XMDECN4 union

A 4D vector for storing signed, normalized values as 10 bit signed x-,y-, and z- components and a 2 bit signed w-component.

For a list of additional functionality such as constructors and operators that are available using XMDECN4 when you are programming in C++, see XMDECN4 Extensions.

Note   See DirectXMath Library Type Equivalences for information about equivalent D3DDECLTYPE, D3DFORMAT,and DXGI_FORMAT objects.


union XMDECN4 {
  union {
    struct {
      int32_t x;
      int32_t y;
      int32_t z;
      int32_t w;
    uint32_t v;



Signed integer value in the range [-511, 511] describing the x-coordinate of the vector.


Signed integer value in the range [-511, 511] describing the y-coordinate of the vector.


Signed integer value in the range [-511, 511] describing the z-coordinate of the vector.


Signed integer value in the range [-1, 1] describing the w-coordinate of the vector.


Unsigned 32-bit integer representing the 4D vector.


Those XMDECN4 constructors using floating point arguments require normalized input, which must be in the range of [-1.0.-1.0]. During instantiation, the inputs specifying the x-, y-, and z-components are then multiplied by 511.0f, the results are rounded and then assigned to the appropriate members of XMDECN4.

XMDECN4 can be used to load instances of XMVECTOR from normalized values, by using XMLoadDecN4, which divides the x-, y-, and z-components by 511.0f, rounds the result, and then assigns the components to an XMVECTOR instance.

XMVECTOR instances containing normalized values can be stored into XMDECN4 using XMStoreDecN4, which multiplies the x-, y-,and z-components by 511.0f , rounding the result, before assigning the values to the appropriate XMDECN4 members.

Namespace: Use DirectX::PackedVector

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.




See also

DirectXMath Library Structures
XMDECN4 Extensions