C / C++ SHIFT / OFFSET / MOVE a Bitmap to the LEFT or RIGHT?

#include <iostream>

int main()
{
    // Some constants
    const size_t width = 6;
    const size_t height = 4;
    const size_t bitmapBytes = width*height;

    // Actual data
    char oldBitmapBytes[bitmapBytes] =
    {
        '1', '2', '3', '4', '5', '6',
        'a', 'b', 'c', 'd', 'e', 'f',
        '.', ',', '/', '~', '#', '$',
        '!', '-', '!', '+', '!', '?'
    };

    char newBitmapBytes[bitmapBytes];

    // Variables
    const size_t x_offset = 2;

    // Some utilities
    auto convertCoordsToIndex = [&](const size_t x, const size_t y)
    {
        return y*width + x;
    };

    auto printBitmap = [&](const char* bitmapBytes)
    {
        for (size_t row = 0; row < height; row++)
        {
            for (size_t col = 0; col < width; col++)
                std::cout << bitmapBytes[convertCoordsToIndex(col, row)];
            std::cout << '\n';
        }
    };

    // Display original bitmap
    printBitmap(oldBitmapBytes);

    // Shift by x_offset

    for (size_t row = 0; row < height; row++)
    {
       for (size_t col = 0; col < width; col++)
       {
          const size_t adjustedCol = (col + x_offset) % width;
          const size_t oldIndex = convertCoordsToIndex(col, row);
          const size_t newIndex = convertCoordsToIndex(adjustedCol, row);

          newBitmapBytes[newIndex] = oldBitmapBytes[oldIndex];
        }
    }

    // Display shifted bitmap
    std::cout << '\n';
    printBitmap(newBitmapBytes);
}

// Output:
//   123456
//   abcdef
//   .,/~#$
//   !-!+!?
//   
//   561234
//   efabcd
//   #$.,/~
//   !?!-!+