EngStretchBltROP function (winddi.h)

Article
10/13/2021

The EngStretchBltROP function performs a stretching bit-block transfer using a ROP.

Syntax

ENGAPI BOOL EngStretchBltROP(
       SURFOBJ         *psoDest,
       SURFOBJ         *psoSrc,
       SURFOBJ         *psoMask,
       CLIPOBJ         *pco,
       XLATEOBJ        *pxlo,
       COLORADJUSTMENT *pca,
       POINTL          *pptlHTOrg,
  [in] RECTL           *prclDest,
  [in] RECTL           *prclSrc,
       POINTL          *pptlMask,
  [in] ULONG           iMode,
       BRUSHOBJ        *pbo,
  [in] DWORD           rop4
);

Parameters

psoDest

Pointer to a SURFOBJ structure that describes the surface on which to draw.

psoSrc

Pointer to a SURFOBJ structure that describes the source surface for the bit-block transfer.

psoMask

Pointer to a SURFOBJ structure that defines a mask for the source surface. The mask is defined by a logic map, which is a bitmap with 1 bit per pixel. Typically, a mask limits the area that is to be modified in the destination surface. This mask should always be the same size as the source surface.

pco

Pointer to a CLIPOBJ structure that limits the area to be modified in the destination. The CLIPOBJ_Xxx service routines are provided to enumerate the clip region as a set of rectangles.

Whenever possible, GDI simplifies the clipping involved. However, unlike EngBitBlt, EngStretchBltROP can be called with a single clipping rectangle. This prevents rounding errors in clipping the output.

pxlo

Pointer to a XLATEOBJ structure that specifies how color indices are to be translated between the source and target surfaces.

This XLATEOBJ structure can also be queried to find the RGB color for any source index. A high quality stretching bit-block transfer will need to interpolate colors in some cases.

pca

Pointer to a COLORADJUSTMENT structure that defines the color adjustment values to be applied to the source bitmap before stretching the bits. For more information see the Windows SDK documentation.

pptlHTOrg

Pointer to a POINTL structure that defines the origin of the halftone brush on the destination surface. When using halftone brushes, GDI aligns the upper left pixel of the brush's pattern at this point and repeats the brush according to its dimensions. GDI ignores this parameter if the rop4 parameter does not require a pattern.

[in] prclDest

Pointer to a RECTL structure that defines the rectangular area to be modified. This rectangle is specified in the coordinate system of the destination surface and is defined by two points: upper left and lower right. The two points that define the rectangle are not always well ordered, meaning the coordinates of the second point are not necessarily larger than those of the first point. If the destination rectangle is not well ordered, GDI makes it so.

The rectangle is lower-right exclusive; that is, its lower and right edges are not a part of the copy.

EngStretchBltROP must never be called with an empty destination rectangle.

[in] prclSrc

Pointer to a RECTL structure that defines the area to be copied. This rectangle is specified in the coordinate system of the source surface and is defined by two points: upper left and lower right. The two points that define the rectangle are always well ordered.

The rectangle is lower-right exclusive; that is, its lower and right edges are not a part of the copy.

This rectangle maps to the rectangle to which prclDest points.

EngStretchBltROP must never be called with an empty source rectangle.

pptlMask

Pointer to a POINTL structure that defines the pixel in the mask to which prclMask points. This pixel corresponds to the upper-left pixel in the source rectangle to which prclSrc points. This parameter is ignored if no mask is specified; that is, GDI ignores pptlMask when prclMask is NULL.

[in] iMode

Specifies how source pixels are combined to get output pixels. The HALFTONE mode is slower than the other modes, but produces higher quality images. This parameter can be one of the following values:

Value	Meaning
BLACKONWHITE	On a shrinking bit-block transfer, GDI combines pixels with a Boolean AND operation. On a stretching bit-block transfer, pixels are replicated.
COLORONCOLOR	On a shrinking bit-block transfer, GDI ignores enough pixels so that pixels need not be combined. On a stretching bit-block transfer, pixels are replicated.
HALFTONE	GDI uses groups of pixels in the output surface to best approximate the color or gray level of the input.
WHITEONBLACK	On a shrinking bit-block transfer, pixels should be combined with a Boolean OR operation. On a stretching bit-block transfer, pixels should be replicated.

pbo

Pointer to the BRUSHOBJ structure to be used to define the pattern for the bit-block transfer. GDI's BRUSHOBJ_pvGetRbrush service routine retrieves the device's realization of the brush. GDI ignores this parameter if the rop4 parameter does not require a pattern.

[in] rop4

Represents a raster operation that defines how the mask, pattern, source, and destination pixels are combined to write an output pixel to the destination surface.

This is a quaternary raster operation, which is a natural extension of the usual ternary Rop3 operation. A Rop4 has 16 relevant bits, which are similar to the 8 defining bits of a Rop3. (The other redundant bits of the Rop3 are ignored.) The simplest way to implement a Rop4 is to consider its 2 bytes separately. The lower byte specifies a Rop3 that should be computed wherever the mask to which psoMask points is 1. The high byte specifies a Rop3 that can be computed and applied wherever the mask is zero.

Return value

EngStretchBltROP returns TRUE upon success. Otherwise, it reports an error and returns FALSE.

Remarks

The driver should call EngStretchBltROP if it has hooked DrvStretchBltROP but cannot support all operations.

The mapping is defined by prclSrc and prclDest. The points specified in prclDest and prclSrc lie on integer coordinates that correspond to pixel centers. A rectangle defined by two such points is considered to be a geometric rectangle with two vertices whose coordinates are the given points, but with 0.5 subtracted from each coordinate. (POINTL structures are shorthand notation for specifying these fractional coordinate vertices.)

Requirements

Requirement	Value
Minimum supported client	Available in Windows 2000 and later versions of the Windows operating systems.
Target Platform	Universal
Header	winddi.h (include Winddi.h)
Library	Win32k.lib
DLL	Win32k.sys