worked on 3d models within map

adjusted grid factory
adjusted nav mesh factory
minoor changes/fixes
new helper classes
refactoring

math/distribution/ChiSquared.h

@@ -0,0 +1,59 @@
+#ifndef CHISQUARED_H
+#define CHISQUARED_H
+
+#include <cmath>
+
+namespace Distribution {
+
+	/**
+	 * https://en.wikipedia.org/wiki/Chi-squared_distribution
+	 * @brief The ChiSquared class
+	 */
+	template <typename Scalar> class ChiSquared {
+
+	private:
+
+		// degrees of freedom
+		int k;
+
+	public:
+
+		/** ctor */
+		ChiSquared(const int k) : k(k) {
+			;
+		}
+
+		Scalar get(const Scalar val) const {
+
+			const Scalar k2 = k/((Scalar)2);
+			const Scalar k2_1 = k2 - 1;
+			const Scalar gamma = std::tgamma(k2);
+
+			return 1.0 / (std::pow(2, k2)*gamma) * std::pow(val, k2_1) * std::exp(-val/2);
+
+		}
+
+
+		Scalar getInvCDF(const Scalar val) const {
+
+			// brute-force get the inverse CDF...
+
+			const Scalar ss = 0.002;
+			Scalar sum = 0;
+
+			for (float t = 0; t < 20; t += ss) {
+				sum += get(t) * ss;
+				if (sum >= val) {
+					return t;
+				}
+			}
+
+			throw "failed";
+
+		}
+
+	};
+
+}
+
+#endif // CHISQUARED_H