From 148ddcd2c0613bb96050b8a72e9f6f83513ca9ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dominik=20Madar=C3=A1sz?= <zaklaus@madaraszd.net>
Date: Sun, 15 Aug 2021 18:32:11 +0200
Subject: [PATCH] code: updated flecs to 2.4.1

---
 code/game/src/debug_replay.c     |   5 +
 code/game/src/debug_ui.c         |   1 +
 code/game/src/debug_ui_actions.c |  24 ++
 code/vendors/flecs/flecs.c       | 123 ++++--
 code/vendors/flecs/flecs.h       | 670 +++++++++++++++++++------------
 5 files changed, 523 insertions(+), 300 deletions(-)

diff --git a/code/game/src/debug_replay.c b/code/game/src/debug_replay.c
index 7c612f4..d2a8390 100644
--- a/code/game/src/debug_replay.c
+++ b/code/game/src/debug_replay.c
@@ -10,6 +10,7 @@ typedef enum {
     // NOTE(zaklaus): Special actions
     RPKIND_SPAWN_CAR,
     RPKIND_PLACE_ICE_RINK,
+    RPKIND_SPAWN_CIRCLING_DRIVER,
 } replay_kind;
 
 typedef struct {
@@ -150,6 +151,7 @@ void debug_replay_run(void) {
 }
 
 void ActPlaceIceRink();
+void ActSpawnCirclingDriver(void);
 
 void debug_replay_update(void) {
     if (!is_playing) return;
@@ -178,6 +180,9 @@ void debug_replay_update(void) {
         case RPKIND_PLACE_ICE_RINK: {
             ActPlaceIceRink();
         }break;
+        case RPKIND_SPAWN_CIRCLING_DRIVER: {
+            ActSpawnCirclingDriver();
+        }break;
         default: {
             ZPL_PANIC("unreachable");
         }break;
diff --git a/code/game/src/debug_ui.c b/code/game/src/debug_ui.c
index 1c75893..61c3108 100644
--- a/code/game/src/debug_ui.c
+++ b/code/game/src/debug_ui.c
@@ -112,6 +112,7 @@ static debug_item items[] = {
             .items = (debug_item[]) {
                 { .kind = DITEM_BUTTON, .name = "spawn car", .on_click = ActSpawnCar },
                 { .kind = DITEM_BUTTON, .name = "place ice rink", .on_click = ActPlaceIceRink },
+                { .kind = DITEM_BUTTON, .name = "spawn circling driver", .on_click = ActSpawnCirclingDriver },
                 { 
                     .kind = DITEM_LIST,
                     .name = "demo npcs",
diff --git a/code/game/src/debug_ui_actions.c b/code/game/src/debug_ui_actions.c
index cd9f841..013cfef 100644
--- a/code/game/src/debug_ui_actions.c
+++ b/code/game/src/debug_ui_actions.c
@@ -18,6 +18,30 @@ ActSpawnCar(void) {
     debug_replay_special_action(RPKIND_SPAWN_CAR);
 }
 
+void
+ActSpawnCirclingDriver(void) {
+    ecs_entity_t plr = camera_get().ent_id;
+    ecs_entity_t ve = vehicle_spawn();
+    ecs_entity_t e = entity_spawn(EKIND_DEMO_NPC);
+    
+    Position const *origin = ecs_get(world_ecs(), plr, Position);
+    Position *veh_dest = ecs_get_mut(world_ecs(), ve, Position, NULL);
+    Position *dest = ecs_get_mut(world_ecs(), e, Position, NULL);
+    *veh_dest = *origin;
+    *dest = *origin;
+    
+    Input *input = ecs_get_mut(world_ecs(), e, Input, NULL);
+    input->x = input->y = 1.0f;
+    input->use = false;
+    
+    Vehicle *veh = ecs_get_mut(world_ecs(), ve, Vehicle, NULL);
+    veh->seats[0] = e;
+    
+    ecs_set(world_ecs(), e, IsInVehicle, { .veh = ve });
+    
+    debug_replay_special_action(RPKIND_SPAWN_CIRCLING_DRIVER);
+}
+
 void
 ActPlaceIceRink(void) {
     ecs_entity_t plr = camera_get().ent_id;
diff --git a/code/vendors/flecs/flecs.c b/code/vendors/flecs/flecs.c
index f5fc0cc..a926d6c 100644
--- a/code/vendors/flecs/flecs.c
+++ b/code/vendors/flecs/flecs.c
@@ -2948,8 +2948,9 @@ void dtor_component(
     if (cdata && (dtor = cdata->lifecycle.dtor)) {
         void *ctx = cdata->lifecycle.ctx;
         int16_t size = column->size;
-        int16_t alignment = column->alignment;    
+        int16_t alignment = column->alignment;
 
+        ecs_assert(column->data != NULL, ECS_INTERNAL_ERROR, NULL);
         void *ptr = ecs_vector_get_t(column->data, size, alignment, row);
         ecs_assert(ptr != NULL, ECS_INTERNAL_ERROR, NULL);
 
@@ -4549,6 +4550,9 @@ bool flecs_table_match_filter(
     const ecs_table_t *table,
     const ecs_filter_t * filter)
 {
+    ecs_assert(world != NULL, ECS_INTERNAL_ERROR, NULL);
+    ecs_assert(table != NULL, ECS_INTERNAL_ERROR, NULL);
+
     if (!filter) {
         return true;
     }
@@ -4767,13 +4771,13 @@ void* get_base_component(
 
     ecs_type_t type = table->type;
     ecs_id_t *ids = ecs_vector_first(type, ecs_id_t);
-    int32_t i = tr_isa->column, count = tr_isa->count;
+    int32_t i = tr_isa->column, end = tr_isa->count + tr_isa->column;
     void *ptr = NULL;
 
     do {
-        ecs_id_t pair = ids[i];
-
+        ecs_id_t pair = ids[i ++];
         ecs_entity_t base = ecs_pair_object(world, pair);
+
         ecs_record_t *r = ecs_eis_get(world, base);
         if (!r) {
             continue;
@@ -4794,8 +4798,7 @@ void* get_base_component(
             int32_t row = flecs_record_to_row(r->row, &is_monitored);
             ptr = get_component_w_index(table, tr->column, row);
         }
-        i ++;
-    } while (!ptr && (i < count));
+    } while (!ptr && (i < end));
 
     return ptr;
 }
@@ -6275,7 +6278,7 @@ ecs_entity_t ecs_new_id(
     }
 
     ecs_assert(!unsafe_world->stats.max_id || 
-        entity <= unsafe_world->stats.max_id, 
+        ecs_entity_t_lo(entity) <= unsafe_world->stats.max_id, 
         ECS_OUT_OF_RANGE, NULL);
 
     return entity;
@@ -6444,7 +6447,7 @@ ecs_table_t *traverse_from_expr(
     if (ptr) {
         ecs_term_t term = {0};
         while (ptr[0] && (ptr = ecs_parse_term(world, name, expr, ptr, &term))){
-            if (!ecs_term_is_set(&term)) {
+            if (!ecs_term_is_initialized(&term)) {
                 break;
             }
 
@@ -6530,7 +6533,7 @@ void defer_from_expr(
     if (ptr) {
         ecs_term_t term = {0};
         while (ptr[0] && (ptr = ecs_parse_term(world, name, expr, ptr, &term))) {
-            if (!ecs_term_is_set(&term)) {
+            if (!ecs_term_is_initialized(&term)) {
                 break;
             }
 
@@ -7891,6 +7894,8 @@ ecs_entity_t ecs_get_case(
     ecs_assert(ecs_is_valid(world, entity), ECS_INVALID_PARAMETER, NULL);
     ecs_assert(ecs_is_valid(world, sw_id), ECS_INVALID_PARAMETER, NULL);
 
+    world = ecs_get_world(world);
+
     ecs_entity_info_t info;
     ecs_table_t *table;
     if (!flecs_get_info(world, entity, &info) || !(table = info.table)) {
@@ -11270,7 +11275,7 @@ int ecs_plecs_from_str(
     }
 
     while (ptr[0] && (ptr = ecs_parse_term(world, name, expr, ptr, &term))) {
-        if (!ecs_term_is_set(&term)) {
+        if (!ecs_term_is_initialized(&term)) {
             break;
         }
         
@@ -12203,10 +12208,7 @@ ecs_data_t* duplicate_data(
         ecs_entity_t component = components[i];
         ecs_column_t *column = &result->columns[i];
 
-        if (component > ECS_HI_COMPONENT_ID) {
-            column->data = NULL;
-            continue;
-        }
+        component = ecs_get_typeid(world, component);
 
         const ecs_type_info_t *cdata = flecs_get_c_info(world, component);
         int16_t size = column->size;
@@ -12287,7 +12289,6 @@ ecs_snapshot_t* snapshot_create(
         }
 
         ecs_table_leaf_t *l = ecs_vector_add(&result->tables, ecs_table_leaf_t);
-
         l->table = t;
         l->type = t->type;
         l->data = duplicate_data(world, t, data);
@@ -16601,6 +16602,12 @@ bool ecs_id_match(
     return false;
 }
 
+bool ecs_id_is_pair(
+    ecs_id_t id)
+{
+    return ECS_HAS_ROLE(id, PAIR);
+}
+
 bool ecs_id_is_wildcard(
     ecs_id_t id)
 {
@@ -16620,7 +16627,7 @@ bool ecs_term_id_is_set(
     return id->entity != 0 || id->name != NULL;
 }
 
-bool ecs_term_is_set(
+bool ecs_term_is_initialized(
     const ecs_term_t *term)
 {
     return term->id != 0 || ecs_term_id_is_set(&term->pred);
@@ -16819,7 +16826,7 @@ int ecs_filter_init(
     } else {
         terms = (ecs_term_t*)desc->terms;
         for (i = 0; i < ECS_TERM_CACHE_SIZE; i ++) {
-            if (!ecs_term_is_set(&terms[i])) {
+            if (!ecs_term_is_initialized(&terms[i])) {
                 break;
             }
 
@@ -16848,7 +16855,7 @@ int ecs_filter_init(
         const char *ptr = desc->expr;
         ecs_term_t term = {0};
         while (ptr[0] && (ptr = ecs_parse_term(world, name, expr, ptr, &term))){
-            if (!ecs_term_is_set(&term)) {
+            if (!ecs_term_is_initialized(&term)) {
                 break;
             }
             
@@ -16925,6 +16932,42 @@ error:
     return -1;
 }
 
+void ecs_filter_copy(
+    ecs_filter_t *dst,
+    const ecs_filter_t *src)   
+{
+    if (src) {
+        *dst = *src;
+
+        if (src->terms == src->term_cache) {
+            dst->terms = dst->term_cache;
+        } else {
+            /* Copying allocated term arrays is unsupported at this moment */
+            ecs_abort(ECS_UNSUPPORTED, NULL);
+        }
+    } else {
+        ecs_os_memset_t(dst, 0, ecs_filter_t);
+    }
+}
+
+void ecs_filter_move(
+    ecs_filter_t *dst,
+    ecs_filter_t *src)   
+{
+    if (src) {
+        *dst = *src;
+
+        if (src->terms == src->term_cache) {
+            dst->terms = dst->term_cache;
+        }
+
+        src->terms = NULL;
+        src->term_count = 0;
+    } else {
+        ecs_os_memset_t(dst, 0, ecs_filter_t);
+    }
+}
+
 void ecs_filter_fini(
     ecs_filter_t *filter) 
 {
@@ -17195,6 +17238,10 @@ bool flecs_filter_match_table(
             result = !result;
         }
 
+        if (oper == EcsOptional) {
+            result = true;
+        }
+
         if (is_or) {
             or_result |= result;
         } else if (!result) {
@@ -17215,16 +17262,14 @@ bool flecs_filter_match_table(
             int32_t t_i = term->index;
 
             void **ptr = ptrs ? &ptrs[t_i] : NULL;
-            bool has_data = populate_from_column(world, table, term->id, column, 
+            populate_from_column(world, table, term->id, column, 
                 source, &ids[t_i], &types[t_i], &subjects[t_i], &sizes[t_i], 
                 ptr);
 
-            if (!source) {
-                if (has_data) {
-                    columns[t_i] = column + 1;
-                } else {
-                    columns[t_i] = 0;
-                }
+            if (column != -1) {
+                columns[t_i] = column + 1;
+            } else {
+                columns[t_i] = 0;
             }
         }
     }
@@ -17427,7 +17472,7 @@ ecs_iter_t ecs_filter_iter(
     const ecs_filter_t *filter)
 {
     ecs_assert(world != NULL, ECS_INVALID_PARAMETER, NULL);
-    
+
     ecs_iter_t it = {
         .world = world
     };
@@ -19717,8 +19762,6 @@ add_pair:
                 references = add_ref(world, query, references, term,
                     component, entity);
                 table_data.columns[c] = -ecs_vector_count(references);
-            } else {
-                table_data.columns[c] = 0;
             }
 
             table_data.subjects[c] = entity;
@@ -19729,9 +19772,7 @@ add_pair:
             const EcsComponent *cptr = ecs_get(world, type_id, EcsComponent);
             if (!cptr || !cptr->size) {
                 int32_t column = table_data.columns[c];
-                if (column > 0) {
-                    table_data.columns[c] = 0;
-                } else if (column) {
+                if (column < 0) {
                     ecs_ref_t *r = ecs_vector_get(
                         references, ecs_ref_t, -column - 1);
                     r->component = 0;
@@ -21877,11 +21918,12 @@ void mark_columns_dirty(
         for (i = 0; i < count; i ++) {
             ecs_term_t *term = &terms[i];
             ecs_term_id_t *subj = &term->args[0];
+
             if (term->inout != EcsIn && (term->inout != EcsInOutDefault || 
                 (subj->entity == EcsThis && subj->set.mask == EcsSelf)))
             {
                 int32_t table_column = table_data->columns[c];
-                if (table_column > 0) {
+                if (table_column > 0 && table_column <= table->column_count) {
                     table->dirty_state[table_column] ++;
                 }
             }
@@ -23708,6 +23750,7 @@ bool ecs_term_is_owned(
     int32_t term)
 {
     ecs_assert(it->is_valid, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(term > 0, ECS_INVALID_PARAMETER, NULL);
     return it->subjects == NULL || it->subjects[term - 1] == 0;
 }
 
@@ -23716,6 +23759,7 @@ bool ecs_term_is_readonly(
     int32_t term_index)
 {
     ecs_assert(it->is_valid, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(term_index > 0, ECS_INVALID_PARAMETER, NULL);
 
     ecs_query_t *query = it->query;
 
@@ -23743,10 +23787,21 @@ bool ecs_term_is_readonly(
             }
         }
     }
-    
+
     return false;
 }
 
+bool ecs_term_is_set(
+    const ecs_iter_t *it,
+    int32_t term)
+{
+    ecs_assert(it->is_valid, ECS_INVALID_PARAMETER, NULL);
+    ecs_assert(it->columns != NULL, ECS_INTERNAL_ERROR, NULL);
+    ecs_assert(term > 0, ECS_INVALID_PARAMETER, NULL);
+
+    return it->columns[term - 1] != 0;
+}
+
 ecs_entity_t ecs_term_source(
     const ecs_iter_t *it,
     int32_t term)
@@ -24179,7 +24234,7 @@ ecs_entity_t ecs_trigger_init(
                 goto error;
             }
 
-            if (!ecs_term_is_set(&term)) {
+            if (!ecs_term_is_initialized(&term)) {
                 ecs_parser_error(
                     name, expr, 0, "invalid empty trigger expression");
                 goto error;
diff --git a/code/vendors/flecs/flecs.h b/code/vendors/flecs/flecs.h
index a007cf8..3694dc7 100644
--- a/code/vendors/flecs/flecs.h
+++ b/code/vendors/flecs/flecs.h
@@ -1109,6 +1109,8 @@ private:
     int m_index;
 };
 
+/* C++ class mainly used as wrapper around internal ecs_vector_t. Do not use
+ * this class as a replacement for STL datastructures! */
 template <typename T>
 class vector {
 public:
@@ -1150,6 +1152,10 @@ public:
         ecs_vector_clear(m_vector);
     }
 
+    void destruct() {
+        ecs_vector_free(m_vector);
+    }
+
     void add(T& value) {
         T* elem = static_cast<T*>(_ecs_vector_add(&m_vector, ECS_VECTOR_T(T)));
         *elem = value;
@@ -1402,6 +1408,8 @@ void ecs_map_memory(
 
 namespace flecs {
 
+/* C++ class mainly used as wrapper around internal ecs_map_t. Do not use
+ * this class as a replacement for STL datastructures! */
 template <typename K, typename T>
 class map {
 public:
@@ -1437,6 +1445,10 @@ public:
             reinterpret_cast<ecs_map_key_t>(key)));
     }
 
+    void destruct() {
+        ecs_map_free(m_map);
+    }
+
 private:
     void init(size_t count) {
         m_map = ecs_map_new(T, static_cast<ecs_size_t>(count));
@@ -2549,6 +2561,7 @@ struct ecs_iter_t {
 
     ecs_table_t *table;           /**< Current table */
     ecs_data_t *data;
+    
     ecs_id_t *ids;
     ecs_type_t *types;
     int32_t *columns;
@@ -6061,7 +6074,7 @@ bool ecs_term_id_is_set(
  * @return True when set, false when not set.
  */
 FLECS_API
-bool ecs_term_is_set(
+bool ecs_term_is_initialized(
     const ecs_term_t *term);
 
 /** Test whether a term is a trivial term.
@@ -6166,6 +6179,15 @@ bool ecs_id_match(
     ecs_id_t id,
     ecs_id_t pattern);
 
+/** Utility to check if id is a pair.
+ *
+ * @param id The id.
+ * @return True if id is a pair.
+ */
+FLECS_API
+bool ecs_id_is_pair(
+    ecs_id_t id);
+
 /** Utility to check if id is a wildcard.
  *
  * @param id The id.
@@ -6272,6 +6294,18 @@ FLECS_API
 bool ecs_filter_next(
     ecs_iter_t *iter);
 
+/** Move resources of one filter to another. */
+FLECS_API
+void ecs_filter_move(
+    ecs_filter_t *dst,
+    ecs_filter_t *src);
+
+/** Copy resources of one filter to another. */
+FLECS_API
+void ecs_filter_copy(
+    ecs_filter_t *dst,
+    const ecs_filter_t *src);
+
 /** @} */
 
 /**
@@ -6673,6 +6707,20 @@ bool ecs_term_is_readonly(
     const ecs_iter_t *it,
     int32_t index);    
 
+/** Test whether term is set.
+ * This function returns false for terms with the Not operator and for terms
+ * with the Optional operator if the matched entities (table) do not have the
+ * (component) id of the term. 
+ *
+ * @param it The iterator.
+ * @param term The term.
+ * @return True if term is set, false if it is not set.
+ */
+FLECS_API
+bool ecs_term_is_set(
+    const ecs_iter_t *it,
+    int32_t term);
+
 /** Test whether the term is owned
  * This operation returns whether the term is owned by the currently iterated
  * entity. This function will return false when the term is owned by another
@@ -9248,13 +9296,15 @@ class type;
 class pipeline;
 class iter;
 class term;
-class filter;
 class filter_iterator;
 class child_iterator;
 class world_filter;
 class snapshot_filter;
 class query_base;
 
+template<typename ... Components>
+class filter;
+
 template<typename ... Components>
 class query;
 
@@ -9264,6 +9314,9 @@ class system;
 template<typename ... Components>
 class observer;
 
+template <typename ... Components>
+class filter_builder;
+
 template <typename ... Components>
 class query_builder;
 
@@ -9448,6 +9501,7 @@ using std::is_const;
 using std::is_pointer;
 using std::is_reference;
 using std::is_volatile;
+using std::is_same;
 
 
 // Apply cv modifiers from source type to destination type
@@ -9966,6 +10020,7 @@ struct function_traits
 
 } // _
 
+
 template <typename T>
 struct is_callable {
     static constexpr bool value = _::function_traits<T>::is_callable;
@@ -9982,6 +10037,23 @@ using return_type_t = typename _::function_traits<T>::return_type;
 template <typename T>
 using arg_list_t = typename _::function_traits<T>::args;
 
+
+template<typename Func, typename ... Args>
+struct first_arg_impl;
+
+template<typename Func, typename T, typename ... Args>
+struct first_arg_impl<Func, _::arg_list<T, Args ...> > {
+    using type = T;
+};
+
+template<typename Func>
+struct first_arg {
+    using type = typename first_arg_impl<Func, arg_list_t<Func>>::type;
+};
+
+template <typename Func>
+using first_arg_t = typename first_arg<Func>::type;
+
 } // flecs
 namespace flecs 
 {
@@ -10826,14 +10898,14 @@ public:
      */
     bool is_owned(int32_t index) const {
         return ecs_term_is_owned(m_iter, index);
-    }    
+    }
 
     /** Returns whether term is set.
      * 
      * @param index The term index.
      */
     bool is_set(int32_t index) const {
-        return ecs_term_w_size(m_iter, 0, index) != NULL;
+        return ecs_term_is_set(m_iter, index);
     }
 
     /** Returns whether term is readonly.
@@ -11744,89 +11816,6 @@ public:
      */
     void use(flecs::entity entity, const char *alias = nullptr);   
 
-    /** Delete all entities matching a filter.
-     *
-     * @param filter The filter to use for matching.
-     */
-    void delete_entities(flecs::filter filter) const;
-
-    /** Add component to all entities matching a filter.
-     *
-     * @tparam T The component to add.
-     * @param filter The filter to use for matching.
-     */
-    template <typename T>
-    void add(flecs::filter filter) const;
-
-    /** Add type to all entities.
-     *
-     * @param type The type to add.
-     */
-    void add(flecs::type type) const;
-
-    /** Add type to all entities matching a filter.
-     *
-     * @param type The type to add.
-     * @param filter The filter to use for matching.
-     */    
-    void add(flecs::type type, flecs::filter filter) const;
-
-    /** Add entity to all entities.
-     *
-     * @param entity The entity to add.
-     */
-    void add(flecs::entity entity) const;
-
-    /** Add entity to all entities matching a filter.
-     *
-     * @param entity The entity to add.
-     * @param filter The filter to use for matching.
-     */    
-    void add(flecs::entity entity, flecs::filter filter) const;
-
-    /** Remove component from all entities matching a filter.
-     *
-     * @tparam T The component to remove.
-     * @param filter The filter to use for matching.
-     */    
-    template <typename T>
-    void remove(flecs::filter filter) const;
-
-    /** Remove type from all entities.
-     *
-     * @param type The component to remove.
-     */ 
-    void remove(flecs::type type) const;
-
-    /** Remove type from all entities matching a filter.
-     *
-     * @tparam T The component to remove.
-     * @param filter The filter to use for matching.
-     */     
-    void remove(flecs::type type, flecs::filter filter) const;
-
-    /** Remove entity from all entities.
-     *
-     * @param entity The entity to remove.
-     */ 
-    void remove(flecs::entity entity) const;
-
-    /** Remove entity from all entities matching a filter.
-     *
-     * @param entity The entity to remove.
-     * @param filter The filter to use for matching.
-     */     
-    void remove(flecs::entity entity, flecs::filter filter) const;
-
-    /** Create iterable filter for entities in world.
-     *
-     * @param filter The filter to create.
-     */ 
-    world_filter filter(const flecs::filter& filter) const;
-
-    flecs::filter_iterator begin() const;
-    flecs::filter_iterator end() const;
-
     /** Count entities matching a component.
      *
      * @tparam T The component to use for matching.
@@ -11836,11 +11825,8 @@ public:
         return ecs_count_id(m_world, _::cpp_type<T>::id(m_world));
     }
 
-    /** Count entities matching a filter.
-     *
-     * @param filter The filter to use for matching.
-     */
-    int count(flecs::filter filter) const;
+    flecs::filter_iterator begin() const;
+    flecs::filter_iterator end() const;
 
     /** Enable locking.
      * 
@@ -11920,6 +11906,9 @@ public:
     }
 
     /** Iterate over all entities with provided component.
+     * The function parameter must match the following signature:
+     *   void(*)(T&) or
+     *   void(*)(flecs::entity, T&)
      */
     template <typename T, typename Func>
     void each(Func&& func) const;
@@ -11929,6 +11918,14 @@ public:
     template <typename Func>
     void each(flecs::id_t term_id, Func&& func) const;
 
+    /** Iterate over all entities with components in argument list of function.
+     * The function parameter must match the following signature:
+     *   void(*)(T&, U&, ...) or
+     *   void(*)(flecs::entity, T&, U&, ...)
+     */
+    template <typename Func>
+    void each(Func&& func) const;
+
     /** Create a prefab.
      */
     template <typename... Args>
@@ -11973,6 +11970,16 @@ public:
     template <typename... Comps, typename... Args>
     flecs::observer_builder<Comps...> observer(Args &&... args) const;
 
+    /** Create a filter.
+     */
+    template <typename... Comps, typename... Args>
+    flecs::filter<Comps...> filter(Args &&... args) const;
+
+    /** Create a filter builder.
+     */
+    template <typename... Comps, typename... Args>
+    flecs::filter_builder<Comps...> filter_builder(Args &&... args) const;
+
     /** Create a query.
      */
     template <typename... Comps, typename... Args>
@@ -15472,7 +15479,7 @@ public:
     }
 
     bool is_set() {
-        return ecs_term_is_set(&value);
+        return ecs_term_is_initialized(&value);
     }
 
     bool is_trivial() {
@@ -15522,7 +15529,7 @@ public:
         ecs_assert(term_index > 0, ECS_INVALID_PARAMETER, NULL);
         m_term_index = term_index - 1;
         this->term();
-        ecs_assert(ecs_term_is_set(this->m_term), ECS_INVALID_PARAMETER, NULL);
+        ecs_assert(ecs_term_is_initialized(this->m_term), ECS_INVALID_PARAMETER, NULL);
         return *this;
     }    
 
@@ -15916,6 +15923,66 @@ private:
     int32_t m_event_count;
 };
 
+// Filter builder
+template<typename ... Components>
+class filter_builder_base
+    : public filter_builder_i<filter_builder_base<Components...>, Components ...>
+{
+public:
+    filter_builder_base(flecs::world_t *world) 
+        : filter_builder_i<filter_builder_base<Components...>, Components ...>(&m_desc)
+        , m_desc({})
+        , m_world(world)
+    { 
+        this->populate_filter_from_pack();
+    }
+
+    filter_builder_base(const filter_builder_base& obj) 
+        : filter_builder_i<filter_builder_base<Components...>, Components ...>(&m_desc, obj.m_term_index)
+    {
+        m_world = obj.m_world;
+        m_desc = obj.m_desc;
+    }
+
+    filter_builder_base(filter_builder_base&& obj) 
+        : filter_builder_i<filter_builder_base<Components...>, Components ...>(&m_desc, obj.m_term_index)
+    {
+        m_world = obj.m_world;
+        m_desc = obj.m_desc;
+    }
+
+    operator filter<Components ...>() const;
+
+    operator ecs_filter_t() const {
+        ecs_filter_t f;
+
+        int res = ecs_filter_init(this->m_world, &f, &this->m_desc);
+        if (res != 0) {
+            ecs_abort(ECS_INVALID_PARAMETER, NULL);
+        }
+
+        return f;
+    }    
+
+    filter<Components ...> build() const;
+
+    ecs_filter_desc_t m_desc;
+
+    flecs::world_t* world() override { return m_world; }
+
+protected:
+    flecs::world_t *m_world;
+};
+
+template<typename ... Components>
+class filter_builder final : public filter_builder_base<Components...> {
+public:
+    filter_builder(flecs::world_t *world)
+        : filter_builder_base<Components ...>(world) { }
+
+    operator filter<>() const;
+};
+
 // Query builder
 template<typename ... Components>
 class query_builder_base
@@ -16025,7 +16092,7 @@ private:
         if (is_trigger) {
             ecs_trigger_desc_t desc = {};
             ecs_term_t term = m_desc.query.filter.terms[0];
-            if (ecs_term_is_set(&term)) {
+            if (ecs_term_is_initialized(&term)) {
                 desc.term = term;
             } else {
                 desc.expr = m_desc.query.filter.expr;
@@ -16458,94 +16525,157 @@ flecs::entity import(world& world) {
 }
 
 } // namespace flecs
-
 namespace flecs 
 {
 
 ////////////////////////////////////////////////////////////////////////////////
-//// A filter is used to match subsets of tables
+//// Ad hoc queries (filters)
 ////////////////////////////////////////////////////////////////////////////////
- 
-enum match_kind {
-    MatchAll = EcsMatchAll,
-    MatchAny = EcsMatchAny,
-    MatchExact = EcsMatchExact
-};
 
-class filter {
+class filter_base {
 public:
-    filter() 
-        : m_world( nullptr )
-        , m_filter{ } {}
-
-    explicit filter(const world& world) 
-        : m_world( world.c_ptr() )
-        , m_filter{ } { }
-
-    filter& include(type type) {
-        m_filter.include = ecs_type_merge(m_world, m_filter.include, type.c_ptr(), nullptr);
-        return *this;
-    }
-
-    filter& include(entity entity) {
-        m_filter.include = ecs_type_add(m_world, m_filter.include, entity.id());
-        return *this;
-    }
-
-    template <typename T>
-    filter& include() {
-        m_filter.include = ecs_type_add(m_world, m_filter.include, _::cpp_type<T>::id(m_world));
-        return *this;
-    }
-
-    filter& include_kind(match_kind kind) {
-        m_filter.include_kind = static_cast<ecs_match_kind_t>(kind);
-        return *this;
-    }
-
-    type include() {
-        return type(m_world, m_filter.include);
-    }
-
-    filter& exclude(type type) {
-        m_filter.exclude = ecs_type_merge(m_world, m_filter.exclude, type.c_ptr(), nullptr);
-        return *this;
-    }
-
-    filter& exclude(entity entity) {
-        m_filter.exclude = ecs_type_add(m_world, m_filter.exclude, entity.id());
-        return *this;
-    }
-
-    template <typename T>
-    filter& exclude() {
-        m_filter.exclude = ecs_type_add(m_world, m_filter.exclude, _::cpp_type<T>::id(m_world));
-        return *this;
-    }
- 
-    filter& exclude_kind(match_kind kind) {
-        m_filter.exclude_kind = static_cast<ecs_match_kind_t>(kind);
-        return *this;
-    }
-
-    type exclude() {
-        return type(m_world, m_filter.exclude);
-    }  
+    filter_base()
+        : m_world(nullptr)
+        , m_filter({}) { }   
+    
+    filter_base(world_t *world, ecs_filter_t *filter = NULL)
+        : m_world(world) {
+            ecs_filter_move(&m_filter, filter);
+        }
 
+    /** Get pointer to C filter object.
+     */
     const filter_t* c_ptr() const {
-        if (m_world) {
+        if (m_filter.term_count) {
             return &m_filter;
         } else {
-            return nullptr;
+            return NULL;
         }
     }
 
-private:
+    filter_base(const filter_base& obj) {
+        this->m_world = obj.m_world;
+        ecs_filter_copy(&m_filter, &obj.m_filter);
+    }
+
+    filter_base& operator=(const filter_base& obj) {
+        this->m_world = obj.m_world;
+        ecs_filter_copy(&m_filter, &obj.m_filter);
+        return *this; 
+    }
+
+    filter_base(filter_base&& obj) {
+        this->m_world = obj.m_world;
+        ecs_filter_move(&m_filter, &obj.m_filter);
+    }
+
+    filter_base& operator=(filter_base&& obj) {
+        this->m_world = obj.m_world;
+        ecs_filter_move(&m_filter, &obj.m_filter);
+        return *this; 
+    }
+
+
+    /** Free the filter.
+     */
+    ~filter_base() {
+        ecs_filter_fini(&m_filter);
+    }
+
+    template <typename Func>
+    void iter(Func&& func) const {
+        ecs_iter_t it = ecs_filter_iter(m_world, &m_filter);
+        while (ecs_filter_next(&it)) {
+            _::iter_invoker<Func>(func).invoke(&it);
+        }
+    }  
+
+    template <typename Func>
+    void each_term(const Func& func) {
+        for (int i = 0; i < m_filter.term_count; i ++) {
+            flecs::term t(m_world, m_filter.terms[i]);
+            func(t);
+        }
+    }
+
+    flecs::term term(int32_t index) {
+        return flecs::term(m_world, m_filter.terms[index]);
+    }
+
+    int32_t term_count() {
+        return m_filter.term_count;
+    }
+
+    flecs::string str() {
+        char *result = ecs_filter_str(m_world, &m_filter);
+        return flecs::string(result);
+    }
+
+protected:
     world_t *m_world;
     filter_t m_filter;
 };
 
-} // namespace flecs
+
+template<typename ... Components>
+class filter : public filter_base {
+    using Terms = typename _::term_ptrs<Components...>::array;
+
+public:
+    filter() { }
+
+    filter(world_t *world, filter_t *f)
+        : filter_base(world, f) { }
+
+    explicit filter(const world& world, const char *expr = nullptr) 
+        : filter_base(world.c_ptr())
+    {
+        auto qb = world.filter_builder<Components ...>()
+            .expr(expr);
+
+        if (!expr) {
+            qb.substitute_default();
+        }
+
+        flecs::filter_t f = qb;
+        ecs_filter_move(&m_filter, &f);
+    }
+
+    filter(const filter& obj) : filter_base(obj) { }
+
+    filter& operator=(const filter& obj) {
+        *this = obj;
+        return *this;
+    }
+
+    filter(filter&& obj) : filter_base(std::move(obj)) { }
+
+    filter& operator=(filter&& obj) {
+        filter_base(std::move(obj));
+        return *this;
+    }
+
+    template <typename Func>
+    void each(Func&& func) const {
+        iterate<_::each_invoker>(std::forward<Func>(func), ecs_filter_next);
+    } 
+
+    template <typename Func>
+    void iter(Func&& func) const { 
+        iterate<_::iter_invoker>(std::forward<Func>(func), ecs_filter_next);
+    }
+
+private:
+    template < template<typename Func, typename ... Comps> class Invoker, typename Func, typename NextFunc, typename ... Args>
+    void iterate(Func&& func, NextFunc next, Args &&... args) const {
+        ecs_iter_t it = ecs_filter_iter(m_world, &m_filter);
+        while (next(&it, std::forward<Args>(args)...)) {
+            Invoker<Func, Components...>(std::move(func)).invoke(&it);
+        }
+    }
+};
+
+}
 
 namespace flecs 
 {
@@ -16596,15 +16726,17 @@ public:
         m_snapshot = ecs_snapshot_take(m_world.c_ptr());
     }
 
-    void take(flecs::filter filter) {
+    template <typename F>
+    void take(const F& f) {
         if (m_snapshot) {
             ecs_snapshot_free(m_snapshot);
         }
 
-        ecs_iter_t it = ecs_filter_iter(m_world.c_ptr(), filter.c_ptr());
-        m_snapshot = ecs_snapshot_take_w_iter(
-            &it, ecs_filter_next);
-    }
+        ecs_iter_t it = ecs_filter_iter(m_world, f.c_ptr());
+
+        printf("filter = %s\n", ecs_filter_str(m_world, f.c_ptr()));
+        m_snapshot = ecs_snapshot_take_w_iter(&it, ecs_filter_next);
+    }    
 
     void restore() {
         if (m_snapshot) {
@@ -16623,8 +16755,6 @@ public:
         return m_snapshot;
     }
 
-    snapshot_filter filter(const filter& filter);
-
     filter_iterator begin();
 
     filter_iterator end();
@@ -16651,17 +16781,17 @@ public:
         , m_iter{ } 
         , m_action(action) { }
 
-    filter_iterator(const world& world, const filter& filter, ecs_iter_next_action_t action)
+    filter_iterator(const world& world, ecs_iter_next_action_t action)
         : m_world( world.c_ptr() )
-        , m_iter( ecs_filter_iter(m_world, filter.c_ptr()) ) 
+        , m_iter( ecs_filter_iter(m_world, NULL) ) 
         , m_action(action)
     { 
         m_has_next = m_action(&m_iter);
     }
 
-    filter_iterator(const world& world, const snapshot& snapshot, const filter& filter, ecs_iter_next_action_t action) 
+    filter_iterator(const world& world, const snapshot& snapshot, ecs_iter_next_action_t action) 
         : m_world( world.c_ptr() )
-        , m_iter( ecs_snapshot_iter(snapshot.c_ptr(), filter.c_ptr()) )
+        , m_iter( ecs_snapshot_iter(snapshot.c_ptr(), NULL) )
         , m_action(action)
     {
         m_has_next = m_action(&m_iter);
@@ -16723,18 +16853,18 @@ private:
     ecs_iter_t m_iter;
 };
 
+
 ////////////////////////////////////////////////////////////////////////////////
 //// Utility for creating a world-based filter iterator
 ////////////////////////////////////////////////////////////////////////////////
 
 class world_filter {
 public:
-    world_filter(const world& world, const filter& filter) 
-        : m_world( world )
-        , m_filter( filter ) { }
+    world_filter(const world& world) 
+        : m_world( world ) { }
 
     inline filter_iterator begin() const {
-        return filter_iterator(m_world, m_filter, ecs_filter_next);
+        return filter_iterator(m_world, ecs_filter_next);
     }
 
     inline filter_iterator end() const {
@@ -16743,7 +16873,6 @@ public:
 
 private:
     const world& m_world;
-    const filter& m_filter;
 };
 
 
@@ -16753,13 +16882,12 @@ private:
 
 class snapshot_filter {
 public:
-    snapshot_filter(const world& world, const snapshot& snapshot, const filter& filter) 
+    snapshot_filter(const world& world, const snapshot& snapshot) 
         : m_world( world )
-        , m_snapshot( snapshot )
-        , m_filter( filter ) { }
+        , m_snapshot( snapshot ) { }
 
     inline filter_iterator begin() const {
-        return filter_iterator(m_world, m_snapshot, m_filter, ecs_snapshot_next);
+        return filter_iterator(m_world, m_snapshot, ecs_snapshot_next);
     }
 
     inline filter_iterator end() const {
@@ -16769,7 +16897,6 @@ public:
 private:
     const world& m_world;
     const snapshot& m_snapshot;
-    const filter& m_filter;
 };
 
 
@@ -16801,12 +16928,8 @@ private:
 //// Filter fwd declared functions
 ////////////////////////////////////////////////////////////////////////////////
 
-inline snapshot_filter snapshot::filter(const flecs::filter& filter) {
-    return snapshot_filter(m_world, *this, filter);
-}
-
 inline filter_iterator snapshot::begin() {
-    return filter_iterator(m_world, *this, flecs::filter(m_world), ecs_snapshot_next);
+    return filter_iterator(m_world, *this, ecs_snapshot_next);
 }
 
 inline filter_iterator snapshot::end() {
@@ -17022,13 +17145,6 @@ public:
         iterate<_::each_invoker>(std::forward<Func>(func), ecs_query_next);
     } 
 
-    template <typename Func>
-    void each(const flecs::filter& filter, Func&& func) const {
-        const filter_t* filter_ptr = filter.c_ptr();
-        iterate<_::each_invoker>(std::forward<Func>(func), 
-            ecs_query_next_w_filter, filter_ptr);
-    }
-
     template <typename Func>
     void each_worker(int32_t stage_current, int32_t stage_count, Func&& func) const {
         iterate<_::each_invoker>(std::forward<Func>(func), 
@@ -17040,13 +17156,6 @@ public:
         iterate<_::iter_invoker>(std::forward<Func>(func), ecs_query_next);
     }
 
-    template <typename Func>
-    void iter(const flecs::filter& filter, Func&& func) const {
-        const filter_t* filter_ptr = filter.c_ptr();
-        iterate<_::iter_invoker>(std::forward<Func>(func), 
-            ecs_query_next_w_filter, filter_ptr);
-    }
-
     template <typename Func>
     void iter_worker(int32_t stage_current, int32_t stage_count, Func&& func) const {
         iterate<_::iter_invoker>(std::forward<Func>(func), 
@@ -17097,8 +17206,9 @@ public:
         , m_stage_current(stage_current)
         , m_stage_count(stage_count) { }
 
-    system_runner_fluent& filter(filter filter) {
-        m_filter = filter;
+    template <typename F>
+    system_runner_fluent& filter(const F& f) {
+        m_filter = f;
         return *this;
     }
 
@@ -17128,12 +17238,13 @@ public:
                 m_filter.c_ptr(), m_param);
         }
     }
+
 private:
     world_t *m_stage;
     entity_t m_id;
     FLECS_FLOAT m_delta_time;
     void *m_param;
-    flecs::filter m_filter;
+    flecs::filter<> m_filter;
     int32_t m_offset;
     int32_t m_limit;
     int32_t m_stage_current;
@@ -17746,70 +17857,14 @@ inline flecs::id world::pair(entity_t r, entity_t o) const {
         ecs_pair(r, o));
 }    
 
-inline void world::delete_entities(flecs::filter filter) const {
-    ecs_bulk_delete(m_world, filter.c_ptr());
-}
-
-template <typename T>
-inline void world::add(flecs::filter filter) const {
-    ecs_bulk_add_remove_type(
-        m_world, _::cpp_type<T>::type(m_world), nullptr, filter.c_ptr());
-}
-
-inline void world::add(flecs::type t) const {
-    ecs_bulk_add_remove_type(m_world, t.c_ptr(), nullptr, nullptr);
-}
-
-inline void world::add(flecs::type t, flecs::filter filter) const {
-    ecs_bulk_add_remove_type(m_world, t.c_ptr(), nullptr, filter.c_ptr());
-}
-
-inline void world::add(class flecs::entity e) const {
-    ecs_bulk_add_remove_type(m_world, e.to_type().c_ptr(), nullptr, nullptr);
-}
-
-inline void world::add(class flecs::entity e, flecs::filter filter) const {
-    ecs_bulk_add_remove_type(m_world, e.to_type().c_ptr(), nullptr, filter.c_ptr());
-}
-
-template <typename T>
-inline void world::remove(flecs::filter filter) const {
-    ecs_bulk_add_remove_type(
-        m_world, nullptr, _::cpp_type<T>::type(m_world), filter.c_ptr());
-}
-
-inline void world::remove(flecs::type t) const {
-    ecs_bulk_add_remove_type(m_world, nullptr, t.c_ptr(), nullptr);
-}
-
-inline void world::remove(flecs::type t, flecs::filter filter) const {
-    ecs_bulk_add_remove_type(m_world, nullptr, t.c_ptr(), filter.c_ptr());
-}
-
-inline void world::remove(class entity e) const {
-    ecs_bulk_add_remove_type(m_world, nullptr, e.to_type().c_ptr(), nullptr);
-}
-
-inline void world::remove(class entity e, flecs::filter filter) const {
-    ecs_bulk_add_remove_type(m_world, nullptr, e.to_type().c_ptr(), filter.c_ptr());
-}
-
-inline flecs::world_filter world::filter(const flecs::filter& filter) const {
-    return flecs::world_filter(*this, filter);
-}
-
 inline filter_iterator world::begin() const {
-    return filter_iterator(*this, flecs::filter(*this), ecs_filter_next);
+    return filter_iterator(*this, ecs_filter_next);
 }
 
 inline filter_iterator world::end() const {
     return filter_iterator(ecs_filter_next);
 }
 
-inline int world::count(flecs::filter filter) const {
-    return ecs_count_w_filter(m_world, filter.c_ptr());
-}
-
 /** All entities created in function are created in scope. All operations
     * called in function (such as lookup) are relative to scope.
     */
@@ -17957,6 +18012,16 @@ inline flecs::observer_builder<Comps...> world::observer(Args &&... args) const
     return flecs::observer_builder<Comps...>(*this, std::forward<Args>(args)...);
 }
 
+template <typename... Comps, typename... Args>
+inline flecs::filter<Comps...> world::filter(Args &&... args) const {
+    return flecs::filter<Comps...>(*this, std::forward<Args>(args)...);
+}
+
+template <typename... Comps, typename... Args>
+inline flecs::filter_builder<Comps...> world::filter_builder(Args &&... args) const {
+    return flecs::filter_builder<Comps...>(*this, std::forward<Args>(args)...);
+}
+
 template <typename... Comps, typename... Args>
 inline flecs::query<Comps...> world::query(Args &&... args) const {
     return flecs::query<Comps...>(*this, std::forward<Args>(args)...);
@@ -18020,7 +18085,7 @@ inline void world::each(Func&& func) const {
 
     while (ecs_term_next(&it)) {
         _::each_invoker<Func, T>(func).invoke(&it);
-    }        
+    }
 }
 
 template <typename Func>
@@ -18034,6 +18099,61 @@ inline void world::each(flecs::id_t term_id, Func&& func) const {
     }
 }
 
+namespace _ {
+
+// Each with entity parameter
+template<typename Func, typename ... Args>
+struct filter_invoker_w_ent;
+
+template<typename Func, typename E, typename ... Args>
+struct filter_invoker_w_ent<Func, arg_list<E, Args ...> >
+{
+    filter_invoker_w_ent(const flecs::world& world, Func&& func) {
+        flecs::filter<Args ...> f(world);
+        f.each(std::move(func));
+    }
+};
+
+// Each without entity parameter
+template<typename Func, typename ... Args>
+struct filter_invoker_no_ent;
+
+template<typename Func, typename ... Args>
+struct filter_invoker_no_ent<Func, arg_list<Args ...> >
+{
+    filter_invoker_no_ent(const flecs::world& world, Func&& func) {
+        flecs::filter<Args ...> f(world);
+        f.each(std::move(func));
+    }
+};
+
+// Switch between function with & without entity parameter
+template<typename Func, typename T = int>
+class filter_invoker;
+
+template <typename Func>
+class filter_invoker<Func, if_t<is_same<first_arg_t<Func>, flecs::entity>::value> > {
+public:
+    filter_invoker(const flecs::world& world, Func&& func) {
+        filter_invoker_w_ent<Func, arg_list_t<Func>>(world, std::move(func));
+    }
+};
+
+template <typename Func>
+class filter_invoker<Func, if_not_t<is_same<first_arg_t<Func>, flecs::entity>::value> > {
+public:
+    filter_invoker(const flecs::world& world, Func&& func) {
+        filter_invoker_no_ent<Func, arg_list_t<Func>>(world, std::move(func));
+    }
+};
+
+}
+
+template <typename Func>
+inline void world::each(Func&& func) const {
+    _::filter_invoker<Func> f_invoker(*this, std::move(func));
+}
+
 } // namespace flecs
 
 namespace flecs 
@@ -18046,6 +18166,24 @@ inline Base& term_builder_i<Base>::id(const flecs::type& type) {
     return *this;
 }      
 
+template <typename ... Components>
+inline filter_builder_base<Components...>::operator filter<Components ...>() const {
+    ecs_filter_t filter = *this;
+    return flecs::filter<Components...>(m_world, &filter);
+}
+
+template <typename ... Components>
+inline filter_builder<Components ...>::operator filter<>() const {
+    ecs_filter_t filter = *this;
+    return flecs::filter<>(this->m_world, &filter);
+}
+
+template <typename ... Components>
+inline filter<Components ...> filter_builder_base<Components...>::build() const {
+    ecs_filter_t filter = *this;
+    return flecs::filter<Components...>(m_world, &filter);
+}
+
 template <typename ... Components>
 inline query_builder_base<Components...>::operator query<Components ...>() const {
     ecs_query_t *query = *this;