Fixes#79036. sign(NAN) now returns 0.
This should not impact performance much in any way.
Adds a test for the NAN case. Updates the documentation to clarify the new behavior.
GDScript has the following built-in trigonometry functions:
- `sin()`
- `cos()`
- `tan()`
- `asin()`
- `acos()`
- `atan()`
- `atan()`
- `sinh()`
- `cosh()`
- `tanh()`
However, it lacks the hyperbolic arc (also known as inverse
hyperbolic) functions:
- `asinh()`
- `acosh()`
- `atanh()`
Implement them by just exposing the C++ Math library, but clamping
its values to the closest real defined value.
For the cosine, clamp input values lower than 1 to 1.
In the case of the tangent, where the limit value is infinite,
clamp it to -inf or +inf.
References #78377Fixesgodotengine/godot-proposals#7110
A common bug with using acos and asin is that input outside -1 to 1 range will result in Nan output. This can occur due to floating point error in the input.
The standard solution is to provide safe_acos function with clamped input. For Godot it may make more sense to make the standard functions safe.
As many open source projects have started doing it, we're removing the
current year from the copyright notice, so that we don't need to bump
it every year.
It seems like only the first year of publication is technically
relevant for copyright notices, and even that seems to be something
that many companies stopped listing altogether (in a version controlled
codebase, the commits are a much better source of date of publication
than a hardcoded copyright statement).
We also now list Godot Engine contributors first as we're collectively
the current maintainers of the project, and we clarify that the
"exclusive" copyright of the co-founders covers the timespan before
opensourcing (their further contributions are included as part of Godot
Engine contributors).
Also fixed "cf." Frenchism - it's meant as "refer to / see".
