Epic/mods/mobs_monster/spider.lua

local S = mobs.intllib_monster

local get_velocity = function(self)

   local v = self.object:get_velocity()

   -- sanity check
   if not v then return 0 end

   return (v.x * v.x + v.z * v.z) ^ 0.5
end


local spider_types = {

   {  nodes = {"default:snow", "default:snowblock", "default:dirt_with_snow"},
      skins = {"mobs_spider_snowy.png"},
      docile = true,
      drops = {
         {name = "farming:string", chance = 1, min = 0, max = 2},
         {name = "commoditymarket:gold_coins", chance = 11, min = 3, max = 15},
         {name = "scorpion:shell", chance = 1, min = 1, max = 4}},
   },

   {  nodes = {"default:dirt_with_rainforest_litter", "default:jungletree"},
      skins = {"mobs_spider_orange.png"},
      docile = true,
      drops = {
         {name = "farming:string", chance = 1, min = 0, max = 5},
         {name = "commoditymarket:gold_coins", chance = 11, min = 3, max = 15},
         {name = "scorpion:shell", chance = 1, min = 1, max = 4}},
      shoot = true
   },

   {   nodes = {"default:stone", "default:gravel"},
      skins = {"mobs_spider_grey.png"},
      docile = nil,
      drops = {
         {name = "farming:string", chance = 1, min = 0, max = 4},
         {name = "commoditymarket:gold_coins", chance = 11, min = 3, max = 15},
         {name = "scorpion:shell", chance = 1, min = 1, max = 4}},
      small = true
   },

   {  nodes = {"default:mese", "default:stone_with_mese"},
      skins = {"mobs_spider_mese.png"},
      docile = nil,
      drops = {
         {name = "farming:string", chance = 1, min = 0, max = 4},
         {name = "default:mese_crystal_fragment", chance = 2, min = 1, max = 4},
         {name = "commoditymarket:gold_coins", chance = 11, min = 3, max = 15},
		   {name = "scorpion:shell", chance = 1, min = 1, max = 4}}
   },

   {  nodes = {"ethereal:crystal_dirt", "ethereal:crystal_spike"},
      skins = {"mobs_spider_crystal.png"},
      docile = true,
      drops = {
         {name = "farming:string", chance = 1, min = 0, max = 2},
         {name = "ethereal:crystal_spike", chance = 15, min = 1, max = 2},
         {name = "scorpion:shell", chance = 2, min = 1, max = 8}}
   }
}


-- Spider by AspireMint (CC-BY-SA 3.0 license)

mobs:register_mob("mobs_monster:spider", {
   --docile_by_day = true,
   group_attack = true,
   type = "monster",
   passive = false,
   attack_type = "dogfight",
   reach = 2,
   damage = 5,
   damage_max = 7,
   damage_chance = 50,
   hp_min = 10,
   hp_max = 30,
   armor = 200,
   collisionbox = {-0.8, -0.5, -0.8, 0.8, 0, 0.8},
   visual_size = {x = 1, y = 1},
   visual = "mesh",
   mesh = "mobs_spider.b3d",
   textures = {
      {"mobs_spider_mese.png"},
      {"mobs_spider_orange.png"},
      {"mobs_spider_snowy.png"},
      {"mobs_spider_grey.png"},
      {"mobs_spider_crystal.png"}
   },
   makes_footstep_sound = false,
   sounds = {
      random = "mobs_spider",
      attack = "mobs_spider"
   },
   walk_velocity = 1,
   run_velocity = 3,
   jump = true,
   view_range = 15,
   floats = 0,
   drops = {
      {name = "farming:string", chance = 1, min = 0, max = 2}
   },
   water_damage = 5,
   lava_damage = 5,
   light_damage = 0,
   animation = {
      speed_normal = 15,
      speed_run = 20,
      stand_start = 0,
      stand_end = 0,
      walk_start = 1,
      walk_end = 21,
      run_start = 1,
      run_end = 21,
      punch_start = 25,
      punch_end = 45
   },

   -- check surrounding nodes and spawn a specific spider
   on_spawn = function(self)

      local pos = self.object:get_pos() ; pos.y = pos.y - 1
      local tmp

      for n = 1, #spider_types do

         tmp = spider_types[n]

         if minetest.find_node_near(pos, 1, tmp.nodes) then

            self.base_texture = tmp.skins
            self.object:set_properties({textures = tmp.skins})
            self.docile_by_day = tmp.docile

            if tmp.drops then
               self.drops = tmp.drops
            end

            if tmp.shoot then
               self.attack_type = "dogshoot"
               self.arrow = "mobs_monster:cobweb"
               self.dogshoot_switch = 1
               self.dogshoot_count_max = 60
               self.dogshoot_count2_max = 20
               self.shoot_interval = 2
               self.shoot_offset = 2
            end

            if tmp.small then
               self.object:set_properties({
                  collisionbox = {-0.2, -0.2, -0.2, 0.2, 0, 0.2},
                  visual_size = {x = 0.25, y = 0.25}
               })
            end

            return true
         end
      end

      return true -- run only once, false/nil runs every activation
   end,

   -- custom function to make spiders climb vertical facings
   do_custom = function(self, dtime)

      -- quarter second timer
      self.spider_timer = (self.spider_timer or 0) + dtime
      if self.spider_timer < 0.25 then
         return
      end
      self.spider_timer = 0

      -- need to be stopped to go onwards
      if get_velocity(self) > 0.5 then
         self.disable_falling = nil
         return
      end

      local pos = self.object:get_pos()
      local yaw = self.object:get_yaw()

      -- sanity check
      if not yaw then return end

      pos.y = pos.y + self.collisionbox[2] - 0.2

      local dir_x = -math.sin(yaw) * (self.collisionbox[4] + 0.5)
      local dir_z = math.cos(yaw) * (self.collisionbox[4] + 0.5)
      local nod = minetest.get_node_or_nil({
         x = pos.x + dir_x,
         y = pos.y + 0.5,
         z = pos.z + dir_z
      })

      -- get current velocity
      local v = self.object:get_velocity()

      -- can only climb solid facings
      if not nod or not minetest.registered_nodes[nod.name]
      or not minetest.registered_nodes[nod.name].walkable then
         self.disable_falling = nil
         v.y = 0
         self.object:set_velocity(v)
         return
      end

--print ("----", nod.name, self.disable_falling, dtime)

      -- turn off falling if attached to facing
      self.disable_falling = true

      -- move up facing
      v.x = 0 ; v.y = 0
      v.y = self.jump_height
      mobs:set_animation(self, "jump")
      self.object:set_velocity(v)
   end,

   -- make spiders jump at you on attack
   custom_attack = function(self, pos)

      local vel = self.object:get_velocity()

      self.object:set_velocity({
         x = vel.x * self.run_velocity,
         y = self.jump_height * 1.5,
         z = vel.z * self.run_velocity
      })

      self.pausetimer = 0.5

      return true -- continue rest of attack function
   end
})


if not mobs.custom_spawn_monster then

   -- above ground spawn
   mobs:spawn({
      name = "mobs_monster:spider",
      nodes = {
         "default:dirt_with_rainforest_litter", "default:snowblock",
         "default:snow", "ethereal:crystal_dirt", "ethereal:cold_dirt"
      },
      min_light = 0,
      max_light = 8,
      chance = 7000,
      active_object_count = 1,
      min_height = 25,
      max_height = 31000
   })

   -- below ground spawn
   mobs:spawn({
      name = "mobs_monster:spider",
      nodes = {"default:stone_with_mese", "default:mese", "default:stone"},
      min_light = 0,
      max_light = 7,
      chance = 7000,
      active_object_count = 1,
      min_height = -31000,
      max_height = -40
   })
end


mobs:register_egg("mobs_monster:spider", S("Spider"), "mobs_cobweb.png", 1)


mobs:alias_mob("mobs_monster:spider2", "mobs_monster:spider") -- compatibility
mobs:alias_mob("mobs:spider", "mobs_monster:spider")


-- cobweb
minetest.register_node(":mobs:cobweb", {
   description = S("Cobweb"),
   drawtype = "plantlike",
   visual_scale = 1.2,
   tiles = {"mobs_cobweb.png"},
   inventory_image = "mobs_cobweb.png",
   paramtype = "light",
   sunlight_propagates = true,
   liquid_viscosity = 11,
   liquidtype = "source",
   liquid_alternative_flowing = "mobs:cobweb",
   liquid_alternative_source = "mobs:cobweb",
   liquid_renewable = false,
   liquid_range = 0,
   walkable = false,
   groups = {snappy = 1, disable_jump = 1},
   drop = "farming:string",
   sounds = default and default.node_sound_leaves_defaults()
})

minetest.register_craft({
   output = "mobs:cobweb",
   recipe = {
      {"farming:string", "", "farming:string"},
      {"", "farming:string", ""},
      {"farming:string", "", "farming:string"}
   }
})


local web_place = function(pos)

   if minetest.find_node_near(pos, 1, {"ignore"}) then return end

   local pos2 = minetest.find_node_near(pos, 1, {"air", "group:leaves"}, true)

   if pos2 then
      minetest.swap_node(pos2, {name = "mobs:cobweb"})
   end
end

mobs:register_arrow("mobs_monster:cobweb", {
   visual = "sprite",
   visual_size = {x = 1, y = 1},
   textures = {"mobs_cobweb.png"},
   collisionbox = {-0.1, -0.1, -0.1, 0.1, 0.1, 0.1},
   velocity = 15,
   tail = 1,
   tail_texture = "mobs_cobweb.png",
   tail_size = 5,
   glow = 2,
   expire = 0.1,

   hit_player = function(self, player)

      player:punch(self.object, 1.0, {
         full_punch_interval = 2.0,
         damage_groups = {fleshy = 3}
      }, nil)

      web_place(self.object:get_pos())
   end,

   hit_node = function(self, pos, node)
      web_place(pos)
   end,

   hit_mob = function(self, player)

      player:punch(self.object, 1.0, {
         full_punch_interval = 2.0,
         damage_groups = {fleshy = 3}
      }, nil)
   end
})