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/**
* Copyright 2013 JogAmp Community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community 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.
*
* The views and conclusions contained in the software and documentation are those of the
* authors and should not be interpreted as representing official policies, either expressed
* or implied, of JogAmp Community.
*/
package com.jogamp.opengl.math;
/**
* Functions for interrogating <code>binary32</code> (float) values.
*/
public final class Binary32
{
static final int NEGATIVE_ZERO_BITS;
static final int MASK_SIGN;
static final int MASK_EXPONENT;
static final int MASK_SIGNIFICAND;
static final int BIAS;
static {
NEGATIVE_ZERO_BITS = 0x80000000;
MASK_SIGN = 0x80000000;
MASK_EXPONENT = 0x7ff00000;
MASK_SIGNIFICAND = 0x7fffff;
BIAS = 127;
}
/**
* <p>
* Extract and unbias the exponent of the given packed <code>float</code>
* value.
* </p>
* <p>
* The exponent is encoded <i>biased</i> as a number in the range
* <code>[0, 255]</code>, with <code>0</code> indicating that the number is
* <i>subnormal</i> and <code>[1, 254]</code> denoting the actual exponent
* plus {@link #BIAS}. Infinite and <code>NaN</code> values always have a
* biased exponent of <code>255</code>.
* </p>
* <p>
* This function will therefore return:
* </p>
* <ul>
* <li>
* <code>0 - {@link #BIAS} = -127</code> iff the input is a <i>subnormal</i>
* number.</li>
* <li>An integer in the range
* <code>[1 - {@link #BIAS}, 254 - {@link #BIAS}] = [-126, 127]</code> iff
* the input is a <i>normal</i> number.</li>
* <li>
* <code>255 - {@link #BIAS} = 128</code> iff the input is
* {@link #POSITIVE_INFINITY}, {@link #NEGATIVE_INFINITY}, or
* <code>NaN</code>.</li>
* </ul>
*
* @see #packSetExponentUnbiasedUnchecked(int)
*/
public static int unpackGetExponentUnbiased(
final float d)
{
final int b = Float.floatToRawIntBits(d);
final int em = b & Binary32.MASK_EXPONENT;
final int es = em >> 23;
return es - Binary32.BIAS;
}
/**
* <p>
* Return the sign of the given float value.
* </p>
*/
public static int unpackGetSign(
final float d)
{
final int b = Float.floatToRawIntBits(d);
return ((b & Binary32.MASK_SIGN) >> 31) & 1;
}
/**
* <p>
* Return the significand of the given float value.
* </p>
*/
public static int unpackGetSignificand(
final float d)
{
final int b = Float.floatToRawIntBits(d);
return b & Binary32.MASK_SIGNIFICAND;
}
}
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