                    file >> object >> objectCount;
                    for (int i = 0; i < matCount; i++)
                    {
                     file>>tempMat.mat;
                      //here I am facing problem.

                    } }}

could you please suggest me what is the best way to directly read data into object.

Barmak Shemirani · Accepted Answer · 2017-11-10 09:03:26Z

vector<Mat> mat;
...
file >> mat >> matCount;

mat is a vector, file >> mat will not work.

If your file content is the following:

mat
ka   0.5 0.5 0.5
kd   1 0 0
ks   1 1 1
triangle
tka   0.5 0.5 0.5
tkd   1 0 0
tks   1 1 1

Read the file line by line. Convert each line to stream. Read the stream in to a temporary Mat. Add the temporary Mat to the vector. Example:

#include <string>
#include <vector>
#include <fstream>
#include <sstream>
...

class Mat
{
public:
    string name;
    double red, green, blue;
};

vector<Mat> mat;
string line;
while(getline(file, line))
{
    stringstream ss(line);
    Mat temp;
    if(ss >> temp.name >> temp.red >> temp.green >> temp.blue)
    {
        cout << "A " << temp.name << endl;
        mat.push_back(temp);
    }
    else
    {
        cout << "Error: " << line << endl;
    }
}

for(auto e : mat)
    cout << e.name << ", " << e.red << ", " << e.green << ", " << e.blue << "\n";

This will work for the following file content

Collectives™ on Stack Overflow

Reading Values Object wise from data file in c++

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related