Merge pull request #15 from BlackMATov/dev

Dev

README.md

@@ -79,8 +79,8 @@ private:
 };
 
 ecs_hpp::registry world;
-world.add_system<movement_system>();
+world.add_system<movement_system>(0);
-world.add_system<gravity_system>(9.8f);
+world.add_system<gravity_system>(1, 9.8f);
 
 auto entity_one = world.create_entity();
 world.assign_component<position_component>(entity_one, 4.f, 2.f);
@@ -90,7 +90,7 @@ auto entity_two = world.create_entity();
 entity_two.assign_component<position_component>(4.f, 2.f);
 entity_two.assign_component<velocity_component>(10.f, 20.f);
 
-world.process_systems();
+world.process_all_systems();
 ```
 
 ## API

ecs.hpp

@@ -13,6 +13,7 @@
 #include <tuple>
 #include <memory>
 #include <vector>
+#include <limits>
 #include <utility>
 #include <iterator>
 #include <stdexcept>
@@ -41,6 +42,7 @@ namespace ecs_hpp
 
     using family_id = std::uint16_t;
     using entity_id = std::uint32_t;
+    using priority_t = std::int32_t;
 
     constexpr std::size_t entity_id_index_bits = 22u;
     constexpr std::size_t entity_id_version_bits = 10u;
@@ -1072,8 +1074,12 @@ namespace ecs_hpp
         void for_joined_components(F&& f) const;
 
         template < typename T, typename... Args >
-        void add_system(Args&&... args);
+        void add_system(priority_t priority, Args&&... args);
-        void process_systems();
+
+        void process_all_systems();
+        void process_systems_above(priority_t min);
+        void process_systems_below(priority_t max);
+        void process_systems_in_range(priority_t min, priority_t max);
     private:
         template < typename T >
         detail::component_storage<T>* find_storage_() noexcept;
@@ -1146,7 +1152,7 @@ namespace ecs_hpp
         detail::sparse_map<family_id, storage_uptr> storages_;
 
         using system_uptr = std::unique_ptr<system>;
-        std::vector<system_uptr> systems_;
+        std::vector<std::pair<priority_t, system_uptr>> systems_;
     };
 }
 
@@ -1831,14 +1837,44 @@ namespace ecs_hpp
     }
 
     template < typename T, typename... Args >
-    void registry::add_system(Args&&... args) {
+    void registry::add_system(priority_t priority, Args&&... args) {
-        systems_.emplace_back(
+        auto iter = std::upper_bound(
+            systems_.begin(), systems_.end(), priority,
+            [](priority_t pr, const auto& r){
+                return pr < r.first;
+            });
+        systems_.emplace(
+            iter,
+            priority,
             std::make_unique<T>(std::forward<Args>(args)...));
     }
 
-    inline void registry::process_systems() {
+    inline void registry::process_all_systems() {
-        for ( auto& s : systems_ ) {
+        process_systems_in_range(
-            s->process(*this);
+            std::numeric_limits<priority_t>::min(),
+            std::numeric_limits<priority_t>::max());
+    }
+
+    inline void registry::process_systems_above(priority_t min) {
+        process_systems_in_range(
+            min,
+            std::numeric_limits<priority_t>::max());
+    }
+
+    inline void registry::process_systems_below(priority_t max) {
+        process_systems_in_range(
+            std::numeric_limits<priority_t>::min(),
+            max);
+    }
+
+    inline void registry::process_systems_in_range(priority_t min, priority_t max) {
+        const auto first = std::lower_bound(
+            systems_.begin(), systems_.end(), min,
+            [](const auto& p, priority_t pr) noexcept {
+                return p.first < pr;
+            });
+        for ( auto iter = first; iter != systems_.end() && iter->first <= max; ++iter ) {
+            iter->second->process(*this);
         }
     }
 

ecs_tests.cpp

@@ -909,7 +909,7 @@ TEST_CASE("registry") {
             };
 
             ecs::registry w;
-            w.add_system<movement_system>();
+            w.add_system<movement_system>(0);
 
             auto e1 = w.create_entity();
             auto e2 = w.create_entity();
@@ -919,7 +919,7 @@ TEST_CASE("registry") {
             e2.assign_component<position_c>(5, 6);
             e2.assign_component<velocity_c>(7, 8);
 
-            w.process_systems();
+            w.process_all_systems();
 
             REQUIRE(e1.get_component<position_c>().x == 1 + 3);
             REQUIRE(e1.get_component<position_c>().y == 2 + 4);
@@ -927,6 +927,56 @@ TEST_CASE("registry") {
             REQUIRE(e2.get_component<position_c>().x == 5 + 7);
             REQUIRE(e2.get_component<position_c>().y == 6 + 8);
         }
+        {
+            class system_n : public ecs::system {
+            public:
+                system_n(int& i, int n) : i_(i), n_(n) {}
+                void process(ecs::registry&) override {
+                    i_ += n_;
+                }
+            private:
+                int& i_;
+                int n_;
+            };
+
+            int i = 0;
+            ecs::registry w;
+            w.add_system<system_n>(20, std::ref(i), 2);
+            w.add_system<system_n>(10, std::ref(i), 1);
+            REQUIRE(i == 0);
+            w.process_all_systems();
+            REQUIRE(i == 3);
+            w.process_systems_below(10);
+            REQUIRE(i == 4);
+            w.process_systems_above(20);
+            REQUIRE(i == 6);
+            w.process_systems_below(20);
+            REQUIRE(i == 9);
+            w.process_systems_above(10);
+            REQUIRE(i == 12);
+
+            w.process_systems_below(9);
+            w.process_systems_above(21);
+            REQUIRE(i == 12);
+
+            w.process_systems_in_range(0, 9);
+            w.process_systems_in_range(11, 19);
+            w.process_systems_in_range(21, 30);
+            REQUIRE(i == 12);
+
+            w.process_systems_in_range(0, 10);
+            REQUIRE(i == 13);
+            w.process_systems_in_range(10, 19);
+            REQUIRE(i == 14);
+            w.process_systems_in_range(10, 20);
+            REQUIRE(i == 17);
+            w.process_systems_in_range(20, 30);
+            REQUIRE(i == 19);
+            w.process_systems_in_range(10, 20);
+            REQUIRE(i == 22);
+            w.process_systems_in_range(0, 30);
+            REQUIRE(i == 25);
+        }
     }
 }
 
@@ -976,8 +1026,8 @@ TEST_CASE("example") {
     };
 
     ecs_hpp::registry world;
-    world.add_system<movement_system>();
+    world.add_system<movement_system>(0);
-    world.add_system<gravity_system>(9.8f);
+    world.add_system<gravity_system>(1, 9.8f);
 
     auto entity_one = world.create_entity();
     world.assign_component<position_component>(entity_one, 4.f, 2.f);
@@ -987,5 +1037,5 @@ TEST_CASE("example") {
     entity_two.assign_component<position_component>(4.f, 2.f);
     entity_two.assign_component<velocity_component>(10.f, 20.f);
 
-    world.process_systems();
+    world.process_all_systems();
 }