[OpenGL - SFML] Dessiner un cercle manuellement

#include <SFML/Graphics.hpp>
#include <GL/gl.h>
#include <GL/glu.h>

#include <cmath>

void Draw();

double Angle = 0.f;
double Rayon = 200;

int main()
{
	sf::RenderWindow App(sf::VideoMode(640,480), "SFML - Circle");

	sf::Event Event;

	glMatrixMode( GL_PROJECTION );
	glLoadIdentity( );
	gluOrtho2D( 0, 640, 0, 480);
	
	while(App.IsOpened())
	{
		Draw();

		while(App.GetEvent(Event))
		{
			if(Event.Type == sf::Event::Closed)
			{
				App.Close();
			}
			if((Event.Type == sf::Event::KeyPressed)&&(Event.Key.Code == sf::Key::P))
			{
				App.Capture().SaveToFile("Cercle.png");
			}
		}

		App.Display();
		Angle = 0;

		sf::Sleep(0.015f);
	}
	return 0;
}

void Draw()
{
	int X = 0;
	int Y = 0;

	glClear(GL_COLOR_BUFFER_BIT);

	glBegin(GL_POINTS);
		
	while(Angle <= 360.f)
	{
		X = Rayon * cos(Angle * 3.14/180);
		Y = Rayon * sin(Angle * 3.14/180);

		glColor3ub( X, 255, Y);
		glVertex2i(X + (640 / 2) ,Y + (480 / 2));

		Angle += 0.1f;
	}

	glEnd();
}

void Draw()
{
	int X = 0;
	int Y = 0;

	glClear(GL_COLOR_BUFFER_BIT);

	glBegin(GL_LINE_STRIP);
		
	while(Angle <= 360.f)
	{
		X = Rayon * cos(Angle * Pi/180);
		Y = Rayon * sin(Angle * Pi/180);

		glColor3ub( X, 255, Y);
		glVertex2i(X + (640 / 2) ,Y + (480 / 2));

		Angle ++;
	}

	glEnd();
}

void Draw()
{
	int X = 0;
	int Y = 0;

	glClear(GL_COLOR_BUFFER_BIT | GL_ALPHA_TEST);

	glBegin(GL_LINE_STRIP);
		
	while(Angle <= 360.f)
	{
		X = Rayon * cos(Angle * Pi/180);
		Y = Rayon * sin(Angle * Pi/180);

		//glColor3ub( X, 255, Y);
		glVertex2i(X + (640 / 2) ,Y + (480 / 2));

		glColor4ub(255,255,255, 50);
		glVertex2i(X + (640 / 2) + 1 ,Y + (480 / 2));

		glColor4ub(255,255,255, 25);
		glVertex2i(X + (640 / 2) + 1 ,Y + (480 / 2));

		Angle += 0.1f;
	}

	glEnd();
}

void Draw()
{
	double X = 0;
	double Y = 0;

	double Difference = 0;
	int Alpha = 0;

	glClear(GL_COLOR_BUFFER_BIT);

	glBegin(GL_POINTS);
		
	while(Angle <= 360.f)
	{

		X = Rayon * cos(Angle * Pi/180);
		Y = Rayon * sin(Angle * Pi/180);
		
		X += Hauteur / 2;
		Y += Largeur / 2;
		
		glColor3ub(255, 255, 255);
		glVertex2i(floor(X), floor(Y));

		Difference = ceil(X) - X;
		Alpha = static_cast<int>(Difference * 255);

		glColor4i(255, 255, 255, Alpha);
		glVertex2d(X, Y);

		Angle += 0.1f;
	}

	glEnd();
}