diff --git a/resource/main.cpp b/resource/main.cpp
index 1fea482..9431a04 100644
--- a/resource/main.cpp
+++ b/resource/main.cpp
@@ -10,16 +10,14 @@ using namespace std;
 #include <unordered_map>\n\
 \n\
 namespace Resource {\n\
-typedef std::unordered_map<std::string, const char*> ResourceMap;\n"
-	
-#define FILE_END "\n\
-}\n\
-}\n"
+typedef std::unordered_map<std::string, const char*> ResourceMap;\n\
+typedef std::unordered_map<std::string, size_t> ResourceSizeMap;\n"
 
 unsigned int n = 0;
 
 bool addFile(const string &inFile, FILE *out)
 {
+    unsigned int size = 0;
     FILE *in = fopen(inFile.c_str(), "r");
     if(in == NULL)
     {
@@ -32,12 +30,14 @@ bool addFile(const string &inFile, FILE *out)
     do
     {
         nbRead = fread(ptr, sizeof(char), NB_VAL_PER_LINE, in);
+        size += nbRead;
         for(unsigned int i=0; i<nbRead; ++i)
             fprintf(out, i ? ",0x%x" : "\t0x%x", ptr[i]);
         fprintf(out, ",\n");
     }
     while(nbRead == NB_VAL_PER_LINE);
     fprintf(out, "\t0x00}; // additionnal byte used to null-terminate ascii data\n");
+    fprintf(out, "size_t data%d_size = %d;\n", n, size);
     ++n;
     fclose(in);
     return true;
@@ -93,10 +93,19 @@ int main(int argc, char *argv[])
             offsets.push_back(offset);
         }
     }
-	fprintf(out, "\nvoid getResourcePack_%s(ResourceMap &resourceFilesData)\n{\n", packName.c_str());
-	for(int i=0; i<int(n); ++i)
+    // create the function initializing the data pointers map
+    fprintf(out, "\nvoid getResourcePack_%s(ResourceMap &resourceFilesData)\n{\n", packName.c_str());
+    for(int i=0; i<int(n); ++i)
         fprintf(out, "\tresourceFilesData[\"%s\"] = data%d;\n", argv[3+i]+offsets[i], i);
-    fprintf(out, FILE_END);
+    fprintf(out, "}\n");
+
+    // create the function initializing the data size map
+    fprintf(out, "\nvoid getResourceSizes_%s(ResourceSizeMap &resourceFilesSizes)\n{\n", packName.c_str());
+    for(int i=0; i<int(n); ++i)
+        fprintf(out, "\tresourceFilesSizes[\"%s\"] = data%d_size;\n", argv[3+i]+offsets[i], i);
+    fprintf(out, "}\n");
+
+    fprintf(out, "}\n");
     fclose(out);
     printf("successfully created resource file \"%s\".\n", outFilename.c_str());
     return EXIT_SUCCESS;
diff --git a/resource/resource.h b/resource/resource.h
index 194b498..f6e872d 100644
--- a/resource/resource.h
+++ b/resource/resource.h
@@ -3,19 +3,26 @@
 
 #include <string>
 #include <unordered_map>
+#include <cstdio>
 
 #define RESOURCE_PACK(pack) namespace Resource {\
 void getResourcePack_ ## pack(ResourceMap &resourceFilesData);\
+void getResourceSizes_ ## pack(ResourceSizeMap &resourceFilesSizes);\
 }
 
 /**
  * To load an attached resource pack file, you must declare the pack with :
  *     RESOURCE_PACK(pack_name)
+ *
  * it will allow you to use the function :
  * 	   getResourcePack_pack_name(ResourceMap &map)
  * This function will give access the the embedded data through its original file name,
  * using the provided map.
  *
+ * it will also allow you to use the function :
+ * 	   getResourceSizes_pack_name(ResourceSizeMap &map)
+ * This function will give access the the size of the embedded data.
+ *
  * example :
  * RESOURCE_PACK(shaders) // declaring the resource pack function
  * Resource::ResourceMap myShaders; // defining a resource map
@@ -23,7 +30,59 @@ void getResourcePack_ ## pack(ResourceMap &resourceFilesData);\
  * string *shader = new string(myShaders["shaders/shaderFile.glsl"]); // getting a resource file
  */
 namespace Resource {
-    typedef std::unordered_map<std::string, const char*> ResourceMap;
-}
+
+typedef std::unordered_map<std::string, const char*> ResourceMap;
+typedef std::unordered_map<std::string, size_t> ResourceSizeMap;
+
+/*
+ * Reader is a wrapper that allows you to read files and resources exactly the same way
+ */
+
+class Reader
+{
+public:
+    /**
+     * inspired from cstdio standard fread
+     * http://www.cplusplus.com/reference/cstdio/fread
+     */
+    virtual size_t read (void * ptr, size_t size, size_t count) = 0;
+};
+
+class FileReader
+{
+    FILE* m_stream;
+
+public:
+    FileReader(FILE* stream) : m_stream(stream) {}
+
+    virtual size_t read (void * ptr, size_t size, size_t count)
+        { return fread ( ptr, size, count, m_stream ); }
+};
+
+class ResourceReader
+{
+    unsigned char* m_ptr;
+    size_t m_size;
+    size_t m_cursor;
+
+public:
+    ResourceReader(unsigned char* ptr, size_t size) : m_ptr(ptr), m_size(size), m_cursor(0) {}
+
+    virtual size_t read (void * ptr, size_t size, size_t count)
+    {
+        size_t nbRead = 0;
+        unsigned char* p = (unsigned char*)ptr;
+        while(m_cursor + size < m_size && nbRead < count)
+        {
+            for(size_t i=0; i<size; ++i)
+                p[nbRead*size + i] = m_ptr[m_cursor + i];
+            m_cursor += size;
+            ++nbRead;
+        }
+        return nbRead;
+    }
+};
+
+} // namespace Resource
 
 #endif // RES_H