Minor Improvements to Win32 GL Init (#568)

Author: BrentDaMage

source/renderer/platform/ogl/Extensions.cpp

@@ -4,7 +4,15 @@
 
 using namespace mce::Platform;
 
-const char* OGL::ERROR_MSG = "Error initializing GL extensions. OpenGL 1.5 or later is required. Update your graphics drivers!";
+#ifdef FEATURE_GFX_SHADERS
+#define MIN_GL_VERSION "2.0"
+#define ERROR_MSG_EXTRA " Try switching to a non-shader build, or update your graphics drivers!"
+#else
+#define MIN_GL_VERSION "1.5"
+#define ERROR_MSG_EXTRA " Update your graphics drivers!"
+#endif
+
+const char* OGL::ERROR_MSG = "Error initializing GL extensions. OpenGL " MIN_GL_VERSION " or later is required." ERROR_MSG_EXTRA;
 
 bool OGL::InitBindings()
 {
@@ -26,7 +34,7 @@ void* OGL::GetProcAddress(const char* name)
     result = (void*)wglGetProcAddress(name);
     if (result == nullptr)
     {
-        HMODULE handle = GetModuleHandle("opengl32.dll");
+        static HMODULE handle = GetModuleHandle("opengl32.dll");
         if (handle != NULL)
         {
             result = (void*)GetProcAddress(handle, name);