extern double db_to_linear (double db);
extern double linear_to_db (double linear);
+/** @return linear gain according to a logarithmic curve, for fading in.
+ * t < 0: linear gain of 0
+ * 0 >= t >= 1: logarithmic fade in curve
+ * t > 1: linear gain of 1
+ */
+extern float logarithmic_fade_in_curve (float t);
+
+
+/** @return linear gain according to a logarithmic curve, for fading out.
+ * t > 1: linear gain of 0
+ * 0 >= t >= 1: logarithmic fade out curve
+ * t < 0: linear gain of 1
+ */
+extern float logarithmic_fade_out_curve (float t);
+
template <class T>
T clamp (T val, T minimum, T maximum)