From 46aba822d0a3024d7177261b18844e130a2ff65a Mon Sep 17 00:00:00 2001
From: Mergul <wismerchil@interia.eu>
Date: Wed, 6 May 2020 10:55:40 +0200
Subject: [PATCH] Improved documentation and removed some old code

---
 source/bubel/ecs/id_manager.d    | 27 ---------------------------
 source/bubel/ecs/simple_vector.d |  8 ++++++++
 source/bubel/ecs/system.d        | 26 +++++++++++++-------------
 3 files changed, 21 insertions(+), 40 deletions(-)

diff --git a/source/bubel/ecs/id_manager.d b/source/bubel/ecs/id_manager.d
index c8eadec..4c3a2c3 100644
--- a/source/bubel/ecs/id_manager.d
+++ b/source/bubel/ecs/id_manager.d
@@ -17,10 +17,6 @@ struct IDManager
     */
     pragma(inline, false) EntityID getNewID() nothrow @nogc
     {
-        //uint current = m_next_id;
-        //uint next;// = m_ids_array[m_next_id].next_id;
-//begin:
-        //if (current == uint.max)//> m_last_id)
         int current = m_stack_top.atomicOp!"-="(1) + 1;
         if(current < 0)
         {
@@ -48,29 +44,11 @@ struct IDManager
             return id;
         }
 
-
-        //current += 1;
         uint index = m_free_stack[current];
         EntityID id;
         id.id = index;
         id.counter = m_ids_array[index].counter;
-        //current = m_ids_array[index].next_id;
         return id;
-
-        /*next = m_ids_array[current].next_id;
-        if(cas(&m_next_id,current,next))
-        {
-            EntityID id;
-            id.id = current;
-            id.counter = m_ids_array[current].counter;
-            m_next_id = m_ids_array[current].next_id;
-            return id;
-        }
-        else 
-        {
-            current = next;
-            goto begin;
-        }*/
     }
 
     /************************************************************************************************************************
@@ -82,9 +60,7 @@ struct IDManager
         if (data.counter != id.counter)
             return;
         data.counter++;
-        //data.next_id = m_next_id;
         data.entity = null;
-        ///m_next_id = id.id;
 
         m_stack_top.atomicOp!"+="(1);
         m_free_stack[m_stack_top] = id.id;
@@ -241,13 +217,10 @@ struct IDManager
 
 private:
     Mutex* add_mutex;
-    //shared uint m_next_id = 0;
     
-    //shared uint m_last_id = 0;
     Data[] m_ids_array = null;
     uint m_blocks_count = 0;
     Block[] m_blocks;
-    //shared int m_stack_top = -1;
     uint[] m_free_stack = null;
     
     align(64) shared uint m_last_id = 0;
diff --git a/source/bubel/ecs/simple_vector.d b/source/bubel/ecs/simple_vector.d
index 28d4707..1de026e 100644
--- a/source/bubel/ecs/simple_vector.d
+++ b/source/bubel/ecs/simple_vector.d
@@ -4,11 +4,16 @@ import bubel.ecs.std;
 
 //import core.stdc.string;
 
+/************************************************************************************************************************
+Vector for byte data. Simpler than standard template-based implementation designed for better performance. \
+Rellocates 1024 elements at once instead of doubling size.
+*/
 struct SimpleVector
 {
 
     @disable this(this);
 
+    ///Add element to vector
     void add(ubyte el) nothrow @nogc
     {
         while(used >= data.length)
@@ -19,6 +24,7 @@ struct SimpleVector
         data[used++] = el;
     }
 
+    ///Add array of elements to vector
     void add(ubyte[] el) nothrow @nogc
     {
         while(used + el.length >= data.length)
@@ -30,6 +36,7 @@ struct SimpleVector
         used += el.length;
     }
 
+    ///Return vector length
     size_t length() nothrow @nogc
     {
         return used;
@@ -55,6 +62,7 @@ struct SimpleVector
 		return used;
 	}
 
+    ///set vector length to 0
     void clear() nothrow @nogc
     {
         used = 0;
diff --git a/source/bubel/ecs/system.d b/source/bubel/ecs/system.d
index 6452e6c..7343831 100644
--- a/source/bubel/ecs/system.d
+++ b/source/bubel/ecs/system.d
@@ -14,16 +14,16 @@ System contain data required to proper glue EntityManager with Systems.
 System callbacks:
 $(LIST
     * void onUpdate(EntitesData);
-    * void onEnable()
-    * void onDisable();
-    * bool onBegin();
-    * void onEnd();
-    * void onCreate()
-    * void onDestroy();
-    * void onAddEntity(EntitesData);
-    * void onRemoveEntity(EntitiesData);
-    * void onChangeEntity(EntitiesData);
-    * void handleEvent(Entity*, Event);
+    * void onEnable() - called inside system.enable() function
+    * void onDisable() - called inside system.disable() function
+    * bool onBegin() - called inside manager.begin()
+    * void onEnd() - called inside manager.end()
+    * void onCreate() - called after registration inside registerSystem function
+    * void onDestroy() - called during re-registration and inside manager destructor
+    * void onAddEntity(EntitesData) - called for every entity which are assigned to system (by adding new entity or changing its components)
+    * void onRemoveEntity(EntitiesData) - called for every entity removed from system update process
+    * void onChangeEntity(EntitiesData) - called for every entity which components are changed but it was previously assigned to system
+    * void handleEvent(Entity*, Event) - called for every event supported by system
 )
 */
 struct System
@@ -66,15 +66,15 @@ struct System
     }
 
     /************************************************************************************************************************
-    Get system priority.
+    Get if system will be executed during current frame. Should be checked after manager.begin(). Its value is setted as result of manager.onBegin() callback.
     */
-    export bool execute() nothrow @nogc
+    export bool willExecute() nothrow @nogc
     {
         return m_execute;
     }
 
     /************************************************************************************************************************
-    Get system priority.
+    Get system id.
     */
     export ushort id() nothrow @nogc
     {