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ns-winddi-surfobj.md

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UID title description helpviewer_keywords old-location tech.root ms.assetid ms.date ms.keywords req.header req.include-header req.target-type req.target-min-winverclnt req.target-min-winversvr req.kmdf-ver req.umdf-ver req.ddi-compliance req.unicode-ansi req.idl req.max-support req.namespace req.assembly req.type-library req.lib req.dll req.irql targetos req.typenames req.redist ms.custom f1_keywords dev_langs topic_type api_type api_location api_name
NS:winddi._SURFOBJ
SURFOBJ (winddi.h)
The SURFOBJ structure is the user object for a surface. A device driver usually calls methods on a surface object only when the surface object represents a GDI bitmap or a device-managed surface.
SURFOBJ
SURFOBJ structure [Display Devices]
display.surfobj
grstrcts_ef22095d-660f-4276-9a10-1ce7451327fc.xml
winddi/SURFOBJ
display\surfobj.htm
display
cee7cb50-1e8a-422b-aebe-7030ae96fb34
12/05/2018
SURFOBJ, SURFOBJ structure [Display Devices], display.surfobj, grstrcts_ef22095d-660f-4276-9a10-1ce7451327fc.xml, winddi/SURFOBJ
winddi.h
Winddi.h
Windows
Windows
SURFOBJ
19H1
_SURFOBJ
winddi/_SURFOBJ
SURFOBJ
winddi/SURFOBJ
c++
APIRef
kbSyntax
HeaderDef
winddi.h
SURFOBJ

SURFOBJ structure

-description

The SURFOBJ structure is the user object for a surface. A device driver usually calls methods on a surface object only when the surface object represents a GDI bitmap or a device-managed surface.

-struct-fields

-field dhsurf

Handle to a surface, provided that the surface is device-managed. Otherwise, this member is zero.

-field hsurf

Handle to the surface.

-field dhpdev

Identifies the device's PDEV that is associated with the specified surface.

-field hdev

GDI's logical handle to the PDEV associated with this device.

-field sizlBitmap

Specifies a SIZEL structure that contains the width and height, in pixels, of the surface. The SIZEL structure is identical to the SIZE structure.

-field cjBits

Specifies the size of the buffer pointed to by pvBits.

-field pvBits

If the surface is a standard format bitmap, this is a pointer to the surface's pixels. For BMF_JPEG or BMF_PNG images, this is a pointer to a buffer containing the image data in a JPEG or PNG format. Otherwise, this member is NULL.

-field pvScan0

Pointer to the first scan line of the bitmap. If iBitmapFormat is BMF_JPEG or BMF_PNG, this member is NULL.

-field lDelta

Specifies the count of bytes required to move down one scan line in the bitmap. If iBitmapFormat is BMF_JPEG or BMF_PNG, this member is NULL.

-field iUniq

Specifies the current state of the specified surface. Every time the surface changes, this value is incremented. This enables drivers to cache source surfaces.

For a surface that should not be cached, iUniq is set to zero. This value is used in conjunction with the BMF_DONTCACHE flag of fjBitmap.

-field iBitmapFormat

Specifies the standard format most closely matching this surface. If the iType member specifies a bitmap (STYPE_BITMAP), this member specifies its format. NT-based operating systems support a set of predefined formats, although applications can also send device-specific formats by using SetDIBitsToDevice. Supported predefined formats include the following:

Value Meaning
BMF_1BPP 1 bit per pixel.
BMF_4BPP 4 bits per pixel.
BMF_8BPP 8 bits per pixel.
BMF_16BPP 16 bits per pixel.
BMF_24BPP 24 bits per pixel.
BMF_32BPP 32 bits per pixel.
BMF_4RLE 4 bits per pixel, run length encoded.
BMF_8RLE 8 bits per pixel, run length encoded.
BMF_JPEG JPEG compressed image.
BMF_PNG PNG compressed image.

-field iType

Surface type, which is one of the following:

Type Definition
STYPE_BITMAP The surface is a bitmap.
STYPE_DEVBITMAP The surface is a device format bitmap.
STYPE_DEVICE The surface is managed by the device.

-field fjBitmap

If the surface is of type STYPE_BITMAP and is a standard uncompressed format bitmap, the following flags can be set. Otherwise, this member should be ignored.

Value Meaning
BMF_DONTCACHE The bitmap should not be cached by the driver because it is a transient bitmap, created by GDI, that the driver will never see again. If this flag is set, the iUniq member of this structure will be set to 0.
BMF_KMSECTION Is used by GDI only and should be ignored by the driver.
BMF_NOTSYSMEM The bitmap is not in system memory. EngModifySurface sets this flag when it moves a bitmap into video memory.
BMF_NOZEROINIT The bitmap was not zero-initialized.
BMF_TOPDOWN The first scan line represents the top of the bitmap.
BMF_WINDOW_BLT GDI sets this flag to notify the driver of a window move from one screen location to another.

-remarks

When information about a particular surface is required by a driver, the driver must access the SURFOBJ. This structure allows quick access to the properties of the surface.

When a SURFOBJ structure represents a GDI bitmap, the driver must be able to determine the format of the bitmap and locate the bitmap bits.

When a SURFOBJ structure represents a device surface, the driver must be able to locate the device handle for the surface.

For more information about supporting JPEG and PNG compressed images, see DEVINFO.