minetest/builtin/game/falling.lua
paramat 3c5da70d7c Builtin/../falling: Fix bugs caused by 'ignore' nodes
Original commit by t4im, rebased and developed by paramat.
Fix CONTENT_IGNORE being replaced by falling nodes or causing large
areas of sand to collapse into itself.
Format some conditional code for clarity.
Add and clarify some comments.
2016-11-07 21:55:17 +00:00

275 lines
7.3 KiB
Lua

-- Minetest: builtin/item.lua
--
-- Falling stuff
--
core.register_entity(":__builtin:falling_node", {
initial_properties = {
visual = "wielditem",
visual_size = {x = 0.667, y = 0.667},
textures = {},
physical = true,
is_visible = false,
collide_with_objects = false,
collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
},
node = {},
set_node = function(self, node)
self.node = node
self.object:set_properties({
is_visible = true,
textures = {node.name},
})
end,
get_staticdata = function(self)
return core.serialize(self.node)
end,
on_activate = function(self, staticdata)
self.object:set_armor_groups({immortal = 1})
local node = core.deserialize(staticdata)
if node then
self:set_node(node)
elseif staticdata ~= "" then
self:set_node({name = staticdata})
end
end,
on_step = function(self, dtime)
-- Set gravity
local acceleration = self.object:getacceleration()
if not vector.equals(acceleration, {x = 0, y = -10, z = 0}) then
self.object:setacceleration({x = 0, y = -10, z = 0})
end
-- Turn to actual node when colliding with ground, or continue to move
local pos = self.object:getpos()
-- Position of bottom center point
local bcp = {x = pos.x, y = pos.y - 0.7, z = pos.z}
-- Avoid bugs caused by an unloaded node below
local bcn = core.get_node_or_nil(bcp)
local bcd = bcn and core.registered_nodes[bcn.name]
if bcn and
(not bcd or bcd.walkable or
(core.get_item_group(self.node.name, "float") ~= 0 and
bcd.liquidtype ~= "none")) then
if bcd and bcd.leveled and
bcn.name == self.node.name then
local addlevel = self.node.level
if not addlevel or addlevel <= 0 then
addlevel = bcd.leveled
end
if core.add_node_level(bcp, addlevel) == 0 then
self.object:remove()
return
end
elseif bcd and bcd.buildable_to and
(core.get_item_group(self.node.name, "float") == 0 or
bcd.liquidtype == "none") then
core.remove_node(bcp)
return
end
local np = {x = bcp.x, y = bcp.y + 1, z = bcp.z}
-- Check what's here
local n2 = core.get_node(np)
local nd = core.registered_nodes[n2.name]
-- If it's not air or liquid, remove node and replace it with
-- it's drops
if n2.name ~= "air" and (not nd or nd.liquidtype == "none") then
core.remove_node(np)
if nd.buildable_to == false then
-- Add dropped items
local drops = core.get_node_drops(n2.name, "")
for _, dropped_item in pairs(drops) do
core.add_item(np, dropped_item)
end
end
-- Run script hook
for _, callback in pairs(core.registered_on_dignodes) do
callback(np, n2)
end
end
-- Create node and remove entity
if core.registered_nodes[self.node.name] then
core.add_node(np, self.node)
end
self.object:remove()
nodeupdate(np)
return
end
local vel = self.object:getvelocity()
if vector.equals(vel, {x = 0, y = 0, z = 0}) then
local npos = self.object:getpos()
self.object:setpos(vector.round(npos))
end
end
})
function spawn_falling_node(p, node)
local obj = core.add_entity(p, "__builtin:falling_node")
obj:get_luaentity():set_node(node)
end
function drop_attached_node(p)
local nn = core.get_node(p).name
core.remove_node(p)
for _, item in pairs(core.get_node_drops(nn, "")) do
local pos = {
x = p.x + math.random()/2 - 0.25,
y = p.y + math.random()/2 - 0.25,
z = p.z + math.random()/2 - 0.25,
}
core.add_item(pos, item)
end
end
function check_attached_node(p, n)
local def = core.registered_nodes[n.name]
local d = {x = 0, y = 0, z = 0}
if def.paramtype2 == "wallmounted" then
-- The fallback vector here is in case 'wallmounted to dir' is nil due
-- to voxelmanip placing a wallmounted node without resetting a
-- pre-existing param2 value that is out-of-range for wallmounted.
-- The fallback vector corresponds to param2 = 0.
d = core.wallmounted_to_dir(n.param2) or {x = 0, y = 1, z = 0}
else
d.y = -1
end
local p2 = vector.add(p, d)
local nn = core.get_node(p2).name
local def2 = core.registered_nodes[nn]
if def2 and not def2.walkable then
return false
end
return true
end
--
-- Some common functions
--
function nodeupdate_single(p)
local n = core.get_node(p)
if core.get_item_group(n.name, "falling_node") ~= 0 then
local p_bottom = {x = p.x, y = p.y - 1, z = p.z}
-- Only spawn falling node if node below is loaded
local n_bottom = core.get_node_or_nil(p_bottom)
local d_bottom = n_bottom and core.registered_nodes[n_bottom.name]
if d_bottom and
(core.get_item_group(n.name, "float") == 0 or
d_bottom.liquidtype == "none") and
(n.name ~= n_bottom.name or (d_bottom.leveled and
core.get_node_level(p_bottom) <
core.get_node_max_level(p_bottom))) and
(not d_bottom.walkable or d_bottom.buildable_to) then
n.level = core.get_node_level(p)
core.remove_node(p)
spawn_falling_node(p, n)
return true
end
end
if core.get_item_group(n.name, "attached_node") ~= 0 then
if not check_attached_node(p, n) then
drop_attached_node(p)
return true
end
end
return false
end
-- This table is specifically ordered.
-- We don't walk diagonals, only our direct neighbors, and self.
-- Down first as likely case, but always before self. The same with sides.
-- Up must come last, so that things above self will also fall all at once.
local nodeupdate_neighbors = {
{x = -1, y = -1, z = 0},
{x = 1, y = -1, z = 0},
{x = 0, y = -1, z = -1},
{x = 0, y = -1, z = 1},
{x = 0, y = -1, z = 0},
{x = -1, y = 0, z = 0},
{x = 1, y = 0, z = 0},
{x = 0, y = 0, z = 1},
{x = 0, y = 0, z = -1},
{x = 0, y = 0, z = 0},
{x = 0, y = 1, z = 0},
}
function nodeupdate(p)
-- Round p to prevent falling entities to get stuck.
p = vector.round(p)
-- We make a stack, and manually maintain size for performance.
-- Stored in the stack, we will maintain tables with pos, and
-- last neighbor visited. This way, when we get back to each
-- node, we know which directions we have already walked, and
-- which direction is the next to walk.
local s = {}
local n = 0
-- The neighbor order we will visit from our table.
local v = 1
while true do
-- Push current pos onto the stack.
n = n + 1
s[n] = {p = p, v = v}
-- Select next node from neighbor list.
p = vector.add(p, nodeupdate_neighbors[v])
-- Now we check out the node. If it is in need of an update,
-- it will let us know in the return value (true = updated).
if not nodeupdate_single(p) then
-- If we don't need to "recurse" (walk) to it then pop
-- our previous pos off the stack and continue from there,
-- with the v value we were at when we last were at that
-- node
repeat
local pop = s[n]
p = pop.p
v = pop.v
s[n] = nil
n = n - 1
-- If there's nothing left on the stack, and no
-- more sides to walk to, we're done and can exit
if n == 0 and v == 11 then
return
end
until v < 11
-- The next round walk the next neighbor in list.
v = v + 1
else
-- If we did need to walk the neighbor, then
-- start walking it from the walk order start (1),
-- and not the order we just pushed up the stack.
v = 1
end
end
end
--
-- Global callbacks
--
function on_placenode(p, node)
nodeupdate(p)
end
core.register_on_placenode(on_placenode)
function on_dignode(p, node)
nodeupdate(p)
end
core.register_on_dignode(on_dignode)
function on_punchnode(p, node)
nodeupdate(p)
end
core.register_on_punchnode(on_punchnode)