ImageGear for C and C++ on Linux v20.0 - Updated
API Reference Guide > Core Component API Reference > Core Component Functions Reference > Display Functions > IG_dspl_update_rect_set

This function sets the new value to update rectangle. Usually this value is received from Expose X event.


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AT_ERRCOUNT ACCUAPI IG_dspl_update_rect_set(
     [IN] HIGEAR hIGear,
     [IN] DWORD dwGrpID,
     [IN] const LPAT_RECTANGLE lpUpdateRect


Name Type Description
hIGear HIGEAR Image handle of an image.
dwGrpID DWORD Identifier of the group in which to set the update rectangle.
lpUpdateRect const LPAT_RECTANGLE Sets new value to UpdateRect option.

Return Value:

Returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

All pixel formats supported by ImageGear for C and C++.




Copy Code
void wndDrawImage_callback( Widget w, XtPointer data, XtPointer call_data )
   XmDrawingAreaCallbackStruct*cbs =
   XExposeEvent*event = (XExposeEvent*)cbs->event;
   /* Redisplay only on last event of the series */
   if( IG_image_is_valid( hIGear ) )
      /* Set the dirty rectangle for repaint */
      UpdateRect.x= event->x;
      UpdateRect.y= event->y;
      UpdateRect.width= event->width;
      UpdateRect.height = event->height;
      IG_dspl_update_rect_set( hIGear, IG_GRP_DEFAULT, &UpdateRect );
      /* Repaint window on expose events */
      IG_dspl_image_draw( hIGear, IG_GRP_DEFAULT, XtWindow(w),
      XDefaultGCOfScreen(XtScreen(w)), NULL );

See Also:

Geometric Layout

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