Move core.get_connected_players() implementation to C++

[dragonfireclient.git] / builtin / game / misc.lua

-- Minetest: builtin/misc.lua

--
-- Misc. API functions
--

function core.check_player_privs(name, ...)
        if core.is_player(name) then
                name = name:get_player_name()
        elseif type(name) ~= "string" then
                error("core.check_player_privs expects a player or playername as " ..
                        "argument.", 2)
        end

        local requested_privs = {...}
        local player_privs = core.get_player_privs(name)
        local missing_privileges = {}

        if type(requested_privs[1]) == "table" then
                -- We were provided with a table like { privA = true, privB = true }.
                for priv, value in pairs(requested_privs[1]) do
                        if value and not player_privs[priv] then
                                missing_privileges[#missing_privileges + 1] = priv
                        end
                end
        else
                -- Only a list, we can process it directly.
                for key, priv in pairs(requested_privs) do
                        if not player_privs[priv] then
                                missing_privileges[#missing_privileges + 1] = priv
                        end
                end
        end

        if #missing_privileges > 0 then
                return false, missing_privileges
        end

        return true, ""
end


function core.send_join_message(player_name)
        if not core.is_singleplayer() then
                core.chat_send_all("*** " .. player_name .. " joined the game.")
        end
end


function core.send_leave_message(player_name, timed_out)
        local announcement = "*** " ..  player_name .. " left the game."
        if timed_out then
                announcement = announcement .. " (timed out)"
        end
        core.chat_send_all(announcement)
end


core.register_on_joinplayer(function(player)
        local player_name = player:get_player_name()
        if not core.is_singleplayer() then
                local status = core.get_server_status(player_name, true)
                if status and status ~= "" then
                        core.chat_send_player(player_name, status)
                end
        end
        core.send_join_message(player_name)
end)


core.register_on_leaveplayer(function(player, timed_out)
        local player_name = player:get_player_name()
        core.send_leave_message(player_name, timed_out)
end)


function core.is_player(player)
        -- a table being a player is also supported because it quacks sufficiently
        -- like a player if it has the is_player function
        local t = type(player)
        return (t == "userdata" or t == "table") and
                type(player.is_player) == "function" and player:is_player()
end


function core.player_exists(name)
        return core.get_auth_handler().get_auth(name) ~= nil
end


-- Returns two position vectors representing a box of `radius` in each
-- direction centered around the player corresponding to `player_name`

function core.get_player_radius_area(player_name, radius)
        local player = core.get_player_by_name(player_name)
        if player == nil then
                return nil
        end

        local p1 = player:get_pos()
        local p2 = p1

        if radius then
                p1 = vector.subtract(p1, radius)
                p2 = vector.add(p2, radius)
        end

        return p1, p2
end


function core.hash_node_position(pos)
        return (pos.z + 32768) * 65536 * 65536
                 + (pos.y + 32768) * 65536
                 +  pos.x + 32768
end


function core.get_position_from_hash(hash)
        local pos = {}
        pos.x = (hash % 65536) - 32768
        hash  = math.floor(hash / 65536)
        pos.y = (hash % 65536) - 32768
        hash  = math.floor(hash / 65536)
        pos.z = (hash % 65536) - 32768
        return pos
end


function core.get_item_group(name, group)
        if not core.registered_items[name] or not
                        core.registered_items[name].groups[group] then
                return 0
        end
        return core.registered_items[name].groups[group]
end


function core.get_node_group(name, group)
        core.log("deprecated", "Deprecated usage of get_node_group, use get_item_group instead")
        return core.get_item_group(name, group)
end


function core.setting_get_pos(name)
        local value = core.settings:get(name)
        if not value then
                return nil
        end
        return core.string_to_pos(value)
end


-- To be overriden by protection mods

function core.is_protected(pos, name)
        return false
end


function core.record_protection_violation(pos, name)
        for _, func in pairs(core.registered_on_protection_violation) do
                func(pos, name)
        end
end


-- Checks if specified volume intersects a protected volume

function core.is_area_protected(minp, maxp, player_name, interval)
        -- 'interval' is the largest allowed interval for the 3D lattice of checks.

        -- Compute the optimal float step 'd' for each axis so that all corners and
        -- borders are checked. 'd' will be smaller or equal to 'interval'.
        -- Subtracting 1e-4 ensures that the max co-ordinate will be reached by the
        -- for loop (which might otherwise not be the case due to rounding errors).

        -- Default to 4
        interval = interval or 4
        local d = {}

        for _, c in pairs({"x", "y", "z"}) do
                if minp[c] > maxp[c] then
                        -- Repair positions: 'minp' > 'maxp'
                        local tmp = maxp[c]
                        maxp[c] = minp[c]
                        minp[c] = tmp
                end

                if maxp[c] > minp[c] then
                        d[c] = (maxp[c] - minp[c]) /
                                math.ceil((maxp[c] - minp[c]) / interval) - 1e-4
                else
                        d[c] = 1 -- Any value larger than 0 to avoid division by zero
                end
        end

        for zf = minp.z, maxp.z, d.z do
                local z = math.floor(zf + 0.5)
                for yf = minp.y, maxp.y, d.y do
                        local y = math.floor(yf + 0.5)
                        for xf = minp.x, maxp.x, d.x do
                                local x = math.floor(xf + 0.5)
                                local pos = {x = x, y = y, z = z}
                                if core.is_protected(pos, player_name) then
                                        return pos
                                end
                        end
                end
        end
        return false
end


local raillike_ids = {}
local raillike_cur_id = 0
function core.raillike_group(name)
        local id = raillike_ids[name]
        if not id then
                raillike_cur_id = raillike_cur_id + 1
                raillike_ids[name] = raillike_cur_id
                id = raillike_cur_id
        end
        return id
end


-- HTTP callback interface

function core.http_add_fetch(httpenv)
        httpenv.fetch = function(req, callback)
                local handle = httpenv.fetch_async(req)

                local function update_http_status()
                        local res = httpenv.fetch_async_get(handle)
                        if res.completed then
                                callback(res)
                        else
                                core.after(0, update_http_status)
                        end
                end
                core.after(0, update_http_status)
        end

        return httpenv
end


function core.close_formspec(player_name, formname)
        return core.show_formspec(player_name, formname, "")
end


function core.cancel_shutdown_requests()
        core.request_shutdown("", false, -1)
end