Cached.java

package com.volmit.wormholes.geometry;

public class CachedMath
{
	private static final int precision = 128;
	private static final int modulus = 360 * precision;
	private static final float[] sin = new float[modulus];

	/**
	 * Fast sin function
	 *
	 * @param a
	 *            the number
	 * @return the sin
	 */
	public static float sin(float a)
	{
		return sinLookup((int) (a * precision + 0.5f));
	}

	/**
	 * Fast cos function
	 *
	 * @param a
	 *            the number
	 * @return the cos
	 */
	public static float cos(float a)
	{
		return sinLookup((int) ((a + 90f) * precision + 0.5f));
	}

	private static float sinLookup(int a)
	{
		return a >= 0 ? sin[a % (modulus)] : -sin[-a % (modulus)];
	}

	static
	{
		for(int i = 0; i < sin.length; i++)
		{
			sin[i] = (float) Math.sin((i * Math.PI) / (precision * 180));
		}
	}
}