Properly link flecs library

engine/libs/flecs/examples/cpp/observers/two_components/include/two_components.h

@@ -0,0 +1,16 @@
+#ifndef TWO_COMPONENTS_H
+#define TWO_COMPONENTS_H
+
+/* This generated file contains includes for project dependencies */
+#include "two_components/bake_config.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+

engine/libs/flecs/examples/cpp/observers/two_components/include/two_components/bake_config.h

@@ -0,0 +1,24 @@
+/*
+                                   )
+                                  (.)
+                                  .|.
+                                  | |
+                              _.--| |--._
+                           .-';  ;`-'& ; `&.
+                          \   &  ;    &   &_/
+                           |"""---...---"""|
+                           \ | | | | | | | /
+                            `---.|.|.|.---'
+
+ * This file is generated by bake.lang.c for your convenience. Headers of
+ * dependencies will automatically show up in this file. Include bake_config.h
+ * in your main project file. Do not edit! */
+
+#ifndef TWO_COMPONENTS_BAKE_CONFIG_H
+#define TWO_COMPONENTS_BAKE_CONFIG_H
+
+/* Headers of public dependencies */
+#include <flecs.h>
+
+#endif
+

engine/libs/flecs/examples/cpp/observers/two_components/project.json

@@ -0,0 +1,11 @@
+{
+    "id": "two_components",
+    "type": "application",
+    "value": {
+        "use": [
+            "flecs"
+        ],
+        "language": "c++",
+        "public": false
+    }
+}

engine/libs/flecs/examples/cpp/observers/two_components/src/main.cpp

@@ -0,0 +1,39 @@
+#include <two_components.h>
+#include <iostream>
+
+// An observer can match multiple components/tags. Only entities that match the
+// entire observer filter will be forwarded to the callback. For example, an
+// observer for Position,Velocity won't match an entity that only has Position.
+
+struct Position {
+    double x, y;
+};
+
+struct Velocity {
+    double x, y;
+};
+
+int main(int, char *[]) {
+    flecs::world ecs;
+
+    // Create observer for custom event
+    ecs.observer<Position, Velocity>()
+        .event(flecs::OnSet)
+        .each([](flecs::iter& it, size_t i, Position& p, Velocity& v) {
+            std::cout << " - " << it.event().name() << ": " 
+                << it.event_id().str() << ": "
+                << it.entity(i).name() << ": "
+                << "p: {" << p.x << ", " << p.y << "} "
+                << "v: {" << v.x << ", " << v.y << "}\n";
+        });
+
+    // Create entity, set Position (emits EcsOnSet, does not yet match observer)
+    flecs::entity e = ecs.entity("e")
+        .set<Position>({10, 20});
+
+    // Set Velocity (emits EcsOnSet, matches observer)
+    e.set<Velocity>({1, 2});
+
+    // Output
+    //   - OnSet: Velocity: e: p: {10, 20} v: {1, 2}
+}