EngDitherColor

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

ULONG
  EngDitherColor(
    IN HDEV  hdev,
    IN ULONG  iMode,
    IN ULONG  rgb,
    OUT 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.

Headers

Declared in winddi.h. Include winddi.h.

Comments

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

See Also

DrvRealizeBrush