/* Copyright: (c) Kayne Ruse 2013-2015
 * 
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 
 * 3. This notice may not be removed or altered from any source
 * distribution.
*/
#ifndef BOUNDINGBOX_HPP_
#define BOUNDINGBOX_HPP_

#include "vector2.hpp"

#include <type_traits>
#include <algorithm>

class BoundingBox {
public:
	//This is explicitly a POD
	int x, y;
	int w, h;

	BoundingBox() = default;
	BoundingBox(int i, int j, int k, int l): x(i), y(j), w(k), h(l) {};
	~BoundingBox() = default;
	BoundingBox& operator=(BoundingBox const&) = default;

	int Size() {
		return (w-x) * (h-y);
	}

	bool CheckCollision(BoundingBox rhs) {
		return !(
			x >= rhs.x + rhs.w ||
			y >= rhs.y + rhs.h ||
			rhs.x >= x + w ||
			rhs.y >= y + h);
	}

	Vector2 CalcShift(BoundingBox rhs) {
		if (!CheckCollision(rhs)) {
			return {0, 0};
		}

		//DOCS: Given two BoundingBox objects, how does the other have to move so that they are no longer colliding?
		Vector2 horizontal = {0, 0};
		Vector2 vertical = {0, 0};

		horizontal.x = std::abs(x + w - rhs.x) < std::abs(rhs.x + rhs.w - x) ? x + w - rhs.x -1 : -(rhs.x + rhs.w - x -1);
		vertical.y = std::abs(y + h - rhs.x) < std::abs(rhs.y + rhs.h - y) ? y + h - rhs.y -1 : -(rhs.y + rhs.h - y -1);

		return std::abs(vertical.y) < std::abs(horizontal.x) ? vertical : horizontal;
	}
};

//This is explicitly a POD
static_assert(std::is_pod<BoundingBox>::value, "BoundingBox is not a POD");

//operators
inline BoundingBox operator+(BoundingBox b, Vector2 v) {
	return {b.x + (int)v.x, b.y + (int)v.y, b.w, b.h};
}
inline BoundingBox operator+(Vector2 v, BoundingBox b) {
	return b + v;
}

#endif