entity_area can accept entity as a starting bounding box.

src/main/java/carpet/script/api/Auxiliary.java

@@ -332,7 +332,7 @@ public class Auxiliary {
             {
                 Value nameValue = lv.get(0).evalValue(c);
                 name = nameValue instanceof NullValue ? "" : nameValue.getString();
-                pointLocator = Vector3Argument.findIn(cc, lv, 1, true);
+                pointLocator = Vector3Argument.findIn(cc, lv, 1, true, false);
                 if (lv.size()>pointLocator.offset)
                 {
                     BlockArgument blockLocator = BlockArgument.findIn(cc, lv, pointLocator.offset, true, true, false);

src/main/java/carpet/script/api/Entities.java

@@ -194,14 +194,24 @@ public class Entities {
             if (lv.size()<3) throw new InternalExpressionException("'entity_area' requires entity type, center and range arguments");
             String who = lv.get(0).evalValue(c).getString();
             CarpetContext cc = (CarpetContext)c;
-            Vector3Argument centerLocator = Vector3Argument.findIn(cc, lv, 1);
-            Vec3d center = centerLocator.vec;
-            if (centerLocator.fromBlock) center.add(0.5, 0.5, 0.5);
+            Vector3Argument centerLocator = Vector3Argument.findIn(cc, lv, 1, false, true);
+
+            Box centerBox;
+            if (centerLocator.entity != null)
+            {
+                centerBox = centerLocator.entity.getBoundingBox();
+            }
+            else
+            {
+                Vec3d center = centerLocator.vec;
+                if (centerLocator.fromBlock) center.add(0.5, 0.5, 0.5);
+                centerBox = new Box(center, center);
+            }
             Vector3Argument rangeLocator = Vector3Argument.findIn(cc, lv, centerLocator.offset);
             if (rangeLocator.fromBlock)
                 throw new InternalExpressionException("Range of 'entity_area' cannot come from a block argument");
             Vec3d range = rangeLocator.vec;
-            Box area = new Box(center, center).expand(range.x, range.y, range.z);
+            Box area = centerBox.expand(range.x, range.y, range.z);
             EntityValue.EntityClassDescriptor eDesc = EntityValue.getEntityDescriptor(who);
             List<? extends Entity> entityList = ((CarpetContext)c).s.getWorld().getEntitiesByType(eDesc.directType, area,eDesc.filteringPredicate);
             Value retval = ListValue.wrap(entityList.stream().map(EntityValue::new).collect(Collectors.toList()));

src/main/java/carpet/script/argument/Vector3Argument.java

@@ -4,9 +4,11 @@ import carpet.script.CarpetContext;
 import carpet.script.LazyValue;
 import carpet.script.exception.InternalExpressionException;
 import carpet.script.value.BlockValue;
+import carpet.script.value.EntityValue;
 import carpet.script.value.ListValue;
 import carpet.script.value.NumericValue;
 import carpet.script.value.Value;
+import net.minecraft.entity.Entity;
 import net.minecraft.util.math.Vec3d;
 
 import java.util.List;
@@ -16,7 +18,8 @@ public class Vector3Argument extends Argument
     public Vec3d vec;
     public final double yaw;
     public final double pitch;
-    public boolean fromBlock;
+    public boolean fromBlock = false;
+    public Entity entity = null;
     private Vector3Argument(Vec3d v, int o)
     {
         super(o);
@@ -38,13 +41,19 @@ public class Vector3Argument extends Argument
         return this;
     }
 
+    private Vector3Argument withEntity(Entity e)
+    {
+        entity = e;
+        return this;
+    }
+
 
     public static Vector3Argument findIn(CarpetContext c, List<LazyValue> params, int offset)
     {
-        return findIn(c,params, offset, false);
+        return findIn(c,params, offset, false, false);
     }
 
-    public static Vector3Argument findIn(CarpetContext c, List<LazyValue> params, int offset, boolean optionalDirection)
+    public static Vector3Argument findIn(CarpetContext c, List<LazyValue> params, int offset, boolean optionalDirection, boolean optionalEntity)
     {
         try
         {
@@ -54,6 +63,11 @@ public class Vector3Argument extends Argument
                 // pos + 0.5v
                 return (new Vector3Argument(Vec3d.ofCenter(((BlockValue) v1).getPos()), 1+offset)).fromBlock();
             }
+            if (optionalEntity && v1 instanceof EntityValue)
+            {
+                Entity e = ((EntityValue) v1).getEntity();
+                return new Vector3Argument(e.getPos(), 1+offset).withEntity(e);
+            }
             if (v1 instanceof ListValue)
             {
                 List<Value> args = ((ListValue) v1).getItems();

src/main/resources/assets/carpet/scripts/ai_tracker.sc

@@ -145,9 +145,8 @@ global_functions = {
                   [10+half_width,10+height,10+half_width],
                   0x65432100, 'buddy detection', false
             );
-            [x,y,z] = pos(e);
             current_id = e~'id';
-            buddies = entity_area('villager', x, y+height/2, z, 10+half_width, 10+height/2, 10+half_width);
+            buddies = entity_area('villager', e, 10, 10, 10);
             nb = length(buddies);
             for (filter(buddies, _~'id' != current_id),
                visuals+=['line', global_duration, 'from', pos(e), 'to', pos(_), 'color', 0xffff00ff];
@@ -518,9 +517,8 @@ __tick_tracker() ->
       return()
    );
    p = player();
-   [px, py, pz] = pos(p);
    in_dimension(p,
-      for (entity_area('valid', px, py, pz, global_range, global_range, global_range),
+      for (entity_area('valid', p, global_range, global_range, global_range),
          __handle_entity(_)
       )
    );