Struct query_base

Synopsis

#include <include/flecs/addons/cpp/mixins/query/impl.hpp>

struct query_base

Description

No description yet.

Methods

	query_base overload
	changed	Returns whether the query data changed since the last iteration
	destruct	Free the query.
	each_term
	entity
	field_count
	filter
	operator query
	operator query_t *
	orphaned	Returns whether query is orphaned
	str
	term

Source

Lines 11-111 in include/flecs/addons/cpp/mixins/query/impl.hpp.

struct query_base {
    query_base()
        : m_world(nullptr)
        , m_query(nullptr) { }

    query_base(world_t *world, query_t *query = nullptr)
        : m_world(world)
        , m_query(query) { }

    query_base(world_t *world, ecs_query_desc_t *desc) 
        : m_world(world)
    {
        m_query = ecs_query_init(world, desc);

        if (!m_query) {
            ecs_abort(ECS_INVALID_PARAMETER, NULL);
        }

        if (desc->filter.terms_buffer) {
            ecs_os_free(desc->filter.terms_buffer);
        }
    }

    operator query_t*() const {
        return m_query;
    }

    /** Returns whether the query data changed since the last iteration.
     * This operation must be invoked before obtaining the iterator, as this will
     * reset the changed state. The operation will return true after:
     * - new entities have been matched with
     * - matched entities were deleted
     * - matched components were changed
     * 
     * @return true if entities changed, otherwise false.
     */
    bool changed() {
        return ecs_query_changed(m_query, 0);
    }

    /** Returns whether query is orphaned.
     * When the parent query of a subquery is deleted, it is left in an orphaned
     * state. The only valid operation on an orphaned query is deleting it. Only
     * subqueries can be orphaned.
     *
     * @return true if query is orphaned, otherwise false.
     */
    bool orphaned() {
        return ecs_query_orphaned(m_query);
    }

    /** Free the query.
     */
    void destruct() {
        ecs_query_fini(m_query);
        m_world = nullptr;
        m_query = nullptr;
    }

    template <typename Func>
    void each_term(const Func& func) {
        const ecs_filter_t *f = ecs_query_get_filter(m_query);
        ecs_assert(f != NULL, ECS_INVALID_PARAMETER, NULL);

        for (int i = 0; i < f->term_count; i ++) {
            flecs::term t(m_world, f->terms[i]);
            func(t);
        }
    }

    filter_base filter() {
        return filter_base(m_world, ecs_query_get_filter(m_query));
    }

    flecs::term term(int32_t index) {
        const ecs_filter_t *f = ecs_query_get_filter(m_query);
        ecs_assert(f != NULL, ECS_INVALID_PARAMETER, NULL);
        return flecs::term(m_world, f->terms[index]);
    }

    int32_t field_count() {
        const ecs_filter_t *f = ecs_query_get_filter(m_query);
        return f->term_count;   
    }

    flecs::string str() {
        const ecs_filter_t *f = ecs_query_get_filter(m_query);
        char *result = ecs_filter_str(m_world, f);
        return flecs::string(result);
    }

    flecs::entity entity() {
        return flecs::entity(m_world, ecs_query_entity(m_query));
    }

    operator query<>() const;

protected:
    world_t *m_world;
    query_t *m_query;
};