Use dedicated function to handle sky textures

lib/graphics_engine/src/ge_main.cpp

@@ -0,0 +1,27 @@
+#include "ge_main.hpp"
+
+namespace GE
+{
+irr::video::IVideoDriver* g_driver = NULL;
+GEConfig g_config = {};
+
+void init(irr::video::IVideoDriver* driver)
+{
+    g_driver = driver;
+}
+
+irr::video::IVideoDriver* getDriver()
+{
+    return g_driver;
+}
+
+GEConfig* getGEConfig()
+{
+    return &g_config;
+}
+
+void deinit()
+{
+}
+
+}

lib/graphics_engine/src/ge_texture.cpp

@@ -0,0 +1,45 @@
+#include "ge_main.hpp"
+#include "ge_texture.hpp"
+
+#include <IVideoDriver.h>
+#include <IAttributes.h>
+
+namespace GE
+{
+using namespace irr;
+video::IImage* getResizedImage(const std::string& path)
+{
+    video::IImage* image = getDriver()->createImageFromFile(path.c_str());
+    if (image == NULL)
+        return NULL;
+
+    core::dimension2du img_size = image->getDimension();
+    bool has_npot = !getGEConfig()->m_disable_npot_texture &&
+        getDriver()->queryFeature(video::EVDF_TEXTURE_NPOT);
+
+    core::dimension2du tex_size = img_size.getOptimalSize(!has_npot);
+    const core::dimension2du& max_size = getDriver()->getDriverAttributes().
+        getAttributeAsDimension2d("MAX_TEXTURE_SIZE");
+
+    if (tex_size.Width > max_size.Width)
+        tex_size.Width = max_size.Width;
+    if (tex_size.Height > max_size.Height)
+        tex_size.Height = max_size.Height;
+
+    if (image->getColorFormat() != video::ECF_A8R8G8B8 ||
+        tex_size != img_size)
+    {
+        video::IImage* new_texture = getDriver()->createImage(
+            video::ECF_A8R8G8B8, tex_size);
+        if (tex_size != img_size)
+            image->copyToScaling(new_texture);
+        else
+            image->copyTo(new_texture);
+        image->drop();
+        return new_texture;
+    }
+
+    return image;
+}
+
+}