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THIS DOCUMENT IS OBSOLETE, AND ONLY A GUIDELINE
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- entity programming should use object:method() design.
- creating an entity should use simple methods as follows:
minetest.register_entity("sofar:sheep", { object = {}, ..., on_activate = entity_ai:on_activate, on_step = entity_ai:on_step, on_punch = entity_ai:on_punch, on_rightclick = entity_ai:on_rightclick, get_staticdata = entity_ai:get_staticdata, })
entity activity is a structure organized as a graph:
events may cause: -> [flee] -> [defend] -> [dead] -> [return] initial states [roam] [guard] [hunt]
etc..
Each state may have several substates
[idle] -> { idle.1, idle.2, idle.3 }
Each state has a "driver". This is the algorithm that makes the entity do stuff. "do stuff" can mean "stand still", "move to a pos", "attack something" or a combination of any of these, including "use a node", "place a node" etc.
-- returns: nil obj:driver_eat_grass = function(self) end obj:driver_idle = function(self) end obj:driver_find_food = function(self) end obj:driver_defend = ... obj:driver_death = ... obj:driver_mate = ...
Each state has several "factors". These are conditions that may be met at any point in time. Factors can be "A node is nearby that can be grazed on", "close to water", "fertile", "was hit recently", "took damage recently", "a hostile faction is nearby"
-- returns: bool obj:factor_is_fertile = function(self) end obj:factor_is_near_grass = function(self) end obj:factor_was_hit = function(self) end obj:factor_is_near_mate = ...
sheep_script = { "roam" = { driver = "roaming", factors = { got_hit = "startle", became_fertile = "fertile", attractor_nearby = "attracted", too_far_from_home = "homing", }, } "eat" = { driver = "eat", factors = { ate_enough = "roam", became_fertile = "fertile", attractor_nearby = "attracted", } }, "startle" = { driver = "startle", factors = { got_hit = "flee", }, "flee" = { driver = "flee", factors = { got_hit = "startle", fleed_too_long = "roam", }, }, "attracted" = { driver = "approach", factors = { became_fertile = "fertile", approached_too_long = "roam", } }, "fertile" = { driver = "mate", factors = { got_hit = "startle", } "homing" = { driver = "homing", factors = { near_home = "roam", got_hit = "startle", } }, "death" = { driver = "death", } }