correct mipmap generation

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@5039 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CSoftwareTexture2.cpp

@@ -56,8 +56,8 @@ CSoftwareTexture2::CSoftwareTexture2(IImage* image, const io::path& name,
 
 		core::dimension2d<u32> optSize(
 				OriginalSize.getOptimalSize(0 != (Flags & NP2_SIZE),
-				false, false,
-				( Flags & NP2_SIZE ) ? SOFTWARE_DRIVER_2_TEXTURE_MAXSIZE : 0)
+				false, true,
+				SOFTWARE_DRIVER_2_TEXTURE_MAXSIZE)
 			);
 
 		if (OriginalSize == optSize)