[−][src]Function directx_math::XMVectorATan2Est
pub fn XMVectorATan2Est(Y: FXMVECTOR, X: FXMVECTOR) -> XMVECTOR
Estimates the arctangent of Y/X.
Parameters
Y
First vector.
X
Second vector.
Return value
Returns a vector. Each component is an estimate of the arctangent of the corresponding Y
component divided
by the corresponding X
component. Each component is in the range (-PI/2
, PI/2
).
XMVectorATan2Est returns the following values for the specified special input values.
Input Value | Return Value |
---|---|
Y == 0 and X < 0 | Pi with the same sign as Y |
Y == 0 and X > 0 | 0 with the same sign as Y |
Y != 0 and X == 0 | Pi / 2 with the same sign as Y |
X == -Infinity and Y is finite | Pi with the same sign as Y |
X == +Infinity and Y is finite | 0 with the same sign as Y |
Y == Infinity and X is finite | Pi / 2 with the same sign as Y |
Y == Infinity and X == -Infinity | 3Pi / 4 with the same sign as Y |
Y == Infinity and X == +Infinity | Pi / 4 with the same sign as Y |
Remarks
Est
functions offer increased performance at the expense of reduced accuracy. Est
functions are appropriate
for non-critical calculations where accuracy can be sacrificed for speed. The exact amount of lost accuracy
and speed increase are platform dependent.
This function uses a 9-degree minimax approximation.
Reference
https://docs.microsoft.com/en-us/windows/win32/api/directxmath/nf-directxmath-XMVectorATan2Est