# sight.ludic - in the picture, within reach, and actually seen. A frustum says a subject is in FRONT
# of the lens, not that the lens can see it: the line must be clear of the ground and the still
# things (the port's). It is forgiving on purpose - the subject passes if its body or its head is clear.
function pht_ray_point(x: float, y: float, z: float) -> bool { return PhotoLens.clear(PhotoLens.x(), PhotoLens.y(), PhotoLens.z(), x, y, z) }

# is (x, y, z) in the picture, within `far`, and can the lens see it?
export function photo_in_view(x: float, y: float, z: float, far: float) -> bool {
  let dx = x - PhotoLens.x()
  let dy = y - PhotoLens.y()
  let dz = z - PhotoLens.z()
  let d = Math.sqrt(dx * dx + dy * dy + dz * dz)
  if d > far or d < 0.5 { return false }
  if (dx * PhotoLens.fx() + dy * PhotoLens.fy() + dz * PhotoLens.fz()) / d < 0.72 { return false }
  if not PhotoLens.visible(x, y, z, 1.0) { return false }
  return pht_ray_point(x, y, z) or pht_ray_point(x, y + 0.55, z)
}