Files
yoga/csharp/Facebook.Yoga/YogaConstants.cs
David Aurelio b26e637c81 Back out Stack D13119110..D13236159
Summary: backout, causes failures

Reviewed By: adityasharat

Differential Revision: D13376210

fbshipit-source-id: 1fa8823f2dce601c47738f34ddb2674288197e79
2018-12-07 13:01:06 -08:00

42 lines
1.8 KiB
C#

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
namespace Facebook.Yoga
{
public static class YogaConstants
{
/**
* Large positive number signifies that the property(float) is undefined. Earlier we used to have
* YGundefined as NAN, but the downside of this is that we can't use -ffast-math compiler flag as
* it assumes all floating-point calculation involve and result into finite numbers. For more
* information regarding -ffast-math compiler flag in clang, have a look at
* https://clang.llvm.org/docs/UsersManual.html#cmdoption-ffast-math
*/
public const float Undefined = 10E20F;
public static bool IsUndefined(float value)
{
// Value of a float in the case of it being not defined is 10.1E20. Earlier it used to be NAN,
// the benefit of which
// was that if NAN is involved in any mathematical expression the result was NAN. But since we
// want to have `-ffast-math`
// flag being used by compiler which assumes that the floating point values are not NAN and Inf,
// we represent YGUndefined as 10.1E20.
// But now if YGUndefined is involved in any mathematical operations this value(10.1E20) would
// change.
// So the following check makes sure that if the value is outside a range (-10E8, 10E8) then it
// is undefined.
return value >= 10E8F || value <= -10E8;
}
public static bool IsUndefined(YogaValue value)
{
return value.Unit == YogaUnit.Undefined;
}
}
}