crown-engine/engine/core/math/Point2.h

/*
Copyright (c) 2013 Daniele Bartolini, Michele Rossi
Copyright (c) 2012 Daniele Bartolini, Simone Boscaratto

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
*/

#pragma once

#include "Assert.h"
#include "Types.h"
#include "MathUtils.h"
#include "Vec2.h"
#include "Vec3.h"

namespace crown
{

/// 2D point.
class Point2
{
public:

	int32_t					x, y;

public:

							Point2();							//!< Constructor, does nothing for efficiency
							Point2(int32_t nx, int32_t ny);		//! Constructs from two components
							Point2(const int32_t a[2]);			//! Constructs from the array
							Point2(const Point2& a);			//! Copy constructor
							~Point2();							//! Destructor

	int32_t					operator[](uint32_t i) const;		//! Random access by index
	int32_t&				operator[](uint32_t i);				//! Random access by index

	Point2					operator+(const Point2& a) const;	//! Addition
	Point2&					operator+=(const Point2& a);		//! Addition
	Point2					operator-(const Point2& a) const;	//! Subtraction
	Point2&					operator-=(const Point2& a);		//! Subtraction
	Point2					operator*(int32_t k) const;			//! Multiplication by scalar
	Point2&					operator*=(int32_t k);				//! Multiplication by scalar
	Point2					operator/(int32_t k) const;			//! Division by scalar
	Point2&					operator/=(int32_t k);				//! Division by scalar
	int32_t					dot(const Point2& a);				//! dot product

	friend Point2			operator*(int32_t k, const Point2& a);	//! For simmetry

	bool					operator==(const Point2& other) const;	//! Equality operator
	bool					operator!=(const Point2& other) const;	//! Disequality operator
	bool					operator<(const Point2& other) const;	//! Returns whether all the components of this point32_t are smaller than all of the "other" point32_t
	bool					operator>(const Point2& other) const;	//! Returns whether all the components of this point32_t are greater than all of the "other" point32_t

	float					length() const;						//! Returns the point32_t's length
	int32_t					squared_length() const;				//! Returns the point32_t's squared length
	void					negate();							//! Negates the point32_t (i.e. builds the inverse)

	float					get_distance_to(const Point2& a);	//!< Returns the distance
	float					get_angle_between(const Point2& a);	//!< Returns the angle in radians

	Point2					operator-() const;					//! Negates the point32_t (i.e. builds the inverse)

	void					zero();								//! Builds the zero point32_t

	int32_t*				to_int_ptr();						//! Returns the point32_ter to the point32_t's data
	const int32_t*			to_int_ptr() const;					//! Returns the point32_ter to the point32_t's data
	Vec2					to_vec2() const;					//! Returns a vector from this point32_t
	Vec3					to_vec3() const;					//! Returns a vector from this point32_t

	static const Point2		ZERO;
	static const Point2		ONE;
	static const Point2		XAXIS;
	static const Point2		YAXIS;
};

//-----------------------------------------------------------------------------
inline Point2::Point2() : x(0), y(0)
{
}

//-----------------------------------------------------------------------------
inline Point2::Point2(int32_t nx, int32_t ny) : x(nx), y(ny)
{
}

//-----------------------------------------------------------------------------
inline Point2::Point2(const int32_t a[2]) : x(a[0]), y(a[1])
{
}

//-----------------------------------------------------------------------------
inline Point2::Point2(const Point2& a) : x(a.x), y(a.y)
{
}

//-----------------------------------------------------------------------------
inline Point2::~Point2()
{
}

//-----------------------------------------------------------------------------
inline int32_t Point2::operator[](uint32_t i) const
{
	CE_ASSERT(i < 2, "Index must be < 2");

	return (&x)[i];
}

//-----------------------------------------------------------------------------
inline int32_t& Point2::operator[](uint32_t i)
{
	CE_ASSERT(i < 2, "Index must be < 2");

	return (&x)[i];
}

//-----------------------------------------------------------------------------
inline Point2 Point2::operator+(const Point2& a) const
{
	return Point2(x + a.x, y + a.y);
}

//-----------------------------------------------------------------------------
inline Point2& Point2::operator+=(const Point2& a)
{
	x += a.x;
	y += a.y;

	return *this;
}

//-----------------------------------------------------------------------------
inline Point2 Point2::operator-(const Point2& a) const
{
	return Point2(x - a.x, y - a.y);
}

//-----------------------------------------------------------------------------
inline Point2& Point2::operator-=(const Point2& a)
{
	x -= a.x;
	y -= a.y;

	return *this;
}

//-----------------------------------------------------------------------------
inline Point2 Point2::operator*(int32_t k) const
{
	return Point2(x * k, y * k);
}

//-----------------------------------------------------------------------------
inline Point2& Point2::operator*=(int32_t k)
{
	x *= k;
	y *= k;

	return *this;
}

//-----------------------------------------------------------------------------
inline Point2 Point2::operator/(int32_t k) const
{
	CE_ASSERT(k != 0, "Division by zero");

	return Point2(x / k, y / k);
}

//-----------------------------------------------------------------------------
inline Point2& Point2::operator/=(int32_t k)
{
	CE_ASSERT(k != 0, "Division by zero");

	x /= k;
	y /= k;

	return *this;
}

//-----------------------------------------------------------------------------
inline int32_t Point2::dot(const Point2& a)
{
	return x * a.x + y * a.y;
}


//-----------------------------------------------------------------------------
inline Point2 operator*(int32_t k, const Point2& a)
{
	return a * k;
}

//-----------------------------------------------------------------------------
inline bool Point2::operator==(const Point2& other) const
{
	return x == other.x && y == other.y;
}

//-----------------------------------------------------------------------------
inline bool Point2::operator!=(const Point2& other) const
{
	return x != other.x || y != other.y;
}

//-----------------------------------------------------------------------------
inline bool Point2::operator<(const Point2& other) const
{
	return ((x < other.x) && (y < other.y));
}

//-----------------------------------------------------------------------------
inline bool Point2::operator>(const Point2& other) const
{
	return ((x > other.x) && (y > other.y));
}

//-----------------------------------------------------------------------------
inline float Point2::length() const
{
	return math::acos((float)(x * x + y * y));
}

//-----------------------------------------------------------------------------
inline int32_t Point2::squared_length() const
{
	return x * x + y * y;
}

//-----------------------------------------------------------------------------
inline void Point2::negate()
{
	x = -x;
	y = -y;
}

//-----------------------------------------------------------------------------
inline float Point2::get_distance_to(const Point2& a)
{
	return (*this - a).length();
}

//-----------------------------------------------------------------------------
inline float Point2::get_angle_between(const Point2& a)
{
	return math::acos(this->dot(a) / (this->length() * a.length()));
}

//-----------------------------------------------------------------------------
inline Point2 Point2::operator-() const
{
	return Point2(-x, -y);
}

//-----------------------------------------------------------------------------
inline void Point2::zero()
{
	x = y = 0;
}

//-----------------------------------------------------------------------------
inline int32_t* Point2::to_int_ptr()
{
	return &x;
}

//-----------------------------------------------------------------------------
inline const int32_t* Point2::to_int_ptr() const
{
	return &x;
}

//-----------------------------------------------------------------------------
inline Vec2 Point2::to_vec2() const
{
	return Vec2((float)x, (float)y);
}

//-----------------------------------------------------------------------------
inline Vec3 Point2::to_vec3() const
{
	return Vec3((float)x, (float)y, 0.0);
}

} // namespace crown