VEraseOverlay

 
Name
  VEraseOverlay - erases a 1-bit overlay image.
 
Synopsis
  VEraseOverlay(win, ovl, xloc, yloc, width, height)
  Window win;
  int ovl;
  int xloc, yloc;
  int width, height;
 
Description
  VEraseOverlay erases a 1-bit overlay image within a rectangle in the
image window or one of its subwindows. 

Return Value
  0 - work successfully.
  6 - invalid window ID.
  225 - no overlay created.
  237 - the overlay is not on.
 
Parameters
  win - the image window ID or one of its subwindows' ID.
  xloc, yloc - specifies x and y coordinates of the upper left corner of the
        rectangle, relative to the origin of the image window.
  width, height - specifies the width and height in pixels of the overlay.
  ovl - specifies the overlay number to be used to erase the 1-bit image.
 
Side Effects
  Any other graphics in that overlay within that rectangle will also be
erased.
 
Entry Conditions
  VTurnOnOverlay should be called first. If ovl, xloc, yloc, width, or height 
is invalid, or VCreateColormap is not called earlier, or the overlay image to 
be erased is totally out of the specified window boundary, VEraseOverlay 
prints an error message to the standard error stream, produces a core dump 
file and exits from the current process.
 
Related Functions