com.artemis.utils.TrigLUT Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of artemis-odb Show documentation

Fork of Artemis Entity System Framework.

There is a newer version: 2.3.0

package com.artemis.utils;


/**
 * Thanks to Riven.
 * 
 * From: http://riven8192.blogspot.com/2009/08/fastmath-sincos-lookup-tables.html
 * 
 *
 * @author Arni Arent
 *
 * @deprecated
 */
@Deprecated
public class TrigLUT {

	public static void main(String[] args) {
		System.out.println(cos((float) Math.PI));
		System.out.println(cosDeg(180f));
	}

	public static final float sin(float rad) {
		return sin[(int) (rad * radToIndex) & SIN_MASK];
	}

	public static final float cos(float rad) {
		return cos[(int) (rad * radToIndex) & SIN_MASK];
	}

	public static final float sinDeg(float deg) {
		return sin[(int) (deg * degToIndex) & SIN_MASK];
	}

	public static final float cosDeg(float deg) {
		return cos[(int) (deg * degToIndex) & SIN_MASK];
	}

	private static final int SIN_BITS, SIN_MASK, SIN_COUNT;
	private static final float radFull, radToIndex;
	private static final float degFull, degToIndex;
	private static final float[] sin, cos;

	static {
		SIN_BITS = 12;
		SIN_MASK = ~(-1 << SIN_BITS);
		SIN_COUNT = SIN_MASK + 1;

		radFull = (float) (Math.PI * 2.0);
		degFull = (float) (360.0);
		radToIndex = SIN_COUNT / radFull;
		degToIndex = SIN_COUNT / degFull;

		sin = new float[SIN_COUNT];
		cos = new float[SIN_COUNT];

		for (int i = 0; i < SIN_COUNT; i++) {
			sin[i] = (float) Math.sin((i + 0.5f) / SIN_COUNT * radFull);
			cos[i] = (float) Math.cos((i + 0.5f) / SIN_COUNT * radFull);
		}
	}

}