Bastion/scripts/Libraries/Math.lua

local Tinkr, Bastion = ...

local NAN = math.huge * 0
local IS_NAN_GT_INF = (NAN or 0 ) > math.huge
local NAN_STR = tostring(NAN)

Bastion:RegisterLibrary(Bastion.Library:New({
    name = 'Math',
    exports = {
        default = function(self) -- Function exports are called when the library is loaded
            -- Return default first, and then the remaining exports
            local Math = {}

            Math.__index = Math

            ---Returns NAN
            ---@return number
            function Math.GetNan()
                assert(NAN)
                return NAN
            end
            ---checks if a value is NAN
            ---@param value number
            ---@return boolean @whether or not the value is NAN
            function Math.IsNan(value)
                if not NAN then error("NAN not set") end
                if IS_NAN_GT_INF then
                    -- if NAN > math.huge (which it is in Wow's version of lua)
                    return value > math.huge and tostring(value) == NAN_STR
                else
                    return tostring(value) == NAN_STR
                end
            end

            ---Rounds a number to the nearest significant value
            ---@param value number The number to be rounded
            ---@param sig number  The value to round to the nearest multiple of (defaults to 1)
            ---@return number
            function Math.Round(value, sig)
                sig = sig or 1
                return math.floor((value / sig) + 0.5) * sig
            end


            ---Rounds a value down to a specified significant value.
            ---@param value number The number to be rounded
            ---@param sig? number The value to round down to the nearest multiple of (defaults to 1)
            ---@return number
            function Math.Floor(value, sig)
                sig = sig or 1
                return math.floor(value / sig) * sig
            end

            ---Rounds a value up to a specified significant value.
            ---@param value number The number to be rounded
            ---@param sig? number The value to round up to the nearest multiple of (defaults to 1)
            ---@return number
            function Math.Ceil(value, sig)
                sig = sig or 1
                return math.ceil(value / sig) * sig
            end

            ---Scales a value from one range to another.
            ---@param value number The number to be scaled
            ---@param fromStart number The start value of the range to scale from
            ---@param fromEnd number The end value of the range to scale from (can be less than fromStart)
            ---@param toStart number The start value of the range to scale to
            ---@param toEnd number The end value of the range to scale to (can be less than toStart)
            ---@return number
            function Math.Scale(value, fromStart, fromEnd, toStart, toEnd)
                assert(value >= math.min(fromStart, fromEnd) and value <= math.max(fromStart, fromEnd))
                return toStart + ((value - fromStart) / (fromEnd - fromStart)) * (toEnd - toStart)
            end

            ---Bounds a number between a min and max value.
            ---@param value number The number to be bounded
            ---@param minValue number The min value
            ---@param maxValue number The max value
            ---@return number
            function Math.Bound(value, minValue, maxValue)
                return math.min(math.max(value, minValue), maxValue)
            end

            ---This code is a method that generates a random number within a given range. 
            ---It ensures that there are at least 50 possible choices by making multiple copies of the range if necessary. 
            --- It also allows for the number to be divided by a specified divisor for decimals
            ---@param lowRange number The low end of the range
            ---@param highRange number The high end of the range
            ---@param divisor? number The divisor to divide the number by
            ---@return number
            function Math.RandomNumberGenerator(lowRange, highRange, divisor)
                local lowNum, highNum
                if not highRange then
                    highNum = lowRange
                    lowNum = 1
                else
                    lowNum = lowRange
                    highNum = highRange
                end
                local total = 1
                if math.abs(highNum - lowNum + 1) < 50 then -- if total values is less than 50
                    total = math.modf(50/math.abs(highNum - lowNum + 1)) -- make x copies required to be above 50
                end
                local choices = {}
                for i = 1, total do -- iterate required number of times
                    for x = lowNum, highNum do -- iterate between the range
                        choices[#choices +1] = x -- add each entry to a table
                    end
                end
                local rtnVal = math.random(#choices) -- will now do a math.random of at least 50 choices
                for i = 1, 10 do
                    rtnVal = math.random(#choices) -- iterate a few times for random randomness
                end
                if divisor then
                    return choices[rtnVal] / divisor
                end
                return choices[rtnVal]
            end

            return Math
        end
    }
}))