# DXBNDS structure

Describes either a continuous or a discrete boundary for a transform object.

## Syntax

```
typedef struct DXBNDS {
DXBNDTYPE eType;
union {
DXDBND D[4];
DXDBND64 LD[4];
DXCBND C[4];
DXCBND64 LC[4];
} u;
} DXBNDS;
```

## Members

**eType**

Member of the**DXBNDTYPE**enumeration, describing which member of the union to use.**u**

Union of the structures that can be used to describe a boundary. This can contain one of the following structures.**D**

Array of**DXDBND**discrete bounds, containing 32-bit**long**minimum and maximum values.**LD**

Array of**DXDBND64**discrete bounds, containing 64-bit**LONGLONG**minimum and maximum values.**C**

Array of**DXCBND**continuous bounds, containing 32-bit**float**minimum and maximum values.**LC**

Array of**DXCBND64**continuous bounds, containing 64-bit**double**minimum and maximum values.

## Remarks

The value of **eType** member determines which member of the union is used. The following table shows the value of the **eType** and the corresponding member of the union.

Value of eType |
Union member |
---|---|

DXBT_DISCRETE |
D |

DXBT_DISCRETE64 |
LD |

DXBT_CONTINUOUS |
C |

DXBT_CONTINUOUS64 |
LC |

You should never have to use this union directly. Instead, it is used by the CDXBnds template class (found in DXBounds.h) to create and manipulate image boundary objects. The most commonly used boundary object is the discrete CDXDBnds object.

The four members of this continuous or discrete array consist of an x-dimension, y-dimension, z-dimension, and t-dimension (time). Specify a minimum value of zero and a maximum value of one for any dimensions you use. For example, you can set the z-dimension and t-dimension this way for a 2-D image. If you use the CDXBnds template class, proper initialization is done for you.

The time dimension is intended for special data types, such as video or Graphics Interchange Format (GIF) animations.

## Requirements

Minimum supported client |
Windows XP |

Minimum supported server |
Windows 2000 Server |

Header |
Dxtrans.h |

IDL |
Dxtrans.idl |

## See also

**Reference**