DXRUNINFO Structure

Describes run information associated with a DXSurface object. A run of samples is a number of adjacent samples in a row of a DXSurface with similar alpha characteristics. An entire row can be made of many runs, or only one, depending on the image stored in the DXSurface.

Arrays of DXRUNINFO structures are returned from the IDXARGBReadPtr::MoveAndGetRunInfo method to describe a row, and can be used to optimize alpha blending operations on DXSurfaces.

Syntax

typedef struct DXRUNINFO
{
    ULONG  Type  : 2;         
    ULONG  Count : 30;     
} DXRUNINFO;

Members

Type
Type of samples in the run. This can be one of the following types.
DXRUNTYPE_CLEAR

The corresponding samples are clear (alpha equals zero). They either have the alpha set to zero, or they match the color key.
DXRUNTYPE_TRANS

The corresponding samples are translucent. Alpha has a value between 0 and 255.
DXRUNTYPE_OPAQUE

The corresponding samples are opaque (alpha equals 255).
DXRUNTYPE_UNKNOWN

The pixel types have not been recorded by the surface; you should examine each sample when processing.

Count
Number of samples in the run.