electric/mods/ebiometrees/sapling.lua

ebiometrees = {}
ebiometrees.directions = {
  up     = vector.new( 0,  1,  0),
  down   = vector.new( 0, -1,  0),
  north  = vector.new( 0,  0,  1),
  east   = vector.new( 1,  0,  0),
  south  = vector.new( 0,  0, -1),
  west   = vector.new(-1,  0,  0)
}


function ebiometrees.grow_closure(nextstage)
  local function growtree(pos)
    minetest.set_node(pos, {name=nextstage})
  end
  return growtree
end

function ebiometrees.where_to_grow_trunk_closure(grow_preferences, leaves_name)
  local function where_to_grow_trunk(pos)
    for _, directions in ipairs(grow_preferences)
    do
      table.shuffle(directions)
      local candidate_dir = directions[1]
      local candidate = vector.copy(pos):add(candidate_dir)
      local node = minetest.get_node_or_nil(candidate)
      if node and node.name == leaves_name
      then
        return candidate
      end
    end
  end
  return where_to_grow_trunk
end

function ebiometrees.grow_trunk_closure(trunk_terminal_name, grow_preferences, leaves_name)
  local function grow_trunk(pos)
    local where = ebiometrees.where_to_grow_trunk_closure(
      grow_preferences, leaves_name
    )
    local there = where(pos)
    if there
    then
      minetest.set_node(there, {name=trunk_terminal_name})
    end
  end
  return grow_trunk
end

function ebiometrees.grow_leaves_closure(leaves_name)
  local function grow_leaves(pos)
    local free_node = minetest.find_node_near(pos, 1, "air")
    if free_node
    then
      minetest.set_node(free_node, {name=leaves_name})
    end
    return true
  end
  return grow_leaves
end


function ebiometrees.tree_grower(leaves_name, grow_preferences, terminal_name, nextstage, age_max)
  local grow_trunk =  ebiometrees.grow_trunk_closure(terminal_name, grow_preferences, leaves_name)
  local grow_leaves = ebiometrees.grow_leaves_closure(leaves_name)
  local function grow_tree(pos)
    local meta = minetest.get_meta(pos)
    meta:set_int("ebiometrees:age", meta:get_int("ebiometrees:age")+1)
    grow_trunk(pos)
    grow_leaves(pos)
    if nextstage
    then
      if meta:get_int("ebiometrees:age") > age_max
      then
        minetest.set_node(pos, {name=nextstage})
      end
    end
    return true
  end
  return grow_tree
end

function ebiometrees.root_sapling(pos)
  minetest.set_node(pos, {name="ebiome:oak_sprout"})
  return false
end