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EngDitherColor function (winddi.h)

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The EngDitherColor function returns a standard 8x8 dither that approximates the specified RGB color.

Syntax

ENGAPI ULONG EngDitherColor(
  HDEV  hdev,
  ULONG iMode,
  ULONG rgb,
  ULONG *pul
);

Parameters

hdev

Handle to the device. This is the handle that GDI passed to DrvCompletePDEV.

iMode

Determines the palette that GDI should dither against. This parameter can be one of the following values:

Value Meaning
DM_DEFAULT Requests that GDI create a dither for the native, default color space of the device. For example, if the device is running at 16bpp, the resulting dither is in a 16bpp format.
DM_MONOCHROME Requests that GDI create the dither for monochrome color space; that is, the dither is returned as a 1bpp bitmap.

rgb

Specifies the RGB color that is to be dithered. GDI ignores the high byte of this ULONG value.

pul

Pointer to the memory location in which GDI returns the dithering information. The driver must have allocated memory for a standard-format bitmap with dithered brush dimensions of 8x8. The driver must also set the cxDither and cyDither members of the DEVINFO structure to 8.

Return value

The return value is DCR_DRIVER if the dither values have been calculated by the driver, or DCR_SOLID if the engine should use the best solid color approximation of the color.

Remarks

EngDitherColor can be called for bitmaps that are 8bpp or higher.

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

See also

DrvRealizeBrush