#pragma once
#include <SDL_stdinc.h>

/* 48.16, with bad overflowing mul & div. */
class fixed {
public:
  enum { FRAC = 16 };
  fixed(void) : v(0) {}
  
  fixed(Sint64 raw) : v(raw) {}
  fixed(Sint64 num, Sint64 denom) : v((num<<FRAC) / denom) {}

  friend fixed operator+(const fixed a, const int b) { return a+fixed(b<<FRAC); }
  friend fixed operator-(const fixed a, const int b) { return a-fixed(b<<FRAC); }
  friend fixed operator*(const fixed a, const int b) { return a*fixed(b<<FRAC); }
  friend fixed operator/(const fixed a, const int b) { return a/fixed(b<<FRAC); }
  friend fixed operator+(const int a, const fixed b) { return fixed(a<<FRAC)+b; }
  friend fixed operator-(const int a, const fixed b) { return fixed(a<<FRAC)-b; }
  friend fixed operator*(const int a, const fixed b) { return fixed(a<<FRAC)*b; }
  friend fixed operator/(const int a, const fixed b) { return fixed(a<<FRAC)/b; }

  friend bool operator==(const fixed a, const int b) { return a == fixed(b<<FRAC); }
  friend bool operator==(const int a, const fixed b) { return b == fixed(a<<FRAC); }
  friend bool operator>=(const fixed a, const int b) { return a >= fixed(b<<FRAC); }
  friend bool operator>=(const int a, const fixed b) { return b >= fixed(a<<FRAC); }
  friend bool operator<=(const fixed a, const int b) { return a <= fixed(b<<FRAC); }
  friend bool operator<=(const int a, const fixed b) { return b <= fixed(a<<FRAC); }

  friend bool operator>(const fixed a, const int b) { return a > fixed(b<<FRAC); }
  friend bool operator>(const int a, const fixed b) { return b > fixed(a<<FRAC); }
  friend bool operator<(const fixed a, const int b) { return a < fixed(b<<FRAC); }
  friend bool operator<(const int a, const fixed b) { return b < fixed(a<<FRAC); }

  friend fixed operator>>(const fixed a, const int b) { return fixed(a.v >> b); }
  friend fixed operator<<(const fixed a, const int b) { return fixed(a.v << b); }

  fixed &operator*=(const fixed a)  { (*this) = (*this)*a; return (*this); }
  fixed &operator*=(const int a)    { (*this) = (*this)*a; return (*this); }
  fixed &operator/=(const fixed a)  { (*this) = (*this)/a; return (*this); }
  fixed &operator/=(const int a)    { (*this) = (*this)/a; return (*this); }
  fixed &operator+=(const fixed a)  { (*this) = (*this)+a; return (*this); }
  fixed &operator+=(const int a)    { (*this) = (*this)+a; return (*this); }
  fixed &operator-=(const fixed a)  { (*this) = (*this)-a; return (*this); }
  fixed &operator-=(const int a)    { (*this) = (*this)-a; return (*this); }
  
  fixed &operator>>=(const int a)   { v >>= a; return (*this); }
  fixed &operator<<=(const int a)   { v <<= a; return (*this); }

  friend fixed operator+(const fixed a, const fixed b) { return fixed(a.v+b.v); }
  friend fixed operator-(const fixed a, const fixed b) { return fixed(a.v-b.v); }
  friend fixed operator*(const fixed a, const fixed b) { return fixed((a.v*b.v)>>FRAC); }
  friend fixed operator/(const fixed a, const fixed b) { return fixed((a.v<<FRAC)/b.v); }
  friend bool operator==(const fixed a, const fixed b) { return a.v == b.v; }
  friend bool operator>(const fixed a, const fixed b)  { return a.v > b.v;  }
  friend bool operator<(const fixed a, const fixed b)  { return a.v < b.v;  }
  friend bool operator>=(const fixed a, const fixed b) { return a.v >= b.v; }
  friend bool operator<=(const fixed a, const fixed b) { return a.v <= b.v; }

  /* Implicit operator float() is bad. */
  Sint64 ToInt64(void)  const { return v>>FRAC; }
  float ToFloat(void)   const { return v/(float)(1<<FRAC); }
  double ToDouble(void) const { return v/(double)(1<<FRAC); }

  Sint64 v;
};