Function to perform manipulations before rendering. This function is called with the ol.Map as first and an optional olx.FrameState as second argument. Return true to keep this function for the next frame, false to remove it.
true
false
可選
Function to perform manipulations before rendering. This function is called with the ol.Map as first and an optional olx.FrameState as second argument. Return
trueto keep this function for the next frame,falseto remove it.