builtin/game/falling.lua

   1 -- Minetest: builtin/item.lua
   2
   3 local builtin_shared = ...
   4 local SCALE = 0.667
   5
   6 local facedir_to_euler = {
   7         {y = 0, x = 0, z = 0},
   8         {y = -math.pi/2, x = 0, z = 0},
   9         {y = math.pi, x = 0, z = 0},
  10         {y = math.pi/2, x = 0, z = 0},
  11         {y = math.pi/2, x = -math.pi/2, z = math.pi/2},
  12         {y = math.pi/2, x = math.pi, z = math.pi/2},
  13         {y = math.pi/2, x = math.pi/2, z = math.pi/2},
  14         {y = math.pi/2, x = 0, z = math.pi/2},
  15         {y = -math.pi/2, x = math.pi/2, z = math.pi/2},
  16         {y = -math.pi/2, x = 0, z = math.pi/2},
  17         {y = -math.pi/2, x = -math.pi/2, z = math.pi/2},
  18         {y = -math.pi/2, x = math.pi, z = math.pi/2},
  19         {y = 0, x = 0, z = math.pi/2},
  20         {y = 0, x = -math.pi/2, z = math.pi/2},
  21         {y = 0, x = math.pi, z = math.pi/2},
  22         {y = 0, x = math.pi/2, z = math.pi/2},
  23         {y = math.pi, x = math.pi, z = math.pi/2},
  24         {y = math.pi, x = math.pi/2, z = math.pi/2},
  25         {y = math.pi, x = 0, z = math.pi/2},
  26         {y = math.pi, x = -math.pi/2, z = math.pi/2},
  27         {y = math.pi, x = math.pi, z = 0},
  28         {y = -math.pi/2, x = math.pi, z = 0},
  29         {y = 0, x = math.pi, z = 0},
  30         {y = math.pi/2, x = math.pi, z = 0}
  31 }
  32
  33 local gravity = tonumber(core.settings:get("movement_gravity")) or 9.81
  34
  35 --
  36 -- Falling stuff
  37 --
  38
  39 core.register_entity(":__builtin:falling_node", {
  40         initial_properties = {
  41                 visual = "item",
  42                 visual_size = vector.new(SCALE, SCALE, SCALE),
  43                 textures = {},
  44                 physical = true,
  45                 is_visible = false,
  46                 collide_with_objects = true,
  47                 collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
  48         },
  49
  50         node = {},
  51         meta = {},
  52         floats = false,
  53
  54         set_node = function(self, node, meta)
  55                 node.param2 = node.param2 or 0
  56                 self.node = node
  57                 meta = meta or {}
  58                 if type(meta.to_table) == "function" then
  59                         meta = meta:to_table()
  60                 end
  61                 for _, list in pairs(meta.inventory or {}) do
  62                         for i, stack in pairs(list) do
  63                                 if type(stack) == "userdata" then
  64                                         list[i] = stack:to_string()
  65                                 end
  66                         end
  67                 end
  68                 local def = core.registered_nodes[node.name]
  69                 if not def then
  70                         -- Don't allow unknown nodes to fall
  71                         core.log("info",
  72                                 "Unknown falling node removed at "..
  73                                 core.pos_to_string(self.object:get_pos()))
  74                         self.object:remove()
  75                         return
  76                 end
  77                 self.meta = meta
  78
  79                 -- Cache whether we're supposed to float on water
  80                 self.floats = core.get_item_group(node.name, "float") ~= 0
  81
  82                 -- Set entity visuals
  83                 if def.drawtype == "torchlike" or def.drawtype == "signlike" then
  84                         local textures
  85                         if def.tiles and def.tiles[1] then
  86                                 local tile = def.tiles[1]
  87                                 if type(tile) == "table" then
  88                                         tile = tile.name
  89                                 end
  90                                 if def.drawtype == "torchlike" then
  91                                         textures = { "("..tile..")^[transformFX", tile }
  92                                 else
  93                                         textures = { tile, "("..tile..")^[transformFX" }
  94                                 end
  95                         end
  96                         local vsize
  97                         if def.visual_scale then
  98                                 local s = def.visual_scale
  99                                 vsize = vector.new(s, s, s)
 100                         end
 101                         self.object:set_properties({
 102                                 is_visible = true,
 103                                 visual = "upright_sprite",
 104                                 visual_size = vsize,
 105                                 textures = textures,
 106                                 glow = def.light_source,
 107                         })
 108                 elseif def.drawtype ~= "airlike" then
 109                         local itemstring = node.name
 110                         if core.is_colored_paramtype(def.paramtype2) then
 111                                 itemstring = core.itemstring_with_palette(itemstring, node.param2)
 112                         end
 113                         -- FIXME: solution needed for paramtype2 == "leveled"
 114                         local vsize
 115                         if def.visual_scale then
 116                                 local s = def.visual_scale * SCALE
 117                                 vsize = vector.new(s, s, s)
 118                         end
 119                         self.object:set_properties({
 120                                 is_visible = true,
 121                                 wield_item = itemstring,
 122                                 visual_size = vsize,
 123                                 glow = def.light_source,
 124                         })
 125                 end
 126
 127                 -- Set collision box (certain nodeboxes only for now)
 128                 local nb_types = {fixed=true, leveled=true, connected=true}
 129                 if def.drawtype == "nodebox" and def.node_box and
 130                         nb_types[def.node_box.type] and def.node_box.fixed then
 131                         local box = table.copy(def.node_box.fixed)
 132                         if type(box[1]) == "table" then
 133                                 box = #box == 1 and box[1] or nil -- We can only use a single box
 134                         end
 135                         if box then
 136                                 if def.paramtype2 == "leveled" and (self.node.level or 0) > 0 then
 137                                         box[5] = -0.5 + self.node.level / 64
 138                                 end
 139                                 self.object:set_properties({
 140                                         collisionbox = box
 141                                 })
 142                         end
 143                 end
 144
 145                 -- Rotate entity
 146                 if def.drawtype == "torchlike" then
 147                         self.object:set_yaw(math.pi*0.25)
 148                 elseif ((node.param2 ~= 0 or def.drawtype == "nodebox" or def.drawtype == "mesh")
 149                                 and (def.wield_image == "" or def.wield_image == nil))
 150                                 or def.drawtype == "signlike"
 151                                 or def.drawtype == "mesh"
 152                                 or def.drawtype == "normal"
 153                                 or def.drawtype == "nodebox" then
 154                         if (def.paramtype2 == "facedir" or def.paramtype2 == "colorfacedir") then
 155                                 local fdir = node.param2 % 32
 156                                 -- Get rotation from a precalculated lookup table
 157                                 local euler = facedir_to_euler[fdir + 1]
 158                                 if euler then
 159                                         self.object:set_rotation(euler)
 160                                 end
 161                         elseif (def.paramtype2 == "wallmounted" or def.paramtype2 == "colorwallmounted" or def.drawtype == "signlike") then
 162                                 local rot = node.param2 % 8
 163                                 if (def.drawtype == "signlike" and def.paramtype2 ~= "wallmounted" and def.paramtype2 ~= "colorwallmounted") then
 164                                         -- Change rotation to "floor" by default for non-wallmounted paramtype2
 165                                         rot = 1
 166                                 end
 167                                 local pitch, yaw, roll = 0, 0, 0
 168                                 if def.drawtype == "nodebox" or def.drawtype == "mesh" then
 169                                         if rot == 0 then
 170                                                 pitch, yaw = math.pi/2, 0
 171                                         elseif rot == 1 then
 172                                                 pitch, yaw = -math.pi/2, math.pi
 173                                         elseif rot == 2 then
 174                                                 pitch, yaw = 0, math.pi/2
 175                                         elseif rot == 3 then
 176                                                 pitch, yaw = 0, -math.pi/2
 177                                         elseif rot == 4 then
 178                                                 pitch, yaw = 0, math.pi
 179                                         end
 180                                 else
 181                                         if rot == 1 then
 182                                                 pitch, yaw = math.pi, math.pi
 183                                         elseif rot == 2 then
 184                                                 pitch, yaw = math.pi/2, math.pi/2
 185                                         elseif rot == 3 then
 186                                                 pitch, yaw = math.pi/2, -math.pi/2
 187                                         elseif rot == 4 then
 188                                                 pitch, yaw = math.pi/2, math.pi
 189                                         elseif rot == 5 then
 190                                                 pitch, yaw = math.pi/2, 0
 191                                         end
 192                                 end
 193                                 if def.drawtype == "signlike" then
 194                                         pitch = pitch - math.pi/2
 195                                         if rot == 0 then
 196                                                 yaw = yaw + math.pi/2
 197                                         elseif rot == 1 then
 198                                                 yaw = yaw - math.pi/2
 199                                         end
 200                                 elseif def.drawtype == "mesh" or def.drawtype == "normal" or def.drawtype == "nodebox" then
 201                                         if rot >= 0 and rot <= 1 then
 202                                                 roll = roll + math.pi
 203                                         else
 204                                                 yaw = yaw + math.pi
 205                                         end
 206                                 end
 207                                 self.object:set_rotation({x=pitch, y=yaw, z=roll})
 208                         elseif (def.drawtype == "mesh" and def.paramtype2 == "degrotate") then
 209                                 local p2 = (node.param2 - (def.place_param2 or 0)) % 240
 210                                 local yaw = (p2 / 240) * (math.pi * 2)
 211                                 self.object:set_yaw(yaw)
 212                         elseif (def.drawtype == "mesh" and def.paramtype2 == "colordegrotate") then
 213                                 local p2 = (node.param2 % 32 - (def.place_param2 or 0) % 32) % 24
 214                                 local yaw = (p2 / 24) * (math.pi * 2)
 215                                 self.object:set_yaw(yaw)
 216                         end
 217                 end
 218         end,
 219
 220         get_staticdata = function(self)
 221                 local ds = {
 222                         node = self.node,
 223                         meta = self.meta,
 224                 }
 225                 return core.serialize(ds)
 226         end,
 227
 228         on_activate = function(self, staticdata)
 229                 self.object:set_armor_groups({immortal = 1})
 230                 self.object:set_acceleration(vector.new(0, -gravity, 0))
 231
 232                 local ds = core.deserialize(staticdata)
 233                 if ds and ds.node then
 234                         self:set_node(ds.node, ds.meta)
 235                 elseif ds then
 236                         self:set_node(ds)
 237                 elseif staticdata ~= "" then
 238                         self:set_node({name = staticdata})
 239                 end
 240         end,
 241
 242         try_place = function(self, bcp, bcn)
 243                 local bcd = core.registered_nodes[bcn.name]
 244                 -- Add levels if dropped on same leveled node
 245                 if bcd and bcd.paramtype2 == "leveled" and
 246                                 bcn.name == self.node.name then
 247                         local addlevel = self.node.level
 248                         if (addlevel or 0) <= 0 then
 249                                 addlevel = bcd.leveled
 250                         end
 251                         if core.add_node_level(bcp, addlevel) < addlevel then
 252                                 return true
 253                         elseif bcd.buildable_to then
 254                                 -- Node level has already reached max, don't place anything
 255                                 return true
 256                         end
 257                 end
 258
 259                 -- Decide if we're replacing the node or placing on top
 260                 local np = vector.new(bcp)
 261                 if bcd and bcd.buildable_to and
 262                                 (not self.floats or bcd.liquidtype == "none") then
 263                         core.remove_node(bcp)
 264                 else
 265                         np.y = np.y + 1
 266                 end
 267
 268                 -- Check what's here
 269                 local n2 = core.get_node(np)
 270                 local nd = core.registered_nodes[n2.name]
 271                 -- If it's not air or liquid, remove node and replace it with
 272                 -- it's drops
 273                 if n2.name ~= "air" and (not nd or nd.liquidtype == "none") then
 274                         if nd and nd.buildable_to == false then
 275                                 nd.on_dig(np, n2, nil)
 276                                 -- If it's still there, it might be protected
 277                                 if core.get_node(np).name == n2.name then
 278                                         return false
 279                                 end
 280                         else
 281                                 core.remove_node(np)
 282                         end
 283                 end
 284
 285                 -- Create node
 286                 local def = core.registered_nodes[self.node.name]
 287                 if def then
 288                         core.add_node(np, self.node)
 289                         if self.meta then
 290                                 core.get_meta(np):from_table(self.meta)
 291                         end
 292                         if def.sounds and def.sounds.place then
 293                                 core.sound_play(def.sounds.place, {pos = np}, true)
 294                         end
 295                 end
 296                 core.check_for_falling(np)
 297                 return true
 298         end,
 299
 300         on_step = function(self, dtime, moveresult)
 301                 -- Fallback code since collision detection can't tell us
 302                 -- about liquids (which do not collide)
 303                 if self.floats then
 304                         local pos = self.object:get_pos()
 305
 306                         local bcp = pos:offset(0, -0.7, 0):round()
 307                         local bcn = core.get_node(bcp)
 308
 309                         local bcd = core.registered_nodes[bcn.name]
 310                         if bcd and bcd.liquidtype ~= "none" then
 311                                 if self:try_place(bcp, bcn) then
 312                                         self.object:remove()
 313                                         return
 314                                 end
 315                         end
 316                 end
 317
 318                 assert(moveresult)
 319                 if not moveresult.collides then
 320                         return -- Nothing to do :)
 321                 end
 322
 323                 local bcp, bcn
 324                 local player_collision
 325                 if moveresult.touching_ground then
 326                         for _, info in ipairs(moveresult.collisions) do
 327                                 if info.type == "object" then
 328                                         if info.axis == "y" and info.object:is_player() then
 329                                                 player_collision = info
 330                                         end
 331                                 elseif info.axis == "y" then
 332                                         bcp = info.node_pos
 333                                         bcn = core.get_node(bcp)
 334                                         break
 335                                 end
 336                         end
 337                 end
 338
 339                 if not bcp then
 340                         -- We're colliding with something, but not the ground. Irrelevant to us.
 341                         if player_collision then
 342                                 -- Continue falling through players by moving a little into
 343                                 -- their collision box
 344                                 -- TODO: this hack could be avoided in the future if objects
 345                                 --       could choose who to collide with
 346                                 local vel = self.object:get_velocity()
 347                                 self.object:set_velocity(vector.new(
 348                                         vel.x,
 349                                         player_collision.old_velocity.y,
 350                                         vel.z
 351                                 ))
 352                                 self.object:set_pos(self.object:get_pos():offset(0, -0.5, 0))
 353                         end
 354                         return
 355                 elseif bcn.name == "ignore" then
 356                         -- Delete on contact with ignore at world edges
 357                         self.object:remove()
 358                         return
 359                 end
 360
 361                 local failure = false
 362
 363                 local pos = self.object:get_pos()
 364                 local distance = vector.apply(vector.subtract(pos, bcp), math.abs)
 365                 if distance.x >= 1 or distance.z >= 1 then
 366                         -- We're colliding with some part of a node that's sticking out
 367                         -- Since we don't want to visually teleport, drop as item
 368                         failure = true
 369                 elseif distance.y >= 2 then
 370                         -- Doors consist of a hidden top node and a bottom node that is
 371                         -- the actual door. Despite the top node being solid, the moveresult
 372                         -- almost always indicates collision with the bottom node.
 373                         -- Compensate for this by checking the top node
 374                         bcp.y = bcp.y + 1
 375                         bcn = core.get_node(bcp)
 376                         local def = core.registered_nodes[bcn.name]
 377                         if not (def and def.walkable) then
 378                                 failure = true -- This is unexpected, fail
 379                         end
 380                 end
 381
 382                 -- Try to actually place ourselves
 383                 if not failure then
 384                         failure = not self:try_place(bcp, bcn)
 385                 end
 386
 387                 if failure then
 388                         local drops = core.get_node_drops(self.node, "")
 389                         for _, item in pairs(drops) do
 390                                 core.add_item(pos, item)
 391                         end
 392                 end
 393                 self.object:remove()
 394         end
 395 })
 396
 397 local function convert_to_falling_node(pos, node)
 398         local obj = core.add_entity(pos, "__builtin:falling_node")
 399         if not obj then
 400                 return false
 401         end
 402         -- remember node level, the entities' set_node() uses this
 403         node.level = core.get_node_level(pos)
 404         local meta = core.get_meta(pos)
 405         local metatable = meta and meta:to_table() or {}
 406
 407         local def = core.registered_nodes[node.name]
 408         if def and def.sounds and def.sounds.fall then
 409                 core.sound_play(def.sounds.fall, {pos = pos}, true)
 410         end
 411
 412         obj:get_luaentity():set_node(node, metatable)
 413         core.remove_node(pos)
 414         return true, obj
 415 end
 416
 417 function core.spawn_falling_node(pos)
 418         local node = core.get_node(pos)
 419         if node.name == "air" or node.name == "ignore" then
 420                 return false
 421         end
 422         return convert_to_falling_node(pos, node)
 423 end
 424
 425 local function drop_attached_node(p)
 426         local n = core.get_node(p)
 427         local drops = core.get_node_drops(n, "")
 428         local def = core.registered_items[n.name]
 429         if def and def.preserve_metadata then
 430                 local oldmeta = core.get_meta(p):to_table().fields
 431                 -- Copy pos and node because the callback can modify them.
 432                 local pos_copy = vector.new(p)
 433                 local node_copy = {name=n.name, param1=n.param1, param2=n.param2}
 434                 local drop_stacks = {}
 435                 for k, v in pairs(drops) do
 436                         drop_stacks[k] = ItemStack(v)
 437                 end
 438                 drops = drop_stacks
 439                 def.preserve_metadata(pos_copy, node_copy, oldmeta, drops)
 440         end
 441         if def and def.sounds and def.sounds.fall then
 442                 core.sound_play(def.sounds.fall, {pos = p}, true)
 443         end
 444         core.remove_node(p)
 445         for _, item in pairs(drops) do
 446                 local pos = {
 447                         x = p.x + math.random()/2 - 0.25,
 448                         y = p.y + math.random()/2 - 0.25,
 449                         z = p.z + math.random()/2 - 0.25,
 450                 }
 451                 core.add_item(pos, item)
 452         end
 453 end
 454
 455 function builtin_shared.check_attached_node(p, n)
 456         local def = core.registered_nodes[n.name]
 457         local d = vector.new()
 458         if def.paramtype2 == "wallmounted" or
 459                         def.paramtype2 == "colorwallmounted" then
 460                 -- The fallback vector here is in case 'wallmounted to dir' is nil due
 461                 -- to voxelmanip placing a wallmounted node without resetting a
 462                 -- pre-existing param2 value that is out-of-range for wallmounted.
 463                 -- The fallback vector corresponds to param2 = 0.
 464                 d = core.wallmounted_to_dir(n.param2) or vector.new(0, 1, 0)
 465         else
 466                 d.y = -1
 467         end
 468         local p2 = vector.add(p, d)
 469         local nn = core.get_node(p2).name
 470         local def2 = core.registered_nodes[nn]
 471         if def2 and not def2.walkable then
 472                 return false
 473         end
 474         return true
 475 end
 476
 477 --
 478 -- Some common functions
 479 --
 480
 481 function core.check_single_for_falling(p)
 482         local n = core.get_node(p)
 483         if core.get_item_group(n.name, "falling_node") ~= 0 then
 484                 local p_bottom = vector.offset(p, 0, -1, 0)
 485                 -- Only spawn falling node if node below is loaded
 486                 local n_bottom = core.get_node_or_nil(p_bottom)
 487                 local d_bottom = n_bottom and core.registered_nodes[n_bottom.name]
 488                 if d_bottom then
 489                         local same = n.name == n_bottom.name
 490                         -- Let leveled nodes fall if it can merge with the bottom node
 491                         if same and d_bottom.paramtype2 == "leveled" and
 492                                         core.get_node_level(p_bottom) <
 493                                         core.get_node_max_level(p_bottom) then
 494                                 convert_to_falling_node(p, n)
 495                                 return true
 496                         end
 497                         -- Otherwise only if the bottom node is considered "fall through"
 498                         if not same and
 499                                         (not d_bottom.walkable or d_bottom.buildable_to) and
 500                                         (core.get_item_group(n.name, "float") == 0 or
 501                                         d_bottom.liquidtype == "none") then
 502                                 convert_to_falling_node(p, n)
 503                                 return true
 504                         end
 505                 end
 506         end
 507
 508         if core.get_item_group(n.name, "attached_node") ~= 0 then
 509                 if not builtin_shared.check_attached_node(p, n) then
 510                         drop_attached_node(p)
 511                         return true
 512                 end
 513         end
 514
 515         return false
 516 end
 517
 518 -- This table is specifically ordered.
 519 -- We don't walk diagonals, only our direct neighbors, and self.
 520 -- Down first as likely case, but always before self. The same with sides.
 521 -- Up must come last, so that things above self will also fall all at once.
 522 local check_for_falling_neighbors = {
 523         vector.new(-1, -1,  0),
 524         vector.new( 1, -1,  0),
 525         vector.new( 0, -1, -1),
 526         vector.new( 0, -1,  1),
 527         vector.new( 0, -1,  0),
 528         vector.new(-1,  0,  0),
 529         vector.new( 1,  0,  0),
 530         vector.new( 0,  0,  1),
 531         vector.new( 0,  0, -1),
 532         vector.new( 0,  0,  0),
 533         vector.new( 0,  1,  0),
 534 }
 535
 536 function core.check_for_falling(p)
 537         -- Round p to prevent falling entities to get stuck.
 538         p = vector.round(p)
 539
 540         -- We make a stack, and manually maintain size for performance.
 541         -- Stored in the stack, we will maintain tables with pos, and
 542         -- last neighbor visited. This way, when we get back to each
 543         -- node, we know which directions we have already walked, and
 544         -- which direction is the next to walk.
 545         local s = {}
 546         local n = 0
 547         -- The neighbor order we will visit from our table.
 548         local v = 1
 549
 550         while true do
 551                 -- Push current pos onto the stack.
 552                 n = n + 1
 553                 s[n] = {p = p, v = v}
 554                 -- Select next node from neighbor list.
 555                 p = vector.add(p, check_for_falling_neighbors[v])
 556                 -- Now we check out the node. If it is in need of an update,
 557                 -- it will let us know in the return value (true = updated).
 558                 if not core.check_single_for_falling(p) then
 559                         -- If we don't need to "recurse" (walk) to it then pop
 560                         -- our previous pos off the stack and continue from there,
 561                         -- with the v value we were at when we last were at that
 562                         -- node
 563                         repeat
 564                                 local pop = s[n]
 565                                 p = pop.p
 566                                 v = pop.v
 567                                 s[n] = nil
 568                                 n = n - 1
 569                                 -- If there's nothing left on the stack, and no
 570                                 -- more sides to walk to, we're done and can exit
 571                                 if n == 0 and v == 11 then
 572                                         return
 573                                 end
 574                         until v < 11
 575                         -- The next round walk the next neighbor in list.
 576                         v = v + 1
 577                 else
 578                         -- If we did need to walk the neighbor, then
 579                         -- start walking it from the walk order start (1),
 580                         -- and not the order we just pushed up the stack.
 581                         v = 1
 582                 end
 583         end
 584 end
 585
 586 --
 587 -- Global callbacks
 588 --
 589
 590 local function on_placenode(p, node)
 591         core.check_for_falling(p)
 592 end
 593 core.register_on_placenode(on_placenode)
 594
 595 local function on_dignode(p, node)
 596         core.check_for_falling(p)
 597 end
 598 core.register_on_dignode(on_dignode)
 599
 600 local function on_punchnode(p, node)
 601         core.check_for_falling(p)
 602 end
 603 core.register_on_punchnode(on_punchnode)