Implement stuck arrow timeout properly

[MineClone/MineClone2.git] / mods / ITEMS / mcl_bows / arrow.lua

-- Time in seconds after which a stuck arrow is deleted
local ARROW_TIMEOUT = 60
-- Time after which stuck arrow is rechecked for being stuck
local STUCK_RECHECK_TIME = 5

local GRAVITY = 9.81

local YAW_OFFSET = -math.pi/2

local mod_mcl_hunger = minetest.get_modpath("mcl_hunger")
local mod_awards = minetest.get_modpath("awards") and minetest.get_modpath("mcl_achievements")
local mod_button = minetest.get_modpath("mesecons_button")

minetest.register_craftitem("mcl_bows:arrow", {
        description = "Arrow",
        _doc_items_longdesc = [[Arrows are ammunition for bows and dispensers.
An arrow fired from a bow has a regular damage of 1-9. At full charge, there's a 20% chance of a critical hit dealing 10 damage instead. An arrow fired from a dispenser always deals 3 damage.
Arrows might get stuck on solid blocks and can be retrieved again. They are also capable of pushing wooden buttons.]],
        _doc_items_usagehelp = "To use arrows as ammunition for a bow, just put them anywhere in your inventory, they will be used up automatically. To use arrows as ammunition for a dispenser, place them in the dispenser's inventory. To retrieve an arrow that sticks in a block, simply walk close to it.",
        inventory_image = "mcl_bows_arrow_inv.png",
        groups = { ammo=1, ammo_bow=1 },
        _on_dispense = function(itemstack, dispenserpos, droppos, dropnode, dropdir)
                -- Shoot arrow
                local shootpos = vector.add(dispenserpos, vector.multiply(dropdir, 0.51))
                local yaw = math.atan2(dropdir.z, dropdir.x) + YAW_OFFSET
                mcl_bows.shoot_arrow(itemstack:get_name(), shootpos, dropdir, yaw, nil, 19, 3)
        end,
})

-- This is a fake node, used as model for the arrow entity.
-- It's not supposed to be usable as item or real node.
-- TODO: Use a proper mesh for the arrow entity
minetest.register_node("mcl_bows:arrow_box", {
        drawtype = "nodebox",
        is_ground_content = false,
        node_box = {
                type = "fixed",
                fixed = {
                        -- Shaft
                        {-6.5/17, -1.5/17, -1.5/17, -4.5/17, 1.5/17, 1.5/17},
                        {-4.5/17, -0.5/17, -0.5/17, 5.5/17, 0.5/17, 0.5/17},
                        {5.5/17, -1.5/17, -1.5/17, 6.5/17, 1.5/17, 1.5/17},
                        -- Tip
                        {-4.5/17, 2.5/17, 2.5/17, -3.5/17, -2.5/17, -2.5/17},
                        {-8.5/17, 0.5/17, 0.5/17, -6.5/17, -0.5/17, -0.5/17},
                        -- Fletching
                        {6.5/17, 1.5/17, 1.5/17, 7.5/17, 2.5/17, 2.5/17},
                        {7.5/17, -2.5/17, 2.5/17, 6.5/17, -1.5/17, 1.5/17},
                        {7.5/17, 2.5/17, -2.5/17, 6.5/17, 1.5/17, -1.5/17},
                        {6.5/17, -1.5/17, -1.5/17, 7.5/17, -2.5/17, -2.5/17},

                        {7.5/17, 2.5/17, 2.5/17, 8.5/17, 3.5/17, 3.5/17},
                        {8.5/17, -3.5/17, 3.5/17, 7.5/17, -2.5/17, 2.5/17},
                        {8.5/17, 3.5/17, -3.5/17, 7.5/17, 2.5/17, -2.5/17},
                        {7.5/17, -2.5/17, -2.5/17, 8.5/17, -3.5/17, -3.5/17},
                }
        },
        tiles = {"mcl_bows_arrow.png^[transformFX", "mcl_bows_arrow.png^[transformFX", "mcl_bows_arrow_back.png", "mcl_bows_arrow_front.png", "mcl_bows_arrow.png", "mcl_bows_arrow.png^[transformFX"},
        paramtype = "light",
        paramtype2 = "facedir",
        sunlight_propagates = true,
        groups = {not_in_creative_inventory=1, dig_immediate=3},
})

-- FIXME: Arrow velocity is a bit strange. If the arrow flies VERY long, the acceleration can cause the velocity to become negative
-- and the arrow flies backwards.
local ARROW_ENTITY={
        physical = true,
        visual = "wielditem",
        visual_size = {x=0.4, y=0.4},
        textures = {"mcl_bows:arrow_box"},
        collisionbox = {-0.19, -0.125, -0.19, 0.19, 0.125, 0.19},
        collide_with_objects = false,

        _lastpos={},
        _startpos=nil,
        _damage=1,      -- Damage on impact
        _stuck=false,   -- Whether arrow is stuck
        _stucktimer=nil,-- Amount of time (in seconds) the arrow has been stuck so far
        _stuckrechecktimer=nil,-- An additional timer for periodically re-checking the stuck status of an arrow
        _stuckin=nil,   --Position of node in which arow is stuck.
        _shooter=nil,   -- ObjectRef of player or mob who shot it
}

-- Destroy arrow entity self at pos and drops it as an item
local spawn_item = function(self, pos)
        if not minetest.settings:get_bool("creative_mode") then
                local item = minetest.add_item(pos, "mcl_bows:arrow")
                item:set_velocity({x=0, y=0, z=0})
                item:set_yaw(self.object:get_yaw())
        end
        self.object:remove()
end

ARROW_ENTITY.on_step = function(self, dtime)
        local pos = self.object:getpos()
        local dpos = table.copy(pos) -- digital pos
        dpos = vector.round(dpos)
        local node = minetest.get_node(dpos)

        if self._stuck then
                self._stucktimer = self._stucktimer + dtime
                self._stuckrechecktimer = self._stuckrechecktimer + dtime
                if self._stucktimer > ARROW_TIMEOUT then
                        self.object:remove()
                        return
                end
                -- Drop arrow as item when it is no longer stuck
                -- FIXME: Arrows are a bit slot to react and continue to float in mid air for a few seconds.
                if self._stuckrechecktimer > STUCK_RECHECK_TIME then
                        local stuckin_def
                        if self._stuckin then
                                stuckin_def = minetest.registered_nodes[minetest.get_node(self._stuckin).name]
                        end
                        -- TODO: In MC, arrow just falls down without turning into an item
                        if stuckin_def and stuckin_def.walkable == false then
                                spawn_item(self, pos)
                                return
                        end
                        self._stuckrechecktimer = 0
                end
                local objects = minetest.get_objects_inside_radius(pos, 2)
                for _,obj in ipairs(objects) do
                        if obj:is_player() then
                                if not minetest.settings:get_bool("creative_mode") then
                                        -- Pickup arrow if player is nearby
                                        if obj:get_inventory():room_for_item("main", "mcl_bows:arrow") then
                                                obj:get_inventory():add_item("main", "mcl_bows:arrow")
                                                minetest.sound_play("item_drop_pickup", {
                                                        pos = pos,
                                                        max_hear_distance = 16,
                                                        gain = 1.0,
                                                })
                                                self.object:remove()
                                                return
                                        end
                                else
                                        self.object:remove()
                                        return
                                end
                        end
                end

        -- Check for object collision. Done every tick (hopefully this is not too stressing)
        else
                local objs = minetest.get_objects_inside_radius(pos, 2)
                local closest_object
                local closest_distance
                local ok = false

                -- Iterate through all objects and remember the closest attackable object
                for k, obj in pairs(objs) do
                        -- Arrows can only damage players and mobs
                        if obj ~= self._shooter and obj:is_player() then
                                ok = true
                        elseif obj:get_luaentity() ~= nil then
                                if obj ~= self._shooter and obj:get_luaentity()._cmi_is_mob then
                                        ok = true
                                end
                        end

                        if ok then
                                local dist = vector.distance(pos, obj:getpos())
                                if not closest_object or not closest_distance then
                                        closest_object = obj
                                        closest_distance = dist
                                elseif dist < closest_distance then
                                        closest_object = obj
                                        closest_distance = dist
                                end
                        end
                end

                -- If an attackable object was found, we will damage the closest one only
                if closest_object ~= nil then
                        local obj = closest_object
                        local is_player = obj:is_player()
                        local lua = obj:get_luaentity()
                        if obj ~= self._shooter and (is_player or (lua and lua._cmi_is_mob)) then
                                obj:punch(self.object, 1.0, {
                                        full_punch_interval=1.0,
                                        damage_groups={fleshy=self._damage},
                                }, nil)

                                if is_player then
                                        if self._shooter and self._shooter:is_player() then
                                                -- “Ding” sound for hitting another player
                                                minetest.sound_play({name="mcl_bows_hit_player", gain=0.1}, {to_player=self._shooter})
                                        end
                                        if mod_mcl_hunger then
                                                mcl_hunger.exhaust(obj:get_player_name(), mcl_hunger.EXHAUST_DAMAGE)
                                        end
                                end

                                if lua then
                                        local entity_name = lua.name
                                        -- Achievement for hitting skeleton, wither skeleton or stray (TODO) with an arrow at least 50 meters away
                                        -- NOTE: Range has been reduced because mobs unload much earlier than that ... >_>
                                        -- TODO: This achievement should be given for the kill, not just a hit
                                        if self._shooter and self._shooter:is_player() and vector.distance(pos, self._startpos) >= 20 then
                                                if mod_awards and (entity_name == "mobs_mc:skeleton" or entity_name == "mobs_mc:stray" or entity_name == "mobs_mc:witherskeleton") then
                                                        awards.unlock(self._shooter:get_player_name(), "mcl:snipeSkeleton")
                                                end
                                        end
                                end
                                self.object:remove()
                                return
                        end
                end
        end

        -- Check for node collision
        if self._lastpos.x~=nil and not self._stuck then
                local def = minetest.registered_nodes[node.name]
                local vel = self.object:get_velocity()
                -- Arrow has stopped in one axis, so it probably hit something
                if (math.abs(vel.x) < 0.0001) or (math.abs(vel.z) < 0.0001) or (math.abs(vel.y) < 0.00001) then
                        -- Check for the node to which the arrow is pointing
                        local dir
                        if math.abs(vel.y) < 0.00001 then
                                if self._lastpos.y < pos.y then
                                        dir = {x=0, y=1, z=0}
                                else
                                        dir = {x=0, y=-1, z=0}
                                end
                        else
                                dir = minetest.facedir_to_dir(minetest.dir_to_facedir(minetest.yaw_to_dir(self.object:get_yaw()-YAW_OFFSET)))
                        end
                        self._stuckin = vector.add(pos, dir)
                        local snode = minetest.get_node(self._stuckin)
                        local sdef = minetest.registered_nodes[snode.name]

                        -- If node is non-walkable, unknown or ignore, don't make arrow stuck.
                        -- This causes a deflection in the engine.
                        if not sdef or sdef.walkable == false or snode.name == "ignore" then
                                self._stuckin = nil
                                -- Lose 1/3 of velocity on deflection
                                self.object:set_velocity(vector.multiply(vel, 0.6667))
                                return
                        end

                        -- Node was walkable, make arrow stuck
                        self._stuck = true
                        self._stucktimer = 0
                        self._stuckrechecktimer = 0

                        self.object:set_velocity({x=0, y=0, z=0})
                        self.object:set_acceleration({x=0, y=0, z=0})

                        -- Push the button! Push, push, push the button!
                        if mod_button and minetest.get_item_group(node.name, "button") > 0 and minetest.get_item_group(node.name, "button_push_by_arrow") == 1 then
                                mesecon.push_button(dpos, node)
                        end
                elseif (def and def.liquidtype ~= "none") then
                        -- Slow down arrow in liquids
                        local v = def.liquid_viscosity
                        if not v then
                                v = 0
                        end
                        local vpenalty = math.max(0.1, 0.98 - 0.1 * v)
                        if math.abs(vel.x) > 0.001 then
                                vel.x = vel.x * vpenalty
                        end
                        if math.abs(vel.z) > 0.001 then
                                vel.z = vel.z * vpenalty
                        end
                        self.object:set_velocity(vel)
                end
        end

        -- Update yaw
        if not self._stuck then
                local vel = self.object:get_velocity()
                self.object:set_yaw(minetest.dir_to_yaw(vel)+YAW_OFFSET)
        end

        -- Update internal variable
        self._lastpos={x=pos.x, y=pos.y, z=pos.z}
end

-- Force recheck of stuck arrows when punched.
-- Otherwise, punching has no effect.
ARROW_ENTITY.on_punch = function(self)
        if self._stuck then
                self._stuckrechecktimer = STUCK_RECHECK_TIME
        end
end

ARROW_ENTITY.get_staticdata = function(self)
        local out = {
                lastpos = self._lastpos,
                startpos = self._startpos,
                damage = self._damage,
                stuck = self._stuck,
                stuckin = self._stuckin,
        }
        if self._stuck then
                -- If _stucktimer is missing for some reason, assume the maximum
                if not self._stucktimer then
                        self._stucktimer = ARROW_TIMEOUT
                end
                out.stuckstarttime = minetest.get_gametime() - self._stucktimer
        end
        if self._shooter and self._shooter:is_player() then
                out.shootername = self._shooter:get_player_name()
        end
        return minetest.serialize(out)
end

ARROW_ENTITY.on_activate = function(self, staticdata, dtime_s)
        local data = minetest.deserialize(staticdata)
        if data then
                self._stuck = data.stuck
                if data.stuck then
                        if data.stuckstarttime then
                                -- First, check if the stuck arrow is aleady past its life timer.
                                -- If yes, delete it.
                                self._stucktimer = minetest.get_gametime() - data.stuckstarttime
                                if self._stucktimer > ARROW_TIMEOUT then
                                        self.object:remove()
                                        return
                                end
                        end

                        -- Perform a stuck recheck on the next step.
                        self._stuckrechecktimer = STUCK_RECHECK_TIME

                        self._stuckin = data.stuckin
                end

                -- Get the remaining arrow state
                self._lastpos = data.lastpos
                self._startpos = data.startpos
                self._damage = data.damage
                if data.shootername then
                        local shooter = minetest.get_player_by_name(data.shootername)
                        if shooter and shooter:is_player() then
                                self._shooter = shooter
                        end
                end
        end
end

minetest.register_entity("mcl_bows:arrow_entity", ARROW_ENTITY)

if minetest.get_modpath("mcl_core") and minetest.get_modpath("mcl_mobitems") then
        minetest.register_craft({
                output = 'mcl_bows:arrow 4',
                recipe = {
                        {'mcl_core:flint'},
                        {'mcl_core:stick'},
                        {'mcl_mobitems:feather'}
                }
        })
end

if minetest.get_modpath("doc_identifier") ~= nil then
        doc.sub.identifier.register_object("mcl_bows:arrow_entity", "craftitems", "mcl_bows:arrow")
end