type TTile = object
  x, y, w, h: int
type TJob = object
  tile*: TTile

proc foo_update_img(tile: TTile) = #, img_tile: PHDRImg) =
   #discard put_subrect(dst: scene.img, src: img_tile, x:tile.x, y:tile.y
   #Acquire(IMGLock)

var job: TJob
job.tile = TTile(x: 1, y: 1, h: 1, w: 1)
foo_update_img(tile: job)