sum_airship/init.lua

local S = minetest.get_translator(minetest.get_current_modname())


local S = minetest.get_translator(minetest.get_current_modname())

local boat_visual_size = {x = 1, y = 1, z = 1}
local paddling_speed = 22
local boat_y_offset = 0.35
local boat_y_offset_ground = boat_y_offset + 0.6
local boat_side_offset = 1.001
local boat_max_hp = 4

local function is_group(pos, group)
	local nn = minetest.get_node(pos).name
	return minetest.get_item_group(nn, group) ~= 0
end

local function is_river_water(p)
	return true
end

local function is_ice(pos)
	return false
end

local function get_sign(i)
	if i == 0 then
		return 0
	else
		return i / math.abs(i)
	end
end

local function get_velocity(v, yaw, y)
	local x = -math.sin(yaw) * v
	local z =  math.cos(yaw) * v
	return {x = x, y = y, z = z}
end

local function get_v(v)
	return math.sqrt(v.x ^ 2 + v.z ^ 2)
end

local function check_object(obj)
	return obj and (obj:is_player() or obj:get_luaentity()) and obj
end

local function get_visual_size(obj)
	return obj:is_player() and {x = 1, y = 1, z = 1} or obj:get_luaentity()._old_visual_size or obj:get_properties().visual_size
end

local function set_attach(boat)
	boat._driver:set_attach(boat.object, "",
		{x = 0, y = 0.42, z = -1}, {x = 0, y = 0, z = 0})
end

local function set_double_attach(boat)
	boat._driver:set_attach(boat.object, "",
		{x = 0, y = 0.42, z = 0.8}, {x = 0, y = 0, z = 0})
	boat._passenger:set_attach(boat.object, "",
		{x = 0, y = 0.42, z = -2.2}, {x = 0, y = 0, z = 0})
end

local function attach_object(self, obj)
	if self._driver then
		if self._driver:is_player() then
			self._passenger = obj
		else
			self._passenger = self._driver
			self._driver = obj
		end
		set_double_attach(self)
	else
		self._driver = obj
		set_attach(self)
	end

	local visual_size = get_visual_size(obj)
	local yaw = self.object:get_yaw()
	obj:set_properties({visual_size = vector.divide(visual_size, boat_visual_size)})

	if obj:is_player() then
		local name = obj:get_player_name()
		mcl_player.player_attached[name] = true
		minetest.after(0.2, function(name)
			local player = minetest.get_player_by_name(name)
			if player then
				mcl_player.player_set_animation(player, "sit" , 30)
			end
		end, name)
		obj:set_look_horizontal(yaw)
		mcl_title.set(obj, "actionbar", {text=S("Sneak to dismount"), color="white", stay=60})
	else
		obj:get_luaentity()._old_visual_size = visual_size
	end
end

local function detach_object(obj, change_pos)
	obj:set_detach()
	obj:set_properties({visual_size = get_visual_size(obj)})
	if obj:is_player() then
		mcl_player.player_attached[obj:get_player_name()] = false
		mcl_player.player_set_animation(obj, "stand" , 30)
	else
		obj:get_luaentity()._old_visual_size = nil
	end
	if change_pos then
		 obj:set_pos(vector.add(obj:get_pos(), vector.new(0, 0.2, 0)))
	end
end

--
-- Boat entity
--

local boat = {
	physical = true,
	pointable = true,
	-- Warning: Do not change the position of the collisionbox top surface,
	-- lowering it causes the boat to fall through the world if underwater
	collisionbox = {-0.5, -0.35, -0.5, 0.5, 0.3, 0.5},
	selectionbox = {-0.7, -0.35, -0.7, 0.7, 0.3, 0.7},
	visual = "mesh",
	mesh = "sum_airship_boat.b3d",
	textures = {"sum_airship_texture_oak_boat.png", "sum_airship_texture_oak_boat.png", "sum_airship_texture_oak_boat.png", "sum_airship_texture_oak_boat.png", "sum_airship_texture_oak_boat.png"},
	visual_size = boat_visual_size,
	hp_max = boat_max_hp,
	damage_texture_modifier = "^[colorize:white:0",

	_driver = nil, -- Attached driver (player) or nil if none
	_passenger = nil,
	_v = 0, -- Speed
	_last_v = 0, -- Temporary speed variable
	_removed = false, -- If true, boat entity is considered removed (e.g. after punch) and should be ignored
	_itemstring = "sum_airship:boat", -- Itemstring of the boat item (implies boat type)
	_animation = 0, -- 0: not animated; 1: paddling forwards; -1: paddling forwards
	_regen_timer = 0,
	_damage_anim = 0,
}

minetest.register_on_respawnplayer(detach_object)

function boat.on_rightclick(self, clicker)
	if self._passenger or not clicker or clicker:get_attach() then
		return
	end
	attach_object(self, clicker)
end


function boat.on_activate(self, staticdata, dtime_s)
	self.object:set_armor_groups({fleshy = 100})
	local data = minetest.deserialize(staticdata)
	if type(data) == "table" then
		self._v = data.v
		self._last_v = self._v
		self._itemstring = data.itemstring

		while #data.textures < 5 do
			table.insert(data.textures, data.textures[1])
		end

		self.object:set_properties({textures = data.textures})
	end
end

function boat.get_staticdata(self)
	return minetest.serialize({
		v = self._v,
		itemstring = self._itemstring,
		textures = self.object:get_properties().textures
	})
end

function boat.on_death(self, killer)
	mcl_burning.extinguish(self.object)

	if killer and killer:is_player() and minetest.is_creative_enabled(killer:get_player_name()) then
		local inv = killer:get_inventory()
		if not inv:contains_item("main", self._itemstring) then
			inv:add_item("main", self._itemstring)
		end
	else
		minetest.add_item(self.object:get_pos(), self._itemstring)
	end
	if self._driver then
		detach_object(self._driver)
	end
	if self._passenger then
		detach_object(self._passenger)
	end
	self._driver = nil
	self._passenger = nil
end

function boat.on_punch(self, puncher, time_from_last_punch, tool_capabilities, dir, damage)
	if damage > 0 then
		self._regen_timer = 0
	end
end

function boat.on_step(self, dtime, moveresult)
	mcl_burning.tick(self.object, dtime, self)

	self._v = get_v(self.object:get_velocity()) * get_sign(self._v)
	local v_factor = 1
	local v_slowdown = 0.1
	local p = self.object:get_pos()
	local on_water = true
	local on_ice = false
	local in_water = false
	local in_river_water = false
	local waterp = {x=p.x, y=p.y-boat_y_offset - 0.1, z=p.z}

	local hp = self.object:get_hp()
	local regen_timer = self._regen_timer + dtime
	if hp >= boat_max_hp then
		regen_timer = 0
	elseif regen_timer >= 0.5 then
		hp = hp + 1
		self.object:set_hp(hp)
		regen_timer = 0
	end
	self._regen_timer = regen_timer

	if moveresult and moveresult.collides then
		for _, collision in pairs(moveresult.collisions) do
			local pos = collision.node_pos
			if collision.type == "node" and minetest.get_item_group(minetest.get_node(pos).name, "dig_by_boat") > 0 then
				minetest.dig_node(pos)
			end
		end
	end


  local climb = 0
  local forward = 0


	local had_passenger = self._passenger

	self._driver = check_object(self._driver)
	self._passenger = check_object(self._passenger)

	if self._passenger then
		if not self._driver then
			self._driver = self._passenger
			self._passenger = nil
		else
			local ctrl = self._passenger:get_player_control()
			if ctrl and ctrl.sneak then
				detach_object(self._passenger, true)
				self._passenger = nil
			end
		end
	end

	if self._driver then
		if had_passenger and not self._passenger then
			set_attach(self)
		end
		local ctrl = self._driver:get_player_control()
		if ctrl and ctrl.sneak then
			detach_object(self._driver, true)
			self._driver = nil
			return
		end
		local yaw = self.object:get_yaw()

		if ctrl and ctrl.up then
			-- Forwards
			forward = forward + 1
    elseif ctrl and ctrl.down then
      forward = forward - 1
    end
		if ctrl and ctrl.aux1 then
			climb = climb - 1
    elseif ctrl and ctrl.jump then
      climb = climb + 1
    end

		if ctrl and ctrl.left then
			if self._v < 0 then
				self.object:set_yaw(yaw - (1 + dtime) * 0.03 * v_factor)
			else
				self.object:set_yaw(yaw + (1 + dtime) * 0.03 * v_factor)
			end
		elseif ctrl and ctrl.right then
			if self._v < 0 then
				self.object:set_yaw(yaw + (1 + dtime) * 0.03 * v_factor)
			else
				self.object:set_yaw(yaw - (1 + dtime) * 0.03 * v_factor)
			end
		end
	end

		-- for _, obj in pairs(minetest.get_objects_inside_radius(self.object:get_pos(), 1.3)) do
		-- 	local entity = obj:get_luaentity()
		-- 	if entity and entity.is_mob then
		-- 		attach_object(self, obj)
		-- 		break
		-- 	end
		-- end
	local s = get_sign(self._v)

	local new_velo
	local new_acce
  new_acce = {x = 0, y = 0, z = 0}
  new_velo = get_velocity(self._v, self.object:get_yaw(), self.object:get_velocity().y)
  self.object:set_pos(self.object:get_pos())
	-- Terminal velocity: 8 m/s per axis of travel
	local terminal_velocity = 50
	for _,axis in pairs({"z","y","x"}) do
		if math.abs(new_velo[axis]) > terminal_velocity then
			new_velo[axis] = terminal_velocity * get_sign(new_velo[axis])
		end
	end

	local yaw = self.object:get_yaw()
  local yaw_dir = minetest.yaw_to_dir(yaw)
	local anim = (boat_max_hp - hp - regen_timer * 2) / boat_max_hp * math.pi / 4

	self.object:set_rotation(vector.new(anim, yaw, anim))
	-- self.object:set_velocity(new_velo)
	-- self.object:set_acceleration(new_acce)

  local vel = nil
  if self._driver then
    if self._driver:get_look_dir() and false then
      dir = self._driver:get_look_dir()
    else
      dir = vector.multiply(yaw_dir, forward)
      dir.y = climb
    end
    vel = vector.multiply(dir, 20)
    if vel then
    	self.object:set_acceleration(vel)
    end
  else
    self.object:set_acceleration({x=0,y=-5,z=0})
  end

  local v = self.object:get_velocity()
  v = vector.multiply(v, 0.97)
  self.object:set_velocity(v)
end

-- Register one entity for all boat types
minetest.register_entity("sum_airship:boat", boat)

local boat_ids = { "boat" }
local names = { S("Oak Boat") }
local craftstuffs = {}
if minetest.get_modpath("mcl_core") then
	craftstuffs = { "mcl_core:wood" }
end
local images = { "oak" }

for b=1, #boat_ids do
	local itemstring = "sum_airship:"..boat_ids[b]

	local longdesc, usagehelp, tt_help, help, helpname
	help = false
	-- Only create one help entry for all boats
	if b == 1 then
		help = true
		longdesc = S("Boats are used to travel on the surface of water.")
		usagehelp = S("Rightclick on a water source to place the boat. Rightclick the boat to enter it. Use [Left] and [Right] to steer, [Forwards] to speed up and [Backwards] to slow down or move backwards. Use [Sneak] to leave the boat, punch the boat to make it drop as an item.")
		helpname = S("Boat")
	end
	tt_help = S("Water vehicle")

	minetest.register_craftitem(itemstring, {
		description = names[b],
		_tt_help = tt_help,
		_doc_items_create_entry = help,
		_doc_items_entry_name = helpname,
		_doc_items_longdesc = longdesc,
		_doc_items_usagehelp = usagehelp,
		inventory_image = "sum_airship_"..images[b].."_boat.png",
		liquids_pointable = true,
		groups = { boat = 1, transport = 1},
		stack_max = 1,
		on_place = function(itemstack, placer, pointed_thing)
			if pointed_thing.type ~= "node" then
				return itemstack
			end

			-- Call on_rightclick if the pointed node defines it
			local node = minetest.get_node(pointed_thing.under)
			if placer and not placer:get_player_control().sneak then
				if minetest.registered_nodes[node.name] and minetest.registered_nodes[node.name].on_rightclick then
					return minetest.registered_nodes[node.name].on_rightclick(pointed_thing.under, node, placer, itemstack) or itemstack
				end
			end

			local pos = table.copy(pointed_thing.under)
			local dir = vector.subtract(pointed_thing.above, pointed_thing.under)

			if math.abs(dir.x) > 0.9 or math.abs(dir.z) > 0.9 then
				pos = vector.add(pos, vector.multiply(dir, boat_side_offset))
			-- elseif true then
			-- 	pos = vector.add(pos, vector.multiply(dir, boat_y_offset))
			else
				pos = vector.add(pos, vector.multiply(dir, boat_y_offset_ground))
			end
			local boat = minetest.add_entity(pos, "sum_airship:boat")
			local texture = "sum_airship_texture_"..images[b].."_boat.png"
			boat:get_luaentity()._itemstring = itemstring
			boat:set_properties({textures = { texture, texture, texture, texture, texture }})
			boat:set_yaw(placer:get_look_horizontal())
			if not minetest.is_creative_enabled(placer:get_player_name()) then
				itemstack:take_item()
			end
			return itemstack
		end,
		_on_dispense = function(stack, pos, droppos, dropnode, dropdir)
			local below = {x=droppos.x, y=droppos.y-1, z=droppos.z}
			local belownode = minetest.get_node(below)
			-- Place boat as entity on or in water
			if minetest.get_item_group(dropnode.name, "water") ~= 0 or (dropnode.name == "air" and minetest.get_item_group(belownode.name, "water") ~= 0) then
				minetest.add_entity(droppos, "sum_airship:boat")
			else
				minetest.add_item(droppos, stack)
			end
		end,
	})

	local c = craftstuffs[b]
	minetest.register_craft({
		output = itemstring,
		recipe = {
			{c, "", c},
			{c, c, c},
		},
	})
end

minetest.register_craft({
	type = "fuel",
	recipe = "group:boat",
	burntime = 20,
})

if minetest.get_modpath("doc_identifier") and doc.sub.identifier then
	doc.sub.identifier.register_object("sum_airship:boat", "craftitems", "sum_airship:boat")
end