VDisplayOverlayRectangle
Name
VDisplayOverlayRectangle - displays a 1-bit overlay rectangle.
Synopsis
VDisplayOverlayRectangle(win, ovl, xloc, yloc, width, height)
Window win;
int ovl;
int xloc, yloc;
int width, height;
Description
VDisplayOverlayRectangle displays a 1-bit overlay rectangle in the image
window or one of its subwindows. VTurnOnOverlay should be called to turn on
the overlays, before calling VDisplayOverlayRectangle.
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.
ovl - specifies the overlay number to be used to draw the overlay rectangle.
xloc, yloc - specifies x and y coordinates of the upper left corner of the
rectangle, relative to the origin of the specified window.
width, height - specifies the width and height in pixels of the frame.
Side Effects
None.
Entry Conditions
VTurnOnOverlay should be called first. If ovl, xloc, yloc, width, or height
is not valid, or VCreateColormap is not called earlier, or the rectangle to
be displayed is totally out of the specified window boundary,
VDisplayOverlayRectangle prints an error message to the standard error stream,
produces a core dump file and exits from the current process.
Related Functions
VTurnOnOverlay,
VTurnOffOverlay,
VEraseOverlayRectangle.