compare CGFloat in iOS (refer https://github.com/material-components/material-components-ios/blob/develop/components/private/Math/src/MDCMath.h and https://stackoverflow.com/a/10335601/9315497)

FloatEqual.m

static CGFloat MDCFabs(CGFloat value) {
#if CGFLOAT_IS_DOUBLE
  return fabs(value);
#else
  return fabsf(value);
#endif
}

static BOOL MDCCGFloatEqual(CGFloat a, CGFloat b) {
  const CGFloat constantK = 3;
#if CGFLOAT_IS_DOUBLE
  const CGFloat epsilon = DBL_EPSILON;
  const CGFloat min = DBL_MIN;
#else
  const CGFloat epsilon = FLT_EPSILON;
  const CGFloat min = FLT_MIN;
#endif
  return (MDCFabs(a - b) < constantK * epsilon * MDCFabs(a + b) || MDCFabs(a - b) < min);
}