Properly link flecs library

engine/libs/flecs/examples/cpp/queries/world_query/include/world_query.h

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

engine/libs/flecs/examples/cpp/queries/world_query/include/world_query/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 WORLD_QUERY_BAKE_CONFIG_H
+#define WORLD_QUERY_BAKE_CONFIG_H
+
+/* Headers of public dependencies */
+#include <flecs.h>
+
+#endif
+

engine/libs/flecs/examples/cpp/queries/world_query/project.json

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

engine/libs/flecs/examples/cpp/queries/world_query/src/main.cpp

@@ -0,0 +1,37 @@
+#include <world_query.h>
+#include <iostream>
+
+struct Position { 
+    double x, y;
+};
+
+struct Velocity { 
+    double x, y;
+};
+
+int main(int, char *[]) {
+    flecs::world ecs;
+
+    // Create a few test entities for a Position, Velocity query
+    ecs.entity("e1")
+        .set<Position>({10, 20})
+        .set<Velocity>({1, 2});
+
+    ecs.entity("e2")
+        .set<Position>({10, 20})
+        .set<Velocity>({3, 4});
+
+    // This entity will not match as it does not have Position, Velocity
+    ecs.entity("e3")
+        .set<Position>({10, 20});
+
+    // Ad hoc queries are bit slower to iterate than flecs::query, but are 
+    // faster to create, and in most cases require no allocations. Under the
+    // hood this API uses flecs::filter, which can be used directly for more
+    // complex queries.
+    ecs.each([](flecs::entity e, Position& p, Velocity& v) {
+        p.x += v.x;
+        p.y += v.y;
+        std::cout << e.name() << ": {" << p.x << ", " << p.y << "}\n";
+    });
+}