Properly link flecs library

engine/libs/flecs/examples/c/systems/time_interval/src/main.c

@@ -0,0 +1,51 @@
+#include <time_interval.h>
+#include <stdio.h>
+
+// This example shows how to run a system at a specified time interval.
+
+void Tick(ecs_iter_t *it) {
+    printf("%s\n", ecs_get_name(it->world, it->system));
+}
+
+int main(int argc, char *argv[]) {
+    ecs_world_t *ecs = ecs_init_w_args(argc, argv);
+
+    // Create two systems that are running at different time intervals
+    ecs_system(ecs, {
+        .entity = ecs_entity(ecs, { 
+            .name = "Tick",
+            .add = { ecs_dependson(EcsOnUpdate) } // run in OnUpdate phase
+        }),
+        .callback = Tick,
+        .interval = 1.0  // time in seconds
+    });
+
+    ecs_system(ecs, {
+        .entity = ecs_entity(ecs, { 
+            .name = "FastTick",
+            .add = { ecs_dependson(EcsOnUpdate) }
+        }),
+        .callback = Tick,
+        .interval = 0.5
+    });
+
+    // Run the main loop at 60 FPS
+    ecs_set_target_fps(ecs, 60);
+
+    while (ecs_progress(ecs, 0)) { }
+
+    return ecs_fini(ecs);
+
+    // Output
+    //  FastTick
+    //  Tick
+    //  FastTick
+    //  FastTick
+    //  Tick
+    //  FastTick
+    //  FastTick
+    //  Tick
+    //  FastTick
+    //  FastTick
+    //  ...
+}