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Rampant/libs/MathUtils.lua

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-- Copyright (C) 2022 veden
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
-- You should have received a copy of the GNU General Public License
-- along with this program. If not, see <https://www.gnu.org/licenses/>.
if MathUtilsG then
return MathUtilsG
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end
local MathUtils = {}
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-- imports
-- constants
local TICKS_A_MINUTE = 60 * 60
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-- imported functions
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local mSqrt = math.sqrt
local mLog10 = math.log10
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local mFloor = math.floor
local mAbs = math.abs
-- module code
function MathUtils.roundToFloor(number, multiple)
return mFloor(number / multiple) * multiple
end
function MathUtils.roundToNearest(number, multiple)
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local num = number + (multiple * 0.5)
return num - (num % multiple)
end
function MathUtils.randomTickEvent(rg, tick, low, high)
return tick + MathUtils.randomTickDuration(rg, low, high)
end
function MathUtils.randomTickDuration(rg, low, high)
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local range = high - low
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local minutesToTick = (range * rg()) + low
return MathUtils.roundToNearest(TICKS_A_MINUTE * minutesToTick, 1)
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end
function MathUtils.distort(xorRandom, num, stdDev, min, max)
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local amin = min or num * 0.70
local amax = max or num * 1.30
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local sd = stdDev or 0.17
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if (num < 0) then
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local t = amin
amin = amax
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amax = t
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end
return MathUtils.roundToNearest(MathUtils.gaussianRandomRangeRG(num, num * sd, amin, amax, xorRandom), 0.01)
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end
function MathUtils.linearInterpolation(percent, min, max)
return ((max - min) * percent) + min
end
function MathUtils.xorRandom(state)
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local xor = bit32.bxor
local lshift = bit32.lshift
local rshift = bit32.rshift
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local seed = state + 32685453
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return function()
seed = xor(seed, lshift(seed, 13))
seed = xor(seed, rshift(seed, 17))
seed = xor(seed, lshift(seed, 5))
return seed * 2.32830643654e-10 -- 2.32830643654e-10 = 1 / 2^32, 2.32830643708e-10 = 1 / ((2^32)-1)
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end
end
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--[[
Used for gaussian random numbers
--]]
function MathUtils.gaussianRandomRG(mean, std_dev, rg)
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-- marsagliaPolarMethod
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local iid1
local iid2
local q
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repeat
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iid1 = 2 * rg() + -1
iid2 = 2 * rg() + -1
q = (iid1 * iid1) + (iid2 * iid2)
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until (q ~= 0) and (q < 1)
local s = mSqrt((-2 * mLog10(q)) / q)
local v = iid1 * s
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return mean + (v * std_dev)
end
function MathUtils.gaussianRandomRangeRG(mean, std_dev, min, max, rg)
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local r
if (min >= max) then
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return min
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end
repeat
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local iid1
local iid2
local q
repeat
iid1 = 2 * rg() + -1
iid2 = 2 * rg() + -1
q = (iid1 * iid1) + (iid2 * iid2)
until (q ~= 0) and (q < 1)
local s = mSqrt((-2 * mLog10(q)) / q)
local v = iid1 * s
r = mean + (v * std_dev)
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until (r >= min) and (r <= max)
return r
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end
function MathUtils.euclideanDistanceNamed(p1, p2)
local xs = p1.x - p2.x
local ys = p1.y - p2.y
return ((xs * xs) + (ys * ys)) ^ 0.5
end
function MathUtils.euclideanDistancePoints(x1, y1, x2, y2)
local xs = x1 - x2
local ys = y1 - y2
return ((xs * xs) + (ys * ys)) ^ 0.5
end
function MathUtils.manhattenDistancePoints(x1, y1, x2, y2)
return mAbs((x1 - x2) + (y1 - y2))
end
function MathUtils.euclideanDistanceArray(p1, p2)
local xs = p1[1] - p2[1]
local ys = p1[2] - p2[2]
return ((xs * xs) + (ys * ys)) ^ 0.5
end
function MathUtils.distortPosition(rg, position, size)
local xDistort = MathUtils.gaussianRandomRangeRG(1, 0.5, 0, 2, rg) - 1
local yDistort = MathUtils.gaussianRandomRangeRG(1, 0.5, 0, 2, rg) - 1
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position.x = position.x + (xDistort * size)
position.y = position.y + (yDistort * size)
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return position
end
function MathUtils.distortPositionConcentricCircles(rg, position, size, min)
local xDistort = MathUtils.gaussianRandomRangeRG(1, 0.5, 0, 2, rg) - 1
local yDistort = MathUtils.gaussianRandomRangeRG(1, 0.5, 0, 2, rg) - 1
local xModifier = (xDistort * size)
if xModifier < 0 then
xModifier = xModifier + -min
else
xModifier = xModifier + min
end
local yModifier = (yDistort * size)
if yModifier < 0 then
yModifier = yModifier + -min
else
yModifier = yModifier + min
end
position.x = position.x + xModifier
position.y = position.y + yModifier
return position
end
MathUtilsG = MathUtils
return MathUtils