GetPath

The GetPath function retrieves the coordinates defining the endpoints of lines and the control points of curves found in the path that is selected into the specified device context.

int GetPath(
  HDC hdc,           // handle to device context
  LPPOINT lpPoints,  // pointer to array receiving path vertices
  LPBYTE lpTypes,    // pointer to array of path vertex types
  int nSize          // count of points defining path
);
 

Parameters

hdc

Handle to a device context that contains a closed path.

lpPoints

Pointer to an array of POINT structures that contains the line endpoints and curve control points.

lpTypes

Pointer to an array of bytes where the vertex types are placed. Values are one of the following:

Type	Description
PT_MOVETO	Specifies that the corresponding point in the lpPoints parameter starts a disjoint figure.
PT_LINETO	Specifies that the previous point and the corresponding point in lpPoints are the endpoints of a line.
PT_BEZIERTO	Specifies that the corresponding point in lpPoints is a control point or ending point for a Bézier curve.
	PT_BEZIERTO values always occur in sets of three. The point in the path immediately preceding them defines the starting point for the Bézier curve. The first two PT_BEZIERTO points are the control points, and the third PT_BEZIERTO point is the ending (if hard-coded) point.

A PT_LINETO or PT_BEZIERTO value may be combined with the following value (by using the bitwise operator OR) to indicate that the corresponding point is the last point in a figure and the figure should be closed:

Flag	Description
PT_CLOSEFIGURE	Specifies that the figure is automatically closed after the corresponding line or curve is drawn. The figure is closed by drawing a line from the line or curve endpoint to the point corresponding to the last PT_MOVETO.

nSize

Specifies the total number of POINT structures that may be placed in the array pointed to by lpPoints. This value must be the same as the number of bytes that may be placed in the array pointed to by lpTypes.

Return Values

If the nSize parameter is nonzero, the return value is the number of points enumerated. If nSize is 0, the return value is the total number of points in the path (and GetPath writes nothing to the buffers). If nSize is nonzero and is less than the number of points in the path, the return value is –1.

Windows NT: To get extended error information, call GetLastError. GetLastError may return one of the following error codes:

ERROR_CAN_NOT_COMPLETE
ERROR_INVALID_PARAMETER
ERROR_BUFFER_OVERFLOW

Remarks

The device context identified by the hdc parameter must contain a closed path.

The points of the path are returned in logical coordinates. Points are stored in the path in device coordinates, so GetPath changes the points from device coordinates to logical coordinates by using the inverse of the current transformation.

The FlattenPath function may be called before GetPath to convert all curves in the path into line segments.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in wingdi.h.
  Import Library: Use gdi32.lib.

See Also

Paths Overview, Path Functions, FlattenPath, POINT, PolyDraw, WidenPath