X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fcode.git;a=blobdiff_plain;f=src%2Fbezier.cpp;fp=src%2Fbezier.cpp;h=15a5069a6703c08ec33841b82621176a0e99693c;hp=0000000000000000000000000000000000000000;hb=f59f24dff392428d7219ba2d6be5e1e81c344ee0;hpb=d3e941df79b54b698a5b8a1d4763346c4d6eb3d7

diff --git a/src/bezier.cpp b/src/bezier.cpp
new file mode 100644
index 0000000..15a5069
--- /dev/null
+++ b/src/bezier.cpp
@@ -0,0 +1,48 @@
+#include "bezier.h"
+
+#include <unordered_map>
+#include <cmath>
+
+using namespace std;
+
+namespace IPDF
+{
+
+/**
+ * Factorial
+ * Use dynamic programming / recursion
+ */
+int Factorial(int n)
+{
+	static unordered_map<int, int> dp;
+	static bool init = false;
+	if (!init)
+	{
+		init = true;
+		dp[0] = 1;
+	}
+	auto it = dp.find(n);
+	if (it != dp.end())
+		return it->second;
+	int result = n*Factorial(n-1);
+	dp[n] = result;
+	return result;
+}
+
+/**
+ * Binomial coefficients
+ */
+int BinomialCoeff(int n, int k)
+{
+	return Factorial(n) / Factorial(k) / Factorial(n-k);
+}
+
+/**
+ * Bernstein Basis Polynomial
+ */
+Real Bernstein(int k, int n, const Real & u)
+{
+	return Real(BinomialCoeff(n, k)) * pow(u, k) * pow(Real(1.0) - u, n-k);
+}
+
+}