---clamp
---@param v number @number
---@param Min number @min
---@param Max number @max
---@return number    @clamp v between Min and Max
function math.clamp(v, Min, Max)
	Min = math.min(Min, Max)
	Max = math.max(Min, Max)
	if v < Min then return Min end
	if v > Max then return Max end
	return v
end

--- 随机bool变量
function math.randBool()
	return math.pop() > 0.5;
end

---clamp
---@param a number          @First number to compare
---@param b number          @Second number to compare
---@param Tolerance number  @Maximum allowed difference for considering them as 'nearly equal'
---@return boolean          @true if a and b are nearly equal
function math.isNearlyEqual(a, b, Tolerance)
	if Tolerance == nil then Tolerance = 0.01 end
	return math.abs(a - b) <= Tolerance
end

--- 一个存放随机数的列表
math.RandomList = {};

function math.init(InCount)
	-- 设置一个随机数
	math.randomseed(os.time())
	for i = 1, InCount do table.insert(math.RandomList, math.random()) end
end

function math.pop()
	local val = math.RandomList[1]
	if val == nil then
		math.init(100);
		return math.pop();
	end
	table.remove(math.RandomList, 1)
	return val;
end

--- 在给定圆内随机生成一个给定半径的圆，返回圆的中心点
---@param Center FVector 给定圆
---@param Radius float 给定圆的半径
---@param MinRadius float 目标生成圆的半径圆的半径
function math.randomCircleInCircle(Center, Radius, MinRadius)
	local TargetRadius = Radius - MinRadius;
	if TargetRadius <= 0 then return Center; end
	
	local ResCenter = math.randomPointInCircle(Center, TargetRadius);
	ResCenter.Z = Center.Z;
    return ResCenter;
end

--- 获取圆上一点与圆心连接的线形成 θ 角度的另一个点（逆时针）
---@param o FVector2D 圆点所在坐标
---@param r float 圆的半径
---@param p FVector2D 圆上的一点
---@param t float 跟 <p> 到 <o> 形成夹角为 t 的线，弧度值
function math.getCirclePoint(o, r, p, t)
    local angle = math.atan((p.Y - o.Y) / (p.X - o.X)) + t
    return { X = o.X + r * math.cos(angle), Y = o.Y + r * math.sin(angle), };
end

--- 在一个圆中随机生成一个点
---@param o FVector2D
---@param r float
function math.randomPointInCircle(o, r)
	local angle = math.pop() * 2 * math.pi;
	local tr = r * math.sqrt(math.pop());
	local x = o.X + tr * math.cos(angle);
	local y = o.Y + tr * math.sin(angle);
	return { X = x, Y = y };
end