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use crate::z_ignore_test_common::*;
use flecs_ecs::prelude::*;
// This example extends the component_inheritance example, and shows how
// we can use a single query to match units from different players and platoons
// by setting query variables before we iterate.
//
// The units in this example belong to a platoon, with the platoons belonging
// to a player.
// unit datamodel
#[derive(Component)]
struct Unit;
#[derive(Component)]
struct CombatUnit;
#[derive(Component)]
struct MeleeUnit;
#[derive(Component)]
struct RangedUnit;
#[derive(Component)]
struct Warrior;
#[derive(Component)]
struct Wizard;
#[derive(Component)]
struct Marksman;
#[derive(Component)]
struct Player;
#[derive(Component)]
struct Platoon;
const PLAYER_COUNT: usize = 100;
const PLATOONS_PER_PLAYER: usize = 3;
fn main() {
let world = World::new();
// Make the ECS aware of the inheritance relationships. Note that IsA
// relationship used here is the same as in the prefab example.
world.component::<CombatUnit>().is_a(Unit);
world.component::<MeleeUnit>().is_a(CombatUnit);
world.component::<RangedUnit>().is_a(CombatUnit);
world.component::<Warrior>().is_a(MeleeUnit);
world.component::<Wizard>().is_a(RangedUnit);
world.component::<Marksman>().is_a(RangedUnit);
// Populate store with players and platoons
for p in 0..PLAYER_COUNT {
let player = if p == 0 {
// Give first player a name so we can look it up later
world.entity_named("MyPlayer")
} else {
world.entity()
};
// Add player tag so we can query for all players if we want to
player.add(Player);
for _ in 0..PLATOONS_PER_PLAYER {
let platoon = world
.entity()
.add((Player, player))
// Add platoon tag so we can query for all platoons if we want to
.add(Platoon);
// Add warriors, wizards and marksmen to the platoon
world.entity().add(Warrior).add((Platoon, platoon));
world.entity().add(Marksman).add((Platoon, platoon));
world.entity().add(Wizard).add((Platoon, platoon));
}
}
// Create a query to find all RangedUnits for a platoon/player. The
// equivalent query in the query DSL would look like this:
// (Platoon, $Platoon), Player($Platoon, $Player)
//
// The way to read how this query is evaluated is:
// - find all entities with (Platoon, *), store * in _Platoon
// - check if _Platoon has (Player, *), store * in _Player
let mut query = world
.query::<()>()
.with(RangedUnit)
.with(&Platoon)
.set_second("$platoon")
.with((Player, "$player"))
.set_src("$platoon")
.build();
// If we would iterate this query it would return all ranged units for all
// platoons & for all players. We can limit the results to just a single
// platoon or a single player setting a variable beforehand. In this example
// we'll just find all platoons & ranged units for a single player.
let player_var = query.find_var("player").unwrap();
let platoon_var = query.find_var("platoon").unwrap();
// Iterate query, limit the results to units of MyPlayer
query
.set_var(player_var, world.lookup_recursive("MyPlayer"))
.each_iter(|it, index, _| {
let unit = it.entity(index);
println!(
"Unit id: {} of class {} in platoon id: {} for player {}",
unit,
it.id(0).to_str(),
it.get_var(platoon_var),
it.get_var(player_var)
);
});
// Output:
// Unit id: 529 of class Wizard in platoon id: 526 for player MyPlayer
// Unit id: 533 of class Wizard in platoon id: 530 for player MyPlayer
// Unit id: 537 of class Wizard in platoon id: 534 for player MyPlayer
// Unit id: 528 of class Marksman in platoon id: 526 for player MyPlayer
// Unit id: 532 of class Marksman in platoon id: 530 for player MyPlayer
// Unit id: 536 of class Marksman in platoon id: 534 for player MyPlayer
// Try removing the set_var call, this will cause the iterator to return
// all units in all platoons for all players.
}
#[cfg(feature = "flecs_nightly_tests")]
#[test]
fn test() {
let output_capture = OutputCapture::capture().unwrap();
main();
output_capture.test("query_setting_variables".to_string());
}