Function libeyelink_sys::eyelink_draw_cross_hair

pub unsafe extern "C" fn eyelink_draw_cross_hair(
    chi: *mut CrossHairInfo
) -> INT32

@ingroup display Convenient function to draw cross hair on camera image. It is very tedious to draw and maintain cross hair drawing. This is due to evolving eyelink camera image protocol and the introduction of newer trackers and still single library handle all eyelink trackers. eyelink_draw_cross_hair fixes this issue by allowing the drawing function to draw to the device contexts and does all magic of extracting cursor info from the tracker.

eyelink_draw_cross_hair calls drawLine(), drawEllipse() and getMouseState() to draw the cross hair. eyelink_draw_cross_hair expects both width(w) and height(h) are correct and the function pointers to drawLine, drawEllipse and getMouseState are not NULL. @param[in] chi initialized CrossHairInfo structure.