fluent API for chaining views

src/main/java/net/imglib2/RandomAccessible.java

@@ -34,6 +34,7 @@
 
 package net.imglib2;
 
+import net.imglib2.view.fluent.RandomAccessibleView;
 import net.imglib2.view.Views;
 
 /**
@@ -135,10 +136,10 @@ public interface RandomAccessible< T > extends EuclideanSpace, Typed< T >
 	 * loops, or called many times!!! Use {@link #randomAccess()} when efficiency
 	 * is important.
 	 * <p>
-	 * This method is a short cut for {@code randomAccess().setPositionAndGet( position );}
+	 * This method is a short-cut for {@code randomAccess().setPositionAndGet( position );}
 	 *
 	 * @param position, length must be &ge; {@link #numDimensions()}
-	 * @return value of the the {@link RandomAccessible} at {@code position}.
+	 * @return value of the {@link RandomAccessible} at {@code position}.
 	 */
 	default T getAt( final long... position )
 	{
@@ -153,10 +154,10 @@ default T getAt( final long... position )
 	 * loops, or called many times!!! Use {@link #randomAccess()} when efficiency
 	 * is important.
 	 * <p>
-	 * This method is a short cut for {@code randomAccess().setPositionAndGet( position );}
+	 * This method is a short-cut for {@code randomAccess().setPositionAndGet( position );}
 	 *
 	 * @param position, length must be &ge; {@link #numDimensions()}
-	 * @return value of the the {@link RandomAccessible} at {@code position}.
+	 * @return value of the {@link RandomAccessible} at {@code position}.
 	 */
 	default T getAt( final int... position )
 	{
@@ -171,16 +172,38 @@ default T getAt( final int... position )
 	 * loops, or called many times!!! Use {@link #randomAccess()} when efficiency
 	 * is important.
 	 * <p>
-	 * This method is a short cut for {@code randomAccess().setPositionAndGet( position );}
+	 * This method is a short-cut for {@code randomAccess().setPositionAndGet( position );}
 	 *
 	 * @param position, {@link Localizable#numDimensions()} must be &ge; {@link #numDimensions()}
-	 * @return value of the the {@link RandomAccessible} at {@code position}.
+	 * @return value of the {@link RandomAccessible} at {@code position}.
 	 */
 	default T getAt( final Localizable position )
 	{
 		return randomAccess().setPositionAndGet( position );
 	}
 
+	/**
+	 * Provides a gateway for creating light-weight {@link net.imglib2.view.Views
+	 * views} into this {@code RandomAccessible}.
+	 * <p>
+	 * A view is itself a {@code RandomAccessible} or {@code
+	 * RandomAccessibleInterval} whose accessors transform coordinates and/or
+	 * values on-the-fly without copying the underlying data. Consecutive
+	 * transformations are concatenated and simplified to provide optimally
+	 * efficient accessors.
+	 * <p>
+	 * Note, that accessors provided by a view are read/write. Changing pixels
+	 * in a view changes the underlying image data. (Value converters are an
+	 * exception.)
+	 *
+	 * @return gateway for creating light-weight {@link net.imglib2.view.Views
+	 *         views} into this {@code RandomAccessible}.
+	 */
+	default RandomAccessibleView< T, ? > view()
+	{
+		return RandomAccessibleView.wrap( this );
+	}
+
 	/*
 	 * NB: We cannot have a default implementation here because of
 	 * https://bugs.openjdk.org/browse/JDK-7120669

src/main/java/net/imglib2/RandomAccessibleInterval.java

@@ -36,6 +36,7 @@
 
 import net.imglib2.util.Intervals;
 import net.imglib2.view.RandomAccessibleIntervalCursor;
+import net.imglib2.view.fluent.RandomAccessibleIntervalView;
 
 /**
  * <p>
@@ -98,4 +99,27 @@ default Object iterationOrder()
 	{
 		return new FlatIterationOrder( this );
 	}
+
+	/**
+	 * Provides a gateway for creating light-weight {@link net.imglib2.view.Views
+	 * views} into this {@code RandomAccessibleInterval}.
+	 * <p>
+	 * A view is itself a {@code RandomAccessibleInterval} or {@code
+	 * RandomAccessible} whose accessors transform coordinates and/or values
+	 * on-the-fly without copying the underlying data. Consecutive
+	 * transformations are concatenated and simplified to provide optimally
+	 * efficient accessors.
+	 * <p>
+	 * Note, that accessors provided by a view are read/write. Changing pixels
+	 * in a view changes the underlying image data. (Value converters are an
+	 * exception.)
+	 *
+	 * @return gateway for creating light-weight {@link net.imglib2.view.Views
+	 *         views} into this {@code RandomAccessibleInterval}.
+	 */
+	@Override
+	default RandomAccessibleIntervalView< T > view()
+	{
+		return RandomAccessibleIntervalView.wrap( this );
+	}
 }

src/main/java/net/imglib2/RealRandomAccessible.java

@@ -34,6 +34,8 @@
 
 package net.imglib2;
 
+import net.imglib2.view.fluent.RealRandomAccessibleView;
+
 /**
  * <p>
  * <em>f:R<sup>n</sup>&rarr;T</em>
@@ -120,6 +122,28 @@ default T getAt( final RealLocalizable position )
 		return realRandomAccess().setPositionAndGet( position );
 	}
 
+	/**
+	 * Provides a gateway for creating light-weight {@link net.imglib2.view.Views
+	 * views} into this {@code RealRandomAccessible}.
+	 * <p>
+	 * A view is itself a {@code RealRandomAccessible} or {@code
+	 * RandomAccessible} whose accessors transform coordinates and/or
+	 * values on-the-fly without copying the underlying data. Consecutive
+	 * transformations are concatenated and simplified to provide optimally
+	 * efficient accessors.
+	 * <p>
+	 * Note, that accessors provided by a view are read/write. Changing pixels
+	 * in a view changes the underlying image data. (Value converters are an
+	 * exception.)
+	 *
+	 * @return gateway for creating light-weight views into this {@code
+	 *         RealRandomAccessible}.
+	 */
+	default RealRandomAccessibleView< T > realView()
+	{
+		return RealRandomAccessibleView.wrap( this );
+	}
+
 	/*
 	 * NB: We cannot have a default implementation here because of
 	 * https://bugs.openjdk.org/browse/JDK-7120669

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

@@ -33,12 +33,16 @@
  */
 package net.imglib2.blocks;
 
+import static net.imglib2.outofbounds.OutOfBoundsMirrorFactory.Boundary.SINGLE;
+
+import net.imglib2.blocks.ViewNode.ExtensionViewNode;
 import net.imglib2.outofbounds.OutOfBoundsBorderFactory;
 import net.imglib2.outofbounds.OutOfBoundsConstantValueFactory;
 import net.imglib2.outofbounds.OutOfBoundsFactory;
 import net.imglib2.outofbounds.OutOfBoundsMirrorFactory;
-
-import static net.imglib2.outofbounds.OutOfBoundsMirrorFactory.Boundary.SINGLE;
+import net.imglib2.outofbounds.OutOfBoundsZeroFactory;
+import net.imglib2.type.operators.SetZero;
+import net.imglib2.util.Cast;
 
 interface Extension
 {
@@ -112,4 +116,17 @@ else if ( oobFactory instanceof OutOfBoundsConstantValueFactory )
 			return new ExtensionImpl.UnknownExtension<>( oobFactory );
 		}
 	}
+
+	static Extension of( ExtensionViewNode node )
+	{
+		OutOfBoundsFactory< ?, ? > oobFactory = node.getOutOfBoundsFactory();
+		if ( oobFactory instanceof OutOfBoundsZeroFactory )
+		{
+			final net.imglib2.type.Type< ? > type = Cast.unchecked( node.view().getType() );
+			final SetZero zero = Cast.unchecked( type.createVariable() );
+			zero.setZero();
+			oobFactory = new OutOfBoundsConstantValueFactory<>( zero );
+		}
+		return of( oobFactory );
+	}
 }

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

@@ -50,6 +50,7 @@
 import net.imglib2.img.array.ArrayImg;
 import net.imglib2.img.cell.AbstractCellImg;
 import net.imglib2.img.planar.PlanarImg;
+import net.imglib2.view.fluent.RandomAccessibleView;
 import net.imglib2.transform.integer.BoundingBox;
 import net.imglib2.transform.integer.MixedTransform;
 import net.imglib2.type.NativeType;
@@ -136,6 +137,12 @@ else if ( source instanceof ImgView )
 				nodes.add( new DefaultViewNode( ViewNode.ViewType.IDENTITY, view ) );
 				source = view.getSource();
 			}
+			else if ( source instanceof RandomAccessibleView )
+			{
+				final RandomAccessibleView< ?, ? > view = ( RandomAccessibleView< ?, ? > ) source;
+				nodes.add( new DefaultViewNode( ViewNode.ViewType.IDENTITY, view ) );
+				source = view.delegate();
+			}
 			// INTERVAL,
 			else if ( source instanceof IntervalView )
 			{

src/main/java/net/imglib2/interpolation/Interpolant.java

@@ -53,7 +53,7 @@ final public class Interpolant< T, F > implements RealRandomAccessible< T >, Vie
 
 	protected final int n;
 
-	final InterpolatorFactory< T, F > factory;
+	final InterpolatorFactory< T, ? super F > factory;
 
 	/**
 	 *
@@ -79,7 +79,7 @@ public Interpolant( final EuclideanSpace source, final InterpolatorFactory< T, F
 	 * @param factory
 	 * @param n
 	 */
-	public Interpolant( final F source, final InterpolatorFactory< T, F > factory, final int n )
+	public Interpolant( final F source, final InterpolatorFactory< T, ? super F > factory, final int n )
 	{
 		this.source = source;
 		this.factory = factory;
@@ -118,7 +118,7 @@ public T getType()
 	/**
 	 * @return {@link InterpolatorFactory} used for interpolation
 	 */
-	public InterpolatorFactory< T, F > getInterpolatorFactory()
+	public InterpolatorFactory< T, ? super F > getInterpolatorFactory()
 	{
 		return factory;
 	}

src/main/java/net/imglib2/outofbounds/OutOfBoundsZeroFactory.java

@@ -0,0 +1,59 @@
+/*-
+ * #%L
+ * ImgLib2: a general-purpose, multidimensional image processing library.
+ * %%
+ * Copyright (C) 2009 - 2024 Tobias Pietzsch, Stephan Preibisch, Stephan Saalfeld,
+ * John Bogovic, Albert Cardona, Barry DeZonia, Christian Dietz, Jan Funke,
+ * Aivar Grislis, Jonathan Hale, Grant Harris, Stefan Helfrich, Mark Hiner,
+ * Martin Horn, Steffen Jaensch, Lee Kamentsky, Larry Lindsey, Melissa Linkert,
+ * Mark Longair, Brian Northan, Nick Perry, Curtis Rueden, Johannes Schindelin,
+ * Jean-Yves Tinevez and Michael Zinsmaier.
+ * %%
+ * 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT HOLDERS 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.
+ * #L%
+ */
+package net.imglib2.outofbounds;
+
+import net.imglib2.Interval;
+import net.imglib2.RandomAccessible;
+import net.imglib2.type.Type;
+import net.imglib2.type.operators.SetZero;
+
+/**
+ * Return the zero value of {@code T} when out of bounds.
+ *
+ * @param <T>
+ * 		pixel type
+ *
+ * @author Tobias Pietzsch
+ */
+public class OutOfBoundsZeroFactory< T extends Type< T > & SetZero, F extends Interval & RandomAccessible< T > >
+		implements OutOfBoundsFactory< T, F >
+{
+	@Override
+	public OutOfBoundsConstantValue< T > create( final F f )
+	{
+		final T zero = f.getType().createVariable();
+		zero.setZero();
+		return new OutOfBoundsConstantValue<>( f, zero );
+	}
+}

src/main/java/net/imglib2/view/IntervalView.java

@@ -66,7 +66,7 @@ public class IntervalView< T > extends AbstractInterval implements RandomAccessi
 	 * TODO Javadoc
 	 */
 	protected RandomAccessible< T > fullViewRandomAccessible;
-	
+
 	/**
 	 * TODO Javadoc
 	 */
@@ -76,7 +76,7 @@ public class IntervalView< T > extends AbstractInterval implements RandomAccessi
 	 * Create a view that defines an interval on a source. It is the callers
 	 * responsibility to ensure that the source is defined in the specified
 	 * interval.
-	 * 
+	 *
 	 * @see Views#interval(RandomAccessible, Interval)
 	 */
 	public IntervalView( final RandomAccessible< T > source, final Interval interval )
@@ -92,9 +92,9 @@ public IntervalView( final RandomAccessible< T > source, final Interval interval
 	 * Create a view that defines an interval on a source. It is the callers
 	 * responsibility to ensure that the source is defined in the specified
 	 * interval.
-	 * 
+	 *
 	 * @see Views#interval(RandomAccessible, Interval)
-	 * 
+	 *
 	 * @param min
 	 *            minimum coordinate of the interval.
 	 * @param max
@@ -107,7 +107,7 @@ public IntervalView( final RandomAccessible< T > source, final long[] min, final
 
 	/**
 	 * Gets the underlying source {@link RandomAccessible}.
-	 * 
+	 *
 	 * @return the source {@link RandomAccessible}.
 	 */
 	public RandomAccessible< T > getSource()
@@ -128,7 +128,7 @@ public RandomAccess< T > randomAccess()
 			fullViewRandomAccessible = TransformBuilder.getEfficientRandomAccessible( this, this );
 		return fullViewRandomAccessible.randomAccess();
 	}
-	
+
 	protected IterableInterval< T > getFullViewIterableInterval()
 	{
 		if ( fullViewIterableInterval == null )

src/main/java/net/imglib2/view/Views.java

@@ -36,7 +36,6 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Iterator;
 import java.util.List;
 
 import net.imglib2.EuclideanSpace;
@@ -85,7 +84,7 @@
 
 /**
  * Create light-weight views into {@link RandomAccessible RandomAccessibles}.
- *
+ * <p>
  * A view is itself a {@link RandomAccessible} or
  * {@link RandomAccessibleInterval} that provides {@link RandomAccess accessors}
  * that transform coordinates on-the-fly without copying the underlying data.
@@ -109,7 +108,7 @@ public class Views
 	 *            source
 	 * @return
 	 */
-	public static < T, F extends EuclideanSpace > RealRandomAccessible< T > interpolate( final F source, final InterpolatorFactory< T, F > factory )
+	public static < T, F extends EuclideanSpace > RealRandomAccessible< T > interpolate( final F source, final InterpolatorFactory< T, ? super F > factory )
 	{
 		return new Interpolant<>( source, factory, source.numDimensions() );
 	}