load .obj file

loadObj.h

#pragma once

#include "ofMain.h"

bool loadObj(string path, ofMesh &mesh, ofImage *tex = NULL)
{
	path = ofToDataPath(path);
	if (!ofFile::doesFileExist(path)) return false;
	
	ifstream ifs(path.c_str());
	
	mesh.clear();
	
	vector<ofVec3f> vertices, normals;
	vector<ofFloatColor> colors;
	vector<ofVec2f> texcoords;
	vector< vector<string> > faces;
	
	char line[512];
	while (!ifs.eof())
	{
		ifs.getline(line, sizeof(line), '\n');
		
		vector<string> elem = ofSplitString(line, " ", true, true);
		
		if (elem.empty()) continue;
		else if (elem[0] == "#") continue;
		else if (elem[0] == "v")
		{
			if (elem.size() == 4)
			{
				vertices.push_back(ofVec3f(ofToFloat(elem[1]),
										   ofToFloat(elem[2]),
										   ofToFloat(elem[3])));
			}
			else if (elem.size() == 7)
			{
				vertices.push_back(ofVec3f(ofToFloat(elem[1]),
										   ofToFloat(elem[2]),
										   ofToFloat(elem[3])));
				colors.push_back(ofFloatColor(ofToFloat(elem[4]),
											  ofToFloat(elem[5]),
											  ofToFloat(elem[6])));
			}
		}
		else if (elem[0] == "vn" && elem.size() == 4)
		{
			normals.push_back(ofVec3f(ofToFloat(elem[1]),
									  ofToFloat(elem[2]),
									  ofToFloat(elem[3])));
		}
		else if (elem[0] == "vt" && (elem.size() == 3 || elem.size() == 4) && tex != NULL)
		{
			texcoords.push_back(ofVec2f(tex->getWidth() * ofToFloat(elem[1]),
										tex->getHeight() * (1 - ofToFloat(elem[2]))));
		}
		else if (elem[0] == "f" && elem.size() == 4)
		{
			vector<string> s(3);
			s[0] = elem[1];
			s[1] = elem[2];
			s[2] = elem[3];
			faces.push_back(s);
		}
	}
	
	if (faces.empty())
	{
		for (int i = 0; i < vertices.size(); i++)
			mesh.addVertex(vertices[i]);
		
		for (int i = 0; i < colors.size(); i++)
			mesh.addColor(colors[i]);
		
		for (int i = 0; i < normals.size(); i++)
			mesh.addNormal(normals[i]);
		
		if (tex != NULL)
		{
			for (int i = 0; i < texcoords.size(); i++)
				mesh.addTexCoord(texcoords[i]);
		}
		
		mesh.setMode(OF_PRIMITIVE_POINTS);
	}
	else
	{
		for (int i = 0; i < faces.size(); i++)
		{
			vector<string> &elem = faces[i];
			
			vector<string> v1 = ofSplitString(elem[0], "/", false, true);
			vector<string> v2 = ofSplitString(elem[1], "/", false, true);
			vector<string> v3 = ofSplitString(elem[2], "/", false, true);
			
			if (v1[0] != "")
			{
				mesh.addVertex(vertices[ofToInt(v1[0]) - 1]);
				mesh.addVertex(vertices[ofToInt(v2[0]) - 1]);
				mesh.addVertex(vertices[ofToInt(v3[0]) - 1]);
				
				if (!colors.empty())
				{
					mesh.addColor(colors[ofToInt(v1[0]) - 1]);
					mesh.addColor(colors[ofToInt(v2[0]) - 1]);
					mesh.addColor(colors[ofToInt(v3[0]) - 1]);
				}
			}
			
			if (v1.size() > 1 && v1[1] != "" && tex != NULL)
			{
				mesh.addTexCoord(texcoords[ofToInt(v1[1]) - 1]);
				mesh.addTexCoord(texcoords[ofToInt(v2[1]) - 1]);
				mesh.addTexCoord(texcoords[ofToInt(v3[1]) - 1]);
			}
			
			if (v1.size() > 2 && v1[2] != "")
			{
				mesh.addNormal(normals[ofToInt(v1[2]) - 1]);
				mesh.addNormal(normals[ofToInt(v2[2]) - 1]);
				mesh.addNormal(normals[ofToInt(v3[2]) - 1]);
			}
			
			int t = mesh.getNumIndices();
			mesh.addTriangle(t, t+1, t+2);
		}
		
		mesh.setMode(OF_PRIMITIVE_TRIANGLES);
	}
	

	
	return true;
}