/**
 * Copyright 2012 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.common.util;

public class IntBitfield {
    /** Unit size in bits, here 32 bits for one int unit. */
    public static final int UNIT_SIZE = 32;
    
    final int[] storage;
    final long bits;
    
    /**
     * @param bits
     */
    public IntBitfield(long bits) {
        final int units = (int) ( ( bits + 7L ) / (long)UNIT_SIZE );
        this.storage = new int[units];
        this.bits = units * (long)UNIT_SIZE;
    }
    
    private final void check(long bitnum) {
        if( 0 > bitnum || bitnum >= bits ) {
            throw new ArrayIndexOutOfBoundsException("Bitnum should be within [0.."+(bits-1)+"], but is "+bitnum);
        }
    }
    
    public final long capacity() { return bits; }
    
    public final boolean get(long bitnum) {
        check(bitnum);
        final int u = (int) ( bitnum / UNIT_SIZE );
        final int b = (int) ( bitnum - ( u * UNIT_SIZE ) );
        return 0 != ( storage[u] & ( 1 << b ) ) ;
    }
    
    public final void put(long bitnum, boolean bit) {        
        check(bitnum);
        final int u = (int) ( bitnum / UNIT_SIZE );
        final int b = (int) ( bitnum - ( u * UNIT_SIZE ) );
        if(bit) {
            storage[u] |=    1 << b;
        } else {
            storage[u] &= ~( 1 << b );
        }
    }
}