#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>
#include <SFML/System.hpp>
#include <list>
#include <math.h>
#include <iostream>

#define PI 3.14159265


using namespace std;

struct Point
{
	float x = 0;
	float y = 0;
};

void drawBezier(Point p1, Point p2, Point p3, sf::RenderWindow &window);

int main()
{

	// Fenster öffnen
	sf::RenderWindow window(sf::VideoMode(1920, 1080), "Bezier Curve", sf::Style::Fullscreen);

	// Hintergrundbild
	sf::Sprite s;
	sf::IntRect r;
	sf::Texture t;

	t.loadFromFile("Data/Graphics/Background3.png");
	r.top = 0.0f;
	r.left = 0.0f;
	r.width = 1920.0f;
	r.height = 1080.0f;

	s.setTexture(t);
	s.setTextureRect(r);
	window.draw(s);

	// Punkte
	Point p1;
	p1.x = 100.0f;
	p1.y = 1000.0f;
	Point p2;
	p2.x = 300.0f;
	p2.y = 100.0f;
	Point p3;
	p3.x = 500.0f;
	p3.y = 1000.0f;
	Point p4;
	p4.x = 700.0f;
	p4.y = 100.0f;
	Point p5;
	p5.x = 900.0f;
	p5.y = 1000.0f;

	drawBezier(p1, p2, p3, window);
	drawBezier(p3, p4, p5, window);

	window.display();

	bool beenden = false;
	while (!beenden)
	{

		// Events
		sf::Event e;
		if (window.pollEvent(e))
		{
			if (e.type = sf::Event::KeyPressed)
				if(e.key.code == sf::Keyboard::LAlt)
					beenden = true;
		}

	}

	return 0;
}

void drawBezier(Point p1, Point p2, Point p3, sf::RenderWindow &window)
{
	std::list<Point> p;

	for (float t = 0.0f; t < 1; t += 0.01f)
	{

		Point P;
		P.x = std::pow(1 - t, 2) * p1.x + (1 - t) * 2 * t * p2.x + t * t * p3.x;

		P.y = std::pow(1 - t, 2) * p1.y + (1 - t) * 2 * t * p2.y + t * t * p3.y;
		p.push_back(P);
	}

	// Iterator
	std::list<Point>::iterator it = p.begin();
	Point lastPoint = *it;
	it++;

	while(it != p.end())
	{
		// SFML Graphic
		sf::Sprite *S = new sf::Sprite;
		sf::IntRect *R = new sf::IntRect;
		sf::Texture *T = new sf::Texture;

		// Winkel zwischen Punkten
		float gegenkathete = it->y - lastPoint.y;
		float ankathete = it->x - lastPoint.x;
		float hypothenuse = std::pow(gegenkathete, 2) + std::pow(ankathete, 2);
		float winkel = atan(gegenkathete / ankathete) * 180 / PI;

		T->loadFromFile("Data/Graphics/dot.png");
		R->top = 0.0f;
		R->left = 0.0f;
		R->width = 2.0f;
		R->height = 2.0f;

		S->setTexture(*T);
		S->setTextureRect(*R);
		S->setRotation(winkel);
		S->setScale(std::pow(hypothenuse, 0.5f) / 2.0f, 1);
		//S->setOrigin(R->width / 2, R->height / 2);

		S->setPosition(it->x, it->y);
		lastPoint = *it;
		it++;

		window.draw(*S);
	}
}