Merge pull request ddnet#9494 from Chairn/pr_cbrt

Replace Cubicroot function with std::cbrt

src/game/client/render_map.cpp

@@ -124,16 +124,6 @@ const CEnvPointBezier *CMapBasedEnvelopePointAccess::GetBezier(int Index) const
 	return nullptr;
 }
 
-static double CubicRoot(double x)
-{
-	if(x == 0.0)
-		return 0.0;
-	else if(x < 0.0)
-		return -std::exp(std::log(-x) / 3.0);
-	else
-		return std::exp(std::log(x) / 3.0);
-}
-
 static float SolveBezier(float x, float p0, float p1, float p2, float p3)
 {
 	const double x3 = -p0 + 3.0 * p1 - 3.0 * p2 + p3;
@@ -193,12 +183,12 @@ static float SolveBezier(float x, float p0, float p1, float p2, float p3)
 		{
 			// only one 'real' solution
 			const double s = std::sqrt(D);
-			return CubicRoot(s - q) - CubicRoot(s + q) - sub;
+			return std::cbrt(s - q) - std::cbrt(s + q) - sub;
 		}
 		else if(D == 0.0)
 		{
 			// one single, one double solution or triple solution
-			const double s = CubicRoot(-q);
+			const double s = std::cbrt(-q);
 			const double t = 2.0 * s - sub;
 
 			if(0.0 <= t && t <= 1.0001)