Algorithme de point médian

void ellipseMedian(MyGrillePixels & g, int xC, int yC, int rayonX, int rayonY){
    // Premier quadrant
    int x=0, y=rayonY, d, deltaE, deltaSE;
    int b2=rayonY*rayonY, a2=rayonX*rayonX;

    d = 4*b2 + a2*(1-4*rayonY);

    g.allumerPixel(0+xC,rayonY+yC,126,20,251); // Allumage du promier et de ses 3 symétriques
    g.allumerPixel(0+xC,-rayonY+yC,126,20,251);
    g.allumerPixel(rayonX+xC,0+yC,126,20,251);
    g.allumerPixel(-rayonX+xC,0+yC,126,20,251);

    while(2*b2*(x+1) < a2*(2*y-1)){ // 1ère région
        if(d<0){ // Mouvement vers l'est
            d+=b2*(8*x+12);
            x++;
        }else{ // Mouvement vers Sud Est
            d+= b2*(8*x+12)+8*a2*(1-y);
            x++; y--;
        }

        g.allumerPixel(x+xC,y+yC,126,20,251);
        g.allumerPixel(-x+xC,y+yC,126,20,251);
        g.allumerPixel(-x+xC,-y+yC,126,20,251);
        g.allumerPixel(x+xC,-y+yC,126,20,251);
    }

    // 2ème région
    d = b2*(2*x+1)*(2*x+1) + 4*a2*(y-1)*(y-1)-4*a2*b2;

    while(y>0){
        if(d<0){ // Mvt SE
            d+= a2*(12-8*y)+b2*(8*x+8);
            x++;
            y--;
        }else{ // Mvt S
            d+= a2*(12-8*y);
            y--;
        }
        g.allumerPixel(x+xC,y+yC,126,20,251);
        g.allumerPixel(-x+xC,y+yC,126,20,251);
        g.allumerPixel(-x+xC,-y+yC,126,20,251);
        g.allumerPixel(x+xC,-y+yC,126,20,251);
    }

    while(x<rayonX){
        g.allumerPixel(x+xC,y+yC,126,20,251);
        g.allumerPixel(-x+xC,y+yC,126,20,251);
        g.allumerPixel(-x+xC,-y+yC,126,20,251);
        g.allumerPixel(x+xC,-y+yC,126,20,251);
        x++;
    }
}