diff options
Diffstat (limited to 'src/java/jogamp/common/util/Int32Bitfield.java')
-rw-r--r-- | src/java/jogamp/common/util/Int32Bitfield.java | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/java/jogamp/common/util/Int32Bitfield.java b/src/java/jogamp/common/util/Int32Bitfield.java new file mode 100644 index 0000000..28faf2c --- /dev/null +++ b/src/java/jogamp/common/util/Int32Bitfield.java @@ -0,0 +1,107 @@ +/** + * Copyright 2015 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 jogamp.common.util; + +import com.jogamp.common.util.Bitfield; + +/** + * Simple bitfield interface for efficient storage access in O(1). + * <p> + * Implementation uses one 32bit integer field for storage. + * </p> + */ +public class Int32Bitfield implements Bitfield { + /** Unit size in bits, here 32 bits for one int unit. */ + private static final int UNIT_SIZE = 32; + private int storage; + + public Int32Bitfield() { + this.storage = 0; + } + + @Override + public int getStorageBitSize() { + return UNIT_SIZE; + } + + private final void check(final int limit, final int bitnum) throws ArrayIndexOutOfBoundsException { + if( 0 > bitnum || bitnum >= limit ) { + throw new ArrayIndexOutOfBoundsException("Bitnum should be within [0.."+(limit-1)+"], but is "+bitnum); + } + } + + @Override + public final int getInt32(final int rightBitnum) throws ArrayIndexOutOfBoundsException { + check(UNIT_SIZE-31, rightBitnum); + return storage; + } + + @Override + public final void putInt32(final int rightBitnum, final int mask) throws ArrayIndexOutOfBoundsException { + check(UNIT_SIZE-31, rightBitnum); + storage = mask; + } + + @Override + public final boolean get(final int bitnum) throws ArrayIndexOutOfBoundsException { + check(UNIT_SIZE, bitnum); + return 0 != ( storage & ( 1 << bitnum ) ) ; + } + + @Override + public final boolean put(final int bitnum, final boolean bit) throws ArrayIndexOutOfBoundsException { + check(UNIT_SIZE, bitnum); + final int m = 1 << bitnum; + final boolean prev = 0 != ( storage & m ) ; + if( prev != bit ) { + if( bit ) { + storage |= m; + } else { + storage &= ~m; + } + } + return prev; + } + @Override + public final void set(final int bitnum) throws ArrayIndexOutOfBoundsException { + check(UNIT_SIZE, bitnum); + final int m = 1 << bitnum; + storage |= m; + } + @Override + public final void clear (final int bitnum) throws ArrayIndexOutOfBoundsException { + check(UNIT_SIZE, bitnum); + final int m = 1 << bitnum; + storage &= ~m; + } + + @Override + public int getBitCount() { + return Bitfield.Util.getBitCount(storage); + } +} |