A couple of nits, code LGTM otherwise. Needs testing.
Diff comments:
>
> === modified file 'data/campaigns/bar01.wmf/scripting/mission_thread.lua'
> --- data/campaigns/bar01.wmf/scripting/mission_thread.lua 2016-12-29
> 10:31:07 +
> +++ data/campaigns/bar01.wmf/scripting/mission_thread.lua 2017-07-09
> 10:09:27 +
> @@ -15,15 +15,21 @@
> -- =
>
> function introduction_thread()
> + reveal_concentric(plr, sf, 13)
> sleep(2000)
>
> message_box_objective(plr, briefing_msg_01)
> -- these buildings are still burning, but only for a while
> map:place_immovable("destroyed_building",map:get_field(7,41),"tribes")
> map:place_immovable("destroyed_building",map:get_field(5,52),"tribes")
> - plr:reveal_fields(al_thunran:region(8))
> + -- plr:reveal_fields(al_thunran:region(8))
Remove commented out line.
> + scroll_to_field(al_thunran)
> + reveal_concentric(plr, al_thunran, 8, true, 50)
> message_box_objective(plr, briefing_msg_02) -- Al'thunran
> - plr:reveal_fields(grave:region(4))
> + scroll_to_field(sf)
> + sleep(1000)
> + scroll_to_field(grave)
> + reveal_concentric(plr, grave, 4)
> message_box_objective(plr, briefing_msg_03) -- grave, Boldreth
> message_box_objective(plr, briefing_msg_04) -- wait
> -- introduction of Khantrukh
>
> === modified file 'data/campaigns/bar02.wmf/scripting/mission_thread.lua'
> --- data/campaigns/bar02.wmf/scripting/mission_thread.lua 2017-01-17
> 08:52:14 +
> +++ data/campaigns/bar02.wmf/scripting/mission_thread.lua 2017-07-09
> 10:09:27 +
> @@ -11,6 +12,9 @@
> fr2 = game.map:get_field(85,1)
> fr3 = game.map:get_field(85,11)
>
> +-- Starting field
> +sf = game.map.player_slots[1].starting_field
Check if this also works with local sf = ... local is always better.
> +
> function check_conquered_footprints()
> if p1:seen_field(game.map:get_field(65, 28))
> then
>
> === modified file 'data/campaigns/emp02.wmf/scripting/mission_thread.lua'
> --- data/campaigns/emp02.wmf/scripting/mission_thread.lua 2017-03-16
> 21:54:07 +
> +++ data/campaigns/emp02.wmf/scripting/mission_thread.lua 2017-07-09
> 10:09:27 +
> @@ -111,16 +113,16 @@
> -- Reveal the other mountains
> local coal_mountain = wl.Game().map:get_field(49,22)
> local iron_mountain = wl.Game().map:get_field(38,37)
> - p1:reveal_fields(coal_mountain:region(6))
> +
> + --local move_point = wl.Game().map:get_field(49,22)
Remove commented out line.
> + wait_for_roadbuilding_and_scroll(coal_mountain)
> + reveal_concentric(p1, coal_mountain, 6, false)
> p1:reveal_fields(iron_mountain:region(6))
> run(function() sleep(5000)
>p1:hide_fields(coal_mountain:region(6))
>p1:hide_fields(iron_mountain:region(6))
> end)
>
> - local move_point = wl.Game().map:get_field(49,22)
> - wait_for_roadbuilding_and_scroll(move_point)
> -
> campaign_message_box(saledus_3)
> p1:allow_buildings{
>"empire_coalmine",
>
> === added file 'data/scripting/field_animations.lua'
> --- data/scripting/field_animations.lua 1970-01-01 00:00:00 +
> +++ data/scripting/field_animations.lua 2017-07-09 10:09:27 +
> @@ -0,0 +1,173 @@
> +-- RST
> +-- .. _field_animations:
> +--
> +-- field_animations.lua
> +--
> +--
> +-- This script contain some animations to reveal and hide fields seen
contain -> contains
> +-- by a player. This functions are currently used in the campaigns and
> scenarios
> +-- to tell the prologue to a story.
> +
> +-- RST
> +-- .. function:: reveal_randomly(player, region, time)
> +--
> +--Reveal a given region field by field, where the fields
> +--are chosen randomly. The region get hidden prior revealing.
"The region get hidden prior revealing." - I do not understand this sentence.
The region will be hidden before being revealed?
> +--The animation runs the specified time.
> +--See also :meth:`wl.map.Field.region`
> +--
> +--:arg player: The player who get sight to the region
get -> gets
> +--:arg region: The region that has to be revealed
> +--:type region: :class:`array` of :class:`wl.map.Fields`
> +--:arg time: Optional. The time the whole animation will run.
> +-- Defaults to 1000 (1 sec)
> +
> +function reveal_randomly(plr, region, time)
> + -- If no 'time' is given use a default
> + time = time or 1000
> +
> + -- Make sure the region is hidden
> + plr:hide_fields(region, true)
> +
> + -- Turn off buildhelp during animation
> + local buildhelp_state = wl.ui.MapView().buildhelp
> + if buildhelp_state then
> + wl.ui.MapView().buildhelp = false
> + end
> +
> + -- Calculate delay as integer
> + local delay = math.floor(time / #region)
> + -- Make sure 'delay' is valid
> + if delay < 1 then delay = 1 end
> +
> + -- Reveal field by field
> + while #region > 0 do
> + l
