ScanLR

WORD ScanLR(
  LPPDEVICE lpDestDev, 
  WORD X, 
  WORD Y, 
  PCOLOR dwPhysColor, 
  WORD Style
 );

Scans the display surface horizontally from the given pixel, looking for the first pixel having the given color or a pixel that has any other color.

>0	Number of scanlines copied.
0	Error or no scanlines copied.
-1	GDI must simulate the operation

lpDestDev

Address of a PDEVICE or PBITMAP structure that specifies the destination device or bitmap.

X and Y

Coordinate of the starting pixel.

dwPhysColor

Physical color value.

Style

Action to take. Can be a combination of these values:

0x0001	Scans for a pixel with color matching the dwPhysColor parameter. If this value is not given, the function scans for a pixel with color that does not match.
0x0002	Scans to the left. If this value is not specified, the function scans to the right.

The export ordinal for this function is 12.

The scan can be left or right. GDI calls this function when an application calls the FloodFill or ExtFloodFill function (GDI.25 or GDI.372).

A graphics driver must export the ScanLR function if it sets the DT_RASDISPLAY value in the dpTechnology member of the GDIINFO structure.