Assign tilemap 'tiles' and numerical value for 2d game

Question

I'm currently using a system the reads the x and y of my tilemap in accordance to the tileset and displays the relative image. This works, however i have found that creating a map by hand is incredibly difficult so decided to use a program called 'Tiled', however this does is read the image, in my case every 32px and set it as a number, let me try to explain, imagine each of the numbers below is a 32x32px square, the number represents how Tiled stores the image as a number until it reaches the width (for the example say the image is 160px or 5 tiles wide) of the image, then on a new lines continue the count..

[1] [2] [3] [4] [5]

[6] [7] [8] [9]

This throws out my script as x and y are not used. Ive tried searching and as many things as i can to adjust my code to read the new format but failed completely, below is my current function to load the map.

void LoadMap(const char*filename)
{
std::ifstream openfile(filename);
std::vector<sf::Vector2i> tempMap;
map.clear();

if(openfile.is_open())
{
    std::string tileLocation;
    openfile >> tileLocation;
    tileTexture.loadFromFile(tileLocation);
    tiles.setTexture(tileTexture);
    while(!openfile.eof())
    {
        std::string str, value;
        std::getline(openfile, str);
        std::stringstream stream(str);

        while(std::getline(stream, value, ' '))
        {
            if(value.length() > 0)
            {
                std::string xx = value.substr(0, value.find(','));
                std::string yy = value.substr(value.find(',') + 1);

                int x, y, i, j;

                for(i = 0; i < xx.length(); i++)
                {
                    if(!isdigit(xx[i]))
                        break;
                }

                for(j = 0; j < yy.length(); j++)
                {
                    if(!isdigit(yy[j]))
                        break;
                }

                x = (i == xx.length()) ? atoi(xx.c_str()) : -1;
                y = (j == yy.length()) ? atoi(yy.c_str()) : -1;

                tempMap.push_back(sf::Vector2i(x, y));
            }
        }

        if(tempMap.size() > 0)
        {
            map.push_back(tempMap);
            tempMap.clear();
        }
    }
}
}

All i need is the script to assign every 32x32 square a number then start a new line and continue until it reaches the end of the tilemap.png

I apologize if this is a silly request, im very new to c++ so any pointers on making my code read the new format would be gratefully appreciated, if you need any other info then let me know.

Jarod42 Jarod42 · Accepted Answer · 2013-12-27T01:44:49

If I understand correctly, you have this correspondence and you want to convert N to {x, y} and/or vice versa.

X = 1    2    3    4    5
  [ 1] [ 2] [ 3] [ 4] [ 5] y = 0
  [ 6] [ 7] [ 8] [ 9] [10] y = 1
  [ N]

So, following may help

void NToXY(unsigned int N, unsigned int& x, unsigned int& y)
{
    x = (N - 1) % 5 + 1;
    y = (N - 1) / 5 + 1;
}

void XYToN(unsigned int x, unsigned int y, unsigned int& N)
{
    N = (y - 1) * 5 + x;
}

Assign tilemap 'tiles' and numerical value for 2d game

2 Answers