-- The pictureAt condition:  what the disc's picture is at a point.  One watcher counts the frames
-- the spot reads dark and the frames it reads bright, so a run with no video proves the documented
-- answer (dark everywhere, since the engine reads zeroes when nothing is playing) and a run with
-- --framefile proves the condition sees the picture change.
return {
	title   = "Author test:  the picture at a point",
	players = 1,
	size    = { w = 720, h = 480 },
	layers  = { { kind = "overlay" } },
	vars    = { dark = 0, bright = 0, neither = 0 },

	types = {
		watcher = { look = { kind = "none" } }
	},

	rooms = {
		{ name = "only", reset = true,
		  entities = {
			{ id = "eye", type = "watcher", x = 8, y = 8 }
		  } }
	},

	rules = {
		{ note = "The spot is dark",
		  on   = "frame", each = "watcher",
		  when = { { "pictureAt", x = 200, y = 120, is = "dark" } },
		  act  = { { "addVar", name = "dark", amount = 1 } } },
		{ note = "The spot is bright",
		  on   = "frame", each = "watcher",
		  when = { { "pictureAt", x = 200, y = 120, is = "bright" } },
		  act  = { { "addVar", name = "bright", amount = 1 } } },
		{ note = "The spot is neither",
		  on   = "frame", each = "watcher",
		  when = { { "pictureAt", x = 200, y = 120, is = "unknown" } },
		  act  = { { "addVar", name = "neither", amount = 1 } } }
	}
}