From 2f85ae6d0af893fcba2a82cf3f925cf3c42608e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Benjamin=20=E2=80=98Touky=E2=80=99=20Huet?=
 <huet.benjamin@gmail.com>
Date: Wed, 29 Aug 2012 20:27:53 +0000
Subject: [PATCH]

---
 src/lol/math/math.h   | 10 ++++++++++
 src/lol/math/vector.h |  8 ++++++++
 src/numeric.h         |  8 ++++++++
 3 files changed, 26 insertions(+)

diff --git a/src/lol/math/math.h b/src/lol/math/math.h
index 793cd2e5..8fe3ad7c 100644
--- a/src/lol/math/math.h
+++ b/src/lol/math/math.h
@@ -64,6 +64,16 @@ static inline void sincos(float const &x, float *s, float *c)
     *c = std::cos(x);
 }
 
+static inline double lerp(double const &a, double const &b, double const &x)
+{
+	return a + (b - a) * x;
+}
+static inline float lerp(float const &a, float const &b, float const &x)
+{
+	return a + (b - a) * x;
+}
+
+
 /* These accelerated functions will be merged into the above, one day */
 double lol_sin(double);
 double lol_cos(double);
diff --git a/src/lol/math/vector.h b/src/lol/math/vector.h
index 9d9ce076..ef266205 100644
--- a/src/lol/math/vector.h
+++ b/src/lol/math/vector.h
@@ -1229,6 +1229,14 @@ extern Quat<T> slerp(Quat<T> const &qa, Quat<T> const &qb, T f);
         for (size_t n = 0; n < sizeof(a) / sizeof(t1); n++) \
             ret += a[n] * b[n]; \
         return ret; \
+    } \
+    tprefix \
+    inline tname<tf> lerp(tname<t1> const &a, tname<t2> const &b, tf x) \
+    { \
+        tname<tf> ret; \
+        for (size_t n = 0; n < sizeof(a) / sizeof(t1); n++) \
+            ret[n] = a[n] + (a[n] - b[n]) * x; \
+        return ret; \
     }
 
 #define DECLARE_BINARY_VECTOR_COERCE_OPS(tname, tprefix, t1, t2, tf) \
diff --git a/src/numeric.h b/src/numeric.h
index 9c2211aa..5bf2f565 100644
--- a/src/numeric.h
+++ b/src/numeric.h
@@ -52,6 +52,14 @@ template <typename T> static inline T PotUp(T val)
     return val + 1;
 }
 
+//Lerp for float
+template <typename T1, typename T2, typename Tf> static inline T1 damp(const T1 &a, const T2 &b, const Tf &x, const Tf &dt)
+{
+	if (dt <= .0f)
+		return a;
+    return lol::lerp(a, b, dt / (dt + x));
+}
+
 } /* namespace lol */
 
 #endif // __LOL_NUMERIC_H__