std::ifstream in;

in.open(filename, std::ifstream::in);

if (in.fail()) return;

std::string line;

while (!in.eof()) {

std::getline(in, line);

std::istringstream iss(line.c_str());

char trash;

if (!line.compare(0, 2, "v ")) {

iss >> trash;

vec3 v;

for (int i=0;i<3;i++) iss >> v[i];

verts.push_back(v);

} else if (!line.compare(0, 3, "vn ")) {

iss >> trash >> trash;

vec3 n;

for (int i=0;i<3;i++) iss >> n[i];

norms.push_back(n.normalized());

} else if (!line.compare(0, 3, "vt ")) {

iss >> trash >> trash;

vec2 uv;

for (int i=0;i<2;i++) iss >> uv[i];

tex_coord.push_back({uv.x, 1-uv.y});

} else if (!line.compare(0, 2, "f ")) {

int f,t,n;

iss >> trash;

int cnt = 0;

while (iss >> f >> trash >> t >> trash >> n) {

facet_vrt.push_back(--f);

facet_tex.push_back(--t);

facet_nrm.push_back(--n);

cnt++;

}

if (3!=cnt) {

std::cerr << "Error: the obj file is supposed to be triangulated" << std::endl;

return;

}

}

}

std::cerr << "# v# " << nverts() << " f# " << nfaces() << " vt# " << tex_coord.size() << " vn# " << norms.size() << std::endl;

load_texture(filename, "_diffuse.tga", diffusemap );

load_texture(filename, "_nm_tangent.tga", normalmap );

load_texture(filename, "_spec.tga", specularmap);

size_t dot = filename.find_last_of(".");

if (dot==std::string::npos) return;

std::string texfile = filename.substr(0,dot) + suffix;

std::cerr << "texture file " << texfile << " loading " << (img.read_tga_file(texfile.c_str()) ? "ok" : "failed") << std::endl;