Add railgun cannons (#16)

* feat: add purple and blue cannons (railguns)

* fix: linter warnings

* fix: last commit

Seems I forgot to save some changes that were supposed to be part of the last commit.

* feat: don't change cannon projectile range

Avoid breaking builds on other servers

ammo.lua

@@ -0,0 +1,13 @@
+minetest.register_craftitem("spacecannon:railgun_slug", {
+	description = "Railgun slug",
+    inventory_image = "spacecannon_railgun_slug.png",
+})
+
+minetest.register_craft({
+	output = "spacecannon:railgun_slug 2",
+	recipe = {
+        {                                "",        "technic:uranium0_ingot",                                 ""},
+        {"basic_materials:carbon_steel_bar", "technic:stainless_steel_ingot", "basic_materials:carbon_steel_bar"},
+        {   "technic:stainless_steel_ingot", "technic:stainless_steel_ingot",    "technic:stainless_steel_ingot"}
+	},
+})

cannon.lua

@@ -1,3 +1,4 @@
+-- vi: noexpandtab
 
 local cable_entry = "^technic_cable_connection_overlay.png"
 
@@ -23,6 +24,7 @@ local register_spacecannon = function(def)
 		timer = 0,
 		lifetime = 0,
 		static_save = false,
+		penetrated = 0,
 
 		on_step = function(self, dtime)
 			self.timer = self.timer + dtime
@@ -65,25 +67,33 @@ local register_spacecannon = function(def)
 				local objs = minetest.get_objects_inside_radius({x=pos.x,y=pos.y,z=pos.z}, 1)
 				local collided = false
 				for _, obj in pairs(objs) do
-					if obj:get_luaentity() ~= nil and obj:get_luaentity().name ~= self.name then
+					if obj:get_luaentity() ~= nil
+						and obj:get_luaentity().name ~= self.name
+						and obj:get_luaentity().name ~= "__builtin:item"
+					then
 						collided = true
 						obj:punch(self.object, 1.0, {
 								full_punch_interval=1.0,
-								damage_groups={fleshy=def.range*2},
+								damage_groups={fleshy=def.damage},
 							}, nil)
 					end
 				end
 
 				if collided then
 					spacecannon.destroy(pos, def.range, def.intensity)
+					self.penetrated = self.penetrated + 1
+					if self.penetrated >= def.penetration then
 						self.object:remove()
 					end
+				end
 
 			else
 				-- collision
 				spacecannon.destroy(pos, def.range, def.intensity)
+				self.penetrated = self.penetrated + 1
+				if self.penetrated >= def.penetration then
 					self.object:remove()
-
+				end
 			end
 		end
 	})
@@ -112,7 +122,7 @@ local register_spacecannon = function(def)
 			action_on = function (pos)
 				local meta = minetest.get_meta(pos)
 				local owner = meta:get_string("owner")
-				spacecannon.fire(pos, owner, def.color, def.speed, def.range)
+				spacecannon.fire(pos, owner, def.color, def.speed, def.is_th, def.storage_require_mod)
 			end
 		}},
 
@@ -145,7 +155,13 @@ local register_spacecannon = function(def)
 			-- Set default digiline channel (do before updating formspec).
 			meta:set_string("channel", "spacecannon")
 
-			spacecannon.update_formspec(meta)
+			-- Set inventory (not used for thermal cannons)
+			if not def.is_th then
+				local inv = meta:get_inventory()
+				inv:set_size("src", 1)
+			end
+
+			spacecannon.update_formspec(meta, def.is_th)
 		end,
 
 		technic_run = function(pos)
@@ -154,13 +170,17 @@ local register_spacecannon = function(def)
 			local demand = meta:get_int("HV_EU_demand")
 			local store = meta:get_int("powerstorage")
 
+			local config_store = spacecannon.config.ki_powerstorage * def.storage_require_mod
+			if def.is_th then config_store = spacecannon.config.th_powerstorage * def.storage_require_mod end
+			local config_require = spacecannon.config.ki_powerrequirement
+			if def.is_th then config_require = spacecannon.config.th_powerrequirement end
+
 			meta:set_string("infotext", "Power: " .. eu_input .. "/" .. demand .. " Store: " .. store)
 
-			if store < spacecannon.config.powerstorage * def.range then
+			if store < config_store then
 				-- charge
-				meta:set_int("HV_EU_demand", spacecannon.config.powerrequirement)
-				store = store + eu_input
-				meta:set_int("powerstorage", store)
+				meta:set_int("HV_EU_demand", config_require)
+				meta:set_int("powerstorage", store + eu_input)
 			else
 				-- charged
 				meta:set_int("HV_EU_demand", 0)
@@ -177,16 +197,21 @@ local register_spacecannon = function(def)
 			local meta = minetest.get_meta(pos)
 
 			if fields.fire then
-				spacecannon.fire(pos, playername, def.color, def.speed, def.range)
+				spacecannon.fire(pos, playername, def.color, def.speed, def.is_th, def.storage_require_mod)
 			end
 
 			if fields.set_digiline_channel and fields.digiline_channel then
 				meta:set_string("channel", fields.digiline_channel)
 			end
 
-			spacecannon.update_formspec(meta)
-		end
+			spacecannon.update_formspec(meta, def.is_th)
+		end,
 
+		after_dig_node = function(pos, _node, meta, _digger)
+			if meta.inventory and meta.inventory.src and meta.inventory.src[1] then
+				minetest.add_item(pos, ItemStack(meta.inventory.src[1]))
+			end
+		end
 	})
 
 	technic.register_machine("HV", "spacecannon:cannon_" .. def.color, technic.receiver)
@@ -205,31 +230,75 @@ local register_spacecannon = function(def)
 end
 
 register_spacecannon({
+	is_th = true,
 	color = "green",
 	range = 1,
+	storage_require_mod = 1,
+	damage = 2,
 	intensity = 1,
 	timeout = 8,
 	speed = 10,
+	penetration = 0,
 	desc = "fast,low damage",
 	ingredient = "default:mese_block"
 })
 
 register_spacecannon({
+	is_th = true,
 	color = "yellow",
 	range = 3,
+	storage_require_mod = 3,
 	intensity = 2,
+	damage = 6,
 	timeout = 8,
 	speed = 5,
+	penetration = 0,
 	desc = "medium speed, medium damage",
 	ingredient = "spacecannon:cannon_green"
 })
 
 register_spacecannon({
+	is_th = true,
 	color = "red",
 	range = 5,
+	storage_require_mod = 5,
 	intensity = 4,
+	damage = 10,
 	timeout = 15,
 	speed = 3,
+	penetration = 0,
 	desc = "slow, heavy damage",
 	ingredient = "spacecannon:cannon_yellow"
 })
+
+-- Railguns
+
+-- Regular railgun
+register_spacecannon({
+	is_th = false,
+	color = "blue",
+	range = 0,
+	storage_require_mod = 1,
+	intensity = 2,
+	damage = 5,
+	timeout = 10,
+	speed = 9,
+	penetration = 2,
+	desc = "fast, 2x penetrating damage",
+	ingredient = "technic:copper_coil"
+})
+
+-- Helical railgun
+register_spacecannon({
+	is_th = false,
+	color = "purple",
+	range = 0,
+	storage_require_mod = 1.5,
+	intensity = 4,
+	damage = 10,
+	timeout = 15,
+	speed = 10,
+	penetration = 4,
+	desc = "fast, 4x penetrating damage",
+	ingredient = "spacecannon:cannon_blue"
+})

init.lua

@@ -2,10 +2,12 @@
 spacecannon = {
 	config = {
 		-- technic EU storage value
-		powerstorage = 10000,
+		th_powerstorage = 10000,
+		ki_powerstorage = 300,
 
 		-- charge value in EU
-		powerrequirement = 2500
+		th_powerrequirement = 2500,
+		ki_powerrequirement = 300
 	},
 	node_resilience = {}
 }
@@ -15,6 +17,7 @@ local MP = minetest.get_modpath("spacecannon")
 dofile(MP.."/util.lua")
 dofile(MP.."/digiline.lua")
 dofile(MP.."/cannon.lua")
+dofile(MP.."/ammo.lua")
 dofile(MP.."/node_resilience.lua")
 
 print("[OK] Spacecannon")

mod.conf

@@ -1,4 +1,7 @@
 name = spacecannon
-description = Adds three scifi/space cannons with various projectile-speed and explosion-strength
+description = Adds five scifi/space cannons with various properties
 depends = default, technic
 optional_depends = mesecons, digilines
+release = 6899
+author = BuckarooBanzay
+title = Spacecannon

util.lua

@@ -1,32 +1,58 @@
+-- vi: noexpandtab
+
 local has_digilines = minetest.get_modpath("digilines")
 
-spacecannon.update_formspec_digilines = function(meta)
-	local channel = meta:get_string("channel") or ""
+spacecannon.update_formspec = function(meta, is_th)
+	local formspec = ""
 
-	local formspec =
+	if not is_th then
+		formspec = formspec ..
 			"formspec_version[4]" ..
-		"size[6,4;]" ..
+			"size[10.5,9;]"
 
-		-- Digiline channel
-		"field[0.5,0.5;3.5,1;digiline_channel;Digiline Channel;" ..
-		channel .. "]" ..
-		"button_exit[4.5,0.5;1,1;set_digiline_channel;Set]" ..
+		-- Ammo inventory
+		formspec = formspec ..
+			"list[current_name;src;0.375,0.5;1,1;]" ..
+			"list[current_player;main;0.375,4;8,4;]" ..
+			"listring[]" ..
+			"label[1.75,1;Ammunition]"
 
 		-- Manual "fire" button
-		"button_exit[0.5,2.5;5,1;fire;Fire]"
+		formspec = formspec ..
+			"button_exit[5.125,0.5;5,1;fire;Fire]"
+
+		-- Digiline channel
+		if has_digilines then
+			local channel = meta:get_string("channel") or ""
+			formspec = formspec ..
+				"field[0.375,2.375;4,1;digiline_channel;Digiline Channel;" .. channel .. "]" ..
+				"button_exit[4.5,2.375;1,1;set_digiline_channel;Set]"
+		end
+	else
+		formspec = formspec .. "formspec_version[4]"
+
+		if has_digilines then
+			formspec = formspec .. "size[6,4;]"
+		else
+			formspec = formspec .. "size[6,2;]"
+		end
+
+		-- Manual "fire" button
+		formspec = formspec ..
+			"button_exit[0.5,0.5;5,1;fire;Fire]"
+
+		-- Digiline channel
+		if has_digilines then
+			local channel = meta:get_string("channel") or ""
+			formspec = formspec ..
+				"field[0.5,2.5;3.5,1;digiline_channel;Digiline Channel;" .. channel .. "]" ..
+				"button_exit[4.5,2.5;1,1;set_digiline_channel;Set]"
+		end
+	end
 
 	meta:set_string("formspec", formspec)
 end
 
-spacecannon.update_formspec = function(meta)
-	if has_digilines then
-		spacecannon.update_formspec_digilines(meta)
-	else
-		meta:set_string("formspec", "size[8,2;]" ..
-			"button_exit[0,1;8,1;fire;Fire]")
-	end
-end
-
 spacecannon.can_shoot = function()
 	-- arguments: pos, playername
 	return true
@@ -37,8 +63,7 @@ spacecannon.can_destroy = function()
 	return true
 end
 
-spacecannon.fire = function(pos, playername, color, speed, range)
-
+spacecannon.fire = function(pos, playername, color, speed, is_th, storage_require_mod)
 	if not spacecannon.can_shoot(pos, playername) then
 		return
 	end
@@ -46,13 +71,36 @@ spacecannon.fire = function(pos, playername, color, speed, range)
 	-- check fuel/power
 	local meta = minetest.get_meta(pos)
 
-	if meta:get_int("powerstorage") < spacecannon.config.powerstorage * range then
+	local config_store = spacecannon.config.ki_powerstorage * storage_require_mod
+	if is_th then config_store = spacecannon.config.th_powerstorage * storage_require_mod end
+
+	if meta:get_int("powerstorage") < config_store then
 		-- not enough power
 		return
+	end
+
+	-- check ammunition
+	if not is_th then
+		local inv = meta:get_inventory()
+		if inv:is_empty("src") then
+			--minetest.chat_send_player(playername, "No ammunition loaded!")
+			return false
+		end
+		local src_stack = inv:get_list("src")[1]
+		if not src_stack or src_stack:get_name() ~= "spacecannon:railgun_slug" then
+			--minetest.chat_send_player(playername, "Incorrect ammunition!")
+			return
+		end
+	end
 
-	else
 	-- use power
 	meta:set_int("powerstorage", 0)
+
+	-- use ammo
+	if not is_th then
+		local src_stack = (meta:get_inventory()):get_list("src")[1]
+		src_stack:take_item();
+		(meta:get_inventory()):set_stack("src", 1, src_stack)
 	end
 
 	minetest.sound_play("spacecannon_shoot", {