spacecannon/cannon.lua

local has_technic_mod = minetest.get_modpath("technic")


minetest.register_entity("spacecannon:energyball", {
	initial_properties = {
		visual = "cube",
		visual_size = {x=0.25, y=0.25},
		textures = {"spark.png"},
		collisionbox = {-0.25,-0.25,-0.25, 0.25,0.25,0.25},
		physical = false,
		timer=0
	},

	on_step = function(self, dtime)
		if self.timer == nil then
			return --XXX
		end
		self.timer=self.timer+dtime
		if self.timer >= 0.3 then
			local pos = self.object:getpos()
			local node = minetest.get_node(pos)

			if node.name == "air" then
				local objs = minetest.get_objects_inside_radius({x=pos.x,y=pos.y,z=pos.z}, 3)
				for k, obj in pairs(objs) do
				if obj:get_luaentity() ~= nil then
					if obj:get_luaentity().name ~= self.name and obj:get_luaentity().name ~= "__builtin:item" then --something other found
						local mob = obj
						-- self.on_mob_hit(self,pos,mob)
						end
					elseif obj:is_player() then --player found
					local player = obj
						-- self.on_player_hit(self,pos,player)
					end		
				end
			elseif node.name ~= "air"  then

			end
		end	
	end,

	on_activate = function(self, staticdata)
			minetest.after(8.0, 
				function(self) 
					self.object:remove()
				end,
				self)
	end,

	on_rightclick=function(self, clicker)
	end,

	on_punch = function(self, hitter)
	end,
})



minetest.register_node("spacecannon:cannon", {
	description = "Spacecannon",
	tiles = {"cannon.png","cannon_front.png","cannon.png","cannon.png","cannon.png","cannon.png"},
	groups = {cracky=3,oddly_breakable_by_hand=3,technic_machine = 1, technic_hv = 1},
	drop = "spacecannon:cannon",
	sounds = default.node_sound_glass_defaults(),

	mesecons = {effector = {
		action_on = function (pos, node)
			local obj = minetest.add_entity({x=pos.x, y=pos.y, z=pos.z+1}, "spacecannon:energyball")
			obj:setvelocity({x=0, y=0, z=1})
			-- obj:setacceleration({x=dir.x*-3, y=-settings.gravity, z=dir.z*-3})
		end
	}},

	connects_to = {"group:technic_hv_cable"},
	connect_sides = {"bottom", "top", "left", "right", "front", "back"},

	after_place_node = function(pos, placer)
		local meta = minetest.get_meta(pos)
		meta:set_string("owner", placer:get_player_name() or "")
	end,

	on_construct = function(pos)
		local meta = minetest.get_meta(pos)
		meta:set_int("powerstorage", 0)

		if has_technic_mod then
			meta:set_int("HV_EU_input", 0)
			meta:set_int("HV_EU_demand", 0)
		end
	end,

	technic_run = function(pos, node)
		local meta = minetest.get_meta(pos)
		local eu_input = meta:get_int("HV_EU_input")
		local demand = meta:get_int("HV_EU_demand")
		local store = meta:get_int("powerstorage")

		meta:set_string("infotext", "Power: " .. eu_input .. "/" .. demand .. " Store: " .. store)

		if store < spacecannon.config.powerstorage then
			-- charge
			meta:set_int("HV_EU_demand", spacecannon.config.powerrequirement)
			store = store + eu_input
			meta:set_int("powerstorage", store)
		else
			-- charged
			meta:set_int("HV_EU_demand", 0)
		end
	end
})

if has_technic_mod then
	technic.register_machine("HV", "spacecannon:cannon", technic.receiver)
end

minetest.register_craft({
	output = 'spacecannon:cannon',
	recipe = {
		{'', 'default:tnt', ''},
		{'default:diamond', 'default:mese_block', 'default:diamond'},
		{'', 'default:tnt', ''}
	}
})