swiftobjective-ccgfloat

What is CGFloat.leastNonzeroMagnitude equivalent in Obj-C

What is the equivalent of CGFloat.leastNonzeroMagnitude equivalent in Objective-C? I googled but could not find any answer.

Solution

  • Note that the documentation of leastNonzeroMagnitude says:

    Compares less than or equal to all positive numbers, but greater than zero. If the target supports subnormal values, this is smaller than leastNormalMagnitude; otherwise they are equal.

    So the value of this also depends on "if the target supports subnormal values". Looking at the implementation, we can see:

    public static var leastNonzeroMagnitude: ${Self} {
#if arch(arm)
  // On 32b arm, the default FPCR has subnormals flushed to zero.
  return leastNormalMagnitude
#else
  return leastNormalMagnitude * ulpOfOne
#endif
}

    It turns out that ARM is the target that doesn't "support subnormal values". :)

    If you translate the two branches into Objective-C separately, it would be:

    CGFLOAT_MIN

    and

    CGFLOAT_MIN * CGFLOAT_EPSILON