Throwing mod

-- Bow and arrow mod
-- Topic on the forum: http://c55.me/minetest/forum/viewtopic.php?id=687

ARROW_DAMAGE=1
ARROW_GRAVITY=9
ARROW_VELOCITY=19

throwing_shoot_arrow=function (item, player, pointed_thing)
    -- Check if arrows in Inventory and remove one of them
    local i=1
    if player:get_inventory():contains_item("main", "throwing:arrow") then
        player:get_inventory():remove_item("main", "throwing:arrow")
        -- Shoot Arrow
        local playerpos=player:getpos()
        local obj=minetest.env:add_entity({x=playerpos.x,y=playerpos.y+1.5,z=playerpos.z}, "throwing:arrow_entity")
        local dir=player:get_look_dir()
        obj:setvelocity({x=dir.x*ARROW_VELOCITY, y=dir.y*ARROW_VELOCITY, z=dir.z*ARROW_VELOCITY})
        obj:setacceleration({x=dir.x*-3, y=-ARROW_GRAVITY, z=dir.z*-3})
    end
    return
end

minetest.register_craftitem("throwing:string", {
    image = "throwing_string.png",
    on_place_on_ground = minetest.craftitem_place_item,
})

minetest.register_craftitem("throwing:bow", {
    image = "throwing_bow.png",
    stack_max = 1,
    on_place_on_ground = minetest.craftitem_place_item,
    on_use = throwing_shoot_arrow,
})

minetest.register_craftitem("throwing:arrow", {
    image = "throwing_arrow.png",
    on_place_on_ground = minetest.craftitem_place_item,
})

-- The Arrow Entity

THROWING_ARROW_ENTITY={
    physical = false,
    timer=0,
    textures = {"throwing_arrow_back.png"},
    lastpos={},
    collisionbox = {0,0,0,0,0,0},
}


-- Arrow_entity.on_step()--> called when arrow is moving
THROWING_ARROW_ENTITY.on_step = function(self, dtime)
    self.timer=self.timer+dtime
    local pos = self.object:getpos()
    local node = minetest.env:get_node(pos)

    -- When arrow is away from player (after 0.2 seconds): Cause damage to mobs and players
    if self.timer>0.2 then
        local objs = minetest.env:get_objects_inside_radius({x=pos.x,y=pos.y,z=pos.z}, 2)
        for k, obj in pairs(objs) do
            obj:set_hp(obj:get_hp()-ARROW_DAMAGE)
            if obj:get_entity_name() ~= "throwing:arrow_entity" then
                if obj:get_hp()<=0 then
                    obj:remove()
                end
                self.object:remove()
            end
        end
    end

    -- Become item when hitting a node
    if self.lastpos.x~=nil then --If there is no lastpos for some reason
        if node.name ~= "air" then
            minetest.env:add_item(self.lastpos, 'throwing:arrow')
            self.object:remove()
        end
    end
    self.lastpos={x=pos.x, y=pos.y, z=pos.z} -- Set lastpos-->Item will be added at last pos outside the node
end

minetest.register_entity("throwing:arrow_entity", THROWING_ARROW_ENTITY)



--CRAFTS
minetest.register_craft({
    output = 'throwing:string',
    recipe = {
        {'default:junglegrass'},
        {'default:junglegrass'},
    }
})

minetest.register_craft({
    output = 'throwing:bow',
    recipe = {
        {'throwing:string', 'default:wood', ''},
        {'throwing:string', '', 'default:wood'},
        {'throwing:string', 'default:wood', ''},
    }
})

minetest.register_craft({
    output = 'throwing:arrow 16',
    recipe = {
        {'default:stick', 'default:stick', 'default:steel_ingot'},
    }
})

print ("[Throwing_mod] Loaded!")