Something works.

init.lua

@@ -0,0 +1,170 @@
+cardgroups = { crumbly=1, falling_node=1 }
+pilegroups = { crumbly=1 }
+
+
+
+local descriptions = {"Three of diamonds","Seven of diamonds","Ace of diamonds" }
+--, "Ace of clubs","Ace of hearts","Ace of spades" }
+local textures = { "3d","7d","ad" }
+--, "ac", "ah", "as" }
+
+local cardnames = {}
+local cardprefix="deck:card_"
+local cardprefixlen=string.len(cardprefix)
+
+for i = 1,table.getn(textures),1 do
+   local name=cardprefix..textures[i]
+   table.insert(cardnames,name)
+	minetest.register_node(name, {
+		description = descriptions[i],
+		groups = cardgroups,
+		tiles = { textures[i]..".png" }
+	})
+end
+
+local function pile_inv_setup(pos, placer, itemstack, pointed_thing)
+   local meta=minetest.get_meta(pos)
+   local inv=meta:get_inventory()
+   local invsize=13*4
+   if inv:set_size("main",invsize) then
+      inv:set_width("main",13)
+      minetest.log("deck_setup: size set to "..invsize)
+   else
+      minetest.log("deck_setup: failed to set size")
+   end
+
+   --for i=1,invsize,1 do
+   --   local stack=inv:get_stack("main",i)
+   --end
+end
+
+local function pile_pop(inv) 
+   local s=inv:get_size("main")
+   for i=1,s,1 do
+      local stack=inv:get_stack("main",i)
+      if stack:get_count() > 0 then
+	 local item=stack:take_item(1)
+	 inv:set_stack("main",i,stack)
+	 return item
+      end
+   end
+end
+
+local function pile_peek_first(inv) 
+   local s=inv:get_size("main")
+   for i=1,s,1 do
+      local stack=inv:get_stack("main",i)
+      if stack:get_count() > 0 then
+	 return stack:get_name()
+      end
+   end
+end
+
+local function pile_add_card(inv,pos)
+   minetest.log("add card "..minetest.pos_to_string(pos))
+   local s=inv:get_size("main")
+   minetest.log("inv size="..s)
+   local place=s
+   for i=1,s,1 do
+      local stack=inv:get_stack("main",i)
+      if stack:get_count() > 0 then
+	 place=i-1
+	 break
+      end
+   end
+   if place > 0 then
+      inv:set_stack("main",place,ItemStack(minetest.get_node(pos).name))
+      minetest.log("deck_edd_card done")
+      return true
+   end
+   return false
+end
+
+local function add_to_inv(inv, cardname)
+   local s=inv:get_size("main")
+   for i=1,s,1 do
+      local stack=inv:get_stack("main",i)
+      if stack:get_count() == 0 then
+	 minetest.log(cardname)
+	 inv:set_stack("main",i,ItemStack(cardname))
+	 return true
+      end
+   end
+   return false
+end
+
+local function draw_card(pos,formname,fields,sender)
+   if fields.draw then
+      local player_inv=minetest.get_inventory({type="player", name=sender:get_player_name()})
+      local meta=minetest.get_meta(pos)
+      local pile_inv=meta:get_inventory()
+      if pile_inv == nil then minetest.log("pile inv=nil") return end
+      local stack=pile_pop(pile_inv)
+      if stack == nil then
+	 minetest.log("empty pile")
+      else
+	 player_inv:add_item("main",stack)
+      end
+   end
+end
+
+minetest.register_node("deck:chestpile", {
+	description = "Card pile that user has full access to. Works also like a minetest chest.",
+	tiles = { "back.png","side.png" },
+	groups = pilegroups,
+	on_construct = function(pos, placer, itemstack, pointed_thing)
+	   pile_inv_setup(pos, placer, itemstack, pointed_thing)
+	   local meta=minetest.get_meta(pos)
+	   meta:set_string("formspec","size[13,10]list[context;main;0,0;13,4;]button[0,4;2,1;draw;Draw]list[current_player;main;0,6;8,4;]")
+	end,
+	on_receive_fields = draw_card
+})
+
+minetest.register_node("deck:stockpile", {
+	description = "Stock pile of cards. Can't be peeked.",
+	groups = pilegroups,
+	tiles = { "back.png" },
+	on_construct = function(pos, placer, itemstack, pointed_thing)
+	   pile_inv_setup(pos, placer, itemstack, pointed_thing)
+	   local meta=minetest.get_meta(pos)
+	   meta:set_string("formspec","size[8,5]button[0,0;2,1;draw;Draw]list[current_player;main;0,1;8,4;]"
+	   )
+	end,
+	on_receive_fields = draw_card
+})
+
+-- minetest.register_on_player_receive_fields(function(player, formname, fields)
+--       minetest.log("xformname="..formname)
+--       if fields.draw then
+-- 	 minetest.chat_send_all("player "..player.name.."draw card")
+--       end
+-- end)
+
+minetest.register_abm({
+      label="Drop a card to deck",
+      nodenames={"deck:chestpile","deck:stockpile"},
+      neighbors=cardnames,
+      interval=1.0,
+      chance = 1,
+      action=function(pos,node,active_object_count,active_object_count_wider)
+	 local above = {x=pos.x,y=pos.y+1,z=pos.z}
+	 local abovenode = minetest.get_node(above)
+	 --minetest.log("abm1"..minetest.pos_to_string(pos).." "..node.name..
+	 --""..abovenode.name)
+	 if not string.sub(abovenode.name,1,cardprefixlen) == cardprefix then return end
+	 local meta=minetest.get_meta(pos)
+	 local inv=meta:get_inventory()
+	 if pile_add_card(inv,above) then
+	    minetest.remove_node(above)
+	    while true do
+		above={x=above.x,y=above.y+1,z=above.z}
+		abovenode = minetest.get_node(above)
+		if string.sub(abovenode.name,1,cardprefixlen) == cardprefix then
+		minetest.spawn_falling_node(above)
+		else
+		return
+		end
+	    end
+	 end
+      end
+})