From 0894ebeef918c81a633a462fabe1abe13614dfb4 Mon Sep 17 00:00:00 2001
From: Ricardo Antunes <me@riscadoa.com>
Date: Tue, 30 Jan 2024 12:21:30 +0000
Subject: [PATCH] docs(scene): showcase relations

---
 engine/samples/scene/assets/main.cubos |  8 +++--
 engine/samples/scene/assets/sub.cubos  |  2 +-
 engine/samples/scene/components.hpp    |  9 ++++--
 engine/samples/scene/main.cpp          | 41 ++++++++++++++++++--------
 4 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/engine/samples/scene/assets/main.cubos b/engine/samples/scene/assets/main.cubos
index 72386ebc50..1b3fda4a0a 100644
--- a/engine/samples/scene/assets/main.cubos
+++ b/engine/samples/scene/assets/main.cubos
@@ -8,10 +8,14 @@
       "Num": 0
     },
     "sub1.root": {
-      "Parent": "main"
+      "OwnedBy": "main",
+      "DistanceTo": {
+        "entity": "sub2.root",
+        "value": 5
+      }
     },
     "sub2.root": {
-      "Parent": "main"
+      "OwnedBy": "main"
     }
   }
 }
diff --git a/engine/samples/scene/assets/sub.cubos b/engine/samples/scene/assets/sub.cubos
index 12bb64ae5e..ce337a0b33 100644
--- a/engine/samples/scene/assets/sub.cubos
+++ b/engine/samples/scene/assets/sub.cubos
@@ -6,7 +6,7 @@
     },
     "child": {
       "Num": 2,
-      "Parent": "root"
+      "OwnedBy": "root"
     }
   }
 }
diff --git a/engine/samples/scene/components.hpp b/engine/samples/scene/components.hpp
index 45ddc33dbc..b739f1cdc3 100644
--- a/engine/samples/scene/components.hpp
+++ b/engine/samples/scene/components.hpp
@@ -10,9 +10,14 @@ struct Num
     int value;
 };
 
-struct Parent
+struct OwnedBy
 {
     CUBOS_REFLECT;
+};
 
-    cubos::core::ecs::Entity entity;
+struct DistanceTo
+{
+    CUBOS_REFLECT;
+
+    int value;
 };
diff --git a/engine/samples/scene/main.cpp b/engine/samples/scene/main.cpp
index 5921665047..62aff8eabd 100644
--- a/engine/samples/scene/main.cpp
+++ b/engine/samples/scene/main.cpp
@@ -20,9 +20,17 @@ CUBOS_REFLECT_IMPL(Num)
     return cubos::core::ecs::TypeBuilder<Num>("Num").withField("value", &Num::value).build();
 }
 
-CUBOS_REFLECT_IMPL(Parent)
+CUBOS_REFLECT_IMPL(OwnedBy)
 {
-    return cubos::core::ecs::TypeBuilder<Parent>("Parent").withField("entity", &Parent::entity).build();
+    return cubos::core::ecs::TypeBuilder<OwnedBy>("OwnedBy").tree().build();
+}
+
+CUBOS_REFLECT_IMPL(DistanceTo)
+{
+    return cubos::core::ecs::TypeBuilder<DistanceTo>("DistanceTo")
+        .symmetric()
+        .withField("value", &DistanceTo::value)
+        .build();
 }
 /// [Component Refl]
 
@@ -44,25 +52,33 @@ static void spawnScene(Commands commands, const Assets& assets)
 /// [Spawning the scene]
 
 /// [Displaying the scene]
-static void printStuff(const World& world, Query<Entity> query)
+static void printStuff(Query<Entity, const Num&> numQuery, Query<const OwnedBy&, Entity> ownedByQuery,
+                       Query<const DistanceTo&, Entity> distanceToQuery)
 {
     using cubos::core::data::DebugSerializer;
     using cubos::core::memory::Stream;
 
     DebugSerializer ser{Stream::stdOut};
 
-    for (auto [entity] : query)
+    for (auto [entity, num] : numQuery)
     {
-        Stream::stdOut.printf("Entity ");
+        Stream::stdOut.print("Entity ");
         ser.write(entity);
-        Stream::stdOut.put('\n');
-        for (auto [type, value] : world.components(entity))
+        Stream::stdOut.printf(":\n- Num = {}\n", num.value);
+
+        for (auto [distanceTo, what] : distanceToQuery.pin(0, entity))
+        {
+            Stream::stdOut.print("- DistanceTo(");
+            ser.write(what);
+            Stream::stdOut.printf(") = {}\n", distanceTo.value);
+        }
+
+        for (auto [ownedBy, owner] : ownedByQuery.pin(0, entity))
         {
-            Stream::stdOut.printf("- {}: ", type->name());
-            ser.write(*type, value);
-            Stream::stdOut.put('\n');
+            Stream::stdOut.print("- OwnedBy(");
+            ser.write(owner);
+            Stream::stdOut.print(")\n");
         }
-        Stream::stdOut.put('\n');
     }
 }
 /// [Displaying the scene]
@@ -76,7 +92,8 @@ int main(int argc, char** argv)
     /// [Adding the plugin]
 
     cubos.addComponent<Num>();
-    cubos.addComponent<Parent>();
+    cubos.addRelation<OwnedBy>();
+    cubos.addRelation<DistanceTo>();
 
     cubos.startupSystem(settings).tagged("cubos.settings");