Multithread texture loading

Twice faster
Thanks tatarinrafa, @qweasdd136963 for initial code and @jazzvaz for thread pool

src/Layers/xrRender/ResourceManager.cpp

@@ -14,6 +14,7 @@
 #include "tss.h"
 #include "blenders\blender.h"
 #include "blenders\blender_recorder.h"
+#include "xrCore/Threading/ThreadPool.hpp"
 
 //	Already defined in Texture.cpp
 void fix_texture_name(LPSTR fn);
@@ -337,14 +338,44 @@ void CResourceManager::Delete(const Shader* S)
     Msg("! ERROR: Failed to find complete shader");
 }
 
+xr_vector<CTexture*> textures_to_load;
+
+void LoadTextures(const size_t thread_num, const size_t textures_per_worker)
+{
+    const auto upperbound = thread_num * textures_per_worker;
+    const auto lowerbound = upperbound - textures_per_worker;
+    for (auto i = lowerbound; i < upperbound; i++)
+    {
+        if (i < textures_to_load.size())
+            textures_to_load[i]->Load();
+        else
+            break;
+    }
+}
+
 void CResourceManager::DeferredUpload()
 {
     if (!RDEVICE.b_is_Ready)
         return;
-    for (auto t = m_textures.begin(); t != m_textures.end(); t++)
-    {
-        t->second->Load();
-    }
+
+    Msg("%s, amount of textures = %d", __FUNCTION__ , m_textures.size());
+
+    CTimer timer;
+    timer.Start();
+
+    const auto nWorkers = ttapi.threads.size();
+    const auto textures_per_worker = m_textures.size() / nWorkers;
+
+    for (auto& t : m_textures)
+        textures_to_load.push_back(t.second);
+
+    for (auto i = 1; i < nWorkers; ++i)
+        ttapi.threads[i]->addJob([=] { LoadTextures(i, textures_per_worker); });
+
+    ttapi.wait();
+
+    textures_to_load.clear();
+    Msg("%s, texture loading time = %d", __FUNCTION__, timer.GetElapsed_ms());
 }
 /*
 void	CResourceManager::DeferredUnload	()