mods/minecart/init.lua

   1 local path = minetest.get_modpath("minecart")
   2 dofile(path.."/rail.lua")
   3
   4
   5 --get if rail
   6 local function rail(pos)
   7       return(minetest.get_node_group(minetest.get_node(pos).name,"rail")>0)
   8 end
   9
  10 --check if on rail
  11 local function on_rail(self,pos)
  12       if not rail(pos) and not self.slope then
  13             self.axis = nil
  14             return(false)
  15       else
  16             return(true)
  17       end
  18 end
  19
  20 --set physical state
  21 local function physical(self,pos)
  22       if on_rail(self,pos) then
  23             self.object:set_properties({physical = false})
  24             self.object:setacceleration(vector.new(0,0,0))
  25       elseif not self.slope then
  26             self.object:set_properties({physical = true})
  27             self.object:setacceleration(vector.new(0,-9.81,0))
  28       end
  29 end
  30
  31 --get if node in minecarts direction
  32 local function node_ahead(self,pos)
  33       local vel = self.object:getvelocity()
  34       local dir = vector.normalize(vel)
  35       return(rail(vector.add(pos,dir)))
  36 end
  37
  38 --get current axis (prefers x)
  39 local function axis(pos)
  40       if rail(pos) then
  41             if rail(vector.new(pos.x-1,pos.y,pos.z)) or rail(vector.new(pos.x+1,pos.y,pos.z)) then return("x") end
  42             if rail(vector.new(pos.x,pos.y,pos.z-1)) or rail(vector.new(pos.x,pos.y,pos.z+1)) then return("z") end
  43       end
  44 end
  45
  46 --snap object to rail
  47 local function snap_rail(self,pos)
  48       local slopy = self.slope
  49       if not slopy then print("the slope is nil") else
  50             print("the slope is ".. slopy)
  51       end
  52       local railpos = vector.floor(vector.add(pos, 0.5))
  53       local vel = self.object:getvelocity()
  54       if self.axis == "x" and pos.x ~= railpos.x then
  55             self.object:moveto(vector.new(pos.x,railpos.y,railpos.z))
  56             self.object:setvelocity(vector.new(vel.x,0,0))
  57             print("snapped to x")
  58             return
  59       end
  60       if self.axis == "z" and pos.z ~= railpos.z then
  61             self.object:moveto(vector.new(railpos.x,railpos.y,pos.z))
  62             self.object:setvelocity(vector.new(0,0,vel.z))
  63             print("snapped to z")
  64             return
  65       end
  66 end
  67
  68 --check if entering new position
  69 local function newnode(self,pos)
  70       local pos = vector.floor(vector.add(pos,0.5))
  71
  72       pos.y = 0
  73
  74       local equals = false
  75
  76
  77       if self.oldpos then
  78             equals = vector.equals(pos,self.oldpos)
  79       end
  80
  81       self.oldpos = pos
  82       return(not equals)
  83 end
  84
  85 --check if past center - used for turning
  86 local function pastcenter(self,pos)
  87
  88       local center = vector.floor(vector.add(pos,0.5))
  89       center.y = 0
  90       local pos2d = vector.new(pos.x,0,pos.z)
  91
  92       local vel = self.object:getvelocity()
  93       local dir = vector.normalize(vel)
  94       dir.y = 0
  95       local checker = vector.round(vector.normalize(vector.subtract(pos2d,center)))
  96       checker.y = 0
  97       local past = vector.equals(checker, dir)
  98       return(past)
  99 end
 100
 101 --check if node ahead
 102 local function node_forward(self,pos)
 103       local vel = self.object:getvelocity()
 104       local dir = vector.normalize(vel)
 105       return(rail(vector.add(pos,dir)))
 106 end
 107
 108 --check if node above or below
 109 local function check_hill(self,pos)
 110       local vel = self.object:getvelocity()
 111       local dirup = vector.normalize(vel)
 112
 113       dirup.y = dirup.y + 1
 114
 115       print(dump(dirup))
 116
 117       minetest.add_particlespawner({
 118             amount = 5,
 119             time = 0,
 120             minpos = vector.add(pos,dirup),
 121             maxpos = vector.add(pos,dirup),
 122             minvel = vector.new(0,0,0),
 123             maxvel = vector.new(0,0,0),
 124             minacc = {x=0, y=0, z=0},
 125             maxacc = {x=0, y=0, z=0},
 126             minexptime = 5,
 127             maxexptime = 5,
 128             minsize = 1,
 129             maxsize = 1,
 130             attached = player,
 131             collisiondetection = true,
 132             vertical = false,
 133             texture = "treecapitator.png"
 134       })
 135
 136       local dirdown = vector.new(0,-0.5,0)
 137
 138       if rail(vector.add(pos,dirup)) then
 139             self.slope = "up"
 140             return("up")
 141       elseif rail(vector.add(pos,dirdown)) then
 142             self.slope = "down"
 143             return("down")
 144       else
 145             self.slope = nil
 146             return(nil)
 147       end
 148 end
 149
 150 local function gravity(self,pos)
 151
 152       if self.slope == up then
 153             local vel = vector.multiply(self.object:getvelocity(), 0.95)
 154             self.object:set_velocity(vel)
 155       end
 156       if self.slope == up then
 157             local vel = vector.multiply(self.object:getvelocity(), 1.05)
 158             self.object:set_velocity(vel)
 159       end
 160
 161 end
 162
 163 --make the minecart go up and down hills
 164 local function navigate_hill(self)
 165       if self.slope then
 166             local vel = self.object:getvelocity()
 167             if self.slope == "up" then
 168
 169                   local yvel = 0
 170                   if self.axis == "x" then
 171                         yvel = math.abs(vel.x)*1.1
 172                   end
 173                   if self.axis == "z" then
 174                         yvel = math.abs(vel.z)*1.1
 175                   end
 176                   self.object:setvelocity(vector.new(vel.x,yvel,vel.z))
 177             elseif self.slope == "down" then
 178
 179                   local yvel = 0
 180                   if self.axis == "x" then
 181                         yvel = math.abs(vel.x)*-1
 182                   end
 183                   if self.axis == "z" then
 184                         yvel = math.abs(vel.z)*-1
 185                   end
 186
 187                   self.object:setvelocity(vector.new(vel.x,yvel,vel.z))
 188             end
 189       end
 190 end
 191
 192 --swap axis and speed 90 degrees
 193 local function turn_check(self,pos)
 194       local axis = self.axis
 195       local vel = self.object:getvelocity()
 196       vel.x = math.abs(vel.x)
 197       vel.y = math.abs(vel.y)
 198       vel.z = math.abs(vel.z)
 199
 200       if axis == "x" then
 201             if rail(vector.new(pos.x,pos.y,pos.z-1)) then
 202                   print("-x")
 203                   self.object:setvelocity(vector.new(0,0,vel.x*-1))
 204                   self.axis = "z"
 205                   snap_rail(self,pos)
 206                   self.turn_timer = 0
 207                   return
 208             elseif rail(vector.new(pos.x,pos.y,pos.z+1)) then
 209                   print("+x")
 210                   self.object:setvelocity(vector.new(0,0,vel.x))
 211                   self.axis = "z"
 212                   snap_rail(self,pos)
 213                   self.turn_timer = 0
 214                   return
 215             end
 216       end
 217       if axis == "z" then
 218             if rail(vector.new(pos.x-1,pos.y,pos.z)) then
 219                   print("-z")
 220                   self.object:setvelocity(vector.new(vel.z*-1,0,0))
 221                   self.axis = "x"
 222                   snap_rail(self,pos)
 223                   self.turn_timer = 0
 224                   return
 225             elseif rail(vector.new(pos.x+1,pos.y,pos.z)) then
 226                   print("+z")
 227                   self.object:setvelocity(vector.new(vel.z,0,0))
 228                   self.axis = "x"
 229                   snap_rail(self,pos)
 230                   self.turn_timer = 0
 231                   return
 232             end
 233       end
 234 end
 235 --try to turn
 236 local function turn(self,pos)
 237       if pastcenter(self,pos) then
 238             if not node_forward(self,pos) and self.axis then
 239                   turn_check(self,pos)
 240             end
 241       end
 242 end
 243
 244 --the main mechanics of the minecart
 245 local function minecart_brain(self,dtime)
 246       if self.turn_timer < 5 then
 247             self.turn_timer = self.turn_timer + dtime
 248       end
 249       local pos = self.object:getpos()
 250       pos.y = pos.y - 0.5
 251
 252
 253       if not self.axis then
 254             self.axis = axis(pos)
 255       end
 256
 257       if newnode(self,pos) then
 258             snap_rail(self,pos)
 259       end
 260       --check_hill(self,pos)
 261       --navigate_hill(self)
 262
 263
 264       turn(self,pos)
 265
 266       on_rail(self,pos)
 267       physical(self,pos)
 268       --print(self.axis)
 269
 270       --check if falling and then fall at the same speed to go down
 271 end
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312 minetest.register_entity("minecart:minecart", {
 313       initial_properties = {
 314             physical = true, -- otherwise going uphill breaks
 315             collisionbox = {-0.4, -0.5, -0.4, 0.4, 0.45, 0.4},--{-0.5, -0.4, -0.5, 0.5, 0.25, 0.5},
 316             visual = "mesh",
 317             mesh = "minecart.obj",
 318             visual_size = {x=1, y=1},
 319             textures = {"minecart.png"},
 320             automatic_face_movement_dir = 90.0,
 321             automatic_face_movement_max_rotation_per_sec = 600,
 322       },
 323
 324       rider = nil,
 325       punched = false,
 326       speed = 0,
 327       turn_timer = 0,
 328       incline = nil,
 329       turn_timer = 5,
 330
 331       on_rightclick = function(self,clicker)
 332             if not clicker or not clicker:is_player() then
 333                   return
 334             end
 335             local player_name = clicker:get_player_name()
 336
 337             if self.rider and player_name == self.rider then
 338                   self.rider = nil
 339                   --carts:manage_attachment(clicker, nil)
 340             elseif not self.rider then
 341                   self.rider = player_name
 342                   clicker:set_attach(self.object, "", {x=0, y=-4.5, z=0}, {x=0, y=0, z=0})
 343                   --player:set_eye_offset({x=0, y=-4, z=0},{x=0, y=-4, z=0})
 344                   --carts:manage_attachment(clicker, self.object)
 345
 346                   -- player_api does not update the animation
 347                   -- when the player is attached, reset to default animation
 348
 349                   --player_api.set_animation(clicker, "stand")
 350             end
 351       end,
 352
 353       on_activate = function(self,staticdata, dtime_s)
 354             self.object:set_armor_groups({immortal=1})
 355             if string.sub(staticdata, 1, string.len("return")) ~= "return" then
 356                   return
 357             end
 358             local data = minetest.deserialize(staticdata)
 359             if type(data) ~= "table" then
 360                   return
 361             end
 362             self.railtype = data.railtype
 363             if data.old_dir then
 364                   self.old_dir = data.old_dir
 365             end
 366       end,
 367
 368       get_staticdata = function(self)
 369             return minetest.serialize({
 370             })
 371       end,
 372
 373       on_punch = function(self,puncher, time_from_last_punch, tool_capabilities, dir, damage)
 374             local obj = minetest.add_item(self.object:getpos(), "minecart:minecart")
 375             obj:get_luaentity().collection_timer = 2
 376             self.object:remove()
 377       end,
 378
 379       --repel from players on track "push"
 380       push = function(self)
 381             if self.turn_timer > 0.3 then
 382                   local pos = self.object:getpos()
 383                   local radius = 1.2
 384                   for _,object in ipairs(minetest.get_objects_inside_radius(pos, radius)) do
 385                         if object:is_player() and object:get_player_name() ~= self.rider then
 386                               local player_pos = object:getpos()
 387                               pos.y = 0
 388                               player_pos.y = 0
 389
 390                               local currentvel = self.object:getvelocity()
 391                               local vel = vector.subtract(pos, player_pos)
 392                               vel = vector.normalize(vel)
 393                               local distance = vector.distance(pos,player_pos)
 394                               distance = (radius-distance)*20
 395                               vel = vector.multiply(vel,distance)
 396                               local acceleration = vector.new(vel.x-currentvel.x,0,vel.z-currentvel.z)
 397
 398
 399                               if self.axis == "x"      then
 400                                     self.object:add_velocity(vector.new(acceleration.x,0,0))
 401                               elseif self.axis == "z" then
 402                                     self.object:add_velocity(vector.new(0,0,acceleration.z))
 403                               else
 404                                     self.object:add_velocity(acceleration)
 405                               end
 406
 407                               acceleration = vector.multiply(acceleration, -0.5)
 408                               object:add_player_velocity(acceleration)
 409                         end
 410                   end
 411             end
 412       end,
 413
 414       --slows the minecart down
 415       slowdown = function(self)
 416             if not self.moving == true then
 417                   local vel = self.object:getvelocity()
 418                   local deceleration = vector.multiply(vel, -0.01)
 419                   self.object:add_velocity(deceleration)
 420             end
 421       end,
 422
 423       --mechanics to follow rails
 424       ride_rail = function(self,dtime)
 425             minecart_brain(self,dtime)
 426       end,
 427
 428       on_step = function(self,dtime)
 429             self.push(self)
 430             self.slowdown(self)
 431             self.ride_rail(self,dtime)
 432       end,
 433
 434 })
 435
 436 minetest.register_craftitem("minecart:minecart", {
 437       description = "Minecart",
 438       inventory_image = "minecartitem.png",
 439       wield_image = "minecartitem.png",
 440       on_place = function(itemstack, placer, pointed_thing)
 441             if not pointed_thing.type == "node" then
 442                   return
 443             end
 444
 445             if minetest.get_item_group(minetest.get_node(pointed_thing.under).name, "rail")>0 then
 446                   minetest.add_entity(pointed_thing.under, "minecart:minecart")
 447             else
 448                   return
 449             end
 450
 451             itemstack:take_item()
 452
 453             return itemstack
 454       end,
 455 })
 456
 457 minetest.register_craft({
 458       output = "minecart:minecart",
 459       recipe = {
 460             {"main:iron", "", "main:iron"},
 461             {"main:iron", "main:iron", "main:iron"},
 462       },
 463 })