reflection/basics_bitmask

• C

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  #include <basics_bitmask.h>
  #include <stdio.h>
   
  typedef uint32_t Toppings;
  static const uint32_t Bacon = 0x1;
  static const uint32_t Lettuce = 0x2;
  static const uint32_t Tomato = 0x4;
   
  typedef struct {
      Toppings toppings;
  } Sandwich;
   
  int main(int argc, char *argv[]) {
      ecs_world_t *ecs = ecs_init_w_args(argc, argv);
   
      // Register component as usual
      ECS_COMPONENT(ecs, Toppings);
      ECS_COMPONENT(ecs, Sandwich);
   
      // Add reflection data to components
      ecs_bitmask(ecs,{
          .entity = ecs_id(Toppings), // Make sure to use existing id
          .constants = {
              { .name = "Bacon", .value = Bacon },
              { .name = "Lettuce", .value = Lettuce },
              { .name = "Tomato", .value = Tomato }
          }
      });
   
      ecs_struct(ecs, {
          .entity = ecs_id(Sandwich), // Make sure to use existing id
          .members = {
              { .name = "toppings", .type = ecs_id(Toppings) }
          }
      });
   
      // Create entity with Sandwich as usual
      ecs_entity_t ent = ecs_new(ecs);
      ecs_set(ecs, ent, Sandwich, {Bacon | Lettuce});
   
      // Convert Sandwich component to flecs expression string
      const Sandwich *ptr = ecs_get(ecs, ent, Sandwich);
      char *str = ecs_ptr_to_expr(ecs, ecs_id(Sandwich), ptr);
      printf("%s\n", str); // {toppings: Bacon|Lettuce}
      ecs_os_free(str);
   
      ecs_fini(ecs);
  }

• C++

  View on GitHub

  #include <basics_bitmask.h>
  #include <iostream>
   
  struct Toppings : flecs::bitmask {
      static constexpr uint32_t Bacon = 0x1;
      static constexpr uint32_t Lettuce = 0x2;
      static constexpr uint32_t Tomato = 0x4;
  };
   
  struct Sandwich {
      uint32_t toppings;
  };
   
  int main(int, char *[]) {
      flecs::world ecs;
   
      // Register components with reflection data
      ecs.component<Toppings>()
          .bit("Bacon", Toppings::Bacon)
          .bit("Lettuce", Toppings::Lettuce)
          .bit("Tomato", Toppings::Tomato);
   
      ecs.component<Sandwich>()
          .member<Toppings>("toppings");
   
      // Create entity with Sandwich as usual
      flecs::entity e = ecs.entity()
          .set<Sandwich>({Toppings::Bacon | Toppings::Lettuce});
   
      // Convert Sandwich component to flecs expression string
      const Sandwich& c = e.get<Sandwich>();
      std::cout << ecs.to_expr(&c).c_str() << "\n"; // {toppings: Lettuce|Bacon}
  }