.DT Terrains Divided Sky Creator Help Terrains Name .SI 5 Terrains - Collections of cloned and unique locations making areas .EI Description .SP 5 5 A terrain is an area in the game that is managed by the terrain handling system. Terrains are generally areas for which large portions are similar such as deserts, forests, mountains, caves and swamps; towns and cities should have every location unique and so are not suited to being managed by the terrain handler. .EP Locations .SP 5 5 The locations that form a terrain come in two types, fixed and floating. Fixed locations are unique rooms while floating locations are cloned to make portions of the area. For example, suppose you have a swamp with an island of dry ground in it: the island would be a fixed location, since it is unique and special, whereas the other swamp locations would all be clones of a single room and are floating locations. This splitting of locations into fixed and floating types frees the creator from having to struggle to describe many very similar rooms, allowing time and energy to be devoted to the unique places - it's a rare player who will complain that each tree in a forest isn't given its own, special description. For the purpose of providing a hook to the terrain handler, fixed locations must have a set_terrain() in their setup() code; this is so that when such a location is loaded, either by someone entering through an exit or by logging into that location, it can notify the terrain handler. Floating locations do not need this call, since they are cloned by the terrain handler, and hence the handler is already aware of their existence. .EP Coordinates .SP 5 5 The terrain handling system relies heavily on coordinates. Before any data can be given to the handler, therefore, the terrain must be planned on paper so that all coordinates are known in advance. Fixed locations require a single set of three coordinates to specify where they are to be found, while floating locations either require a single set of three coordinates or a set of six coordinates specifying a rectanguloid, the first three being the most negative coordinates of the rectanguloid (i.e. one corner) and the other three being the most positive coordinates of the rectanguloid (i.e. the diametrically opposed corner). The locations need not all have the same room size, although they all should have a size that is a multiple of 5, which means that all differences between location coordinates must be multiples of 10 (or, to simplify things, make all coordinates multiples of 10). Room sizes need to be explicitly set using set_room_size() in the actual code for that object; inheriting the room size from a parent is not enough, since the terrain handler will not load an unloaded room, grepping instead to ascertain the room size. .EP Priorities .SP 5 5 When a location, fixed or floating, is put into use by the terrain handler, its exits are calculated and added. Once exits have been calculated for a given location (or, more specifically, for a given coordinate), the connection information is written to a file and then that file is read for the data the next time that location needs to be given exits. When an exit is first calculated, the terrain handler looks for possible locations at coordinates along the line of that exit with displacement steps of 10 units (the sum of the room sizes for the location being assigned exits and the possible destination must be equal to the displacement currently being considered), making the connection to the first valid destination. When the handler looks for a location at a particular set of coordinates, it first looks at the fixed locations and then it looks at the floating locations. There should only be one fixed location for a given coordinate, but there can be more than one possible floating location type for a given coordinate, so floating locations have priority levels. For example, in the case of the swamp above, you might want the locations nearer the island to have descriptions and room items that reflect their proximity to it; you could therefore have a smaller block of "near island" floating locations around the island and inside the bigger block of main swamp locations, and with a higher priority level than the main swamp locations. If the location of highest priority is supposedly a clone of "nothing", no location will actually be put in at that position; this is useful to define the interior of a structure, where the rooms inside, say, a hollow rock or tree are coded conventionally, with one way in from the outside, so the terrain handler should not try to fill the interior with other locations. .EP Terrain Room .SP 5 5 The terrain room (/d/admin/room/terrain) is a utility for managing terrains. Typing "help room" gives you the list of commands, which are as follows. "terrain" sets the current terrain for the room and must be used before any of the other commands can be used. "list" lets you see either the floating or the fixed locations for the terrain, while "member" lets you see what fixed location is at a particular coordinate or what floating locations, with what levels, are at a particular coordinate. "add" lets you add a new fixed or floating location - a fixed location needs the file name and three coordinates while a floating locations needs the file name, three or six coordinates and a priority level. "remove" lets you remove a fixed or floating location - a fixed location can be removed with just the file name while a floating location also needs the relevant coordinates for removal. Finally "clear" wipes the terrain handlers current list of clones for the terrain and, more importantly, deletes all the connection data files for the terrain - this should be used whenever a location is added to or removed from that terrain. .EP See also .SI 5 coordinates, set_room_size dungeons .EI
