Allow stacking by block units with //stack (#1539) (#2973)

- closes #2968

Co-authored-by: Matthew Miller <mnmiller1@me.com>

worldedit-core/src/main/java/com/sk89q/worldedit/EditSession.java

@@ -127,6 +127,7 @@ import com.sk89q.worldedit.regions.FlatRegion;
 import com.sk89q.worldedit.regions.NullRegion;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.regions.RegionIntersection;
+import com.sk89q.worldedit.regions.RegionOperationException;
 import com.sk89q.worldedit.regions.Regions;
 import com.sk89q.worldedit.regions.shape.ArbitraryBiomeShape;
 import com.sk89q.worldedit.regions.shape.ArbitraryShape;
@@ -1804,18 +1805,59 @@ public class EditSession extends PassthroughExtent implements AutoCloseable {
      * @throws MaxChangedBlocksException thrown if too many blocks are changed
      */
     public int stackCuboidRegion(
-            Region region, BlockVector3 offset, int count,
-            boolean copyEntities, boolean copyBiomes, Mask mask
+            Region region,
+            BlockVector3 offset,
+            int count,
+            boolean copyEntities,
+            boolean copyBiomes,
+            Mask mask
     ) throws MaxChangedBlocksException {
         checkNotNull(region);
         checkNotNull(offset);
+
+        BlockVector3 size = region.getMaximumPoint().subtract(region.getMinimumPoint()).add(1, 1, 1);
+        try {
+            return stackRegionBlockUnits(region, offset.multiply(size), count, copyEntities, copyBiomes, mask);
+        } catch (RegionOperationException e) {
+            // Should never be able to happen
+            throw new AssertionError(e);
+        }
+    }
+
+    /**
+     * Stack a region using block units.
+     *
+     * @param region       the region to stack
+     * @param offset       how far to move the contents each stack in block units
+     * @param count        the number of times to stack
+     * @param copyEntities true to copy entities
+     * @param copyBiomes   true to copy biomes
+     * @param mask         source mask for the operation (only matching blocks are copied)
+     * @return number of blocks affected
+     * @throws MaxChangedBlocksException thrown if too many blocks are changed
+     * @throws RegionOperationException  thrown if the region operation is invalid
+     */
+    public int stackRegionBlockUnits(
+            Region region,
+            BlockVector3 offset,
+            int count,
+            boolean copyEntities,
+            boolean copyBiomes,
+            Mask mask
+    ) throws MaxChangedBlocksException, RegionOperationException {
+        checkNotNull(region);
+        checkNotNull(offset);
         checkArgument(count >= 1, "count >= 1 required");
 
         BlockVector3 size = region.getMaximumPoint().subtract(region.getMinimumPoint()).add(1, 1, 1);
+        BlockVector3 offsetAbs = offset.abs();
+        if (offsetAbs.x() < size.x() && offsetAbs.y() < size.y() && offsetAbs.z() < size.z()) {
+            throw new RegionOperationException(Caption.of("worldedit.stack.intersecting-region"));
+        }
         BlockVector3 to = region.getMinimumPoint();
         ForwardExtentCopy copy = new ForwardExtentCopy(this, region, this, to);
         copy.setRepetitions(count);
-        copy.setTransform(new AffineTransform().translate(offset.multiply(size)));
+        copy.setTransform(new AffineTransform().translate(offset));
         copy.setCopyingEntities(copyEntities);
         copy.setCopyingBiomes(copyBiomes);
         final Region allowedRegion;

worldedit-core/src/main/java/com/sk89q/worldedit/command/RegionCommands.java

@@ -594,7 +594,7 @@ public class RegionCommands {
                 session.getRegionSelector(world).learnChanges();
                 session.getRegionSelector(world).explainRegionAdjust(actor, session);
             } catch (RegionOperationException e) {
-                actor.printError(TextComponent.of(e.getMessage()));
+                actor.printError(e.getRichMessage());
             }
         }
 
@@ -640,7 +640,7 @@ public class RegionCommands {
                     int count,
             @Arg(desc = "How far to move the contents each stack", def = Offset.FORWARD)
             @Offset
-                    BlockVector3 direction,
+                    BlockVector3 offset,
             @Switch(name = 's', desc = "Shift the selection to the last stacked copy")
                     boolean moveSelection,
             @Switch(name = 'a', desc = "Ignore air blocks")
@@ -649,6 +649,8 @@ public class RegionCommands {
                     boolean copyEntities,
             @Switch(name = 'b', desc = "Also copy biomes")
                     boolean copyBiomes,
+            @Switch(name = 'r', desc = "Use block units")
+                    boolean blockUnits,
             @ArgFlag(name = 'm', desc = "Set the include mask, non-matching blocks become air")
                     Mask mask
     ) throws WorldEditException {
@@ -668,19 +670,24 @@ public class RegionCommands {
             combinedMask = mask;
         }
 
-        int affected = editSession.stackCuboidRegion(region, direction, count, copyEntities, copyBiomes, combinedMask);
+        int affected;
+        if (blockUnits) {
+            affected = editSession.stackRegionBlockUnits(region, offset, count, copyEntities, copyBiomes, combinedMask);
+        } else {
+            affected = editSession.stackCuboidRegion(region, offset, count, copyEntities, copyBiomes, combinedMask);
+        }
 
         if (moveSelection) {
             try {
                 final BlockVector3 size = region.getMaximumPoint().subtract(region.getMinimumPoint()).add(1, 1, 1);
-
-                final BlockVector3 shiftVector = direction.multiply(size).multiply(count);
+                final BlockVector3 shiftSize = blockUnits ? offset : offset.multiply(size);
+                final BlockVector3 shiftVector = shiftSize.multiply(count);
                 region.shift(shiftVector);
 
                 session.getRegionSelector(world).learnChanges();
                 session.getRegionSelector(world).explainRegionAdjust(actor, session);
             } catch (RegionOperationException e) {
-                actor.printError(TextComponent.of(e.getMessage()));
+                actor.printError(e.getRichMessage());
             }
         }
 

worldedit-core/src/main/resources/lang/strings.json

@@ -478,6 +478,7 @@
   "worldedit.curve.convex-only": "//curve only works with convex polyhedral selections",
   "worldedit.replace.replaced": "{0} blocks have been replaced.",
   "worldedit.stack.changed": "{0} blocks changed. Undo with //undo",
+  "worldedit.stack.intersecting-region": "Stack offset must not collide with the region when using block units",
   "worldedit.regen.regenerated": "Region regenerated.",
   "worldedit.regen.failed": "Unable to regenerate chunks. Check console for details.",
   "worldedit.walls.changed": "{0} blocks have been changed.",