#include <Windows.h>
#include <stdio.h> // for putchar()
#include <math.h> // for sqrtf()

class Vector2
 {
     friend class Dot;
     float x, y;

 public:
     Vector2() { x = y = 0.0f; }
     Vector2(float X, float Y) { x = X; y = Y; }

     void Normalize()
     {
         float m = Length();
         x = x/m;
         y = y/m;
     }

     float Length()
     {
         return sqrtf(x*x + y*y);
     }

     COORD GetConsoleCoords()
     {
         COORD c;
         c.X = (SHORT)x;
         c.Y = (SHORT)y;
         return c;
     }
 };

class Dot
{
    Vector2 mCoords;
    char mChar;

public:
    Dot() : mCoords(0.0f, 0.0f), mChar('*') {}
    Dot(float x, float y) : mCoords(x, y), mChar('*') {}
    Dot(float x, float y, char c) : mCoords(x, y), mChar(c) {}

    void Render(HANDLE hConsole)
    {
        CONSOLE_SCREEN_BUFFER_INFO consoleInfo;
        GetConsoleScreenBufferInfo(hConsole, &consoleInfo);
        SetConsoleCursorPosition(hConsole, mCoords.GetConsoleCoords());
        putchar(mChar);
        SetConsoleCursorPosition(hConsole, consoleInfo.dwCursorPosition);
    }


    void MoveTowards(Vector2 point, int distance)
    {
        if((int)mCoords.x == (int)point.x && (int)mCoords.y == (int)point.y)
            return;
        Vector2 v(point.x-mCoords.x, point.y-mCoords.y);
        v.Normalize();
        mCoords.x += (v.x*distance);
        mCoords.y += (v.y*distance);
    }

    void MoveTowards(Dot& dot, int distance=1)
    {
        MoveTowards(dot.mCoords, distance);
    }
};

void ClearConsole(HANDLE hConsole)
{
    COORD startingPos = { 0, 0 };
    DWORD dwCharsWritten;
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    GetConsoleScreenBufferInfo( hConsole, &csbi );
    DWORD dwConsoleSize = csbi.dwSize.X * csbi.dwSize.Y;

    FillConsoleOutputCharacter( hConsole, (TCHAR)' ',
        dwConsoleSize, startingPos, &dwCharsWritten );

    GetConsoleScreenBufferInfo( hConsole, &csbi );
    FillConsoleOutputAttribute( hConsole, csbi.wAttributes,
        dwConsoleSize, startingPos, &dwCharsWritten );

    SetConsoleCursorPosition( hConsole, startingPos );
}

int main()
{
    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);

    // starting positions and the char used to
    // render the "dot"
    Dot a(0,0,'A'), b(50,5,'B'), c(26,26,'C');
    while(true)
    {
        ClearConsole(hConsole);
        a.Render(hConsole);
        b.Render(hConsole);
        c.Render(hConsole);
        a.MoveTowards(b);
        b.MoveTowards(c);
        c.MoveTowards(a);
        Sleep(300);
    }
}