src/basics.h

/*
 *  LDForge: LDraw parts authoring CAD
 *  Copyright (C) 2013 - 2020 Teemu Piippo
 *
 *  This program 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.
 *
 *  This program 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 <http://www.gnu.org/licenses/>.
 */

#pragma once
#include <algorithm>
#include <cmath>
#include <compare>
#include <memory>
#include <optional>
#include <type_traits>
#include <QDataStream>
#include <QDebug>
#include <QObject>
#include <QPointF>
#include <QSet>
#include <QString>
#include <QStringList>
#include <QVariant>
#include <QVector>
#include <glm/glm.hpp>
#include "geometry.h"
#include "functional.h"

template<typename T>
using opt = std::optional<T>;

Q_DECLARE_METATYPE(glm::vec3)
Q_DECLARE_METATYPE(glm::mat4)

//! \brief count the amount of elements in a basic array
template<typename T, int N>
constexpr int countof(T(&)[N])
{
	return N;
}

//! \brief casts @c x to a suitable unsigned integer
template<typename T>
constexpr auto unsigned_cast(T x)
	-> std::enable_if_t<std::is_integral_v<T>, std::make_unsigned_t<T>>
{
	return static_cast<std::make_unsigned_t<T>>(x);
}

//! \brief casts @c x to a suitable signed integer
template<typename T>
constexpr auto signed_cast(T x)
	-> std::enable_if_t<std::is_integral_v<T>, std::make_signed_t<T>>
{
	return static_cast<std::make_signed_t<T>>(x);
}

//! \brief casts floating point values to float
template<typename T>
constexpr auto float_cast(T x)
	-> std::enable_if_t<std::is_floating_point_v<T>, float>
{
	return static_cast<float>(x);
}

//! \brief casts floating point values to double
template<typename T>
constexpr auto double_cast(T x)
	-> std::enable_if_t<std::is_floating_point_v<T>, double>
{
	return static_cast<double>(x);
}

//! \brief casts floating point values to qreal
template<typename T>
constexpr auto qreal_cast(T x)
	-> std::enable_if_t<std::is_floating_point_v<T>, qreal>
{
	return static_cast<qreal>(x);
}

template<int N, typename T, glm::qualifier Q>
constexpr QPointF toQPointF(const glm::vec<N, T, Q>& vec)
{
	return {double_cast(vec.x), double_cast(vec.y)};
}

constexpr glm::vec2 toVec2(const QPointF& point)
{
	return {point.x(), point.y()};
}


template<typename T, typename R, typename K>
const R* findInMap(const std::map<T, R>& map, K&& key)
{
	auto pair = map.find(key);
	if (pair != map.end())
	{
		return &pair->second;
	}
	else
	{
		return nullptr;
	}
}

template<typename T, typename R, typename K>
R* findInMap(std::map<T, R>& map, K&& key)
{
	auto pair = map.find(key);
	if (pair != map.end())
	{
		return &pair->second;
	}
	else
	{
		return nullptr;
	}
}

template<typename T, typename R>
void removeFromMap(std::map<T, R>& map, T&& key)
{
	const auto it = map.find(key);
	if (it != map.end()) {
		map.erase(it);
	}
}

template<typename T = float>
constexpr std::enable_if_t<std::is_floating_point_v<T>, T> pi = static_cast<T>(M_PIl);

inline QSizeF sizeToSizeF(const QSize& size)
{
	return {static_cast<qreal>(size.width()), static_cast<qreal>(size.height())};
}

//! \brief Hints to the specified vector that a certain amount of new elements
//! are going to be added.
template<typename T>
void reserveMore(std::vector<T>& vector, std::size_t amount)
{
	vector.reserve(vector.size() + amount);
}

inline QString vectorToString(const glm::vec2& vec)
{
	return QStringLiteral("(%1, %2)")
		.arg(double_cast(vec.x))
		.arg(double_cast(vec.y));
}

inline QString vectorToString(const glm::vec3& vec)
{
	return QStringLiteral("(%1, %2, %3)")
		.arg(double_cast(vec.x))
		.arg(double_cast(vec.y))
		.arg(double_cast(vec.z));
}

inline QString vectorToString(const glm::vec4& vec)
{
	return QStringLiteral("%1, %2, %3, %4)")
		.arg(double_cast(vec.x))
		.arg(double_cast(vec.y))
		.arg(double_cast(vec.z))
		.arg(double_cast(vec.w));
}

template<typename T, typename IdentifierType>
struct TypeValue
{
	T value;
	auto operator<=>(TypeValue other) const = default;
};

template<typename T, typename R>
int qHash(TypeValue<T, R> value)
{
	return qHash(value.value);
}

/**
 * Iterates a @c glm::mat
 */
template<int X, int Y, typename T, glm::qualifier Q, typename Fn>
void iter_matrix(const glm::mat<X, Y, T, Q>& matrix, Fn&& fn)
{
	for (int i = 0; i < X; ++i)
	{
		for (int j = 0; j < Y; ++j)
		{
			fn(i, j, matrix[i][j]);
		}
	}
}

inline QDataStream& operator<<(QDataStream& stream, const glm::vec3& vec)
{
	return stream << vec.x << vec.y << vec.z;
}

inline QDataStream& operator>>(QDataStream& stream, glm::vec3& vec)
{
	return stream >> vec.x >> vec.y >> vec.z;
}

template<int X, int Y, typename T, glm::qualifier Q>
QDataStream& operator<<(QDataStream& stream, const glm::mat<X, Y, T, Q>& mat)
{
	iter_matrix(mat, [&stream](int, int, float x)
	{
		stream << x;
	});
	return stream;
}

template<int X, int Y, typename T, glm::qualifier Q>
QDataStream& operator>>(QDataStream& stream, glm::mat<X, Y, T, Q>& mat)
{
	iter_matrix(mat, [&stream](int, int, float x)
	{
		stream >> x;
	});
	return stream;
}

//! \brief Converts a pointer value to an \c std::optional value. If p has a
//! value, it will be copied into the result value.
template<typename T>
std::optional<T> pointerToOptional(const T* p)
{
	std::optional<T> result;
	if (p != nullptr) {
		result = *p;
	}
	return result;
}

// some magic code from https://en.cppreference.com/w/cpp/utility/variant/visit
// for use with std::visit
template<class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
template<class... Ts> overloaded(Ts...) -> overloaded<Ts...>;

// http://stackoverflow.com/a/18204188/3629665
template<typename T>
constexpr T rotl10(T x)
{
	return (x << 10) | ((x >> 22) & 0x000000ff);
}

template<typename T>
constexpr T rotl20(T x)
{
	return (x << 20) | ((x >> 12) & 0x000000ff);
}

inline QString quoted(QString string)
{
	if (string.contains("'"))
	{
		string.replace("\"", "\\\"");
		string = "\"" + string + "\"";
	}
	else
	{
		string = "'" + string + "'";
	}
	return string;
}

inline QString vertexToString(const glm::vec3& vertex)
{
	return QStringLiteral("%1 %2 %3").arg(vertex.x).arg(vertex.y).arg(vertex.z);
}

inline QString vertexToStringParens(const glm::vec3& vertex)
{
	return QStringLiteral("(%1 %2 %3)").arg(vertex.x).arg(vertex.y).arg(vertex.z);
}

inline QString transformToString(const glm::mat4& matrix)
{
	return QStringLiteral("%1 %2 %3 %4 %5 %6 %7 %8 %9 %10 %11 %12")
		.arg(matrix[3][0]).arg(matrix[3][1]).arg(matrix[3][2])
		.arg(matrix[0][0]).arg(matrix[1][0]).arg(matrix[2][0])
		.arg(matrix[0][1]).arg(matrix[1][1]).arg(matrix[2][1])
		.arg(matrix[0][2]).arg(matrix[1][2]).arg(matrix[2][2]);
}

template<typename T, glm::qualifier Q>
constexpr unsigned int qHash(const glm::vec<3, T, Q>& key)
{
	return qHash(key.x) ^ rotl10(qHash(key.y)) ^ rotl20(qHash(key.z));
}