From 06b2a531133ffc1bbc080dd28f8d91692e46c532 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Wed, 11 Jul 2018 11:29:47 +0300
Subject: [PATCH] cubic bezier interpolation

---
 include/cglm/bezier.h | 36 ++++++++++++++++++++++++++++++++++++
 include/cglm/cglm.h   |  1 +
 2 files changed, 37 insertions(+)
 create mode 100644 include/cglm/bezier.h

diff --git a/include/cglm/bezier.h b/include/cglm/bezier.h
new file mode 100644
index 0000000..4e8ae27
--- /dev/null
+++ b/include/cglm/bezier.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c), Recep Aslantas.
+ *
+ * MIT License (MIT), http://opensource.org/licenses/MIT
+ * Full license can be found in the LICENSE file
+ */
+
+#ifndef cglm_bezier_h
+#define cglm_bezier_h
+
+#include "common.h"
+
+/*!
+ * @brief cubic bezier interpolation
+ *
+ * @param[in]  t    time between 0 and 1
+ * @param[in]  p0   begin point
+ * @param[in]  c0   control point 1
+ * @param[in]  c1   control point 2
+ * @param[in]  p1   end point
+ *
+ * @return B(s)
+ */
+CGLM_INLINE
+float
+glm_bezier_cubic(float t, float p0, float c0, float c1, float p1) {
+  float s, ss, tt;
+
+  s  = 1.0f - t;
+  ss = s * s;
+  tt = t * t;
+
+  return p0 * ss * s + 3.0f * c0 * t * ss + 3.0f * c1 * tt * s + p1 * tt * t;
+}
+
+#endif /* cglm_bezier_h */
diff --git a/include/cglm/cglm.h b/include/cglm/cglm.h
index 8b37162..87feb0f 100644
--- a/include/cglm/cglm.h
+++ b/include/cglm/cglm.h
@@ -26,5 +26,6 @@
 #include "project.h"
 #include "sphere.h"
 #include "ease.h"
+#include "bezier.h"
 
 #endif /* cglm_h */