minetest/builtin/game/misc.lua
hecks 80d12dbedb
Add a simple PNG image encoder with Lua API (#11485)
* Add a simple PNG image encoder with Lua API
Add ColorSpec to RGBA converter
Make a safety wrapper for the encoder
Create devtest examples

Co-authored-by: hecktest <>
Co-authored-by: sfan5 <sfan5@live.de>
2021-07-29 05:10:10 +02:00

332 lines
7.9 KiB
Lua

-- Minetest: builtin/misc.lua
local S = core.get_translator("__builtin")
--
-- 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("*** " .. S("@1 joined the game.", player_name))
end
end
function core.send_leave_message(player_name, timed_out)
local announcement = "*** " .. S("@1 left the game.", player_name)
if timed_out then
announcement = "*** " .. S("@1 left the game (timed out).", player_name)
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 x = (hash % 65536) - 32768
hash = math.floor(hash / 65536)
local y = (hash % 65536) - 32768
hash = math.floor(hash / 65536)
local z = (hash % 65536) - 32768
return vector.new(x, y, z)
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
-- See l_env.cpp for the other functions
function core.get_artificial_light(param1)
return math.floor(param1 / 16)
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
-- To be overridden by Creative mods
local creative_mode_cache = core.settings:get_bool("creative_mode")
function core.is_creative_enabled(name)
return creative_mode_cache
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 = vector.new(x, y, 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
-- Callback handling for dynamic_add_media
local dynamic_add_media_raw = core.dynamic_add_media_raw
core.dynamic_add_media_raw = nil
function core.dynamic_add_media(filepath, callback)
local ret = dynamic_add_media_raw(filepath)
if ret == false then
return ret
end
if callback == nil then
core.log("deprecated", "Calling minetest.dynamic_add_media without "..
"a callback is deprecated and will stop working in future versions.")
else
-- At the moment async loading is not actually implemented, so we
-- immediately call the callback ourselves
for _, name in ipairs(ret) do
callback(name)
end
end
return true
end
-- PNG encoder safety wrapper
local o_encode_png = core.encode_png
function core.encode_png(width, height, data, compression)
if type(width) ~= "number" then
error("Incorrect type for 'width', expected number, got " .. type(width))
end
if type(height) ~= "number" then
error("Incorrect type for 'height', expected number, got " .. type(height))
end
local expected_byte_count = width * height * 4;
if type(data) ~= "table" and type(data) ~= "string" then
error("Incorrect type for 'height', expected table or string, got " .. type(height));
end
local data_length = type(data) == "table" and #data * 4 or string.len(data);
if data_length ~= expected_byte_count then
error(string.format(
"Incorrect length of 'data', width and height imply %d bytes but %d were provided",
expected_byte_count,
data_length
))
end
if type(data) == "table" then
local dataBuf = {}
for i = 1, #data do
dataBuf[i] = core.colorspec_to_bytes(data[i])
end
data = table.concat(dataBuf)
end
return o_encode_png(width, height, data, compression or 6)
end