PATHOBJ_bEnumClipLines function (winddi.h)

Article
10/05/2021

The PATHOBJ_bEnumClipLines function enumerates clipped line segments from a given path.

Syntax

ENGAPI BOOL PATHOBJ_bEnumClipLines(
  PATHOBJ  *ppo,
  ULONG    cb,
  CLIPLINE *pcl
);

Parameters

ppo

Pointer to the PATHOBJ structure containing the clipped line segments that are to be enumerated.

cb

Specifies the size of the output buffer, in bytes. GDI does not write beyond this point in the buffer. The value of this parameter must be large enough to hold a CLIPLINE structure with at least one RUN structure. The driver should allocate space for several RUN structures.

pcl

Pointer to the buffer that receives a CLIPLINE structure. The structure contains the original unclipped control points for a line segment. (The correct pixels for the line cannot be computed without the original points.) RUN structures, which describe sets of pixels along the line that are not clipped away, are written to this buffer.

If a clip region is complex, a single line segment can be broken into many RUN structures. A segment is returned as many times as necessary to list all of its RUN structures.

The CLIPLINE structure contains the starting and ending points of the original unclipped line and the line segments, or RUN structures, of that line that are to appear on the display.

Return value

The return value is TRUE if more line segments are to be enumerated, indicating that this service should be called again. Otherwise, it is FALSE, indicating that the returned segment is the last segment in the path.

Remarks

The enumeration must be started with PATHOBJ_vEnumStartClipLines before the driver makes this call.

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