Added small readme file for overmap system.

code/WorkInProgress/Chinsky/overmap/README.dm

@@ -0,0 +1,99 @@
+/*
+The overmap system allows adding new maps to the big 'galaxy' map.
+Idea is that new sectors can be added by just ticking in new maps and recompiling.
+Not real hot-plugging, but still pretty modular.
+It uses the fact that all ticked in .dme maps are melded together into one as different zlevels.
+Metaobjects are used to make it not affected by map order in .dme and carry some additional info.
+
+*************************************************************
+Metaobject
+*************************************************************
+/obj/effect/mapinfo, sectors.dm
+Used to build overmap in beginning, has basic information needed to create overmap objects and make shuttles work.
+Its name and icon (if non-standard) vars will be applied to resulting overmap object.
+'mapy' and 'mapx' vars are optional, sector will be assigned random overmap coordinates if they are not set.
+Has two important vars:
+	obj_type	-	type of overmap object it spawns. Could be overriden for custom overmap objects.
+	landing_area -	type of area used as inbound shuttle landing, null if no shuttle landing area.
+
+Object could be placed anywhere on zlevel. Should only be placed on zlevel that should appear on overmap as a separate entitety.
+Right after creation it sends itself to nullspace and creates an overmap object, corresponding to this zlevel.
+
+*************************************************************
+Overmap object
+*************************************************************
+/obj/effect/map, sectors.dm
+Represents a zlevel on the overmap. Spawned by metaobjects at the startup.
+	var/area/shuttle/shuttle_landing - keeps a reference to the area of where inbound shuttles should land
+
+-CanPass should be overriden for access restrictions
+-Crossed/Uncrossed can be overriden for applying custom effects.
+Remember to call ..() in children, it updates ship's current sector.
+
+subtype /ship of this object represents spacefaring vessels.
+It has 'current_sector' var that keeps refernce to, well, sector ship currently in.
+
+*************************************************************
+Helm console
+*************************************************************
+/obj/machinery/computer/helm, helm.dm
+On creation console seeks a ship overmap object corresponding to this zlevel and links it.
+Clicking with empty hand on it starts steering, Cancel-Camera-View stops it.
+Helm console relays movement of mob to the linked overmap object.
+Helm console currently has no interface. All travel happens instanceously too.
+Sector shuttles are not supported currently, only ship shuttles.
+
+*************************************************************
+Exploration shuttle terminal
+*************************************************************
+A generic shuttle controller.
+Has a var landing_type defining type of area shuttle should be landing at.
+On initalizing, checks for a shuttle corresponding to this zlevel, and creates one if it's not there.
+Changes desitnation area depending on current sector ship is in.
+Currently updating is called in attack_hand(), until a better place is found.
+Currently no modifications were made to interface to display availability of landing area in sector.
+
+
+*************************************************************
+Guide to how make new sector
+*************************************************************
+0.Map
+Remember to put a helm console on ship maps.
+Remember to define shuttle areas - both for sectors and ships.
+Currently there are no other ways to reach sectors from ships.
+In examples, 4x6 shuttle area is used. In case of shuttle area being too big, it will apear in bottom left corner of it.
+
+1.Metaobject
+All vars needed for it to work could be set directly in map editor, so in most cases you won't have to define new in code.
+Remember to set landing_area var for sectors.
+
+2.Overmap object
+If you need custom behaviour on entering/leaving this sector, or restricting access to it, you can define your custom map object.
+Remember to put this new type into spawn_type var of metaobject.
+
+3.Shuttle console
+Remember to place one on the actual shuttle too, or it won't be able to return from sector without ship-side recall.
+Remember to set landing_type var to ship-side shuttle area type.
+shuttle_tag can be set to custom name (it shows up in console interface)
+
+4.Tick map in and compile.
+Sector should appear on overmap (in random place if you didn't set mapx,mapy)
+
+
+TODO:
+sector-to-ship shuttles.
+ship-ship interactions
+helm console interface:
+	current coordinates
+	list of known locations
+	autopilot
+	manual control
+more mechanics to moving ship:
+	overmap movement delay
+	engine objects
+	'moving stars' effect
+better space travel / stragglers handling
+shuttle console:
+	showing if shuttle has nowhere to be sent to
+	?landing pad size detection
+*/