XMVector3Normalize function

Returns the normalized version of a 3D vector.

Syntax

XMVECTOR XM_CALLCONV XMVector3Normalize(
  FXMVECTOR V
);

Parameters

V

3D vector.

Return Value

Returns the normalized version of V.

Remarks

For a vector of length 0, this function returns a zero vector. For a vector with infinite length, it returns a vector of QNaN.

Note that for most graphics applications, ensuring the vectors have well-defined lengths that don't cause problems for normalization is common practice. However, if you need a robust normalization that works for all floating-point inputs, you can use the following code instead:

inline XMVECTOR XMVector3NormalizeRobust( FXMVECTOR V )
{
    // Compute the maximum absolute value component.
    XMVECTOR vAbs = XMVectorAbs(V);
    XMVECTOR max0 = XMVectorSplatX(vAbs);
    XMVECTOR max1 = XMVectorSplatY(vAbs);
    XMVECTOR max2 = XMVectorSplatZ(vAbs);
    max0 = XMVectorMax(max0, max1);
    max0 = XMVectorMax(max0, max2);
// Divide by the maximum absolute component.
XMVECTOR normalized = XMVectorDivide(V, max0);

// Set to zero when the original length is zero.
XMVECTOR mask = XMVectorNotEqual(g_XMZero, max0);
normalized = XMVectorAndInt(normalized, mask);

XMVECTOR t0 = XMVector3LengthSq(normalized);
XMVECTOR length = XMVectorSqrt(t0);

// Divide by the length to normalize.
normalized = XMVectorDivide(normalized, length);

// Set to zero when the original length is zero or infinity.  In the
// latter case, this is considered to be an unexpected condition.
normalized = XMVectorAndInt(normalized, mask);
return normalized;

}

Platform Requirements

Microsoft Visual Studio 2010 or Microsoft Visual Studio 2012 with the Windows SDK for Windows 8. Supported for Win32 desktop apps, Windows Store apps, and Windows Phone 8 apps.

Requirements

   
Target Platform Windows
Header directxmath.h (include DirectXMath.h)

See Also

DirectXMath Library 3D Vector Geometric Functions

XMVector3NormalizeEst