Logikraft/blocks/component.lua

-- Removes a node without calling on on_destruct()
-- We use this to mess with bed nodes without causing unwanted recursion.
local function remove_no_destruct(pos)
	minetest.swap_node(pos, {name = "air"})
	minetest.remove_node(pos) -- Now clear the meta
	minetest.check_for_falling(pos)
end

-- Everything is described as if dir=0
--  z+
-- /|\    w
--  |    XXX h
--  +−−−−−−−−−−−> x+
-- {name,width,height,{cables_left,cables_right,cables_top,cables_bottom}}
logikraft.components = {
    ["and"] = {
        width = 2,
        height = 3,
        ports = {
            left = {"in_2",nil,"in_1"},
            right = {nil,"out",nil}
        }
    },
    ["switch"] = {
        width = 2,
        height = 1,
        ports = {
            left = {"in"},
            right = {"out"},
            top = {"activate",nil}
        }
    },
    ["demux"] = {
        width = 2,
        height = 8,
        ports = {
            left = {nil,nil,nil,nil,nil,"in_3","in_2","in_1"},
            right = {"out_8","out_7","out_6","out_5","out_4","out_3","out_2","out_1"}
        }
    }
}

-- componentsblocks["block"] = {name = Name of the component,x,y}
logikraft.componentnodes = {}

for name,cmp in pairs(logikraft.components)
do
    local w = cmp.width
    local h = cmp.height
    local cables = cmp.ports

    for x=1,w do
    for y=1,h do

        local nodename = "logikraft:component_"..name.."_"..tostring(x).."_"..tostring(y)
        minetest.register_node(nodename, {
            drawtype = "block",
            description = name.." component",
            tiles = {
                "component_"..name..".png",
                "component.png",
                ((x==w) and (cables.right and cables.right[y] and "component_port.png" or "component.png") or "component.png"), -- x+
                ((x==1) and (cables.left and cables.left[y] and "component_port.png" or "component.png") or "component.png"), -- x-
                ((y==h) and (cables.top and cables.top[x] and "component_port.png" or "component.png") or "component.png"), -- z+
                ((y==1) and (cables.bottom and cables.bottom[x] and "component_port.png" or "component.png") or "component.png"), -- z-
            },
            groups = {circuitry = 1,dig_immediate = 3},
            paramtype2 = "4dir",
            inventory_image = (x == 1 and y == 1 and "component_"..name..".png") or nil,
            drop = "logikraft:component_"..name.."_1_1",
            on_place = (x == 1 and y == 1) and function(itemstack, placer, pointed_thing)
                
                local under = pointed_thing.under
                local node = minetest.get_node(under)
                local udef = minetest.registered_nodes[node.name]
        
                -- Rightclick is prioritary
                if udef and udef.on_rightclick and
                        not (placer and placer:is_player() and
                        placer:get_player_control().sneak) then
                    return udef.on_rightclick(under, node, placer, itemstack,
                        pointed_thing) or itemstack
                end
        
                -- Pos will be the head location
                local pos
                if udef and udef.buildable_to then
                    pos = under
                else
                    pos = pointed_thing.above
                end
                
                local dir8 = logikraft.vecTo8dir(placer:get_look_dir())

                for i = 1,w do
                for j = 1,h do
                    local loc = logikraft.addToPos8dir(dir8,pos,i-1,j-1)
                    local node_def = minetest.registered_nodes[minetest.get_node(loc).name]
                    if not node_def or not node_def.buildable_to then
                        -- Then we cannot build here
                        return itemstack
                    end
                end
                end

                local dir4 = logikraft.dir8to4(dir8)
                local invw = dir8 % 2 == 0

                -- If we reached this point, we can build the component
                for i = 1,w do
                for j = 1,h do
                    local loc = logikraft.addToPos8dir(dir8,pos,invw and (w-i) or (i-1),j-1)
                    minetest.set_node(loc, {name = "logikraft:component_"..name.."_"..tostring(i).."_"..tostring(j), param2 = dir4})
                end
                end

                if not minetest.is_creative_enabled(placer) then
                    itemstack:take_item()
                end
                return itemstack
            end or nil,
            on_destruct = function(pos)
        
                local node = minetest.get_node(pos)
                dir4 = node.param2
                
                for i = 1,w do
                for j = 1,h do
                    local loc = logikraft.addToPos4dir(dir4,pos,i-x,j-y)
                    remove_no_destruct(loc)
                end
                end    
            end
        })
        logikraft.componentnodes[nodename] = {name = name, x = x, y = y}
    end
    end

    minetest.register_alias("logikraft:component_"..name, "logikraft:component_"..name .. "_1_1")
end