Epic/mods/mylandscaping/walls_madison.lua

local colbox_type1 = { --top blocks
   type = 'fixed',
   fixed = {-.5, -.5, -.2, .5, .5, .5}
}
local colbox_type2 = { --bottom blocks
   type = 'fixed',
   fixed = {-.5, -.5, -.2, .5, .5, .5}
}
local colbox_type3 = { --top inside corner
   type = 'fixed',
   fixed = {{-.2, -.5, -.5, .5, .5, .5},
      {-.5, -.5, -.2, .5, .5, .5}}
}
local colbox_type4 = { --bottom inside corner
   type = 'fixed',
   fixed = {{-.2, -.5, -.5, .5, .5, .5},
      {-.5, -.5, -.2, .5, .5, .5}}
}
local colbox_type5 = { --top outside corner
   type = 'fixed',
   fixed = {-.2, -.5, -.2, .5, .5, .5}
}
local colbox_type6 = { --bottom outside corner
   type = 'fixed',
   fixed = {-.2, -.5, -.2, .5, .5, .5}
}

local block_type1 = { -- desc2, typ, obj, colbox, drops, grup
{'Madison Middle',       'middle',       'blockm_m_t',   colbox_type1, 'middle',      {ml=1,cracky=2,not_in_creative_inventory=ml_visible}},
{'Hax0r',    'bmiddle',      'blockm_m_b',   colbox_type2, 'middle',    {not_in_creative_inventory=1}},
{'Madison Inside Corner',   'icorner',   'blockm_ic_t',   colbox_type3,   'icorner', {ml=1,cracky=2,not_in_creative_inventory=ml_visible}},
{'Hax0r',    'bicorner',      'blockm_ic_b',   colbox_type4, 'icorner',    {not_in_creative_inventory=1}},
{'Madison Outside Corner',   'ocorner',   'blockm_oc_t',   colbox_type5,   'ocorner', {ml=1,cracky=2,not_in_creative_inventory=ml_visible}},
{'Hax0r',    'bocorner',      'blockm_oc_b',   colbox_type6, 'ocorner',    {not_in_creative_inventory=1}},
}

for i in ipairs (block_type1) do
   local desc2 = block_type1[i][1]
   local typ = block_type1[i][2]
   local obj = block_type1[i][3]
   local colbox = block_type1[i][4]
   local drops = block_type1[i][5]
   local grup = block_type1[i][6]
   local color_tab = {
   {'black',    'Black',      '^[multiply:#2c2c2c'},
   {'blue',    'Blue',         '^[multiply:#0041f4'},
   {'brown',    'Brown',      '^[multiply:#6c3800'},
   {'cyan',    'Cyan',         '^[multiply:cyan'},
   {'dark_green',    'Dark Green',      '^[multiply:#2b7b00'},
   {'dark_grey',    'Dark Grey',      '^[multiply:#464646'},
   {'green',    'Green',      '^[multiply:#67eb1c'},
   {'grey',    'Grey',         '^[multiply:#818181'},
   {'magenta',    'Magenta',      '^[multiply:#d80481'},
   {'orange',   'Orange',      '^[multiply:#e0601a'},
   {'pink',    'Pink',         '^[multiply:#ffa5a5'},
   {'red',    'Red',         '^[multiply:#c91818'},
   {'violet',    'Violet',      '^[multiply:#480680'},
   {'white',    'White',      '^[multiply:white'},
   {'yellow',    'Yellow',      '^[multiply:#fcf611'},
   {'cement',    'Concrete',      ''},
   }
   for i in ipairs (color_tab) do
      local col = color_tab[i][1]
      local coldesc = color_tab[i][2]
      local alpha = color_tab[i][3]

      minetest.register_node('mylandscaping:mwall_'..typ..'_'..col, {
         _doc_items_create_entry = false,
         description = desc2..' '..coldesc,
         drawtype = 'mesh',
         mesh = 'mylandscaping_'..obj..'.obj',
         tiles = {{name='mylandscaping_madison_wood.png'}, {name='mylandscaping_madison_stone.png'..alpha}},
         groups = grup,
         paramtype = 'light',
         paramtype2 = 'facedir',
         drop = 'mylandscaping:mwall_'..drops..'_'..col,
         selection_box = colbox,
         collision_box = colbox,
         sounds = default.node_sound_stone_defaults(),

      after_place_node = function(pos, placer, itemstack, pointed_thing)
         local nodeu = minetest.get_node({x=pos.x,y=pos.y-1,z=pos.z})
         local nodea = minetest.get_node({x=pos.x,y=pos.y+1,z=pos.z})
         if nodeu.name == 'mylandscaping:mwall_'..typ..'_'..col then
            minetest.swap_node(pos,{name='mylandscaping:mwall_'..typ..'_'..col,param2=nodeu.param2})
            minetest.swap_node({x=pos.x,y=pos.y-1,z=pos.z},{name='mylandscaping:mwall_b'..typ..'_'..col,param2=nodeu.param2})
         end
         if nodea.name == 'mylandscaping:mwall_'..typ..'_'..col then
            minetest.swap_node(pos,{name='mylandscaping:mwall_b'..typ..'_'..col,param2=nodea.param2})
         end
      end,

      after_destruct = function(pos, oldnode)
         local nodeu = minetest.get_node({x=pos.x,y=pos.y-1,z=pos.z})
         if nodeu.name == 'mylandscaping:mwall_b'..typ..'_'..col then
            minetest.swap_node({x=pos.x,y=pos.y-1,z=pos.z},{name='mylandscaping:mwall_'..typ..'_'..col,param2=nodeu.param2})
         end
      end,
      })
   end
end