tntrun-cd2025/tnt.lua

-- Delay in seconds after which TNT falls down when stepping on it directly
local TNT_FALL_DELAY_DIRECT = 0.25
-- Delay in seconds after which TNT falls down when stepping on it indirectly via sneaking
local TNT_FALL_DELAY_SNEAK = 0.5 -- it's intentional that it's a bit longer
-- Distance from TNT node a player can be so it is still considered "stepped on"
-- by the game. The distance takes X and Z into account separately but not Z.
-- Change this if Luanti changes the sneak distance; works only for sneak distance below 0.5
local SNEAK_DISTANCE = 0.3
-- Time in seconds after which to execute tnt_loop() again
local TNT_LOOP_TIME = 0.1
-- Time in seconds after which the TNT entity dies
local TIME_UNTIL_DESPAWN = 5
-- gravity for particles
local GRAVITY = 9.81
-- Animation settings for TNT fuse
local TNT_FUSE_ANIMATION_FRAMES = 4 -- number of frames
local TNT_FUSE_ANIMATION_FRAME_LENGTH = 0.25 -- length of a frame in seconds

-- Translation boilerplate
local S = minetest.get_translator("tntrun")

local tnt_entity_base_textures = {
	"tntrun_tnt_top_burning_animated.png^[verticalframe:"..TNT_FUSE_ANIMATION_FRAMES..":0",
	"tntrun_tnt_bottom.png", "tntrun_tnt_side.png", "tntrun_tnt_side.png", "tntrun_tnt_side.png", "tntrun_tnt_side.png"
}

minetest.register_entity("tntrun:tnt_falling", {
	initial_properties = {
		physical = true,
		collide_with_objects = true,
		pointable = true,
		collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
		selectionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
		visual = "cube",
		visual_size = {x = 1, y = 1, z = 1},
		textures = tnt_entity_base_textures,
		static_save = false,
	},
	_timer = 0,
	_sound_handle = nil,
	_last_anim_frame = 0,
	on_activate = function(self)
		self.object:set_armor_groups({immortal=1})
		local pitch = 1 + math.random(-50,50)*0.001
		self._sound_handle = minetest.sound_play({name="tntrun_fuse"},
			{object=self.object, max_hear_distance=16, gain=0.3, pitch=pitch})
	end,
	on_deactivate = function(self)
		if self._sound_handle then
			minetest.sound_stop(self._sound_handle)
		end
	end,
	on_step = function(self, dtime, moveresult)
		self.object:set_velocity({x = 0, y = -5, z = 0 })

		-- Spawn particles when TNT is removed
		local poof = function(pos)
			-- TNT break particles
			minetest.add_particlespawner({
				amount = math.random(15, 30),
				time = 0.01,
				minpos = vector.add(pos, {x=-0.4, y=-0.5, z=-0.4}),
				maxpos = vector.add(pos, {x=0.4, y=0.5, z=0.4}),
				minvel = {x=-3.5, y=-0.1, z=-3.5},
				maxvel = {x=3.5, y=1.0, z=3.5},
				drag = { x=2, y=0, z=2 },
				minacc = {x=0, y=-GRAVITY, z=0},
				maxacc = {x=0, y=-GRAVITY, z=0},
				minexptime = 0.2,
				maxexptime = 0.7,
				minsize = 1.5,
				maxsize = 2.0,
				collisiondetection = true,
				vertical = false,
				node = {name="tntrun:tnt"},
			})
			-- Smoke
			minetest.add_particle({
				pos = vector.add(pos, {x=0, y=0.2, z=0}),
				velocity = { x=0, y=0.5+math.random(0,5)*0.1, z=0 },
				expirationtime = 1.5,
				size = 7.0,
				collisiondetection = false,
				vertical = false,
				texture = "tntrun_smoke_puff.png",
			})
		end

		local checkpos = self.object:get_pos()
		local tntpos = table.copy(checkpos)
		checkpos.y = checkpos.y - 1
		local node_below = minetest.registered_nodes[minetest.get_node(checkpos).name]
		-- Remove TNT when it collides with node (might be an unknown node, hence the first check)
		if node_below and node_below.walkable then
			poof(tntpos)
			self.object:remove()
			return
		end
		-- Remove TNT after timer
		if self._timer > TIME_UNTIL_DESPAWN then
			poof(tntpos)
			self.object:remove()
			return
		else
			self._timer = self._timer + dtime
		end

		-- Animate texture manually
		-- TODO: Replace this code once Luanti allows to animate
		-- entity textures natively.
		local frametimer = self._timer * (1/TNT_FUSE_ANIMATION_FRAME_LENGTH)
		local frame = math.floor(frametimer) % TNT_FUSE_ANIMATION_FRAMES
		if frame ~= self._last_anim_frame then
			local textures = table.copy(tnt_entity_base_textures)
			textures[1] = "tntrun_tnt_top_burning_animated.png^[verticalframe:"..TNT_FUSE_ANIMATION_FRAMES..":"..frame
			self.object:set_properties({
				textures = textures,
			})
			-- Remember the last frame so we only update the
			-- textures property if neccessary
			self._last_anim_frame = frame
		end
	end,
})

local sounds
if minetest.get_modpath("default") then
	sounds = default.node_sound_wood_defaults()
end

minetest.register_node("tntrun:tnt",{
	tiles = {"tntrun_tnt_top.png", "tntrun_tnt_bottom.png", "tntrun_tnt_side.png"},
	groups = {cracky = 3, not_in_creative_inventory = 1},
	sounds = sounds,
	description = S("TNT in Tntrun"),
	drops = "tntrun:tnt",
	on_punch = function(pos, node, puncher)
	if puncher:get_wielded_item():get_name() == "tntrun:torch" then
		minetest.remove_node(pos)
		minetest.add_entity(pos, "tntrun:tnt_falling")
	end
end,
})

minetest.register_craftitem("tntrun:torch",{
	inventory_image = "tntrun_torch.png",
	description = S("Torch for TNT"),
	groups = { not_in_creative_inventory = 1 },
	sound = {
		punch_use_air = { name = "tntrun_swish", gain = 0.2 },
	},
})


local function tnt_loop(arena)
	if not arena.in_game then return end
	for pl_name, _ in pairs(arena.players) do
	local player = minetest.get_player_by_name(pl_name)
	local pos = player:get_pos()
	pos.y = pos.y - 1
	if minetest.get_node(pos).name == "tntrun:tnt" then
		-- TNT falls if player stands directly on it
		pos.x = math.floor(pos.x+0.5)
		pos.z = math.floor(pos.z+0.5)
		minetest.after(TNT_FALL_DELAY_DIRECT, function()
			if minetest.get_node(pos).name ~= "tntrun:tnt" then
				return
			end
			minetest.remove_node(pos)
			minetest.add_entity(pos, "tntrun:tnt_falling")
		end)
	elseif minetest.get_node(pos).name == "air" then
		-- When player does not stand directly on TNT, check for TNT around the player
		-- within SNEAK_DISTANCE
		for x = -1,1 do
			for z = -1,1 do
				local posb = {x = pos.x+(x*SNEAK_DISTANCE), y = pos.y, z = pos.z+(z*SNEAK_DISTANCE)}
				if minetest.get_node(posb).name == "tntrun:tnt" then
					posb.x = math.floor(posb.x+0.5)
					posb.z = math.floor(posb.z+0.5)
					minetest.after(TNT_FALL_DELAY_SNEAK, function()
						if minetest.get_node(posb).name ~= "tntrun:tnt" then
							return
						end
						minetest.remove_node(posb)
						minetest.add_entity(posb, "tntrun:tnt_falling")
					end)
				end
			end
		end
	end
	end
	minetest.after(TNT_LOOP_TIME, function() tnt_loop(arena) end)
end

arena_lib.on_start("tntrun", function(arena)
	tnt_loop(arena)
end)