45 lines
1.2 KiB
C++
45 lines
1.2 KiB
C++
#include <wildcards.h>
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#include <iostream>
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// Queries can have wildcard terms that can match multiple instances of a
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// relationship or relationship target.
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struct Eats {
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int amount;
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};
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struct Apples { };
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struct Pears { };
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int main(int, char *[]) {
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flecs::world ecs;
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// Create a query that matches edible components
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flecs::query<Eats> q = ecs.query_builder<Eats>()
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.term_at(1).second(flecs::Wildcard) // Change first argument to (Eats, *)
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.build();
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// Create a few entities that match the query
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ecs.entity("Bob")
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.set<Eats, Apples>({10})
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.set<Eats, Pears>({5});
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ecs.entity("Alice")
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.set<Eats, Apples>({4});
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// Iterate the query with a flecs::iter. This makes it possible to inspect
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// the pair that we are currently matched with.
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q.each([](flecs::iter& it, size_t index, Eats& eats) {
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flecs::entity e = it.entity(index);
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flecs::entity food = it.pair(1).second();
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std::cout << e.name() << " eats "
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<< eats.amount << " " << food.name() << std::endl;
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});
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// Output:
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// Bob eats 10 Apples
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// Bob eats 5 Pears
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// Alice eats 4 Apples
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}
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