Old DOOM WAD Reader

#include <cctype>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>

#define COLORMAP    0
#define FLATS       1
#define PLAYPAL     2

using namespace std;

struct lump
{
    int dirPos[3];
    int pos[3];
    int size[3];
};

uint64_t fetchInteger(ifstream &file, int position, int length)
{
    int startingPointer = file.tellg();
    file.seekg(position);

    uint64_t integer = 0;
    for (int token = 0; token < length; ++token)
        integer += (int)file.get() * pow(256, token);

    file.seekg(startingPointer);
    return integer;
}

char* fetchString(ifstream &file, int position, int length)
{
    int startingPointer = file.tellg();
    file.seekg(position);

    char* string = "";
    for (int token = 0; token < length; ++token)
        string += file.get();

    file.seekg(startingPointer);
    return string;
}

void flat(ifstream& wad, lump& lump, char tgaName[9])
{
    int filePointer2 = wad.tellg();
    char tgaPath[] = ".\\tga\\";

    strcat(tgaPath, tgaName);
    strcat(tgaPath, ".tga");

    ofstream tga(tgaPath, fstream::out | fstream::binary);
    char header[] = {0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 64, 0, 64, 0, 24, 64};
    tga.write(header, sizeof(header));

    filePointer2 -= 8;
    wad.seekg(fetchInteger(wad, filePointer2, 4));
    int filePointer3 = filePointer2;

    for (int byte = 0; byte < 4096; ++byte)
    {
        int filePointer5;
        filePointer5 = wad.tellg();

        int filePointer4;
        filePointer4 = lump.pos[PLAYPAL] + (wad.get() * 3);
        wad.seekg(filePointer4);

        char pixelRed[2];
        char pixelGreen[2];
        char pixelBlue[2];

        wad.read(pixelRed, 1);
        wad.read(pixelGreen, 1);
        wad.read(pixelBlue, 1);

        tga.write(pixelBlue, 1);
        tga.write(pixelGreen, 1);
        tga.write(pixelRed, 1);

        wad.seekg(++filePointer5);
    }

    wad.seekg(filePointer2);
}

int main()
{
    lump lump;
    ifstream wad("doom.wad", fstream::out | fstream::binary);
    wad.seekg(fetchInteger(wad, 8, 4));

    while (wad.good())
    {
        char string[8];
        wad.read(string, 8);

        int filePointer;
        filePointer = wad.tellg();
        filePointer -= 8;
        wad.seekg(filePointer);

        if (!strncmp(string, "COLORMAP", 8))
        {
            int tempFilePointer = filePointer;
            lump.dirPos[COLORMAP] = filePointer;
            tempFilePointer -= 4;
            lump.size[COLORMAP] = fetchInteger(wad, tempFilePointer, 4);
            tempFilePointer -= 4;
            lump.pos[COLORMAP] = fetchInteger(wad, tempFilePointer, 4);
        }

        if (!strncmp(string, "F_START\0", 8))
        {
            int tempFilePointer = filePointer;
            lump.dirPos[FLATS] = filePointer;
            tempFilePointer -= 4;
            lump.size[FLATS] = fetchInteger(wad, tempFilePointer, 4);
            tempFilePointer -= 4;
            lump.pos[FLATS] = fetchInteger(wad, tempFilePointer, 4);
        }

        if (!strncmp(string, "PLAYPAL\0", 8))
        {
            int tempFilePointer = filePointer;
            lump.dirPos[PLAYPAL] = filePointer;
            tempFilePointer -= 4;
            lump.size[PLAYPAL] = fetchInteger(wad, tempFilePointer, 4);
            tempFilePointer -= 4;
            lump.pos[PLAYPAL] = fetchInteger(wad, tempFilePointer, 4);
        }

        wad.seekg(++filePointer);
    }

    cout << "Pos:     Flat:" << endl;
    cout << "----     -----" << endl << endl;
    wad.clear();
    wad.seekg(lump.dirPos[FLATS]);
    while (wad.good())
    {
        char string[9];
        wad.read(string, 8);

        int filePointer;
        filePointer = wad.tellg();
        filePointer -= 8;
        wad.seekg(filePointer);

        if (((string[0] == 'F') && isdigit(string[1]) && (string[2] == '_') && (string[3] == 'S') &&
             (string[4] == 'T') && (string[5] == 'A') && (string[6] == 'R') && (string[7] == 'T'))
        ||
            ((string[0] == 'F') && isdigit(string[1]) && (string[2] == '_') && (string[3] == 'E') &&
             (string[4] == 'N') && (string[5] == 'D') && (string[6] == '\0') && (string[7] == '\0'))
        ||
            (!strncmp(string, "F_START\0", 8)))
        {
            wad.seekg(filePointer + 16);
            continue;
        }

        if (!strncmp(string, "F_END\0\0\0", 8))
            break;

        cout << filePointer << " " << string << endl;
        flat(wad, lump, string);

        filePointer += 16;
        wad.seekg(filePointer);
    }

    return 0;
}