Static kCVImageBufferDisplayMaskRectangle_RectangleTopKey 

pub unsafe static kCVImageBufferDisplayMaskRectangle_RectangleTopKey: &'static CFString

Available on crate feature CVImageBuffer only.

Specifies the vertical pixel offset of the rectangle from the top of the bounding raster. The top offset value is a CFNumber of unsigned 16-bit integer that is less than the reference raster height value.

See also Apple’s documentation