split code, add mapgen, add eel, add nyancat, improved api, add growth, etc

README.txt

@@ -15,5 +15,10 @@ Code:
 LGPL v3
 
 Textures: 
-CC-0
+nyancat_front.png, nyancat_rainbow.png created by VanessaE, taken from Minetest Game. 
+Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) [http://creativecommons.org/licenses/by-sa/3.0/]
+
+every other texture is created by Gejan
+CC 0 [https://creativecommons.org/publicdomain/zero/1.0/]
+
   

api.lua

@@ -0,0 +1,314 @@
+local WALKING_PERIOD = worm.config.WALKING_PERIOD
+
+-- Defines a "worm" (spawnitem and nodes)
+-- @param modname   The name of the mod, which registers the nodes
+-- @param name      The name of the creature; Has to be unique
+-- @param data      A table containing:
+--   - leftover       The node placed behind the tail when moving away 
+--   - walking_steps  The number of steps to pass one node
+--   - can_move       A function (Position * Node -> Boolean) defining which nodes 
+--                    can be destroyed by the worm
+--   - flying         Movement behaviour
+--   - *_textures     (See examples)
+-- @return          True if successful
+worm.register_worm = function (modname, name, data)
+  -- default values:
+  if not data.leftover then
+    data.leftover = "air"
+  end  
+  if not data.walking_steps then
+    data.walking_steps = worm.config.DEFAULT_WALKING_STEPS
+  end 
+  if not data.can_move then
+    data.can_move = function(_, node)
+      return node.name == "air"
+    end
+  end
+  -- required values:
+  if not (data.face_texture and data.side_texture and data.tail_texture) then
+    print("[worm] register_worm of "..modname..":"..name.." failed because of incomplete data")
+    return false
+  end
+  -- reusing textures
+  if not data.bottem_texture then
+    data.bottem_texture = data.side_texture
+  end
+  if not data.top_texture then
+    data.top_texture = data.side_texture
+  end
+  if not data.left_texture then
+    data.left_texture = data.side_texture
+  end
+  if not data.inventory_image then
+    data.inventory_image = data.face_texture
+  end
+  if not data.spawn_in then
+    data.spawn_in = "air"
+  end
+  -- Definition of the spawn item
+  minetest.register_craftitem(modname..":"..name.."_spawnegg", {
+    description = "spawn "..name,
+    inventory_image = data.inventory_image,
+    on_use = function(itemstack, user, pointed_thing)
+      if pointed_thing.type ~= "node" then
+        return itemstack
+      end
+      local pos = pointed_thing.above 
+      local player_name = user:get_player_name()
+      if minetest.is_protected(pos, player_name) then
+        return itemstack
+      end
+      if minetest.get_node(pos).name ~= data.spawn_in then
+        return itemstack
+      end
+      local zero = {x = 0, y = 0, z = 0}
+      local player_dir = vector.subtract(zero, user:get_look_dir())
+      local facedir = minetest.dir_to_facedir(player_dir)
+      local dir = minetest.facedir_to_dir(facedir)
+      local length = itemstack:get_count()
+      minetest.set_node(pos, {
+        name = modname..":"..name.."_head_1",
+        param2 = facedir
+      })
+      local headtimer = minetest.get_node_timer(pos)
+      pos = vector.subtract(pos, dir)
+      local i = 0
+      while i < length do
+        if minetest.get_node(pos).name ~= data.spawn_in or 
+            (worm.config.TAIL_PROTECTION and minetest.is_protected(pos, player_name)) then
+          pos = vector.add(pos, dir)
+          minetest.set_node(pos, {
+            name = modname..":"..name.."_tail_1",
+            param2 = facedir
+          })
+          break
+        end
+        minetest.set_node(pos, {
+          name = modname..":"..name.."_body",
+          param2 = facedir
+        })
+        pos = vector.subtract(pos, dir)
+        i = i + 1
+      end
+      minetest.set_node(pos, {
+        name = modname..":"..name.."_tail_1",
+        param2 = facedir
+      })
+      local tailtimer = minetest.get_node_timer(pos)
+      headtimer:set(WALKING_PERIOD, 0)
+      tailtimer:set(WALKING_PERIOD, 0)
+      itemstack:take_item(i)
+      return itemstack
+    end,
+  })
+  
+  -- Definition of head nodes
+  for n = 1, data.walking_steps do
+    -- Called on nodetimer
+    -- Incomplete head -> Update the head
+    local step = function(pos, _)
+      local node = minetest.get_node(pos)
+      node.name = modname..":"..name.."_head_"..(n+1)
+      minetest.set_node(pos, node)
+      local timer = minetest.get_node_timer(pos)
+      timer:set(WALKING_PERIOD, 0)
+      return false
+    end
+    -- Complete head -> Move head to a different position
+    if n == data.walking_steps then
+      step = function(pos, _)
+        local node = minetest.get_node(pos)
+        local facedir = node.param2
+        local dirs         -- Hierarchy of preferred directions
+        if data.flying then
+          dirs = {
+            facedir % 4,  -- 4 -> 0 
+            (facedir + 1) % 4,
+            (facedir + 2) % 4,
+            (facedir + 3) % 4,
+            8,
+            4 
+          }
+        else
+          dirs = {
+            4,
+            facedir % 4,  -- 4 -> 0 
+            (facedir + 1) % 4,
+            (facedir + 2) % 4,
+            (facedir + 3) % 4,
+            8
+          }
+        end
+        for i = 1, 6 do
+          local newpos = vector.add(pos, minetest.facedir_to_dir(dirs[i]))
+          local newnode = minetest.get_node(newpos)
+          local grow = minetest.get_node_group(newnode.name, "swallowable")
+          if grow > 0 then
+            grow = grow + 1
+            if grow > data.walking_steps then
+              grow = data.walking_steps
+            end
+            minetest.set_node(newpos, {
+              name = modname..":"..name.."_head_"..grow, 
+              param2 = dirs[i]
+            })
+            minetest.set_node(pos, {
+              name = modname..":"..name.."_body",
+              param2 = dirs[i]
+            })
+            local timer = minetest.get_node_timer(newpos)
+            timer:set(WALKING_PERIOD, 0)
+            return false
+          elseif data.can_move(newpos, newnode) then
+            minetest.set_node(newpos, {
+              name = modname..":"..name.."_head_1", 
+              param2 = dirs[i]
+            })
+            minetest.set_node(pos, {
+              name = modname..":"..name.."_body",
+              param2 = dirs[i]
+            })
+            local timer = minetest.get_node_timer(newpos)
+            timer:set(WALKING_PERIOD, 0)
+            return false
+          end
+        end
+        -- Worm stuck
+        return true
+      end
+    end
+    local drawtype
+    if data.walking_steps > 1 then
+      drawtype = "nodebox"
+    end
+    minetest.register_node(modname..":"..name.."_head_"..n, {
+      description = name.." head",
+      paramtype = "light",
+      paramtype2 = "facedir",
+      drawtype = drawtype,
+      node_box = {
+        type = "fixed",
+        fixed = {
+          {-0.5, -0.5, -0.5, 0.5, 0.5, -0.5 + (1 / data.walking_steps) * n},
+        },
+      },
+      tiles = {
+        data.top_texture.."^[transform1",
+        data.bottem_texture.."^[transform3",
+        data.side_texture,
+        data.left_texture.."^[transform2",
+        data.face_texture,
+        data.side_texture
+      },
+      groups = {snappy = 1, level = 2, not_in_creative_inventory = 1},
+      damage_per_second = 10,
+      on_timer = step,
+      drop = "",
+    }) 
+  end
+  
+  -- Definition of the body node
+  minetest.register_node(modname..":"..name.."_body", {
+    description = name.." body part",
+    paramtype = "light",
+    paramtype2 = "facedir",
+    tiles = {
+      data.top_texture.."^[transform1",
+      data.bottem_texture.."^[transform3",
+      data.side_texture,
+      data.left_texture.."^[transform2",
+      data.side_texture,
+      data.side_texture
+    },
+    groups = {snappy = 1, level = 2, not_in_creative_inventory = 1},
+    -- Add a new tail to keep demolition
+    after_dig_node = function(pos, node, _, _)
+      local newpos = vector.add(pos, minetest.facedir_to_dir(node.param2))
+      local newnode = minetest.get_node(newpos)
+      if newnode.name == modname..":"..name.."_body" then
+        newnode.name = modname..":"..name.."_tail_1"
+        minetest.set_node(newpos, newnode)
+        local timer = minetest.get_node_timer(newpos)
+        timer:set(WALKING_PERIOD, 0)
+      elseif newnode.name:find(modname..":"..name.."_head") == 1  then
+        newnode.name = "air"
+        minetest.set_node(newpos, newnode)
+      end
+    end,
+    drop = modname..":"..name.."_spawnegg",
+  })
+  
+  -- Definition of tail nodes
+  for n = 1, data.walking_steps do
+    -- Called on nodetimer
+    -- Non empty tail -> update the tail
+    local step = function(pos, _)
+      local node = minetest.get_node(pos)
+      node.name = modname..":"..name.."_tail_"..(n+1)
+      minetest.set_node(pos, node)
+      local timer = minetest.get_node_timer(pos)
+      timer:set(WALKING_PERIOD, 0)
+      return false
+    end
+    -- Empty tail -> Update the head
+    if n == data.walking_steps then
+    step =  function(pos, elapsed)
+        local node = minetest.get_node(pos)
+        local facedir = node.param2
+        local newpos = vector.add(pos, minetest.facedir_to_dir(facedir))
+        local newnode = minetest.get_node(newpos)
+        if newnode.name == modname..":"..name.."_body" then
+          newnode.name = modname..":"..name.."_tail_1"
+          minetest.set_node(newpos, newnode)
+          local timer = minetest.get_node_timer(newpos)
+          timer:set(WALKING_PERIOD, 0)
+        elseif newnode.name:find(modname..":"..name.."_head") == 1 then
+          minetest.set_node(newpos, {name = "air"})
+        end
+        minetest.set_node(pos, {name = data.leftover})
+        return false
+      end
+    end
+    local drawtype
+    if data.walking_steps > 1 then
+      drawtype = "nodebox"
+    end
+    minetest.register_node(modname..":"..name.."_tail_"..n, {
+      description = name.." tail",
+      paramtype = "light",
+      paramtype2 = "facedir",
+      drawtype = drawtype,
+      node_box = {
+          type = "fixed",
+          fixed = {
+            { -0.5, -0.5, -0.5 + (1 / data.walking_steps) * (n - 1), 0.5, 0.5, 0.5},
+          },
+      },
+      tiles = {
+        data.top_texture.."^[transform1",
+        data.bottem_texture.."^[transform3",
+        data.side_texture,
+        data.left_texture.."^[transform2",
+        data.side_texture,
+        data.tail_texture
+      },
+      on_timer = step,
+      after_dig_node = function(pos, node, _, _)
+        local newpos = vector.add(pos, minetest.facedir_to_dir(node.param2))
+        local newnode = minetest.get_node(newpos)
+        if newnode.name == modname..":"..name.."_body" then
+          newnode.name = modname..":"..name.."_tail_1"
+          minetest.set_node(newpos, newnode)
+          local timer = minetest.get_node_timer(newpos)
+          timer:set(WALKING_PERIOD, 0)
+        elseif newnode.name:find(modname..":"..name.."_head") == 1  then
+          newnode.name = "air"
+          minetest.set_node(newpos, newnode)
+        end
+      end,
+      groups = {snappy = 1, level = 2, not_in_creative_inventory = 1},
+      drop = "",
+    })
+  end
+  return true
+end

depends.txt

@@ -0,0 +1,2 @@
+default?
+flowers?

examples.lua

@@ -0,0 +1,51 @@
+-- Worm
+worm.register_worm("worm", "worm", {
+  leftover = "mapgen_dirt", 
+  face_texture = "worm_face.png", 
+  side_texture = "worm_side.png", 
+  tail_texture = "worm_tail.png",
+  can_move = function(_, node)
+    local name = node.name
+    return minetest.registered_nodes[name].buildable_to or 
+        minetest.get_node_group(name, "crumbly") >= 3
+  end,
+})
+
+-- Snake
+worm.register_worm("worm", "snake", {
+  face_texture = "snake_face.png", 
+  side_texture = "snake_side.png", 
+  tail_texture = "snake_tail.png", 
+  can_move = function(_, node)
+    return minetest.registered_nodes[node.name].buildable_to
+  end, 
+})
+
+-- Nyancat
+worm.register_worm("worm", "nyancat", {
+  face_texture = "nyancat_front.png", 
+  side_texture = "nyancat_rainbow.png", 
+  tail_texture = "nyancat_rainbow.png", 
+  flying = true, 
+})
+
+-- Eel
+local spawn_in = "air"
+if default then
+  spawn_in = "default:water_source"
+end
+worm.register_worm("worm", "eel", {
+  leftover = "mapgen_water_source", 
+  spawn_in = spawn_in,
+  walking_steps  = 1,
+  face_texture   = "eel_face.png", 
+  side_texture   = "eel_side.png", 
+  left_texture   = "eel_side.png^[transform6",
+  tail_texture   = "eel_tail.png", 
+  top_texture    = "eel_top.png",
+  bottem_texture = "eel_bottem.png",
+  can_move = function(_, node)
+    return minetest.get_node_group(node.name, "water") > 0
+  end,
+  flying = true, 
+})

init.lua

@@ -1,275 +1,18 @@
 -- Minetest Worm Mod
 -- by Gerald
 
-local WALKING_PERIOD = 1      
+worm = {}
+worm.config = {}
+
+worm.config.WALKING_PERIOD = 1      
 -- Time of a step in seconds, values < 1 are not faster
-local DEFAULT_WALKING_STEPS = 4       
+worm.config.DEFAULT_WALKING_STEPS = 4       
 -- Number of steps to pass one node, needs to be bigger than 0
-local TAIL_PROTECTION = false 
+worm.config.TAIL_PROTECTION = false 
 -- If false check for protection on spawning only at head position
 
-local MODNAME = "worm"
-worm = {}
-
--- Defines a "worm" (spawnitem and nodes)
--- @param modname   The name of the mod, which registers the nodes
--- @param name      The name of the creature; Has to be unique
--- @param leftover  The node placed behind the tail when moving away 
--- @walking_steps   The number of steps to pass one node
--- @can_move        A function (Position -> Boolean) defining which nodes 
---                  can be destroyed by the worm
-worm.register_worm = function (modname, name, leftover, face_texture,
-    side_texture, tail_texture, walking_steps, can_move)
-  -- Definition of the spawn item
-  minetest.register_craftitem(modname..":"..name.."_spawnegg", {
-    description = "spawn "..name,
-    inventory_image = face_texture,
-    on_use = function(itemstack, user, pointed_thing)
-      if pointed_thing.type ~= "node" then
-        return itemstack
-      end
-      local pos = pointed_thing.above 
-      local player_name = user:get_player_name()
-      if minetest.is_protected(pos, player_name) then
-        return itemstack
-      end
-      if minetest.get_node(pos).name ~= "air" then
-        return itemstack
-      end
-      local zero = {x = 0, y = 0, z = 0}
-      local player_dir = vector.subtract(zero, user:get_look_dir())
-      local facedir = minetest.dir_to_facedir(player_dir)
-      local dir = minetest.facedir_to_dir(facedir)
-      local length = itemstack:get_count()
-      minetest.set_node(pos, {
-        name = modname..":"..name.."_head_1",
-        param2 = facedir
-      })
-      local headtimer = minetest.get_node_timer(pos)
-      pos = vector.subtract(pos, dir)
-      local i = 0
-      while i < length do
-        if minetest.get_node(pos).name ~= "air" or 
-            (TAIL_PROTECTION and minetest.is_protected(pos, player_name)) then
-          pos = vector.add(pos, dir)
-          minetest.set_node(pos, {
-            name = modname..":"..name.."_tail_1",
-            param2 = facedir
-          })
-          break
-        end
-        minetest.set_node(pos, {
-          name = modname..":"..name.."_body",
-          param2 = facedir
-        })
-        pos = vector.subtract(pos, dir)
-        i = i + 1
-      end
-      minetest.set_node(pos, {
-        name = modname..":"..name.."_tail_1",
-        param2 = facedir
-      })
-      local tailtimer = minetest.get_node_timer(pos)
-      headtimer:set(WALKING_PERIOD, 0)
-      tailtimer:set(WALKING_PERIOD, 0)
-      itemstack:take_item(i)
-      return itemstack
-    end,
-  })
-  
-  -- Definition of head nodes
-  for n = 1, walking_steps do
-    -- Called on nodetimer
-    -- Incomplete head -> Update the head
-    local step = function(pos, _)
-      local node = minetest.get_node(pos)
-      node.name = modname..":"..name.."_head_"..(n+1)
-      minetest.set_node(pos, node)
-      local timer = minetest.get_node_timer(pos)
-      timer:set(WALKING_PERIOD, 0)
-      return false
-    end
-    -- Complete head -> Move head to a different position
-    if n == walking_steps then
-      step = function(pos, _)
-        local node = minetest.get_node(pos)
-        local facedir = node.param2
-        local dirs = {         -- Hierarchy of preferred directions
-          4, 
-          facedir % 4,  -- 4 -> 0 
-          (facedir + 1) % 4,
-          (facedir + 2) % 4,
-          (facedir + 3) % 4,
-          8 
-        }
-        for i = 1, 6 do
-          local newpos = vector.add(pos, minetest.facedir_to_dir(dirs[i]))
-          if can_move(newpos) then
-            minetest.set_node(newpos, {
-              name = modname..":"..name.."_head_1", 
-              param2 = dirs[i]
-            })
-            minetest.set_node(pos, {
-              name = modname..":"..name.."_body",
-              param2 = dirs[i]
-            })
-            local timer = minetest.get_node_timer(newpos)
-            timer:set(WALKING_PERIOD, 0)
-            return false
-          end
-        end
-        -- Worm stuck
-        return true
-      end
-    end
-    minetest.register_node(modname..":"..name.."_head_"..n, {
-      description = name.." head",
-      paramtype = "light",
-      paramtype2 = "facedir",
-      drawtype = "nodebox",
-      node_box = {
-        type = "fixed",
-        fixed = {
-          {-0.5, -0.5, -0.5, 0.5, 0.5, -0.5 + (1 / walking_steps) * n},
-        },
-      },
-      tiles = {
-        side_texture.."^[transform1",
-        side_texture.."^[transform3",
-        side_texture,
-        side_texture.."^[transform2",
-        face_texture,
-        side_texture
-      },
-      groups = {snappy = 1, level = 2, not_in_creative_inventory = 1},
-      damage_per_second = 10,
-      on_timer = step,
-      drop = "",
-    }) 
-  end
-  
-  -- Definition of the body node
-  minetest.register_node(modname..":"..name.."_body", {
-    description = name.." body part",
-    paramtype = "light",
-    paramtype2 = "facedir",
-    tiles = {
-      side_texture.."^[transform1",
-      side_texture.."^[transform3",
-      side_texture,
-      side_texture.."^[transform2",
-      side_texture,
-      side_texture
-    },
-    groups = {snappy = 1, level = 2, not_in_creative_inventory = 1},
-    -- Add a new tail to keep demolition
-    after_dig_node = function(pos, node, _, _)
-      local newpos = vector.add(pos, minetest.facedir_to_dir(node.param2))
-      local newnode = minetest.get_node(newpos)
-      if newnode.name == modname..":"..name.."_body" then
-        newnode.name = modname..":"..name.."_tail_1"
-        minetest.set_node(newpos, newnode)
-        local timer = minetest.get_node_timer(newpos)
-        timer:set(WALKING_PERIOD, 0)
-      elseif newnode.name:find(modname..":"..name.."_head") == 1  then
-        newnode.name = "air"
-        minetest.set_node(newpos, newnode)
-      end
-    end,
-    drop = "",
-  })
-  
-  -- Definition of tail nodes
-  for n = 1, walking_steps do
-    -- Called on nodetimer
-    -- Non empty tail -> update the tail
-    local step = function(pos, _)
-      local node = minetest.get_node(pos)
-      node.name = modname..":"..name.."_tail_"..(n+1)
-      minetest.set_node(pos, node)
-      local timer = minetest.get_node_timer(pos)
-      timer:set(WALKING_PERIOD, 0)
-      return false
-    end
-    -- Empty tail -> Update the head
-    if n == walking_steps then
-    step =  function(pos, elapsed)
-        local node = minetest.get_node(pos)
-        local facedir = node.param2
-        local newpos = vector.add(pos, minetest.facedir_to_dir(facedir))
-        local newnode = minetest.get_node(newpos)
-        if newnode.name == modname..":"..name.."_body" then
-          newnode.name = modname..":"..name.."_tail_1"
-          minetest.set_node(newpos, newnode)
-          local timer = minetest.get_node_timer(newpos)
-          timer:set(WALKING_PERIOD, 0)
-        elseif newnode.name:find(modname..":"..name.."_head") == 1 then
-          minetest.set_node(newpos, {name = "air"})
-        end
-        minetest.set_node(pos, {name = leftover})
-        return false
-      end
-    end
-    minetest.register_node(modname..":"..name.."_tail_"..n, {
-      description = name.." tail",
-      paramtype = "light",
-      paramtype2 = "facedir",
-      drawtype = "nodebox",
-      node_box = {
-          type = "fixed",
-          fixed = {
-            { -0.5, -0.5, -0.5 + (1 / walking_steps) * (n - 1), 0.5, 0.5, 0.5},
-          },
-      },
-      tiles = {
-        side_texture.."^[transform1",
-        side_texture.."^[transform3",
-        side_texture,
-        side_texture.."^[transform2",
-        side_texture,
-        tail_texture
-      },
-      on_timer = step,
-      after_dig_node = function(pos, node, _, _)
-        local newpos = vector.add(pos, minetest.facedir_to_dir(node.param2))
-        local newnode = minetest.get_node(newpos)
-        if newnode.name == modname..":"..name.."_body" then
-          newnode.name = modname..":"..name.."_tail_1"
-          minetest.set_node(newpos, newnode)
-          local timer = minetest.get_node_timer(newpos)
-          timer:set(WALKING_PERIOD, 0)
-        elseif newnode.name:find(modname..":"..name.."_head") == 1  then
-          newnode.name = "air"
-          minetest.set_node(newpos, newnode)
-        end
-      end,
-      groups = {snappy = 1, level = 2, not_in_creative_inventory = 1},
-      drop = "",
-    })
-  end
-end
-
-
-worm.register_worm(MODNAME, "worm", 
-  "mapgen_dirt", 
-  "worm_face.png", 
-  "worm_side.png", 
-  "worm_tail.png",
-  DEFAULT_WALKING_STEPS,
-  function(pos)
-    local name = minetest.get_node(pos).name
-    return minetest.registered_nodes[name].buildable_to or 
-        minetest.get_node_group(name, "crumbly") >= 3
-  end
-  )
-
-worm.register_worm(MODNAME, "snake",
-  "air", 
-  "snake_face.png", 
-  "snake_side.png", 
-  "snake_tail.png", 
-  DEFAULT_WALKING_STEPS,
-  function(pos)
-    return minetest.registered_nodes[minetest.get_node(pos).name].buildable_to
-  end 
-)
+local path = minetest.get_modpath("worm")
+dofile(path.."/api.lua")
+dofile(path.."/examples.lua")
+dofile(path.."/swallowable_nodes.lua")
+dofile(path.."/mapgen.lua")

mapgen.lua

@@ -0,0 +1,89 @@
+-- Marked mapgen nodes
+local mapgen_node = {
+  description = "worm mapgen node",
+  paramtype = "light",
+  paramtype2 = "facedir",
+  drawtype = "airlike",
+  groups = {not_in_creative_inventory = 1, worm_mapgen = 1},
+}
+minetest.register_node("worm:snake_head_1_mapgen", mapgen_node)
+minetest.register_node("worm:snake_tail_1_mapgen", mapgen_node)
+minetest.register_node("worm:worm_head_1_mapgen", mapgen_node)
+minetest.register_node("worm:worm_tail_1_mapgen", mapgen_node)
+minetest.register_node("worm:eel_head_1_mapgen", mapgen_node)
+minetest.register_node("worm:eel_tail_1_mapgen", mapgen_node)
+
+-- Replace mapgen nodes by real ones and initialize the node timer.
+minetest.register_lbm({
+  name = "worm:init_nodetimers_mapgen",
+  nodenames = "group:worm_mapgen",
+  run_at_every_load = true,
+  action = function(pos, node)
+    node.name = node.name:sub(1, -8)
+    print("[worm]"..node.name.." spawned at "..pos.x..", "..pos.y..", "..pos.z)
+    minetest.swap_node(pos, node)
+    local timer = minetest.get_node_timer(pos)
+    timer:set(worm.config.WALKING_PERIOD, 0)
+  end,
+})
+
+-- Snake
+minetest.register_decoration({
+  deco_type = "schematic",
+  place_on = "mapgen_dirt_with_grass",
+  sidelen = 16,
+  fill_ratio = 0.0001,
+  schematic = {
+    size = {x=4, y=1, z=1},
+    data = {
+      {name="worm:snake_head_1_mapgen", param1=255, param2=3, force_place = true},
+      {name="worm:snake_body",   param1=255, param2=3, force_place = true},
+      {name="worm:snake_body",   param1=255, param2=3, force_place = true},
+      {name="worm:snake_tail_1_mapgen", param1=255, param2=3, force_place = true},
+    },
+  },
+})
+
+-- Worm
+minetest.register_decoration({
+  deco_type = "schematic",
+  place_on = "mapgen_dirt_with_grass",
+  sidelen = 16,
+  fill_ratio = 0.0001,
+  schematic = {
+    size = {x=4, y=1, z=1},
+    data = {
+      {name="worm:worm_head_1_mapgen", param1=255, param2=3, force_place = true},
+      {name="worm:worm_body",   param1=255, param2=3, force_place = true},
+      {name="worm:worm_body",   param1=255, param2=3, force_place = true},
+      {name="worm:worm_tail_1_mapgen", param1=255, param2=3, force_place = true},
+    },
+  },
+})
+
+-- Eel
+minetest.register_decoration({
+  deco_type = "schematic",
+  place_on = "mapgen_water_source",
+  flags = "liquid_surface, place_center_y",
+  sidelen = 16,
+  fill_ratio = 0.0002,
+  schematic = {
+    size = {x=4, y=3, z=1},
+    data = {
+      {name="worm:eel_head_1_mapgen", param1=255, param2=3, force_place = true},
+      {name="worm:eel_body",   param1=255, param2=3, force_place = true},
+      {name="worm:eel_body",   param1=255, param2=3, force_place = true},
+      {name="worm:eel_tail_1_mapgen", param1=255, param2=3, force_place = true},
+      {name="ignore", param1=0, param2=0},
+      {name="ignore", param1=0, param2=0},
+      {name="ignore", param1=0, param2=0},
+      {name="ignore", param1=0, param2=0},
+      {name="ignore", param1=0, param2=0},
+      {name="ignore", param1=0, param2=0},
+      {name="ignore", param1=0, param2=0},
+      {name="ignore", param1=0, param2=0},
+    },
+  },
+  rotation = "random",
+})

swallowable_nodes.lua

@@ -0,0 +1,15 @@
+if default then
+  local groups = minetest.registered_nodes["default:apple"].groups
+  groups.swallowable = 1
+  minetest.override_item("default:apple", {
+    groups = groups,
+  })
+end
+
+if flowers then
+  local groups = minetest.registered_nodes["flowers:mushroom_brown"].groups
+  groups.swallowable = 1
+  minetest.override_item("flowers:mushroom_brown", {
+    groups = groups,
+  })
+end