Rotates one or more annotation objects.


#include "l_bitmap.h"

L_LTANN_API L_INT L_AnnRotate(hObject, dAngle, pCenter, uFlags)



Handle to the annotation object.


The angle of rotation, expressed in double-precision floating point.


Pointer to the LEADTOOLS ANNPOINT structure that specifies the center of rotation.

Pass NULL in this parameter to use the default for each affected object. With the default, if a container is rotated, all objects in it are rotated as a unit, using the container's center as the axis. If an individual object is rotated, it is rotated on its own center.

The ANNPOINT structure is like a Windows POINT structure, except that it uses double-precision floating point values.

Coordinates of an object's points are relative to its container object. The coordinates are interpreted using the container's scaling factors and offsets, which are described in Low-Level Coordinate System for Annotations.

L_UINT uFlags

Flags that determine which objects to process. Most of the flags apply only to container objects. You can combine values when appropriate by using a bitwise OR ( | ). The following are valid values:

Value Meaning
0 Process only the specified object.
ANNFLAG_SELECTED [0x0001] Process only objects that have the selected property set to TRUE. For getting and setting the selected property, use the L_AnnGetSelected and L_AnnSetSelected functions.
ANNFLAG_NOTTHIS [0x0004] Process only one level of objects within the specified container, not the container itself. If there are containers within the container, they are modified, but the objects within them are not.
ANNFLAG_RECURSE [0x0008] Process objects within a container, and within any subcontainers, down to any level.
ANNFLAG_NOTCONTAINER [0x0002] (Used with ANNFLAG_RECURSE) Process objects within containers, not the containers themselves.
ANNFLAG_NOINVALIDATE [0x0010] Do not invalidate the affected rectangle in the window. Use this to avoid generating unwanted paint messages.


Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.


This function applies to multiple and selected objects based on values of the uFlags parameter.

You cannot rotate a note, HotSpot, button, or audio clip. If you rotate a container that includes these objects, they will move to new positions, but will retain their orientation.

L_AnnRotate does not change the bitmap of a Point annotation object. It only changes the position of the point. To change the bitmap you must get the bitmap using L_AnnGetBitmap, change the bitmap, and then set the bitmap using L_AnnSetBitmap.

The center of a protractor object is the angle point (vertex). The center of a cross-product is the intersection of the two rulers. If you pass NULL for pCenter, these center points will be used instead of the center of the bounding rectangle when rotating the object.

Required DLLs and Libraries


Win32, x64.

See Also




This example rotates an object using its lower right corner as the center of rotation.

L_INT AnnRotateExample(HANNOBJECT hAnnObject) 
   L_INT nRet; 
   ANNPOINT RotationPt; /* Point of rotation */ 
   ANNRECT  ObjectRect; /* Defining rectangle of this object */ 
   ANNRECT  ObjectRectName; 
   /* Get the object's rectangle to use for calculating rotation */ 
   nRet = L_AnnGetRect(hAnnObject, &ObjectRect, &ObjectRectName); 
   if (nRet != SUCCESS) 
      return nRet; 
   /* Specify the point of rotation (the object's lower right corner ) */ 
   RotationPt.x = ObjectRect.right; 
   RotationPt.y = ObjectRect.bottom; 
   /* Rotate the object 90 degrees clockwise */ 
   return L_AnnRotate(hAnnObject, 90, &RotationPt, 0); 

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