objLoader.cpp

#include "objLoader.hpp"
#include <fstream>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include "toolbox.hpp"
#include <assert.h>

//#define DEBUG

ObjLoader objectLoader;

ObjLoader::ObjLoader()
{
    fprintf(stderr, "Objloader under replication...\n");
}

ObjLoader::~ObjLoader()
{
    fprintf(stderr, "Objectloader being sold to Russians...\n");
}

// Open a .obj, load its contents into 3 arrays:
// 1. Vertices
// 2. Normals
// 3. Indices
// Returns a vector of vectors containing this data
std::vector<std::vector<double> > ObjLoader::readObjectFile(std::string path)
{
    int const bufferSize(1024);
    char lineBuffer[bufferSize];
    std::string line = "";
    int lineNumber = 0;
    int i = 0;
    std::fstream dataReader(path.c_str());
    std::string decimalNumberString = "";
    std::string integerNumberString = "";
    int coordinatesAdded = 0;
    
    double x, y, z = 0.0;
    int a, b, c = 0;
    
    std::vector<double> vertexData;			// Read vertexes here
    std::vector<double> normalData;			// Read normals here
    std::vector<double> indiceData;			// Read indices here
    std::vector<std::vector<double> > out;	// Return in this container
    
    if (!dataReader)
        std::cout << "Error opening model file: " << path.c_str() << std::endl;

    while (!dataReader.eof())
    {
        #ifdef DEBUG
        std::cout << "Linebreak" << std::endl;
        #endif
        dataReader.getline(lineBuffer, bufferSize);
        line = lineBuffer;
        
        if (line[0] == 'v' && line[1] == ' ')			// Vertex
        {
            coordinatesAdded = 0;
            decimalNumberString = "";
            // Start reading from the first number. Skip the leading v and whitespace
            for (int i = 2; coordinatesAdded <= 3; i++)
            {
                if (line[i] == NULL)
                    break;
                // If we are at a new coordinate
                if (line[i] == ' ' ||
                    i == line.size() - 1)
                {
                    // Convert the string into a double
                    if (coordinatesAdded == 0)
                        x = atof(decimalNumberString.c_str());
                    else if (coordinatesAdded == 1)
                        y = atof(decimalNumberString.c_str());
                    else if (coordinatesAdded == 2)
                        z = atof(decimalNumberString.c_str());
                    
                    coordinatesAdded++;
                    decimalNumberString = "";
                }
                
                // Add the number or decimal dot to the string to be converted
                decimalNumberString.append(tbox.charToString(line[i]));
                
                if (coordinatesAdded > 3 && i > 40)
                {
                    std::cout << "Something broke reading a 3D object. Consult your 3D model exporter" << std::endl;
                    break;
                }
            }
            vertexData.push_back(x);
            vertexData.push_back(y);
            vertexData.push_back(z);

        } else if (line[0] == 'v' && line[1] == 'n')	// Vertex normal
        {
            coordinatesAdded = 0;
            decimalNumberString = "";
            // Start reading from the first number. Skip the leading v and whitespace
            for (int i = 3; coordinatesAdded < 3; i++)
            {
                if (line[i] == NULL)
                    break;
                // If we are at a new coordinate
                if (line[i] == ' ')
                {
                    // Convert the string into a double
                    if (coordinatesAdded == 0)
                        x = atof(decimalNumberString.c_str());
                    else if (coordinatesAdded == 1)
                        y = atof(decimalNumberString.c_str());
                    else if (coordinatesAdded == 2)
                        z = atof(decimalNumberString.c_str());
                    
                    coordinatesAdded++;
                    decimalNumberString = "";
                }
                
                // Add the number or decimal dot to the string to be converted
                decimalNumberString.append(tbox.charToString(line[i]));
                
                if (coordinatesAdded > 3 && i > 40)
                {
                    std::cout << "Something broke reading a 3D object. Consult your 3D model exporter" << std::endl;
                    break;
                }
            }
            normalData.push_back(x);
            normalData.push_back(y);
            normalData.push_back(z);
        } else if (line[0] == 'f' && line[1] == ' ')	// Index
        {
            /*
            The syntax for indices is as follows:
            
            f 14//14474 4483//14474 7448//14474
            
            Where the first value is the vertex index and the following is probably a texture index.
            There is one value missing, and thus there are two "/" in sequence
            */
            
            coordinatesAdded = 0;
            integerNumberString = "";
            bool valueAdded = false;
            a = 0;
            b = 0;
            c = 0;
            // Start reading from the first number. Skip the leading v and whitespace
            for (int i = 2; coordinatesAdded < 3; i++)
            {
                if (line[i] == NULL)
                    break;
                // If we are at a new coordinate
                if (line[i] == ' ' || (coordinatesAdded == 2 && valueAdded == true) )
                {
                    // Convert the string into an int
                    if (coordinatesAdded == 0)
                    {
                        a = atoi(integerNumberString.c_str());
                        #ifdef DEBUG
                        std::cout << "a: " << a << std::endl;
                        #endif
                    }
                    else if (coordinatesAdded == 1)
                    {
                        b = atoi(integerNumberString.c_str());
                        #ifdef DEBUG
                        std::cout << "b: " << b << std::endl;
                        #endif
                    }
                    else if (coordinatesAdded == 2)
                    {
                        c = atoi(integerNumberString.c_str());
                        #ifdef DEBUG
                        std::cout << "c: " << c << std::endl;
                        #endif
                    }
                    
                    coordinatesAdded++;
                    integerNumberString = "";
                    valueAdded = false;
                }
                
                if (line[i] == '/')
                {
                    valueAdded = true;
                    #ifdef DEBUG
                    std::cout << "Hit /" << std::endl;
                    #endif
                }
                // Add the number or decimal dot to the string to be converted
                if (valueAdded == false)
                {
                    #ifdef DEBUG
                    std::cout << "reading an integer into a string: " << line[i] << std::endl;
                    #endif
                    integerNumberString.append(tbox.charToString(line[i]));
                }
                
                if (coordinatesAdded > 3 && i > 40)
                {
                    std::cout << "Something broke reading a 3D object. Consult your 3D model exporter" << std::endl;
                    break;
                }
            }
            
            assert(a);
            assert(b);
            assert(c);
            
            #ifdef DEBUG
            std::cout << "Pushing indices to vector: " << a << ", " << b << ", " << c << std::endl;
            #endif
            
            indiceData.push_back(a-1);
            indiceData.push_back(b-1);
            indiceData.push_back(c-1);
        } else {
            // Non-interesting data
        }
    }
    
    out.push_back(vertexData);
    out.push_back(normalData);
    out.push_back(indiceData);
    dataReader.close();
    
    return out;
}