implement PIDNanny

1 files changed, 68 insertions, 0 deletions

diff --git a/src/org/usfirst/frc/team4272/robotlib/PIDNanny.java b/src/org/usfirst/frc/team4272/robotlib/PIDNanny.java
new file mode 100644
index 0000000..000adef
--- /dev/null
+++ b/src/org/usfirst/frc/team4272/robotlib/PIDNanny.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2016 Luke Shumaker
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the FIRST nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY FIRST AND CONTRIBUTORS``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY NONINFRINGEMENT AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL FIRST OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * @author Luke Shumaker <lukeshu@sbcglobal.net>
+ */
+package org.usfirst.frc.team4272.robotlib;
+
+import edu.wpi.first.wpilibj.PIDOutput;
+
+/**
+ * A PIDOutput that turns a specified value into {@code NaN}.
+ */
+public class PIDNanny implements PIDOutput {
+	private final PIDOutput out;
+	private final double sentinel;
+
+	/**
+	 * Allocate a PIDNanny that wraps {@code out} and turns
+	 * {@code sentinel} into {@link Double#NaN}.
+	 *
+	 * @param out The actual PIDOutput to write to.
+	 * @param sentinel The value to replace with NaN.
+	 */
+	public PIDNanny(PIDOutput out, double sentinel) {
+		this.out = out;
+		this.sentinel = sentinel;
+	}
+
+	/**
+	 * A convenience constructor with {@code sentinel} defaulting
+	 * to {@code 0.0}.
+	 *
+	 * @param out The actual PIDOutput to write to.
+	 */
+	public PIDNanny(PIDOutput out) {
+		this(out, 0.0);
+	}
+
+	public void pidWrite(double v) {
+		if (v == sentinel) {
+			v = Double.NaN;
+		}
+		out.pidWrite(v);
+	}
+}