Class MathHelper

src/main/java/net/minecraft/util/MathHelper.java:7–581

import net.optifine.util.MathUtils;

public class MathHelper
{
    public static final float SQRT_2 = sqrt_float(2.0F);
    private static final int SIN_BITS = 12;
    private static final int SIN_MASK = 4095;
    private static final int SIN_COUNT = 4096;
    private static final int SIN_COUNT_D4 = 1024;
    public static final float PI = MathUtils.roundToFloat(Math.PI);
    public static final float PI2 = MathUtils.roundToFloat((Math.PI * 2D));
    public static final float PId2 = MathUtils.roundToFloat((Math.PI / 2D));
    private static final float radToIndex = MathUtils.roundToFloat(651.8986469044033D);
    public static final float deg2Rad = MathUtils.roundToFloat(0.017453292519943295D);
    private static final float[] SIN_TABLE_FAST = new float[4096];
    public static boolean fastMath = false;

    /**
     * A table of sin values computed from 0 (inclusive) to 2*pi (exclusive), with steps of 2*PI / 65536.
     */
    private static final float[] SIN_TABLE = new float[65536];

    /**
     * Though it looks like an array, this is really more like a mapping.  Key (index of this array) is the upper 5 bits
     * of the result of multiplying a 32-bit unsigned integer by the B(2, 5) De Bruijn sequence 0x077CB531.  Value
     * (value stored in the array) is the unique index (from the right) of the leftmost one-bit in a 32-bit unsigned
     * integer that can cause the upper 5 bits to get that value.  Used for highly optimized "find the log-base-2 of
     * this number" calculations.
     */
    private static final int[] multiplyDeBruijnBitPosition;
    private static final double field_181163_d;
    private static final double[] field_181164_e;
    private static final double[] field_181165_f;

    /**
     * sin looked up in a table
     */
    public static float sin(float p_76126_0_)
    {
        return fastMath ? SIN_TABLE_FAST[(int)(p_76126_0_ * radToIndex) & 4095] : SIN_TABLE[(int)(p_76126_0_ * 10430.378F) & 65535];
    }

    /**
     * cos looked up in the sin table with the appropriate offset
     */
    public static float cos(float value)
    {
        return fastMath ? SIN_TABLE_FAST[(int)(value * radToIndex + 1024.0F) & 4095] : SIN_TABLE[(int)(value * 10430.378F + 16384.0F) & 65535];
    }

    public static float sqrt_float(float value)
    {
        return (float)Math.sqrt(value);
    }

    public static float sqrt_double(double value)
    {
        return (float)Math.sqrt(value);
    }