local oldmath = math;
local newmath = {};
for k,v in pairs(oldmath) do
	newmath[k] = v;
end

local function CheckGlobalFunctionExists(name,func)
	if not _G[name] then
		_G[name] = func;
	end
end

function newmath.clamp(val,min,max)
	return (val <= min) and min or (val >= max) and max or val;
end

function newmath.frac(num)
	return num - math2.trunc(num);
end

function newmath.mod(a,b)
	return a - math.floor(a/b) * b;
end

function newmath.round(num,ndp)
	local multi = 10 ^ (ndp or 0);
	if num > 0 then
		return math.floor(num * multi + 0.5) / multi;
	else
		return math.ceil(num * multi - 0.5) / multi;
	end
end

function newmath.sign(num)
	return num / math.abs(num);
end

function newmath.trunc(num,ndp)
	local multi = 10 ^ (ndp or 0);
	if num > 0 then
		return math.floor(num * multi) / multi;
	else
		return math.ceil(num * multi) / multi;
	end
end

local function approach(val,other_val,to_move)
	if val ~= other_val then
		local delta = other_val - val;
		local sign = delta / math.abs(delta);
		local tomove = sign * to_move;
		if math.abs(tomove) > math.abs(delta) then
			tomove = delta;
		end
		val = val + tomove;
	end
	return val;
end

local function lerp(x,l,h)
	return x * (h - l) + l;
end

local function scale(x,l1,h1,l2,h2)
	return (x - l1) * (h2 - l2) / (h1 - l1) + l2;
end

CheckGlobalFunctionExists('approach',approach);
CheckGlobalFunctionExists('lerp',lerp);
CheckGlobalFunctionExists('scale',scale);

return newmath;