etc/octaspire_easing_amalgamated.c
double octaspire_easing_out_back(double t, double const b, double const c, double const d, double const s)
{
    t = (t / d) -1;
    return c*(t*t*((s+1)*t + s) + 1) + b;
}
// back easing out - moving towards target, overshooting it slightly, then reversing and coming back to target
back easing out - moving towards target, overshooting it slightly, then reversing and coming back to target
back easing out - moving towards target overshooting it slightly then reversing and coming back to target
double octaspire_easing_out_back(double t, double const b, double const c, double const d, double const s)
{
    t = (t / d) -1;
    return c*(t*t*((s+1)*t + s) + 1) + b;
}
double octaspire_easing_out_back ( double t , double const b , double const c , double const d , double const s ) { t = ( t / d ) - 1 ; return c * ( t * t * ( ( s + 1 ) * t + s ) + 1 ) + b ; }
back easing out - moving towards target, overshooting it slightly, then reversing and coming back to target
back easing out - moving towards target overshooting it slightly then reversing and coming back to target