From b4fcd415e4d9d3970574e5672e3b5e708bc67cbc Mon Sep 17 00:00:00 2001
From: "HuYingzhuo(hugo/hyzboy)" <hyzboy@gmail.com>
Date: Thu, 20 Jul 2023 14:26:18 +0800
Subject: [PATCH] added ArrayRearrangeHelper.h

---
 inc/hgl/type/ArrayRearrangeHelper.h | 154 ++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 inc/hgl/type/ArrayRearrangeHelper.h

diff --git a/inc/hgl/type/ArrayRearrangeHelper.h b/inc/hgl/type/ArrayRearrangeHelper.h
new file mode 100644
index 0000000..6580fba
--- /dev/null
+++ b/inc/hgl/type/ArrayRearrangeHelper.h
@@ -0,0 +1,154 @@
+#pragma once
+#include<initializer_list>
+
+namespace hgl
+{
+    /**
+    * 数组重新排列辅助类
+    */
+    class ArrayRearrangeHelper
+    {
+        int data_count;         ///<数据总量
+        int left_count;         ///<剩余数量
+        int data_offset;        ///<当前访问偏移
+
+        int field_count;        //分段数量
+        
+        struct Field
+        {
+            int start;
+            int count;
+        };
+        
+        Field *field_list;
+        int field_index;
+
+    public:
+
+        ArrayRearrangeHelper(int dc,int fc)
+        {
+            data_count=dc;
+            left_count=dc;
+            field_count=fc;
+            data_offset=0;
+
+            field_list=new Field[fc];
+
+            field_index=0;
+        }
+
+        ~ArrayRearrangeHelper()
+        {
+            delete[] field_list;
+        }
+
+        /**
+        * 添加一个分段
+        */
+        bool AddField(int count)
+        {
+            if(count<0)return(false);
+            if(count>left_count)return(false);
+            if(field_index>=field_count)return(false);
+
+            field_list[field_index].start=data_offset;
+            field_list[field_index].count=count;
+
+            data_offset+=count;
+            left_count-=count;
+            ++field_index;
+            return(true);
+        }
+
+        /**
+        * 添加多个分段
+        */
+        bool AddField(const std::initializer_list<int> &count_list)
+        {
+            for(const int count:count_list)
+                if(!AddField(count))
+                   return(false);
+
+            return(true);
+        }
+
+        /**
+        * 结束分段（如果还有剩余数据，将会被添加到最后一个分段）
+        */
+        bool Finish()
+        {
+            if(left_count>0)
+            {
+                if(field_index>=field_count)return(false);                
+
+                field_list[field_index].start=data_offset;
+                field_list[field_index].count=left_count;
+                ++field_index;
+            }
+
+            return(true);
+        }
+
+        void Reset()
+        {
+            data_offset=0;
+            left_count=data_count;
+            field_index=0;
+        }
+
+        /**
+        * 重新排列数据到一个新的数组中
+        */
+        template<typename T>
+        bool Rearrange(T *new_array,const T *old_array,const int *index)
+        {
+            if(!Finish())
+                return(false);
+
+            T *p=new_array;
+            Field *f;
+
+            for(int i=0;i<field_index;i++)
+            {
+                if(*index<0||*index>=field_index)
+                    return(false);
+
+                f=field_list+(*index);
+
+                hgl_cpy<T>(p,old_array+f->start,f->count);
+
+                p+=f->count;
+                ++index;
+            }
+
+            return(true);
+        }
+
+        template<typename T>
+        bool Rearrange(T *new_array,const T *old_array,const std::initializer_list<int> &index)
+        {
+            return Rearrange(new_array,old_array,index.begin());
+        }
+    };//class ArrayRearrangeHelper
+
+    template<typename T>
+    inline bool ArrayRearrange(T *new_array,const T *old_array,const int count,const std::initializer_list<int> &field_list,const std::initializer_list<int> &index)
+    {
+        int field_count=(int)field_list.size();
+
+        int total=0;
+
+        for(const int fc:field_list)total+=fc;
+
+        if(total<count)
+            ++field_count;
+
+        ArrayRearrangeHelper arh(count,field_count);
+
+        if(!arh.AddField(field_list))
+            return(false);
+
+        return arh.Rearrange(new_array,old_array,index);
+    }
+}//namespace hgl
+