ImgMath: OffsetSource, allowing a ViewableFunction (most ops) to be read with an offset.

Author: acardona

src/main/java/net/imglib2/algorithm/math/ImgMath.java

@@ -371,6 +371,11 @@ static public final < T extends RealType< T > > RandomAccessibleSource< T > offs
 		return new RandomAccessibleSource< T >( src, offset );
 	}
 
+	static public final < T extends RealType< T > > OffsetSource< T > offset( final IFunction f, final long[] offset )
+	{
+		return new OffsetSource< T >( f, offset );
+	}
+	
 	static public final < T extends RealType< T > > IFunction source( final RandomAccessible< T > src )
 	{
 		if ( src instanceof RandomAccessibleInterval< ? > )

src/main/java/net/imglib2/algorithm/math/OffsetSource.java

@@ -0,0 +1,46 @@
+package net.imglib2.algorithm.math;
+
+import java.util.Map;
+
+import net.imglib2.RandomAccessible;
+import net.imglib2.algorithm.math.abstractions.IFunction;
+import net.imglib2.algorithm.math.abstractions.OFunction;
+import net.imglib2.algorithm.math.abstractions.RandomAccessOnly;
+import net.imglib2.algorithm.math.abstractions.ViewableFunction;
+import net.imglib2.algorithm.math.execution.IterableRandomAccessibleFunction;
+import net.imglib2.algorithm.math.execution.LetBinding;
+import net.imglib2.algorithm.math.execution.RandomAccessibleOffsetSourceDirect;
+import net.imglib2.algorithm.math.execution.Variable;
+import net.imglib2.converter.Converter;
+import net.imglib2.type.numeric.RealType;
+
+public class OffsetSource< I extends RealType< I > > extends ViewableFunction implements RandomAccessOnly< I >
+{
+	private final IFunction f;
+	private final long[] offset;
+	
+	public OffsetSource( final IFunction f, final long[] offset )
+	{
+		this.f = f;
+		this.offset = offset;
+	}
+	
+	@Override
+	public < O extends RealType< O > > OFunction< O > reInit(
+			final O tmp,
+			final Map< String, LetBinding< O > > bindings,
+			final Converter< RealType< ? >, O > converter,
+			final Map< Variable< O >, OFunction< O > > imgSources )
+	{
+		return new RandomAccessibleOffsetSourceDirect< O >(
+				tmp.copy(),
+				new IterableRandomAccessibleFunction< O, O >( this.f, converter,  tmp.createVariable(), tmp.createVariable(), null ),
+				this.offset );
+	}
+
+	@Override
+	public RandomAccessible< I > getRandomAccessible()
+	{
+		return this.view();
+	}
+}