some documentation on LowpassFilter

vvvv · Apr 22, 2015 · 3d8598b · 3d8598b
1 parent 4f1e56d
commit 3d8598b
Showing 1 changed file with 15 additions and 3 deletions.
diff --git a/common/src/core/Utils/Animation/LowpassFilter.cs b/common/src/core/Utils/Animation/LowpassFilter.cs
@@ -7,6 +7,9 @@ namespace VVVV.Utils.Animation
     /// </summary>
 	public class LowpassFilter
     {
+        /// <summary>
+        /// Initialize the filter
+        /// </summary>
         public LowpassFilter()
         {
             FFirstTime = true;
@@ -15,6 +18,9 @@ public LowpassFilter()
         protected bool FFirstTime;
         protected double FLastFilterValue;
 
+        /// <summary>
+        /// Last filter value
+        /// </summary>
         public double Last
         {
             get
@@ -23,17 +29,23 @@ public double Last
             }
         }
 
-        public double Filter(double x, double alpha)
+        /// <summary>
+        /// Gets the next filter value, applies <c>alpha * value + (1 - alpha) * lastValue</c>
+        /// </summary>
+        /// <param name="value"></param>
+        /// <param name="alpha"></param>
+        /// <returns></returns>
+        public double Filter(double value, double alpha = 1)
         {
             double filterValue = 0;
             if (FFirstTime)
             {
                 FFirstTime = false;
-                filterValue = x;
+                filterValue = value;
             }
             else
             {
-                filterValue = alpha * x + (1 - alpha) * FLastFilterValue;
+                filterValue = alpha * value + (1 - alpha) * FLastFilterValue;
             }
 
             FLastFilterValue = filterValue;