Properly link flecs library

engine/libs/flecs/examples/c/rules/component_inheritance/src/main.c

@@ -0,0 +1,68 @@
+#include <component_inheritance.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+    ecs_world_t *ecs = ecs_init_w_args(argc, argv);
+
+    // Use convenience macros to create simple hierarchy of unit types.
+    // This macro call:
+    //   ECS_ENTITY(ecs, CombatUnit, (IsA, Unit))
+    //
+    // is the same as these C statements:
+    //   ecs_entity_t CombatUnit = ecs_new_entity("CombatUnit");
+    //   ecs_add_pair(ecs, CombatUnit, EcsIsA, Unit);
+
+    ECS_TAG(ecs, Unit);
+    ECS_ENTITY(ecs, CombatUnit, (IsA, Unit));
+    ECS_ENTITY(ecs, MeleeUnit,  (IsA, CombatUnit));
+    ECS_ENTITY(ecs, RangedUnit, (IsA, CombatUnit));
+
+    ECS_ENTITY(ecs, Warrior,    (IsA, MeleeUnit));
+    ECS_ENTITY(ecs, Wizard,     (IsA, RangedUnit));
+    ECS_ENTITY(ecs, Marksman,   (IsA, RangedUnit));
+    ECS_ENTITY(ecs, Builder,    (IsA, Unit));
+
+    // Create a few units
+    ecs_entity_t warrior_1 = ecs_new_entity(ecs, "warrior_1");
+    ecs_add(ecs, warrior_1, Warrior);
+    ecs_entity_t warrior_2 = ecs_new_entity(ecs, "warrior_2");
+    ecs_add(ecs, warrior_2, Warrior);
+
+    ecs_entity_t marksman_1 = ecs_new_entity(ecs, "marksman_1");
+    ecs_add(ecs, marksman_1, Marksman);
+    ecs_entity_t marksman_2 = ecs_new_entity(ecs, "marksman_2");
+    ecs_add(ecs, marksman_2, Marksman);
+
+    ecs_entity_t wizard_1 = ecs_new_entity(ecs, "wizard_1");
+    ecs_add(ecs, wizard_1, Wizard);
+    ecs_entity_t wizard_2 = ecs_new_entity(ecs, "wizard_2");
+    ecs_add(ecs, wizard_2, Wizard);
+
+    ecs_entity_t builder_1 = ecs_new_entity(ecs, "builder_1");
+    ecs_add(ecs, builder_1, Builder);
+    ecs_entity_t builder_2 = ecs_new_entity(ecs, "builder_2");
+    ecs_add(ecs, builder_2, Builder);
+
+    // Create a rule to find all ranged units
+    ecs_rule_t *r = ecs_rule(ecs, {
+        .terms = {{ .id = RangedUnit }}
+    });
+
+    // Iterate the rule
+    ecs_iter_t it = ecs_rule_iter(ecs, r);
+    while (ecs_rule_next(&it)) {
+        for (int i = 0; i < it.count; i ++) {
+            printf("Unit %s found\n", ecs_get_name(ecs, it.entities[i]));
+        }
+    }
+
+    ecs_rule_fini(r);
+
+    // Output
+    //  Unit wizard_1 found
+    //  Unit wizard_2 found
+    //  Unit marksman_1 found
+    //  Unit marksman_2 found
+
+    return ecs_fini(ecs);
+}