Fixed Point Arithmetic

Implementation of fixed-point arithmetic using integers.

Features

• Binary Fixed Point (16.16).
• Decimal Fixed Point (two decimal places for money).

Usage

Binary Fixed Point

#include <iostream>

#include "Fixed16.h"

int main() {
    Fixed16 a{ 3.75f };
    Fixed16 b{ 1.5f };

    Fixed16 sum = a + b;
    Fixed16 diff = a - b;
    Fixed16 prod = a * b;
    Fixed16 quot = a / b;

    std::cout << "a + b = " << sum.to_float() << "\n";
    std::cout << "a - b = " << diff.to_float() << "\n";
    std::cout << "a * b = " << prod.to_float() << "\n";
    std::cout << "a / b = " << quot.to_float() << "\n";

    return 0;
}

Also we can use it without relying on floating point at all.

#include <iostream>

#include "Fixed16.h"

int main() {
    Fixed16 a{ "3.75" };
    Fixed16 b{ "1.5" };

    Fixed16 sum = a + b;
    Fixed16 diff = a - b;
    Fixed16 prod = a * b;
    Fixed16 quot = a / b;

    std::cout << "a + b = " << sum.to_string() << "\n";
    std::cout << "a - b = " << diff.to_string() << "\n";
    std::cout << "a * b = " << prod.to_string() << "\n";
    std::cout << "a / b = " << quot.to_string() << "\n";

    return 0;
}

Decimal Fixed Point

#include <iostream>

#include "Decimal.h"

int main() {
    Decimal a{ "12.34" };
    Decimal b{ "1.66" };

    Decimal sum = a + b;
    Decimal diff = a - b;
    Decimal prod = a * b;
    Decimal quot = a / b;

    std::cout << "a + b = " << sum.to_string() << '\n';
    std::cout << "a - b = " << diff.to_string() << '\n';
    std::cout << "a * b = " << prod.to_string() << '\n';
    std::cout << "a / b = " << quot.to_string() << '\n';

    return 0;
}

Documentation

In /docs directory there are some papers on the topic.