DXCompositeOver function

Composites an alpha premultiplied source sample over a destination sample.

Syntax

void DXCompositeOver(
  _Inout_       DXPMSAMPLE &Dst,
  _In_    const DXPMSAMPLE &Src
);

Parameters

  • Dst [in, out, ref]
    A DXPMSAMPLE object that specifies the sample that lies under the source sample. When the function returns, this parameter holds the return value.

  • Src [in, ref]
    A DXPMSAMPLE object that specifies the sample to be composited over the destination.

Return value

This function does not return a value.

Remarks

A composite over operation uses the alpha value of the source sample to combine the colors. To obtain the result, the source is scaled by alpha, the destination is scaled by the inverse of alpha, and the two values are added.

Requirements

Minimum supported client

Windows XP

Minimum supported server

Windows 2000 Server

Header

Dxhelper.h