ANSLibs/QRCode/Point.h

/*
* Copyright 2020 Axel Waggershauser
*/
// SPDX-License-Identifier: Apache-2.0

#pragma once

#include <algorithm>
#include <cmath>

namespace ZXing {

template <typename T>
struct PointT
{
	using value_t = T;
	T x = 0, y = 0;

	constexpr PointT() = default;
	constexpr PointT(T x, T y) : x(x), y(y) {}

	template <typename U>
	constexpr explicit PointT(const PointT<U>& p) : x(static_cast<T>(p.x)), y(static_cast<T>(p.y))
	{}

	template <typename U>
	PointT& operator+=(const PointT<U>& b)
	{
		x += b.x;
		y += b.y;
		return *this;
	}
};

template <typename T>
bool operator==(const PointT<T>& a, const PointT<T>& b)
{
	return a.x == b.x && a.y == b.y;
}

template <typename T>
bool operator!=(const PointT<T>& a, const PointT<T>& b)
{
	return !(a == b);
}

template <typename T>
auto operator-(const PointT<T>& a) -> PointT<T>
{
	return {-a.x, -a.y};
}

template <typename T, typename U>
auto operator+(const PointT<T>& a, const PointT<U>& b) -> PointT<decltype(a.x + b.x)>
{
	return {a.x + b.x, a.y + b.y};
}

template <typename T, typename U>
auto operator-(const PointT<T>& a, const PointT<U>& b) -> PointT<decltype(a.x - b.x)>
{
	return {a.x - b.x, a.y - b.y};
}

template <typename T, typename U>
auto operator*(const PointT<T>& a, const PointT<U>& b) -> PointT<decltype(a.x * b.x)>
{
	return {a.x * b.x, a.y * b.y};
}

template <typename T, typename U>
PointT<T> operator*(U s, const PointT<T>& a)
{
	return {s * a.x, s * a.y};
}

template <typename T, typename U>
PointT<T> operator/(const PointT<T>& a, U d)
{
	return {a.x / d, a.y / d};
}

template <typename T, typename U>
auto dot(const PointT<T>& a, const PointT<U>& b) -> decltype (a.x * b.x)
{
	return a.x * b.x + a.y * b.y;
}

template <typename T>
auto cross(PointT<T> a, PointT<T> b) -> decltype(a.x * b.x)
{
	return a.x * b.y - b.x * a.y;
}

/// L1 norm
template <typename T>
T sumAbsComponent(PointT<T> p)
{
	return std::abs(p.x) + std::abs(p.y);
}

/// L2 norm
template <typename T>
auto length(PointT<T> p) -> decltype(std::sqrt(dot(p, p)))
{
	return std::sqrt(dot(p, p));
}

/// L-inf norm
template <typename T>
T maxAbsComponent(PointT<T> p)
{
	return std::max(std::abs(p.x), std::abs(p.y));
}

template <typename T>
auto distance(PointT<T> a, PointT<T> b) -> decltype(length(a - b))
{
	return length(a - b);
}

using PointI = PointT<int>;
using PointF = PointT<double>;

/// Calculate a floating point pixel coordinate representing the 'center' of the pixel.
/// This is sort of the inverse operation of the PointI(PointF) conversion constructor.
/// See also the documentation of the GridSampler API.
inline PointF centered(PointI p)
{
	return p + PointF(0.5f, 0.5f);
}

inline PointF centered(PointF p)
{
	return {std::floor(p.x) + 0.5f, std::floor(p.y) + 0.5f};
}

template <typename T>
PointF normalized(PointT<T> d)
{
	return PointF(d) / length(PointF(d));
}

template <typename T>
PointT<T> bresenhamDirection(PointT<T> d)
{
	return d / maxAbsComponent(d);
}

template <typename T>
PointT<T> mainDirection(PointT<T> d)
{
	return std::abs(d.x) > std::abs(d.y) ? PointT<T>(d.x, 0) : PointT<T>(0, d.y);
}


} // ZXing