minetest/builtin/game/item_entity.lua

320 lines
8.7 KiB
Lua

-- Minetest: builtin/item_entity.lua
function core.spawn_item(pos, item)
-- Take item in any format
local stack = ItemStack(item)
local obj = core.add_entity(pos, "__builtin:item")
-- Don't use obj if it couldn't be added to the map.
if obj then
obj:get_luaentity():set_item(stack:to_string())
end
return obj
end
-- If item_entity_ttl is not set, enity will have default life time
-- Setting it to -1 disables the feature
local time_to_live = tonumber(core.settings:get("item_entity_ttl")) or 900
local gravity = tonumber(core.settings:get("movement_gravity")) or 9.81
core.register_entity(":__builtin:item", {
initial_properties = {
hp_max = 1,
physical = true,
collide_with_objects = false,
collisionbox = {-0.3, -0.3, -0.3, 0.3, 0.3, 0.3},
visual = "wielditem",
visual_size = {x = 0.4, y = 0.4},
textures = {""},
spritediv = {x = 1, y = 1},
initial_sprite_basepos = {x = 0, y = 0},
is_visible = false,
},
itemstring = "",
moving_state = true,
slippery_state = false,
physical_state = true,
-- Item expiry
age = 0,
-- Pushing item out of solid nodes
force_out = nil,
force_out_start = nil,
set_item = function(self, item)
local stack = ItemStack(item or self.itemstring)
self.itemstring = stack:to_string()
if self.itemstring == "" then
-- item not yet known
return
end
-- Backwards compatibility: old clients use the texture
-- to get the type of the item
local itemname = stack:is_known() and stack:get_name() or "unknown"
local max_count = stack:get_stack_max()
local count = math.min(stack:get_count(), max_count)
local size = 0.2 + 0.1 * (count / max_count) ^ (1 / 3)
local coll_height = size * 0.75
self.object:set_properties({
is_visible = true,
visual = "wielditem",
textures = {itemname},
visual_size = {x = size, y = size},
collisionbox = {-size, -coll_height, -size,
size, coll_height, size},
selectionbox = {-size, -size, -size, size, size, size},
automatic_rotate = math.pi * 0.5 * 0.2 / size,
wield_item = self.itemstring,
})
end,
get_staticdata = function(self)
return core.serialize({
itemstring = self.itemstring,
age = self.age,
dropped_by = self.dropped_by
})
end,
on_activate = function(self, staticdata, dtime_s)
if string.sub(staticdata, 1, string.len("return")) == "return" then
local data = core.deserialize(staticdata)
if data and type(data) == "table" then
self.itemstring = data.itemstring
self.age = (data.age or 0) + dtime_s
self.dropped_by = data.dropped_by
end
else
self.itemstring = staticdata
end
self.object:set_armor_groups({immortal = 1})
self.object:set_velocity({x = 0, y = 2, z = 0})
self.object:set_acceleration({x = 0, y = -gravity, z = 0})
self:set_item()
end,
try_merge_with = function(self, own_stack, object, entity)
if self.age == entity.age then
-- Can not merge with itself
return false
end
local stack = ItemStack(entity.itemstring)
local name = stack:get_name()
if own_stack:get_name() ~= name or
own_stack:get_meta() ~= stack:get_meta() or
own_stack:get_wear() ~= stack:get_wear() or
own_stack:get_free_space() == 0 then
-- Can not merge different or full stack
return false
end
local count = own_stack:get_count()
local total_count = stack:get_count() + count
local max_count = stack:get_stack_max()
if total_count > max_count then
return false
end
-- Merge the remote stack into this one
local pos = object:get_pos()
pos.y = pos.y + ((total_count - count) / max_count) * 0.15
self.object:move_to(pos)
self.age = 0 -- Handle as new entity
own_stack:set_count(total_count)
self:set_item(own_stack)
entity.itemstring = ""
object:remove()
return true
end,
enable_physics = function(self)
if not self.physical_state then
self.physical_state = true
self.object:set_properties({physical = true})
self.object:set_velocity({x=0, y=0, z=0})
self.object:set_acceleration({x=0, y=-gravity, z=0})
end
end,
disable_physics = function(self)
if self.physical_state then
self.physical_state = false
self.object:set_properties({physical = false})
self.object:set_velocity({x=0, y=0, z=0})
self.object:set_acceleration({x=0, y=0, z=0})
end
end,
on_step = function(self, dtime)
self.age = self.age + dtime
if time_to_live > 0 and self.age > time_to_live then
self.itemstring = ""
self.object:remove()
return
end
local pos = self.object:get_pos()
local node = core.get_node_or_nil({
x = pos.x,
y = pos.y + self.object:get_properties().collisionbox[2] - 0.05,
z = pos.z
})
-- Delete in 'ignore' nodes
if node and node.name == "ignore" then
self.itemstring = ""
self.object:remove()
return
end
local is_stuck = false
local snode = core.get_node_or_nil(pos)
if snode then
local sdef = core.registered_nodes[snode.name] or {}
is_stuck = (sdef.walkable == nil or sdef.walkable == true)
and (sdef.collision_box == nil or sdef.collision_box.type == "regular")
and (sdef.node_box == nil or sdef.node_box.type == "regular")
end
-- Push item out when stuck inside solid node
if is_stuck then
local shootdir
local order = {
{x=1, y=0, z=0}, {x=-1, y=0, z= 0},
{x=0, y=0, z=1}, {x= 0, y=0, z=-1},
}
-- Check which one of the 4 sides is free
for o = 1, #order do
local cnode = core.get_node(vector.add(pos, order[o])).name
local cdef = core.registered_nodes[cnode] or {}
if cnode ~= "ignore" and cdef.walkable == false then
shootdir = order[o]
break
end
end
-- If none of the 4 sides is free, check upwards
if not shootdir then
shootdir = {x=0, y=1, z=0}
local cnode = core.get_node(vector.add(pos, shootdir)).name
if cnode == "ignore" then
shootdir = nil -- Do not push into ignore
end
end
if shootdir then
-- Set new item moving speed accordingly
local newv = vector.multiply(shootdir, 3)
self:disable_physics()
self.object:set_velocity(newv)
self.force_out = newv
self.force_out_start = vector.round(pos)
return
end
elseif self.force_out then
-- This code runs after the entity got a push from the above code.
-- It makes sure the entity is entirely outside the solid node
local c = self.object:get_properties().collisionbox
local s = self.force_out_start
local f = self.force_out
local ok = (f.x > 0 and pos.x + c[1] > s.x + 0.5) or
(f.y > 0 and pos.y + c[2] > s.y + 0.5) or
(f.z > 0 and pos.z + c[3] > s.z + 0.5) or
(f.x < 0 and pos.x + c[4] < s.x - 0.5) or
(f.z < 0 and pos.z + c[6] < s.z - 0.5)
if ok then
-- Item was successfully forced out
self.force_out = nil
self:enable_physics()
end
end
if not self.physical_state then
return -- Don't do anything
end
-- Slide on slippery nodes
local vel = self.object:get_velocity()
local def = node and core.registered_nodes[node.name]
local is_moving = (def and not def.walkable) or
vel.x ~= 0 or vel.y ~= 0 or vel.z ~= 0
local is_slippery = false
if def and def.walkable then
local slippery = core.get_item_group(node.name, "slippery")
is_slippery = slippery ~= 0
if is_slippery and (math.abs(vel.x) > 0.2 or math.abs(vel.z) > 0.2) then
-- Horizontal deceleration
local slip_factor = 4.0 / (slippery + 4)
self.object:set_acceleration({
x = -vel.x * slip_factor,
y = 0,
z = -vel.z * slip_factor
})
elseif vel.y == 0 then
is_moving = false
end
end
if self.moving_state == is_moving and
self.slippery_state == is_slippery then
-- Do not update anything until the moving state changes
return
end
self.moving_state = is_moving
self.slippery_state = is_slippery
if is_moving then
self.object:set_acceleration({x = 0, y = -gravity, z = 0})
else
self.object:set_acceleration({x = 0, y = 0, z = 0})
self.object:set_velocity({x = 0, y = 0, z = 0})
end
--Only collect items if not moving
if is_moving then
return
end
-- Collect the items around to merge with
local own_stack = ItemStack(self.itemstring)
if own_stack:get_free_space() == 0 then
return
end
local objects = core.get_objects_inside_radius(pos, 1.0)
for k, obj in pairs(objects) do
local entity = obj:get_luaentity()
if entity and entity.name == "__builtin:item" then
if self:try_merge_with(own_stack, obj, entity) then
own_stack = ItemStack(self.itemstring)
if own_stack:get_free_space() == 0 then
return
end
end
end
end
end,
on_punch = function(self, hitter)
local inv = hitter:get_inventory()
if inv and self.itemstring ~= "" then
local left = inv:add_item("main", self.itemstring)
if left and not left:is_empty() then
self:set_item(left)
return
end
end
self.itemstring = ""
self.object:remove()
end,
})