extend the Groot example to reproduce issues with arrays

Author: facontidavide

examples/t11_groot_howto.cpp

@@ -7,6 +7,10 @@
 #include "behaviortree_cpp/loggers/groot2_publisher.h"
 #include "behaviortree_cpp/xml_parsing.h"
 
+#include <cstdlib>
+#include <string>
+#include <vector>
+
 /** We are using the same example in Tutorial 5,
  *  But this time we also show how to connect
  */
@@ -28,7 +32,22 @@ BT_JSON_CONVERTER(Position2D, pos)
   add_field("y", &pos.y);
 }
 
+struct Waypoint
+{
+  std::string name;
+  Position2D position;
+  double speed = 1.0;
+};
+
+BT_JSON_CONVERTER(Waypoint, wp)
+{
+  add_field("name", &wp.name);
+  add_field("position", &wp.position);
+  add_field("speed", &wp.speed);
+}
+
 // Simple Action that updates an instance of Position2D in the blackboard
+// and also outputs vectors to reproduce Groot2 issue #55/#77
 class UpdatePosition : public BT::SyncActionNode
 {
 public:
@@ -41,16 +60,63 @@ class UpdatePosition : public BT::SyncActionNode
     _pos.x += 0.2;
     _pos.y += 0.1;
     setOutput("pos", _pos);
+
+    // Vectors that trigger Groot2 issue #55/#77 (crash when viewing blackboard)
+    std::vector<double> doubles = { 1.1, 2.2, 3.3, 4.4, 5.5 };
+    setOutput("vec_double", doubles);
+
+    std::vector<std::string> strings = { "hello", "world", "test" };
+    setOutput("vec_string", strings);
+
+    // Helper to generate random offset [-range, +range]
+    auto randOffset = [](double range) {
+      return (static_cast<double>(std::rand()) / RAND_MAX - 0.5) * 2.0 * range;
+    };
+
+    // Vector of custom types - alternate between 2 and 3 waypoints
+    std::vector<Waypoint> waypoints;
+    if(_execution_count % 2 == 0)
+    {
+      // Even executions: 2 waypoints
+      waypoints = {
+        { "start", { randOffset(5.0), randOffset(5.0) }, 1.0 + randOffset(0.3) },
+        { "goal",
+          { 100.0 + randOffset(10.0), 50.0 + randOffset(10.0) },
+          0.5 + randOffset(0.2) },
+      };
+    }
+    else
+    {
+      // Odd executions: 3 waypoints
+      waypoints = {
+        { "start", { randOffset(5.0), randOffset(5.0) }, 1.0 + randOffset(0.3) },
+        { "checkpoint",
+          { 50.0 + randOffset(15.0), 25.0 + randOffset(15.0) },
+          2.0 + randOffset(0.5) },
+        { "goal",
+          { 100.0 + randOffset(10.0), 50.0 + randOffset(10.0) },
+          0.5 + randOffset(0.2) },
+      };
+    }
+    setOutput("waypoints", waypoints);
+    _execution_count++;
+
     return BT::NodeStatus::SUCCESS;
   }
 
   static BT::PortsList providedPorts()
   {
-    return { BT::OutputPort<Position2D>("pos") };
+    return {
+      BT::OutputPort<Position2D>("pos"),
+      BT::OutputPort<std::vector<double>>("vec_double", "Vector of doubles"),
+      BT::OutputPort<std::vector<std::string>>("vec_string", "Vector of strings"),
+      BT::OutputPort<std::vector<Waypoint>>("waypoints", "Vector of waypoints"),
+    };
   }
 
 private:
   Position2D _pos = { 0, 0 };
+  int _execution_count = 0;
 };
 
 // clang-format off
@@ -61,7 +127,7 @@ static const char* xml_text = R"(
   <BehaviorTree ID="MainTree">
     <Sequence>
       <Script code="door_open:=false" />
-      <UpdatePosition pos="{pos_2D}" />
+      <UpdatePosition pos="{pos_2D}" vec_double="{doubles}" vec_string="{strings}" waypoints="{waypoints}"/>
       <Fallback>
         <Inverter>
           <IsDoorClosed/>
@@ -105,6 +171,7 @@ int main()
 
   // Add this to allow Groot2 to visualize your custom type
   BT::RegisterJsonDefinition<Position2D>();
+  BT::RegisterJsonDefinition<Waypoint>();
 
   auto tree = factory.createTree("MainTree");