MDL_LOAD_ARRAY( meta, &world->ent_prop, ent_prop, heap );
MDL_LOAD_ARRAY( meta, &world->ent_region, ent_region, heap );
MDL_LOAD_ARRAY( meta, &world->ent_glider, ent_glider, heap );
MDL_LOAD_ARRAY( meta, &world->ent_prop, ent_prop, heap );
MDL_LOAD_ARRAY( meta, &world->ent_region, ent_region, heap );
MDL_LOAD_ARRAY( meta, &world->ent_glider, ent_glider, heap );