item_transport.lua: split out determination of next position in go_next() into separate function

This commit is contained in:
thetaepsilon-gamedev 2017-12-19 23:15:44 +00:00
parent fb91ba53f1
commit a2e183c6f3

View File

@ -70,47 +70,24 @@ end
-- function called by the on_step callback of the pipeworks tube luaentity.
-- the routine is passed the current node position, velocity, itemstack,
-- and owner name.
-- returns three values:
-- * a boolean "found destination" status;
-- * a new velocity vector that the tubed item should use, or nil if not found;
-- * a "multi-mode" data table (or nil if N/A) where a stack was split apart.
-- if this is not nil, the luaentity spawns new tubed items for each new fragment stack,
-- then deletes itself (i.e. the original item stack).
local function go_next(pos, velocity, stack, owner)
-- compatibility behaviour for the existing can_go() callbacks,
-- which can only specify a list of possible positions.
local function go_next_compat(pos, cnode, cmeta, cycledir, vel, stack, owner)
local next_positions = {}
local max_priority = 0
local cnode = minetest.get_node(pos)
local cmeta = minetest.get_meta(pos)
local can_go
local speed = math.abs(velocity.x + velocity.y + velocity.z)
if speed == 0 then
speed = 1
end
local vel = {x = velocity.x/speed, y = velocity.y/speed, z = velocity.z/speed,speed=speed}
if speed >= 4.1 then
speed = 4
elseif speed >= 1.1 then
speed = speed - 0.1
else
speed = 1
end
vel.speed = speed
crunch_tube(pos, cnode, cmeta)
-- cycling of outputs:
-- an integer counter is kept in each pipe's metadata,
-- which allows tracking which output was previously chosen.
-- note reliance on get_int returning 0 for uninitialised.
local cycledir = cmeta:get_int("tubedir")
if minetest.registered_nodes[cnode.name] and minetest.registered_nodes[cnode.name].tube and minetest.registered_nodes[cnode.name].tube.can_go then
can_go = minetest.registered_nodes[cnode.name].tube.can_go(pos, cnode, vel, stack)
else
can_go = pipeworks.notvel(adjlist, vel)
end
-- can_go() is expected to return an array-like table of candidate offsets.
-- for each one, look at the node at that offset and determine if it can accept the item.
-- also note the prioritisation:
-- if any tube is found with a greater priority than previously discovered,
-- then the valid positions are reset and and subsequent positions under this are skipped.
-- this has the effect of allowing only equal priorities to co-exist.
for _, vect in ipairs(can_go) do
local npos = vector.add(pos, vect)
pipeworks.load_position(npos)
@ -133,18 +110,66 @@ local function go_next(pos, velocity, stack, owner)
end
end
-- indicate not found if no valid rules were picked up,
-- and don't change the counter.
if not next_positions[1] then
return false, nil, nil
return cycledir, false, nil, nil
end
-- otherwise rotate to the next output direction and return that
local n = (cycledir % (#next_positions)) + 1
local new_velocity = vector.multiply(next_positions[n].vect, vel.speed)
return n, true, new_velocity, nil
end
-- function called by the on_step callback of the pipeworks tube luaentity.
-- the routine is passed the current node position, velocity, itemstack,
-- and owner name.
-- returns three values:
-- * a boolean "found destination" status;
-- * a new velocity vector that the tubed item should use, or nil if not found;
-- * a "multi-mode" data table (or nil if N/A) where a stack was split apart.
-- if this is not nil, the luaentity spawns new tubed items for each new fragment stack,
-- then deletes itself (i.e. the original item stack).
local function go_next(pos, velocity, stack, owner)
local cnode = minetest.get_node(pos)
local cmeta = minetest.get_meta(pos)
local speed = math.abs(velocity.x + velocity.y + velocity.z)
if speed == 0 then
speed = 1
end
local vel = {x = velocity.x/speed, y = velocity.y/speed, z = velocity.z/speed,speed=speed}
if speed >= 4.1 then
speed = 4
elseif speed >= 1.1 then
speed = speed - 0.1
else
speed = 1
end
vel.speed = speed
crunch_tube(pos, cnode, cmeta)
-- cycling of outputs:
-- an integer counter is kept in each pipe's metadata,
-- which allows tracking which output was previously chosen.
-- note reliance on get_int returning 0 for uninitialised.
local cycledir = cmeta:get_int("tubedir")
-- pulled out and factored out into go_next_compat() above.
-- n is the new value of the cycle counter.
-- XXX: this probably needs cleaning up after being split out,
-- seven args is a bit too many
local n, found, new_velocity, multimode = go_next_compat(pos, cnode, cmeta, cycledir, vel, stack, owner)
-- if not using output cycling,
-- don't update the field so it stays the same for the next item.
if pipeworks.enable_cyclic_mode then
cmeta:set_int("tubedir", n)
end
local new_velocity = vector.multiply(next_positions[n].vect, vel.speed)
return true, new_velocity, nil
return found, new_velocity, multimode
end