Restructured project, added gradle, JUnit, logger, and more

Added Gradle (and removed ant), modernized testing via the JUnit framework, moved standalone examples from the tests directory to a separate module, removed sparsely used Java logger and replaced it with SLF4J. More work could be done, however this is a great start to greatly improving the health of the codebase.

1 files changed, 45 insertions, 0 deletions

diff --git a/src/main/java/com/softsynth/math/ChebyshevPolynomial.java b/src/main/java/com/softsynth/math/ChebyshevPolynomial.java
new file mode 100644
index 0000000..bc0e854
--- /dev/null
+++ b/src/main/java/com/softsynth/math/ChebyshevPolynomial.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright 1997 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.softsynth.math;
+
+/**
+ * ChebyshevPolynomial<br>
+ * Used to generate data for waveshaping table oscillators.
+ * 
+ * @author Nick Didkovsky (C) 1997 Phil Burk and Nick Didkovsky
+ */
+
+public class ChebyshevPolynomial {
+    static final Polynomial twoX = new Polynomial(2, 0);
+    static final Polynomial one = new Polynomial(1);
+    static final Polynomial oneX = new Polynomial(1, 0);
+
+    /**
+     * Calculates Chebyshev polynomial of specified integer order. Recursively generated using
+     * relation Tk+1(x) = 2xTk(x) - Tk-1(x)
+     * 
+     * @return Chebyshev polynomial of specified order
+     */
+    public static Polynomial T(int order) {
+        if (order == 0)
+            return one;
+        else if (order == 1)
+            return oneX;
+        else
+            return Polynomial.minus(Polynomial.mult(T(order - 1), (twoX)), T(order - 2));
+    }
+}