SdlSandbox/sdl1/launchCircle/LaunchCircle.cpp

#include "LaunchCircle.h"
#include <cmath>

LaunchCircle::LaunchCircle(int const rayon, Uint32 const couleur, int const stock)
:m_rayon(rayon),m_epaisseur(40),m_stock(stock)
{
	m_pixel = SDL_CreateRGBSurface(SDL_HWSURFACE, 1, 1, 16,0,0,0,0);
	SDL_FillRect(m_pixel,NULL,couleur);
}

LaunchCircle::LaunchCircle(int const rayon, Uint32 const couleur, int const stock, int const epaisseur)
:m_rayon(rayon),m_epaisseur(epaisseur),m_stock(stock)
{
	m_pixel = SDL_CreateRGBSurface(SDL_HWSURFACE, 1, 1, 16,0,0,0,0);
	SDL_FillRect(m_pixel,NULL,couleur);
}

LaunchCircle::~LaunchCircle()
{
    SDL_FreeSurface(m_pixel);
}

void LaunchCircle::afficher(int const x, int const y, int const valeur, SDL_Surface *screen)
{
	// [1] Création du % puis transformation en radians
	double radian((double)valeur/m_stock*2*M_PI);//Entre 0 et 2PI
	radian -= M_PI_2;//Entre -PI/2 et 3PI/2

	// [2] Création de l'équation de droite
	double m(0);
	double p(0);

    m = (sin(radian))/(cos(radian));//En gros c'est ça
    p = -(m*x)+y;//ça c'est fait

	// [3] Trace
	SDL_Rect position;
	for (int i(x-m_rayon); i<=x+m_rayon; i++)
	{
		for (int j(y-m_rayon); j<=y+m_rayon; j++)
		{

			if ((i-x)*(i-x)+(j-y)*(j-y)<m_rayon*m_rayon &&
                (i-x)*(i-x)+(j-y)*(j-y)>m_rayon*m_rayon-m_epaisseur*m_epaisseur)
			{
				position.x=i;
				position.y=j;
				if (radian <=-M_PI_2)
				{}
				else if (radian >= 3*M_PI_2)//Cercle entier
				{
                    SDL_BlitSurface(m_pixel, 0, screen, &position);
				}
				else if (radian == M_PI_2)//Demi cercle
				{
                    if (i<=x)
                        SDL_BlitSurface(m_pixel, 0, screen, &position);
				}
				else if (radian < M_PI_2)//Moins d'une moitié
				{
					if (i<=x && j>m*i+p)
					{
						SDL_BlitSurface(m_pixel, 0, screen, &position);
					}
				}
				else if (radian > M_PI_2)//Plus d'une moitié
				{
					if (i<=x)
					{
						SDL_BlitSurface(m_pixel, 0, screen, &position);
					}
					else if (j<m*i+p)
					{
						SDL_BlitSurface(m_pixel, 0, screen, &position);
                    }
                }
            }
        }
    }
}