View source for GreModifyPath

GreModifyPath modifies a path. When the transform is singular, GreModifyPath is invalid and causes an error to be logged.

This function can be hooked by the presentation driver.

;Simulation support: This function is simulated by a handling routine in the graphics engine.

==Syntax==
 GreModifyPath(hdc, idPath, cmdMode, pInstance, lFunction)

==Parameters==
;hdc (HDC) - input:Device context handle.
;idPath (LONG) - input:Path ID.
;cmdMode (LONG) - input:Modify mode.
:The only valid flag is:
:MPATH_STROKE This replaces the original path (with a path that encloses the shape produced by stroking the original path) using the current geometric wide line attribute. Any open figures within the path are not closed.
:The envelope includes the effects of "line joins" and "line ends" according to the current values of these attributes. For example, where a line joins an arc, the common point is handled according to the line join attribute in the current line attribute bundle. (See Line Attributes.) When a figure is closed by using GreCloseFigure, the line join attribute in the current line bundle is applied to the start and end points. The envelope takes account of any crossings. For example, a stroked X does not have a hole in the middle if it is subsequently drawn in Exclusive-OR mode.
;pInstance (PVOID) - input:Pointer to instance data.
;lFunction (ULONG) - input:High-order WORD=flags; low-order WORD=NGreModifyPath.

==Return Code==
;fSuccess (BOOL) - returns:Return codes.
:This function returns BOOLEAN (fSuccess).
:*TRUE Successful
:*FALSE Error
:Possible Errors Detected: When an error is detected, the handling routine must call WinSetErrorInfo to post the condition. Error codes for conditions that the handling routine is expected to check include:
:*PMERR_BASE_ERROR
:*PMERR_BITMAP_NOT_SELECTED
:*PMERR_COORDINATE_OVERFLOW
:*PMERR_DEV_FUNC_NOT_INSTALLED
:*PMERR_HDC_BUSY
:*PMERR_HRGN_BUSY
:*PMERR_INSUFFICIENT_MEMORY
:*PMERR_INV_COLOR_DATA
:*PMERR_INV_COLOR_INDEX
:*PMERR_INV_COORD_SPACE
:*PMERR_INV_COORDINATE
:*PMERR_INV_FILL_PATH_OPTIONS
:*PMERR_INV_HDC
:*PMERR_INV_HRGN
:*PMERR_INV_IN_AREA
:*PMERR_INV_IN_PATH
:*PMERR_INV_LENGTH_OR_COUNT
:*PMERR_INV_MATRIX_ELEMENT
:*PMERR_INV_MODIFY_PATH_MODE
:*PMERR_INV_PATH_ID
:*PMERR_INV_PATTERN_REF_PT_ATTR
:*PMERR_INV_PICK_APERTURE_POSN
:*PMERR_INV_RECT
:*PMERR_INV_REGION_CONTROL
:*PMERR_INV_TRANSFORM_TYPE
:*PMERR_PATH_LIMIT_EXCEEDED
:*PMERR_PATH_UNKNOWN
:*PMERR_REGION_IS_CLIP_REGION
:Refer to the "Error Explanations" section in the ''Presentation Manager Programming Reference'' for further explanation.

==Sample Code==
<PRE>
#define INCL_GRE_PATHS
#include <os2.h>

HDC      hdc;        /*  Device context handle. */
LONG     idPath;     /*  Path ID. */
LONG     cmdMode;    /*  Modify mode. */
PVOID    pInstance;  /*  Pointer to instance data. */
ULONG    lFunction;  /*  High-order WORD=flags; low-order WORD=NGreModifyPath. */
BOOL     fSuccess;   /*  Return codes. */

fSuccess = GreModifyPath(hdc, idPath, cmdMode, pInstance, lFunction);
</PRE>

[[Category:Gre]]