VoxeLibre/mods/ITEMS/mcl_tnt/init.lua

local S = minetest.get_translator("mcl_tnt")
local tnt_griefing = minetest.settings:get_bool("mcl_tnt_griefing", true)

local mod_death_messages = minetest.get_modpath("mcl_death_messages")

local function spawn_tnt(pos, entname)
	minetest.sound_play("tnt_ignite", {pos = pos,gain = 1.0,max_hear_distance = 15,})
	local tnt = minetest.add_entity(pos, entname)
	tnt:set_armor_groups({immortal=1})
	return tnt
end

local function activate_if_tnt(nname, np, tnt_np, tntr)
    if nname == "mcl_tnt:tnt" then
        local e = spawn_tnt(np, nname)
        e:set_velocity({x=(np.x - tnt_np.x)*5+(tntr / 4), y=(np.y - tnt_np.y)*5+(tntr / 3), z=(np.z - tnt_np.z)*5+(tntr / 4)})
        minetest.remove_node(np)
        minetest.check_for_falling(np)
    end
end

local function do_tnt_physics(tnt_np,tntr)
    local objs = minetest.get_objects_inside_radius(tnt_np, tntr)
    for k, obj in pairs(objs) do
        local ent = obj:get_luaentity()
        local v = obj:get_velocity()
        local p = obj:get_pos()
        if ent and ent.name == "mcl_tnt:tnt" then
            obj:set_velocity({x=(p.x - tnt_np.x) + (tntr / 2) + v.x, y=(p.y - tnt_np.y) + tntr + v.y, z=(p.z - tnt_np.z) + (tntr / 2) + v.z})
        else
            if v ~= nil then
                obj:set_velocity({x=(p.x - tnt_np.x) + (tntr / 4) + v.x, y=(p.y - tnt_np.y) + (tntr / 2) + v.y, z=(p.z - tnt_np.z) + (tntr / 4) + v.z})
            else
                local dist = math.max(1, vector.distance(tnt_np, p))
                local damage = (4 / dist) * tntr
                if obj:is_player() == true then
                    if mod_death_messages then
                        mcl_death_messages.player_damage(obj, S("@1 was caught in an explosion.", obj:get_player_name()))
                    end
                end
                obj:set_hp(obj:get_hp() - damage)
            end
        end
    end
end

tnt = {}
tnt.ignite = function(pos)
	minetest.remove_node(pos)
	spawn_tnt(pos, "mcl_tnt:tnt")
	minetest.check_for_falling(pos)
end

-- Add smoke particle of entity at pos.
-- Intended to be called every step
tnt.smoke_step = function(pos)
	minetest.add_particle({
		pos = {x=pos.x,y=pos.y+0.5,z=pos.z},
		velocity = vector.new(math.random() * 0.2 - 0.1, 1.0 + math.random(), math.random() * 0.2 - 0.1),
		acceleration = vector.new(0, -0.1, 0),
		expirationtime = 0.15 + math.random() * 0.25,
		size = 1.0 + math.random(),
		collisiondetection = false,
		texture = "tnt_smoke.png"
	})
end

tnt.BOOMTIMER = 4
tnt.BLINKTIMER = 0.25

local TNT_RANGE = 3

local sounds
if minetest.get_modpath("mcl_sounds") then
	sounds = mcl_sounds.node_sound_wood_defaults()
end
local tnt_mesecons
if minetest.get_modpath("mesecons") then
	tnt_mesecons = {effector = {
		action_on = tnt.ignite,
		rules = mesecon.rules.alldirs,
	}}
end

local longdesc
if tnt_griefing then
	longdesc = S("An explosive device. When it explodes, it will hurt living beings and destroy blocks around it. TNT has an explosion radius of @1. With a small chance, blocks may drop as an item (as if being mined) rather than being destroyed. TNT can be ignited by tools, explosions, fire, lava and redstone signals.", TNT_RANGE)
else
	longdesc = S("An explosive device. When it explodes, it will hurt living beings. TNT has an explosion radius of @1. TNT can be ignited by tools, explosions, fire, lava and redstone signals.", TNT_RANGE)
end

minetest.register_node("mcl_tnt:tnt", {
	tiles = {"default_tnt_top.png", "default_tnt_bottom.png",
			"default_tnt_side.png", "default_tnt_side.png",
			"default_tnt_side.png", "default_tnt_side.png"},
	is_ground_content = false,
	stack_max = 64,
	description = S("TNT"),
	paramtype = "light",
	sunlight_propagates = true,
	_doc_items_longdesc = longdesc,
	_doc_items_usagehelp = S("Place the TNT and ignite it with one of the methods above. Quickly get in safe distance. The TNT will start to be affected by gravity and explodes in 4 seconds."),
	groups = { dig_immediate = 3, tnt = 1, enderman_takable=1 },
	mesecons = tnt_mesecons,
	_on_ignite = function(player, pointed_thing)
		tnt.ignite(pointed_thing.under)
		return true
	end,
	_on_dispense = function(stack, pos, droppos, dropnode, dropdir)
		-- Place and ignite TNT
		if minetest.registered_nodes[dropnode.name].buildable_to then
			minetest.set_node(droppos, {name = stack:get_name()})
			tnt.ignite(droppos)
		end
	end,
	sounds = sounds,
})

local TNT = {
	-- Static definition
	physical = true, -- Collides with things
	 --weight = -100,
	collisionbox = {-0.5,-0.5,-0.5, 0.5,0.5,0.5},
	visual = "cube",
	textures = {"default_tnt_top.png", "default_tnt_bottom.png",
			"default_tnt_side.png", "default_tnt_side.png",
			"default_tnt_side.png", "default_tnt_side.png"},
	-- Initial value for our timer
	timer = 0,
	blinktimer = 0,
	blinkstatus = true,}

function TNT:on_activate(staticdata)
	local phi = math.random(0, 65535) / 65535 * 2*math.pi
	local hdir_x = math.cos(phi) * 0.02
	local hdir_z = math.sin(phi) * 0.02
	self.object:set_velocity({x=hdir_x, y=2, z=hdir_z})
	self.object:set_acceleration({x=0, y=-10, z=0})
	self.object:set_texture_mod("^mcl_tnt_blink.png")
end

local function add_effects(pos, radius, drops)
	minetest.add_particlespawner({
		amount = 64,
		time = 0.5,
		minpos = vector.subtract(pos, radius / 2),
		maxpos = vector.add(pos, radius / 2),
		minvel = {x = -10, y = -10, z = -10},
		maxvel = {x = 10, y = 10, z = 10},
		minacc = vector.new(),
		maxacc = vector.new(),
		minexptime = 1,
		maxexptime = 2.5,
		minsize = radius * 1,
		maxsize = radius * 3,
		texture = "tnt_smoke.png",
	})

	-- we just dropped some items. Look at the items entities and pick
	-- one of them to use as texture
	local texture = "tnt_smoke.png" --fallback texture
	local most = 0
	for name, stack in pairs(drops) do
		local count = stack:get_count()
		if count > most then
			most = count
			local def = minetest.registered_nodes[name]
			if def and def.tiles and def.tiles[1] then
				texture = def.tiles[1]
			end
		end
	end

	minetest.add_particlespawner({
		amount = 32,
		time = 0.1,
		minpos = vector.subtract(pos, radius / 2),
		maxpos = vector.add(pos, radius / 2),
		minvel = {x = -3, y = 0, z = -3},
		maxvel = {x = 3, y = 5,  z = 3},
		minacc = {x = 0, y = -10, z = 0},
		minexptime = 0.8,
		maxexptime = 2.0,
		minsize = radius * 0.66,
		maxsize = radius * 2,
		texture = texture,
		collisiondetection = true,
	})
end

function TNT:on_step(dtime)
	local pos = self.object:get_pos()
	tnt.smoke_step(pos)
	self.timer = self.timer + dtime
	self.blinktimer = self.blinktimer + dtime
	if self.blinktimer > tnt.BLINKTIMER then
		self.blinktimer = self.blinktimer - tnt.BLINKTIMER
		if self.blinkstatus then
			self.object:set_texture_mod("")
		else
			self.object:set_texture_mod("^mcl_tnt_blink.png")
		end
		self.blinkstatus = not self.blinkstatus
	end
	if self.timer > tnt.BOOMTIMER then
		tnt.boom(self.object:get_pos())
		self.object:remove()
	end
end

tnt.boom = function(pos, info)
	if not info then info = {} end
	local range = info.radius or TNT_RANGE
	local damage_range = info.damage_radius or TNT_RANGE

	pos.x = math.floor(pos.x+0.5)
	pos.y = math.floor(pos.y+0.5)
	pos.z = math.floor(pos.z+0.5)
	do_tnt_physics(pos, range)
	local meta = minetest.get_meta(pos)
	local sound
	if not info.sound then
		sound = "tnt_explode"
	else
		sound = info.sound
	end
	if info.is_tnt == nil then
		info.is_tnt = true
	end
	minetest.sound_play(sound, {pos = pos,gain = 1.0,max_hear_distance = 16,})
	local node = minetest.get_node(pos)
	if minetest.get_item_group("water") == 1 or minetest.get_item_group("lava") == 1 then
		-- Cancel the Explosion
		return
        end
	for x=-range,range do
		for y=-range,range do
			for z=-range,range do
				if x*x+y*y+z*z <= range * range + range then
					local np={x=pos.x+x,y=pos.y+y,z=pos.z+z}
					local n = minetest.get_node(np)
					local def = minetest.registered_nodes[n.name]
					-- Simple blast resistance check (for now). This keeps the important blocks like bedrock, command block, etc. intact.
					-- TODO: Implement the real blast resistance algorithm
					if def and n.name ~= "air" and n.name ~= "ignore" and (def._mcl_blast_resistance == nil or def._mcl_blast_resistance < 1000) then
						activate_if_tnt(n.name, np, pos, 3)
						if (not tnt_griefing) and info.is_tnt ~= false then
							-- No-op
						-- Custom blast function defined by node.
						-- Node removal and drops must be handled manually.
						elseif def.on_blast then
							def.on_blast(np, 1.0)
						-- Default destruction handling: Remove nodes, drop items
						else
							minetest.remove_node(np)
							minetest.check_for_falling(np)
							if n.name ~= "mcl_tnt:tnt" and math.random() > 0.9 then
								local drop = minetest.get_node_drops(n.name, "")
								for _,item in ipairs(drop) do
									if type(item) == "string" then
										if math.random(1,100) > 40 then
											local obj = minetest.add_item(np, item)
										end
									end
								end
							end
						end
					end
				end
			end
		end
		add_effects(pos, range, {})
	end
end

minetest.register_entity("mcl_tnt:tnt", TNT)

if minetest.get_modpath("mcl_mobitems") then
	minetest.register_craft({
		output = "mcl_tnt:tnt",
		recipe = {
			{'mcl_mobitems:gunpowder','group:sand','mcl_mobitems:gunpowder'},
			{'group:sand','mcl_mobitems:gunpowder','group:sand'},
			{'mcl_mobitems:gunpowder','group:sand','mcl_mobitems:gunpowder'}
		}
	})
end

if minetest.get_modpath("doc_identifier") then
	doc.sub.identifier.register_object("mcl_tnt:tnt", "nodes", "mcl_tnt:tnt")
end