static pixel32_t INLINE
calculate(number_t x, number_t y, int periodicity) CONSTF;
static pixel32_t INLINE calculate(number_t x, number_t y, int periodicity)
{
    pixel32_t i;

    rotateback(cfractalc, x, y);
    if (cfractalc.plane) {
	recalculate(cfractalc.plane, &x, &y);
    }
    STAT(ncalculated2++);
#ifndef SLOWFUNCPTR
    if (cfractalc.mandelbrot) {
	if (cformula.flags & STARTZERO)
	    i = cfractalc.calculate[periodicity] (cfractalc.bre,
						  cfractalc.bim, x, y);
	else
	    i = cfractalc.calculate[periodicity] (x + cfractalc.bre,
						  y + cfractalc.bim, x, y);
    } else
	i = cfractalc.calculate[periodicity] (x, y, cfractalc.pre,
					      cfractalc.pim);
#else
    if (cfractalc.mandelbrot) {
	if (cformula.flags & STARTZERO)
	    i = calculateswitch(cfractalc.bre, cfractalc.bim, x, y,
				periodicity);
	else
	    i = calculateswitch(x + cfractalc.bre, y + cfractalc.bim, x, y,
				periodicity);
    } else
	i = calculateswitch(x, y, cfractalc.pre, cfractalc.pim,
			    periodicity);
#endif
    return (i);
}