#ifndef VECTOR2_H
#define VECTOR2_H

/*************************************************************************/
/*  vector2.h                                                            */
/*************************************************************************/
/*                         This file is part of:                         */
/*                          PANDEMONIUM ENGINE                           */
/*             https://github.com/Relintai/pandemonium_engine            */
/*************************************************************************/
/* Copyright (c) 2022-present Péter Magyar.                              */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
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/*************************************************************************/

#include "core/math/math_funcs.h"

#include "core/error/error_macros.h"

class String;
struct Vector2i;

struct _NO_DISCARD_CLASS_ Vector2 {
	static const int AXIS_COUNT = 2;

	enum Axis {
		AXIS_X,
		AXIS_Y,
	};

	union {
		struct {
			union {
				real_t x;
				real_t width;
			};
			union {
				real_t y;
				real_t height;
			};
		};

		real_t coord[2];
	};

	_FORCE_INLINE_ real_t &operator[](int p_idx) {
		DEV_ASSERT((unsigned int)p_idx < 2);
		return coord[p_idx];
	}
	_FORCE_INLINE_ const real_t &operator[](int p_idx) const {
		DEV_ASSERT((unsigned int)p_idx < 2);
		return coord[p_idx];
	}

	_FORCE_INLINE_ void set_all(real_t p_value) {
		x = y = p_value;
	}

	_FORCE_INLINE_ int min_axis() const {
		return x < y ? 0 : 1;
	}

	_FORCE_INLINE_ int max_axis() const {
		return x < y ? 1 : 0;
	}

	void normalize();
	Vector2 normalized() const;
	bool is_normalized() const;

	real_t length() const;
	real_t length_squared() const;
	Vector2 limit_length(const real_t p_len = 1.0) const;

	Vector2 min(const Vector2 &p_vector2) const {
		return Vector2(MIN(x, p_vector2.x), MIN(y, p_vector2.y));
	}

	Vector2 max(const Vector2 &p_vector2) const {
		return Vector2(MAX(x, p_vector2.x), MAX(y, p_vector2.y));
	}

	real_t distance_to(const Vector2 &p_vector2) const;
	real_t distance_squared_to(const Vector2 &p_vector2) const;
	real_t angle_to(const Vector2 &p_vector2) const;
	real_t angle_to_point(const Vector2 &p_vector2) const;
	_FORCE_INLINE_ Vector2 direction_to(const Vector2 &p_to) const;

	real_t dot(const Vector2 &p_other) const;
	real_t cross(const Vector2 &p_other) const;
	Vector2 posmod(const real_t p_mod) const;
	Vector2 posmodv(const Vector2 &p_modv) const;
	Vector2 project(const Vector2 &p_to) const;

	Vector2 plane_project(real_t p_d, const Vector2 &p_vec) const;

	_FORCE_INLINE_ static Vector2 linear_interpolate(const Vector2 &p_a, const Vector2 &p_b, real_t p_weight);
	_FORCE_INLINE_ Vector2 linear_interpolate(const Vector2 &p_to, real_t p_weight) const;
	_FORCE_INLINE_ Vector2 slerp(const Vector2 &p_to, real_t p_weight) const;
	_FORCE_INLINE_ Vector2 cubic_interpolate(const Vector2 &p_b, const Vector2 &p_pre_a, const Vector2 &p_post_b, real_t p_weight) const;
	_FORCE_INLINE_ Vector2 bezier_interpolate(const Vector2 &p_control_1, const Vector2 &p_control_2, const Vector2 &p_end, const real_t p_t) const;

	Vector2 move_toward(const Vector2 &p_to, const real_t p_delta) const;

	Vector2 slide(const Vector2 &p_normal) const;
	Vector2 bounce(const Vector2 &p_normal) const;
	Vector2 reflect(const Vector2 &p_normal) const;

	bool is_equal_approx(const Vector2 &p_v) const;

	Vector2 operator+(const Vector2 &p_v) const;
	void operator+=(const Vector2 &p_v);
	Vector2 operator-(const Vector2 &p_v) const;
	void operator-=(const Vector2 &p_v);
	Vector2 operator*(const Vector2 &p_v1) const;

	Vector2 operator*(const real_t &rvalue) const;
	void operator*=(const real_t &rvalue);
	void operator*=(const Vector2 &rvalue) { *this = *this * rvalue; }

	Vector2 operator/(const Vector2 &p_v1) const;

	Vector2 operator/(const real_t &rvalue) const;

	void operator/=(const real_t &rvalue);
	void operator/=(const Vector2 &rvalue) { *this = *this / rvalue; }

	Vector2 operator-() const;

	bool operator==(const Vector2 &p_vec2) const;
	bool operator!=(const Vector2 &p_vec2) const;

	bool operator<(const Vector2 &p_vec2) const { return x == p_vec2.x ? (y < p_vec2.y) : (x < p_vec2.x); }
	bool operator>(const Vector2 &p_vec2) const { return x == p_vec2.x ? (y > p_vec2.y) : (x > p_vec2.x); }
	bool operator<=(const Vector2 &p_vec2) const { return x == p_vec2.x ? (y <= p_vec2.y) : (x < p_vec2.x); }
	bool operator>=(const Vector2 &p_vec2) const { return x == p_vec2.x ? (y >= p_vec2.y) : (x > p_vec2.x); }

	real_t angle() const;

	void set_rotation(real_t p_radians) {
		x = Math::cos(p_radians);
		y = Math::sin(p_radians);
	}

	_FORCE_INLINE_ Vector2 abs() const {
		return Vector2(Math::abs(x), Math::abs(y));
	}

	Vector2 rotated(real_t p_by) const;
	_FORCE_INLINE_ Vector2 tangent() const {
		return Vector2(y, -x);
	}
	_FORCE_INLINE_ Vector2 orthogonal() const {
		return Vector2(y, -x);
	}

	Vector2 sign() const;
	Vector2 floor() const;
	Vector2 ceil() const;
	Vector2 round() const;
	Vector2 snapped(const Vector2 &p_by) const;
	real_t aspect() const { return width / height; }

	operator String() const;
	operator Vector2i() const;

	_FORCE_INLINE_ Vector2(real_t p_x, real_t p_y) {
		x = p_x;
		y = p_y;
	}
	_FORCE_INLINE_ Vector2() { x = y = 0; }
};

_FORCE_INLINE_ Vector2 Vector2::plane_project(real_t p_d, const Vector2 &p_vec) const {
	return p_vec - *this * (dot(p_vec) - p_d);
}

_FORCE_INLINE_ Vector2 operator*(real_t p_scalar, const Vector2 &p_vec) {
	return p_vec * p_scalar;
}

_FORCE_INLINE_ Vector2 Vector2::operator+(const Vector2 &p_v) const {
	return Vector2(x + p_v.x, y + p_v.y);
}
_FORCE_INLINE_ void Vector2::operator+=(const Vector2 &p_v) {
	x += p_v.x;
	y += p_v.y;
}
_FORCE_INLINE_ Vector2 Vector2::operator-(const Vector2 &p_v) const {
	return Vector2(x - p_v.x, y - p_v.y);
}
_FORCE_INLINE_ void Vector2::operator-=(const Vector2 &p_v) {
	x -= p_v.x;
	y -= p_v.y;
}

_FORCE_INLINE_ Vector2 Vector2::operator*(const Vector2 &p_v1) const {
	return Vector2(x * p_v1.x, y * p_v1.y);
};

_FORCE_INLINE_ Vector2 Vector2::operator*(const real_t &rvalue) const {
	return Vector2(x * rvalue, y * rvalue);
};
_FORCE_INLINE_ void Vector2::operator*=(const real_t &rvalue) {
	x *= rvalue;
	y *= rvalue;
};

_FORCE_INLINE_ Vector2 Vector2::operator/(const Vector2 &p_v1) const {
	return Vector2(x / p_v1.x, y / p_v1.y);
};

_FORCE_INLINE_ Vector2 Vector2::operator/(const real_t &rvalue) const {
	return Vector2(x / rvalue, y / rvalue);
};

_FORCE_INLINE_ void Vector2::operator/=(const real_t &rvalue) {
	x /= rvalue;
	y /= rvalue;
};

_FORCE_INLINE_ Vector2 Vector2::operator-() const {
	return Vector2(-x, -y);
}

_FORCE_INLINE_ bool Vector2::operator==(const Vector2 &p_vec2) const {
	return x == p_vec2.x && y == p_vec2.y;
}
_FORCE_INLINE_ bool Vector2::operator!=(const Vector2 &p_vec2) const {
	return x != p_vec2.x || y != p_vec2.y;
}

Vector2 Vector2::linear_interpolate(const Vector2 &p_to, real_t p_weight) const {
	Vector2 res = *this;

	res.x += (p_weight * (p_to.x - x));
	res.y += (p_weight * (p_to.y - y));

	return res;
}

Vector2 Vector2::slerp(const Vector2 &p_to, real_t p_weight) const {
#ifdef MATH_CHECKS
	ERR_FAIL_COND_V_MSG(!is_normalized(), Vector2(), "The start Vector2 must be normalized.");
#endif
	real_t theta = angle_to(p_to);
	return rotated(theta * p_weight);
}

Vector2 Vector2::bezier_interpolate(const Vector2 &p_control_1, const Vector2 &p_control_2, const Vector2 &p_end, const real_t p_t) const {
	Vector2 res = *this;

	/* Formula from Wikipedia article on Bezier curves. */
	real_t omt = (1.0 - p_t);
	real_t omt2 = omt * omt;
	real_t omt3 = omt2 * omt;
	real_t t2 = p_t * p_t;
	real_t t3 = t2 * p_t;

	return res * omt3 + p_control_1 * omt2 * p_t * 3.0 + p_control_2 * omt * t2 * 3.0 + p_end * t3;
}

Vector2 Vector2::cubic_interpolate(const Vector2 &p_b, const Vector2 &p_pre_a, const Vector2 &p_post_b, const real_t p_weight) const {
	Vector2 res = *this;
	res.x = Math::cubic_interpolate(res.x, p_b.x, p_pre_a.x, p_post_b.x, p_weight);
	res.y = Math::cubic_interpolate(res.y, p_b.y, p_pre_a.y, p_post_b.y, p_weight);
	return res;
}

Vector2 Vector2::direction_to(const Vector2 &p_to) const {
	Vector2 ret(p_to.x - x, p_to.y - y);
	ret.normalize();
	return ret;
}

Vector2 Vector2::linear_interpolate(const Vector2 &p_a, const Vector2 &p_b, real_t p_weight) {
	Vector2 res = p_a;

	res.x += (p_weight * (p_b.x - p_a.x));
	res.y += (p_weight * (p_b.y - p_a.y));

	return res;
}

typedef Vector2 Size2;
typedef Vector2 Point2;

#endif // VECTOR2_H