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diff --git a/src/main/java/com/jsyn/data/SpectralWindowFactory.java b/src/main/java/com/jsyn/data/SpectralWindowFactory.java
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+/*
+ * Copyright 2013 Phil Burk, Mobileer Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jsyn.data;
+
+import com.jsyn.unitgen.SpectralFFT;
+import com.jsyn.unitgen.SpectralFilter;
+import com.jsyn.unitgen.SpectralIFFT;
+
+/**
+ * Create shared windows as needed for use with FFTs and IFFTs.
+ * 
+ * @author Phil Burk (C) 2013 Mobileer Inc
+ * @see SpectralWindow
+ * @see SpectralFFT
+ * @see SpectralIFFT
+ * @see SpectralFilter
+ */
+public class SpectralWindowFactory {
+    private static final int NUM_WINDOWS = 16;
+    private static final int MIN_SIZE_LOG_2 = 2;
+    private static HammingWindow[] hammingWindows = new HammingWindow[NUM_WINDOWS];
+    private static HannWindow[] hannWindows = new HannWindow[NUM_WINDOWS];
+
+    /** @return a shared standard HammingWindow */
+    public static HammingWindow getHammingWindow(int sizeLog2) {
+        int index = sizeLog2 - MIN_SIZE_LOG_2;
+        if (hammingWindows[index] == null) {
+            hammingWindows[index] = new HammingWindow(1 << sizeLog2);
+        }
+        return hammingWindows[index];
+    }
+
+    /** @return a shared HannWindow */
+    public static HannWindow getHannWindow(int sizeLog2) {
+        int index = sizeLog2 - MIN_SIZE_LOG_2;
+        if (hannWindows[index] == null) {
+            hannWindows[index] = new HannWindow(1 << sizeLog2);
+        }
+        return hannWindows[index];
+    }
+}