GL2.1 specific mipmap generation

include/ACGL/OpenGL/Objects/Texture.hh

@@ -306,13 +306,18 @@ public:
     {
         glBindTexture(mTarget, mContext);
 #if (!defined ACGL_OPENGL_PROFILE_CORE)
-        // on some windows systems Texturing has to be enabled to generate MipMaps
+        // on some ATI systems texturing has to be enabled to generate MipMaps
         // this is not needed by the spec an deprecated on core profiles (generates
         // an error on MacOS X Lion)
         glEnable(mTarget);
         openGLRareError();
 #endif
+#ifdef ACGL_OPENGL_VERSION_21
+        // OpenGL 2 way to generate MipMaps
+        glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
+#else
         glGenerateMipmap(mTarget);
+#endif
         openGLRareError();
     }