Algoritmo De La Elipse

public void Elipse(Graphics g, int xc, int yc, int rx, int ry){

int x, y, p, px, py;

int rx2, ry2, tworx2, twory2;

ry2 = ry*ry;

rx2 = rx*rx;

twory2 = 2 * ry2;

tworx2 = 2 * rx2;

/* región 1 */

x = 0;

y = ry;

PlotPoint(x,y);

p = (int)Math.round(ry2 - rx2*ry + 0.25*rx2);

px = 0;

py = tworx2*y;

while (px < py) { /* se cicla hasta trazar la región 1 */

x = x + 1;

px = px + twory2;

if (p < 0)

p = p + ry2 + px;

else {

y = y - 1;

py = py - tworx2;

p = p + ry2 + px - py;

}

PlotPoint(x,y);

}

/* región 2 */

p = (int)Math.round(ry2*(x+0.5)*(x+0.5) + rx2*(y-1)*(y-1) - rx2*ry2);

px = 0;

py = tworx2*y;

while (y > 0) { /* se cicla hasta trazar la región 2 */

y = y - 1;

py = py - tworx2;

if (p > 0)

p = p + rx2 - py;

else {

x = x + 1;

px = px + twory2;

p = p + rx2 + py + px;

}

PlotPoint(x,y);

}

}

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