Add VolumeData utility class for accessing original data from Volume objects

Author: kephale

src/main/kotlin/sc/iview/VolumeData.kt

@@ -0,0 +1,80 @@
+/*-
+ * #%L
+ * Scenery-backed 3D visualization package for ImageJ.
+ * %%
+ * Copyright (C) 2016 - 2024 sciview developers.
+ * %%
+ * 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 sc.iview
+
+import graphics.scenery.volumes.Volume
+import net.imglib2.RandomAccessibleInterval
+import net.imglib2.view.Views
+
+/**
+ * Utility class for accessing and manipulating volume data in SciView.
+ *
+ * This class provides methods for accessing the original data source and the current view
+ * of a volume in SciView, addressing the need to avoid using "magic" metadata keys.
+ *
+ * @author Claude-3.7-Sonnet
+ */
+object VolumeData {
+    
+    /**
+     * Gets the original RandomAccessibleInterval from a Volume.
+     * 
+     * @param volume The volume to get the original data from
+     * @return The original RandomAccessibleInterval or null if not found
+     */
+    @Suppress("UNCHECKED_CAST")
+    fun getOriginalRandomAccessibleInterval(volume: Volume): RandomAccessibleInterval<*>? {
+        return volume.metadata["RandomAccessibleInterval"] as? RandomAccessibleInterval<*>
+    }
+    
+    /**
+     * Gets the current view of the Volume based on the current timepoint.
+     * 
+     * This method returns a view of the original data at the current timepoint.
+     * If the data is not time-dependent (doesn't have dimension 3 as time), 
+     * it returns the original data.
+     * 
+     * @param volume The volume to get the current view from
+     * @return The current view of the data or null if original data not found
+     */
+    @Suppress("UNCHECKED_CAST")
+    fun getCurrentView(volume: Volume): RandomAccessibleInterval<*>? {
+        val rai = getOriginalRandomAccessibleInterval(volume) ?: return null
+        
+        // If the data has more than 3 dimensions, assume the 4th dimension is time
+        val currentTimepoint = volume.currentTimepoint
+        
+        return if (rai.numDimensions() > 3) {
+            Views.hyperSlice(rai, 3, currentTimepoint.toLong())
+        } else {
+            // If data doesn't have a time dimension, return the original data
+            rai
+        }
+    }
+}