calculate locator positions before application

common/api/src/main/java/com/dfsek/terra/api/structure/feature/BinaryColumn.java

@@ -9,6 +9,7 @@ package com.dfsek.terra.api.structure.feature;
 
 import java.util.function.BooleanSupplier;
 import java.util.function.IntConsumer;
+import java.util.stream.IntStream;
 
 import com.dfsek.terra.api.util.Range;
 import com.dfsek.terra.api.util.function.IntToBooleanFunction;
@@ -63,13 +64,15 @@ public class BinaryColumn {
      * @param consumer Action to perform
      */
     public void forEach(IntConsumer consumer) {
-        for(int y = minY; y < maxY; y++) {
+        for(int y : matching()) {
-            if(get(y)) {
+            consumer.accept(y);
-                consumer.accept(y);
-            }
         }
     }
     
+    public int[] matching() {
+        return IntStream.range(minY, maxY).filter(this::get).toArray();
+    }
+    
     /**
      * Return a {@link BinaryColumn} of equal height with a boolean AND operation applied to each height.
      * @param that Other binary column, must match this column's height.