minetest-mod-rocket_launcher/init.lua

local default_radius = tonumber(core.settings:get("rocket_launcher_radius")) or 3
local ballistic = core.settings:get_bool("rocket_launcher_ballistic", true)
local safe_areas = core.settings:get_bool("rocket_launcher_safe_areas", true)

local reloading = {}
local function reload(name)
	if not reloading[name] then
		reloading[name] = true
		core.after(4,function()
			reloading[name] = false
		end)
	end
end

local function can_boom(pos)
	if safe_areas == false then
		return true
	else
		return not core.is_protected(pos,"")
	end
end

core.register_chatcommand("rocket-radius", {
  description = "Set rocket explosion radius for wielded rauncher",
  params = "<number>",
  privs = {server=true},
  func = function(name, param)
	local radius = tonumber(param)
	if not radius then return false, "Invalid radius" end
    local player = core.get_player_by_name(name)
    if not player then return end
    local witem = player:get_wielded_item()
    if not witem then return end
    if witem:get_name() ~= "rocket_launcher:launcher" then return false, "Keep rocket launcher in hand!" end
    local meta = witem:get_meta()
    if meta then
		meta:set_int("radius",radius)
		meta:set_string("count_meta","R"..param)
		player:set_wielded_item(witem)
		return true, "Radius set to "..param
	end
end})
core.register_craftitem("rocket_launcher:rocket", {
	wield_scale = {x=1,y=1,z=1.5},
	stack_max = 16,
	description = "Rocket",
	inventory_image = "rocket.png",
})

core.register_tool("rocket_launcher:launcher", {
	wield_scale = {x=1,y=1,z=2},
	description = "Rocket Launcher",
	inventory_image = "rocket_launcher.png",
	on_use = function(itemstack, user, pointed_thing)
	local name = user:get_player_name()
	local creative = core.check_player_privs(name, {creative = true})
	local inv = user:get_inventory()
	if inv:contains_item("main", "rocket_launcher:rocket") or creative then
		if not creative then
			if reloading[name] then
				core.chat_send_player(name, "Rocket launcher is reloading")
				return
			end
			reload(name)
			inv:remove_item("main", "rocket_launcher:rocket 1")
		end
		local meta = itemstack:get_meta()
		local radius = meta:get("radius") or default_radius
		local pos = user:get_pos()
		local dir = user:get_look_dir()
		local yaw = user:get_look_horizontal()
		if pos and dir then
			pos.y = pos.y + 1.5
			local obj = core.add_entity(pos, "rocket_launcher:rocket",radius)
			if obj then
				obj:set_velocity({x=dir.x * 30, y=dir.y * 30, z=dir.z * 30})
				user:add_velocity({x=dir.x * -4, y=dir.y * -4, z=dir.z * -4})
				if ballistic == true then
					obj:set_acceleration({x=0,z=0,y=-1})
				end
				obj:set_yaw(yaw)
			end
		end
		core.sound_play('fire_extinguish_flame',{to_player = name, gain = 0.5})
		return itemstack
	end
end})

local rocket = {
	armor_groups = {immortal = true},
	physical = true,
	timer = 0,
	visual = "mesh",
	mesh = 'rocket.obj',
	visual_size = {x=0.7, y=0.7,},
	textures = {'rocket_mesh.png'},
	pointable = false,
	collisionbox = {-0.25,-0.25,-0.25,0.25,0.25,0.25},
	collide_with_objects = false,
	automatic_face_movement_dir = 270
}

rocket.on_activate = function(self, staticdata)
	self["radius"] = tonumber(staticdata) or 3
end

rocket.on_step = function(self, dtime, moveresult)
	self.timer = self.timer + dtime
	local pos = self.object:get_pos()
	local rnd = math.random()
	core.after(0.1,function()
		core.add_particle({
			pos = pos,
			velocity = {x=rnd,y=rnd,z=rnd},
			expirationtime = 0.1,
			size = 6,
			collisiondetection = false,
			vertical = false,
			texture = "tnt_boom.png",
			glow = 15})
		core.add_particle({
			pos = pos,
			velocity = {x=rnd,y=rnd,z=rnd},
			expirationtime = 0.7,
			size = 6,
			collisiondetection = false,
			vertical = false,
			texture = "tnt_smoke.png",
			glow = 15})
	end)
	if self.timer >= 60 then
		self.object:remove()
	end
	if self.timer > 0.2 then
		local objs = core.get_objects_inside_radius({x = pos.x, y = pos.y-1, z = pos.z}, 1)
		for k, obj in pairs(objs) do
			if not obj then goto nodes end
			local prop = obj:get_properties()
			if not prop then goto nodes end
			if obj:is_player() or prop.collide_with_objects == true then
				if can_boom(pos) then
					tnt.boom(pos,{radius=self["radius"]})
				end
				self.object:remove()
			end
		end
	end
::nodes::
	if moveresult.collides then
		if can_boom(pos) then
			tnt.boom(pos,{radius=self["radius"]})
		end
		self.object:remove()
	end
end

core.register_entity("rocket_launcher:rocket", rocket)

core.register_craft({
	output = "rocket_launcher:rocket",
	recipe = {
		{"dye:dark_green","default:mese_crystal","dye:dark_green"},
		{"default:steel_ingot","default:mese_crystal","default:steel_ingot"},
		{"default:steel_ingot","tnt:gunpowder","default:steel_ingot"}
	}
})
core.register_craft({
	output = "rocket_launcher:launcher",
	recipe = {
		{"default:steel_ingot","default:steel_ingot","default:steel_ingot"},
		{"dye:dark_green","default:mese","default:obsidian_block"},
		{"default:steel_ingot","default:steel_ingot","default:steel_ingot"}
	}
})