-fixed removingComponents issue (object was transferred to another block, but count of entities in block doesn't increase)

-functions to get System by ID or ECS System by Type
-added system_id to system
-fixed issue with registering systems without update() function

source/ecs/manager.d

@@ -57,13 +57,19 @@ class EntityManager
 
     void registerSystem(Sys)(int priority)
     {
-        alias types = Parameters!(Sys.update);
-        alias storages = ParameterStorageClassTuple!(Sys.update);
-
         alias STC = ParameterStorageClass;
 
         System system;
 
+        static if (!(hasMember!(Sys, "system_id")) || !is(typeof(Sys.system_id) == ushort))
+        {
+            static assert(0, "System should have \"__gshared ushort system_id");
+        }
+
+        static if (hasMember!(Sys, "update"))
+        {
+            alias types = Parameters!(Sys.update);
+            alias storages = ParameterStorageClassTuple!(Sys.update);
             static string genCall()()
             {
                 string ret = "s.update(*cast(Entity*)data_pointer,";
@@ -133,26 +139,6 @@ class EntityManager
                 return ret;
             }
 
-        static string catchFunc()(string member, string func)
-        {
-            string ret = "static if (hasMember!(Sys, \"" ~ func ~ "\"))
-            {
-                static void call" ~ func
-                ~ "(void* system_pointer)
-                {
-
-                    Sys* s = cast(Sys*) system_pointer;
-                    s." ~ func ~ "();
-                }
-
-                system."
-                ~ member ~ " = &call" ~ func ~ ";
-            }";
-            return ret;
-        }
-
-        static if (hasMember!(Sys, "update"))
-        {
             static void callUpdate(ref CallData data, void* entity)
             {
                 static if (hasMember!(Sys, "update"))
@@ -201,6 +187,24 @@ class EntityManager
             system.m_update = &callUpdate;
         }
 
+        static string catchFunc()(string member, string func)
+        {
+            string ret = "static if (hasMember!(Sys, \"" ~ func ~ "\"))
+            {
+                static void call" ~ func
+                ~ "(void* system_pointer)
+                {
+
+                    Sys* s = cast(Sys*) system_pointer;
+                    s." ~ func ~ "();
+                }
+
+                system."
+                ~ member ~ " = &call" ~ func ~ ";
+            }";
+            return ret;
+        }
+
         mixin(catchFunc("m_enable", "onEnable"));
         mixin(catchFunc("m_disable", "onDisable"));
         mixin(catchFunc("m_create", "onCreate"));
@@ -212,13 +216,17 @@ class EntityManager
         system.m_priority = priority;
 
         //system.m_components = Mallocator.instance.makeArray!uint(types.length - 1);
+        static if (hasMember!(Sys, "update"))
+        {
             mixin(genCompList());
+        }
         
         ushort sys_id = systems_map.get(Sys.stringof, ushort.max);
         if (sys_id < systems.length)
         {
             system.enable();
             systems[sys_id] = system;
+            Sys.system_id = sys_id;
         }
         else
         {
@@ -231,6 +239,8 @@ class EntityManager
 
             systems[$ - 1].enable();
 
+            Sys.system_id = cast(ushort)(systems.length - 1);
+
             foreach (info; &entities_infos.byValue)
             {
                 addEntityCaller(*info, cast(uint) systems.length - 1);
@@ -240,6 +250,16 @@ class EntityManager
         updateEntityCallers();
     }
 
+    System* getSystem(ushort id)
+    {
+        return &systems[id];
+    }
+
+    Sys* getSystem(Sys)()
+    {
+        return cast(Sys*)systems[Sys.system_id].system_pointer;
+    }
+
     void registerComponent(Comp)()
     {
         ComponentInfo info;
@@ -538,6 +558,8 @@ class EntityManager
                     cast(void*) entity + info.deltas[comp], components[comp].size);
         }
 
+        new_block.entities_count++;
+
         removeEntityNoID(entity, block);
     }
 

tests/tests.d

@@ -119,6 +119,13 @@ int main()
 
 		}
 
+		struct InputData
+		{
+			TestComp* test;
+			TestComp2* test2;
+			@("optional") TestComp3* test3;
+		}
+
 		void update(ref Entity entity, ref TestComp test, ref TestComp2 test2, TestComp3* test3) //ref TestComp comp)
 		{
 			assert(cast(size_t)&test % TestComp.alignof == 0);