etc/octaspire_easing_amalgamated.c
double octaspire_easing_in_out_circ(double t, double const b, double const c, double const d)
{
    t /= (d * 0.5);

    if (t < 1) return -c/2 * (sqrt(1 - t*t) - 1) + b;
    t -= 2;
    return c/2 * (sqrt(1 - t*t) + 1) + b;
}
// circular easing in/out - acceleration until halfway, then deceleration
circular easing in/out - acceleration until halfway, then deceleration
circular easing in / out - acceleration until halfway then deceleration
double octaspire_easing_in_out_circ(double t, double const b, double const c, double const d)
{
    t /= (d * 0.5);
    if (t < 1) return -c/2 * (sqrt(1 - t*t) - 1) + b;
    t -= 2;
    return c/2 * (sqrt(1 - t*t) + 1) + b;
}
double octaspire_easing_in_out_circ ( double t , double const b , double const c , double const d ) { t /= ( d * 0.5 ) ; if ( t < 1 ) return - c / 2 * ( sqrt ( 1 - t * t ) - 1 ) + b ; t -= 2 ; return c / 2 * ( sqrt ( 1 - t * t ) + 1 ) + b ; }
circular easing in/out - acceleration until halfway, then deceleration
circular easing in / out - acceleration until halfway then deceleration