Add BlockInterval with long[] min and int[] dimensions

src/main/java/net/imglib2/blocks/BlockInterval.java

@@ -0,0 +1,119 @@
+package net.imglib2.blocks;
+
+import net.imglib2.Interval;
+import net.imglib2.util.Util;
+
+import java.util.Arrays;
+
+import static net.imglib2.util.Util.safeInt;
+
+/**
+ * An {@code Interval} where dimensions are {@code int[]}.
+ * <p>
+ * Used internally by {@code PrimitiveBlocks} and {@code BlockProcessor}.
+ */
+public final class BlockInterval implements Interval
+{
+	public BlockInterval( final int numDimensions )
+	{
+		this( new long[ numDimensions ], new int[ numDimensions ] );
+	}
+
+	public static BlockInterval wrap( final long[] min, final int[] size )
+	{
+		return new BlockInterval( min, size );
+	}
+
+	/**
+	 * Return {@code interval} if it is a {@code BlockInterval}.
+	 * Otherwise, copy into a new {@link BlockInterval}.
+	 */
+	public static BlockInterval asBlockInterval( final Interval interval )
+	{
+		return interval instanceof BlockInterval
+				? ( BlockInterval ) interval
+				: new BlockInterval( interval );
+	}
+
+	private final long[] min;
+
+	private final int[] size;
+
+	private BlockInterval( final long[] min, final int[] size )
+	{
+		this.min = min;
+		this.size = size;
+	}
+
+	private BlockInterval( final Interval interval )
+	{
+		this( interval.numDimensions() );
+		interval.min( min );
+		Arrays.setAll( size, d -> safeInt( interval.dimension( d ) ) );
+	}
+
+	public void setFrom( Interval interval )
+	{
+		final int n = numDimensions();
+		if ( n != interval.numDimensions() )
+		{
+			throw new IllegalArgumentException( "Interval dimensions mismatch" );
+		}
+		if ( interval instanceof BlockInterval )
+		{
+			System.arraycopy( ( ( BlockInterval ) interval ).min, 0, min, 0, n );
+			System.arraycopy( ( ( BlockInterval ) interval ).size, 0, size, 0, n );
+		}
+		for ( int d = 0; d < n; ++d )
+		{
+			min[ d ] = interval.min( d );
+			size[ d ] = Util.safeInt( interval.dimension( d ) );
+		}
+	}
+
+	/**
+	 * This returns the internal {@code long[] min}.
+	 * Modifications are reflected in this interval!
+	 *
+	 * @return the internal {@code long[]} storing the min of this interval.
+	 */
+	public long[] min()
+	{
+		return min;
+	}
+
+	/**
+	 * This returns the internal {@code int[] dimensions}.
+	 * Modifications are reflected in this interval!
+	 *
+	 * @return the internal {@code int[]} storing the dimensions of this interval.
+	 */
+	public int[] size()
+	{
+		return size;
+	}
+
+	@Override
+	public int numDimensions()
+	{
+		return size.length;
+	}
+
+	@Override
+	public long min( final int d )
+	{
+		return min[ d ];
+	}
+
+	@Override
+	public long max( final int d )
+	{
+		return min[ d ] + size[ d ] - 1;
+	}
+
+	@Override
+	public long dimension( final int d )
+	{
+		return size[ d ];
+	}
+}