void renderEllipse(SDL_Renderer* renderer, Coordinate center, int a, int b, SDL_Color color) {
SetRenderDrawColor(renderer, color);
int xc = center.x;
int yc = center.y;
int a2 = a * a;
int b2 = b * b;
int twoa2 = 2 * a2;
int twob2 = 2 * b2;
int p;
int x = 0;
int y = b;
int px = 0;
int py = twoa2 * y;
/* Plot the initial point in each quadrant. */
ellipsePlotPoints(renderer, xc, yc, x, y);
/* Region 1 */
p = std::round (b2 - (a2 * b) + (0.25 * a2));
while (px < py) {
x++;
px += twob2;
if (p < 0)
p += b2 + px;
else {
y--;
py -= twoa2;
p += b2 + px - py;
}
ellipsePlotPoints(renderer, xc, yc, x, y);
}
/* Region 2 */
p = std::round (b2 * (x+0.5) * (x+0.5) + a2 * (y-1) * (y-1) - a2 * b2);
while (y > 0) {
y--;
py -= twoa2;
if (p > 0)
p += a2 - py;
else {
x++;
px += twob2;
p += a2 - py + px;
}
ellipsePlotPoints(renderer, xc, yc, x, y);
}
}
void Ellipse::ellipseMid(){
int Rx2 = Rx * Rx;
int Ry2 = Ry * Ry;
int twoRx2=2*Rx2;
int twoRy2=2*Ry2;
int p;
int x=0;
int y=Ry;
int px=0;
int py=twoRx2*y;
ellipsePlotPoints(center.X,center.Y,x,y);
p=round(Ry2 - (Rx2 * Ry) + (0.25 * Rx2));
while(px < py){
x++;
px += twoRy2;
if(p < 0)
p += Ry2 + px;
else{
y--;
py -= twoRx2;
p += Ry2 + px -py;
}
ellipsePlotPoints(center.X,center.Y,x,y);
}
p = round(Ry2 * (x + 0.5) * (x + 0.5) + Rx2 * (y - 1) * (y - 1) - Rx2 * Ry2);
while(y > 0){
y--;
py -= twoRx2;
if(p > 0)
p += Rx2 - py;
else{
x++;
px += twoRy2;
p += Rx2 - py + px;
}
ellipsePlotPoints(center.X,center.Y,x,y);
}
Ellquesize = Ellque.size();
}
