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/* Point.h
Copyright (c) 2014 by Michael Zahniser
Endless Sky is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later version.
Endless Sky is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <https://www.gnu.org/licenses/>.
*/
#pragma once
#ifdef __SSE3__
#include <pmmintrin.h>
#elif defined(__SSE2__)
#include <xmmintrin.h>
#endif
// Class representing a 2D point with functions for a variety of vector operations.
// A Point can represent either a location or a vector (e.g. a velocity, or a
// distance between two points, or a unit vector representing a direction). All
// basic mathematical operations that make sense for vectors are supported.
// Internally the coordinates are stored in a SSE vector and the processor's vector
// extensions are used to optimize all operations.
class Point {
public:
Point() noexcept;
Point(double x, double y) noexcept;
// Check if the point is anything but (0, 0).
explicit operator bool() const noexcept;
bool operator!() const noexcept;
bool operator==(const Point &other) const noexcept;
bool operator!=(const Point &other) const noexcept;
Point operator+(const Point &point) const;
Point &operator+=(const Point &point);
Point operator-(const Point &point) const;
Point &operator-=(const Point &point);
Point operator-() const;
Point operator*(double scalar) const;
friend Point operator*(double scalar, const Point &point);
Point &operator*=(double scalar);
Point operator/(double scalar) const;
Point &operator/=(double scalar);
// Multiply the respective components of each Point.
Point operator*(const Point &other) const;
Point &operator*=(const Point &other);
double &X();
const double &X() const noexcept;
double &Y();
const double &Y() const noexcept;
void Set(double x, double y);
// Operations that treat this point as a vector from (0, 0):
double Dot(const Point &point) const;
double Cross(const Point &point) const;
double Length() const;
double LengthSquared() const;
Point Unit() const;
double Distance(const Point &point) const;
double DistanceSquared(const Point &point) const;
Point Lerp(const Point &to, const double c) const;
// Take the absolute value of both coordinates.
friend Point abs(const Point &p);
// Use the min of each x and each y coordinates.
friend Point min(const Point &p, const Point &q);
// Use the max of each x and each y coordinates.
friend Point max(const Point &p, const Point &q);
private:
#ifdef __SSE2__
// Private constructor, using a vector.
explicit Point(const __m128d &v);
private:
struct PointInternal {
double x;
double y;
};
union {
__m128d v;
PointInternal val;
};
#else
double x;
double y;
#endif
};
// Inline accessor functions, for speed:
inline double &Point::X()
{
#ifdef __SSE2__
return val.x;
#else
return x;
#endif
}
inline const double &Point::X() const noexcept
{
#ifdef __SSE2__
return val.x;
#else
return x;
#endif
}
inline double &Point::Y()
{
#ifdef __SSE2__
return val.y;
#else
return y;
#endif
}
inline const double &Point::Y() const noexcept
{
#ifdef __SSE2__
return val.y;
#else
return y;
#endif
}
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