mirror of
https://github.com/appgurueu/modlib.git
synced 2024-11-22 07:13:45 +01:00
132 lines
3.2 KiB
Lua
132 lines
3.2 KiB
Lua
-- Localize globals
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local math, math_floor, minetest, modlib_table_reverse, os, string_char, setmetatable, table_insert, table_concat
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= math, math.floor, minetest, modlib.table.reverse, os, string.char, setmetatable, table.insert, table.concat
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local inf = math.huge
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-- Set environment
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local _ENV = {}
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setfenv(1, _ENV)
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-- TODO might be too invasive
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-- Make random random
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math.randomseed(minetest and minetest.get_us_time() or os.time() + os.clock())
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for _ = 1, 100 do math.random() end
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negative_nan = 0/0
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positive_nan = negative_nan ^ 1
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function sign(number)
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if number ~= number then return number end -- nan
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if number == 0 then return 0 end
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if number < 0 then return -1 end
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if number > 0 then return 1 end
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end
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function clamp(number, min, max)
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return math.min(math.max(number, min), max)
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end
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log = setmetatable({}, {
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__index = function(self, base)
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local div = math.log(base)
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local function base_log(number)
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return math.log(number) / div
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end
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self[base] = base_log
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return base_log
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end,
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__call = function(_, number, base)
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if not base then
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return math.log(number)
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end
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return math.log(number) / math.log(base)
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end
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})
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-- one-based mod
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function onemod(number, modulus)
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return ((number - 1) % modulus) + 1
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end
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function round(number, steps)
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steps = steps or 1
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return math_floor(number * steps + 0.5) / steps
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end
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local c0 = ("0"):byte()
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local cA = ("A"):byte()
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function default_digit_function(digit)
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if digit <= 9 then return string_char(c0 + digit) end
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return string_char(cA + digit - 10)
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end
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default_precision = 10
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-- See https://github.com/appgurueu/Luon/blob/master/index.js#L724
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function tostring(number, base, digit_function, precision)
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if number ~= number then
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return "nan"
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end
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if number == inf then
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return "inf"
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end
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if number == -inf then
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return "-inf"
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end
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digit_function = digit_function or default_digit_function
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precision = precision or default_precision
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local out = {}
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if number < 0 then
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table_insert(out, "-")
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number = -number
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end
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-- Rounding
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number = number + base ^ -precision / 2
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local digit
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while number >= base do
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digit = math_floor(number % base)
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table_insert(out, digit_function(digit))
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number = (number - digit) / base
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end
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digit = math_floor(number)
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table_insert(out, digit_function(digit))
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modlib_table_reverse(out)
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number = number % 1
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if number ~= 0 and number >= base ^ -precision then
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table_insert(out, ".")
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while precision >= 0 and number >= base ^ -precision do
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number = number * base
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digit = math_floor(number % base)
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table_insert(out, digit_function(digit))
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number = number - digit
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precision = precision - 1
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end
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end
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return table_concat(out)
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end
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-- See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/fround#polyfill
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function fround(number)
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if number == 0 or number ~= number then
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return number
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end
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local sign = 1
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if number < 0 then
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sign = -1
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number = -number
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end
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local exp = math_floor(math.log(number, 2))
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local powexp = 2 ^ math.max(-126, math.min(exp, 127))
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local leading = exp < -127 and 0 or 1
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local mantissa = math_floor((leading - number / powexp) * 0x800000 + 0.5)
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if mantissa <= -0x800000 then
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return sign * inf
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end
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return sign * powexp * (leading - mantissa / 0x800000)
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end
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-- Export environment
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return _ENV
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