Microsoft DirectX 8.1 (C++)

VMRALPHABITMAP Structure

The VMRALPHABITMAP structure is used in the Video Mixing Renderer’s IVMRMixerBitmap methods when the application is providing a static alpha-blended bitmap to be displayed on the composited video frame.

Requirements

Requires Microsoft® Windows® XP.

Syntax

typedef struct _VMRALPHABITMAP {
    DWORD dwFlags;
    HDC hdc;
    LPDIRECTDRAWSURFACE7 pDDS;
    RECT rSrc;
    NORMALIZEDRECT rDest;
    FLOAT fAlpha;
    COLORREF clrSrcKey;
    }  VMRALPHABITMAP;
 
typedef struct _VMRALPHABITMAP *PVMRALPHABITMAP;

Members

dwFlags

Flags that instruct the mixer where to find the bitmap.The following values are defined.

Value	Description
VMRBITMAP_DISABLE	Disable the bitmap for now.
VMRBITMAP_HDC	Obtain the bitmap from the HDC.
VMRBITMAP_ENTIREDDS	Take the entire DirectDraw surface. When this flag is specified, rSrc is ignored.
VMRBITMAP_SRCCOLORKEY	The clrSrcKey value is valid and should be used when blending.

hdc

Specifies the handle to the device context for the bitmap. Specify NULL if the bitmap is located in a DirectDraw surface.

pDDS

Pointer to a DirectDraw surface that contains the bitmap. Specify NULL if the bitmap is to be obtained from a GDI device context.

rSrc

Specifies the source rectangle in either the GDI device context or the DirectDraw surface.

rDest

Specifies the destination rectangle in composition space.

fAlpha

Specifies the alpha blending value; must be a value from 0.0 to 1.0 (inclusive).

clrSrcKey

Specifies the source color key.