Disabled (optionally) alpha in textures, starting subdividing triangular

mesh instead

src/main/java/com/elphel/imagej/tileprocessor/ExtrinsicAdjustment.java

@@ -1996,6 +1996,7 @@ public class ExtrinsicAdjustment {
 		// find largest terrain area
 		int [] iterrains = tn. enumerateClusters(
 				terrain, // boolean [] tiles,
+				null,    // int []     num_clusters,
 				true); //boolean ordered)
 		boolean [] terrain_main = new boolean[clusters];
 		for (int i = 0; i < clusters; i++) {

src/main/java/com/elphel/imagej/tileprocessor/OpticalFlow.java

@@ -11761,6 +11761,7 @@ public class OpticalFlow {
 
 			int [] clusters = tn.enumerateClusters(
 					over_thresh, // boolean [] tiles,
+					null,        // int []     num_clusters,
 					false);      // boolean ordered)
 			// check clusters contain super-threshold tile
 			double max_cluster = mov_thresh*mov_clust_max; // each cluster should have larger tile value to survive
@@ -11829,6 +11830,7 @@ public class OpticalFlow {
 
 			clusters = tn.enumerateClusters(
 					move_mask, // boolean [] tiles,
+					null,      // int []     num_clusters,
 					false);    // boolean ordered)
 			if(show_debug_images) {		
 				for (int nTile = 0; nTile <  motion.length; nTile++) if (clusters[nTile] > 0){

src/main/java/com/elphel/imagej/tileprocessor/TileNeibs.java

@@ -616,11 +616,13 @@ public class TileNeibs{
 	/**
 	 * Enumerate clusters on rectangular area
 	 * @param tiles        selected tiles, size should be sizeX * sizeY
+	 * @param num_clusters if non null, will return number of clusters
 	 * @param ordered      if true, order tiles from largest to smallest5
 	 * @return integer array, where 0 is unused, 1+ cluster it belongs to
 	 */
 	public int [] enumerateClusters(
 			boolean [] tiles,
+			int []     num_clusters,
 			boolean ordered)
 	{
 		int [] waves = new int [tiles.length];
@@ -652,6 +654,9 @@ public class TileNeibs{
 				}
 			}
 		}
+		if (num_clusters != null) {
+			num_clusters[0] = numClust;
+		}
 		if (!ordered) {
 			return enum_clust;
 		}

src/main/java/com/elphel/imagej/tileprocessor/TilePlanes.java

@@ -5660,6 +5660,7 @@ public class TilePlanes {
 								null);           // boolean [] prohibit,
 						int [] clusters = tileNeibs.enumerateClusters(
 								grown_sel, // boolean [] tiles,
+								null,      // int []     num_clusters,
 								false);    // boolean ordered)
 
 						int num_clusters = TileNeibs.getMax(
@@ -5698,6 +5699,7 @@ public class TilePlanes {
 							int [] dbg_clusters = clusters.clone();
 							clusters = tileNeibs.enumerateClusters(
 									grown_sel, // boolean [] tiles,
+									null,      // int []     num_clusters,
 									false);    // boolean ordered)
 							num_clusters = TileNeibs.getMax(
 									clusters);