mpri-graphics-project/util/ObjParser.cpp

#include "ObjParser.hpp"

#include <sstream>
#include <cctype>

ObjParser::ObjParser(const std::string& path)
    : path(path)
{}

Mesh ObjParser::parse() {
    std::ifstream handle(path);
    Mesh output;

    if(!handle.is_open())
       throw std::runtime_error(std::string("Cannot open the file ") + path);

    for(std::string line; std::getline(handle, line); ) {
        std::istringstream lineStream(strip(line));
        char type;
        lineStream >> type;

        if(type == 'v') { // vertice
            double x, y, z;
            lineStream >> x >> y >> z;
            output.add_vertice(Point(x, y, z));
        }
        else if(type == 'f') {
            int v1, v2, v3;
            lineStream >> v1 >> v2 >> v3;
            output.add_face(Face(v1 - 1, v2 - 1, v3 - 1));
        }
        else {
            throw BadObj(path);
        }
    }

    return output;
}

std::string ObjParser::strip(const std::string& str) {
    size_t fPos, lPos;
    for(fPos=0; fPos < str.size(); ++fPos) {
        if(!isspace(str[fPos]))
            break;
    }
    if(fPos == str.size())
        return "";

    for(lPos=str.size() - 1; lPos > 0; --lPos) {
        if(!isspace(str[lPos]))
            break;
    }

    return str.substr(fPos, lPos - fPos + 1);
}