MonoGdx.Graphics.G2D.GdxSpriteBatch.GdxSpriteBatch C# (CSharp) Method

        public GdxSpriteBatch(GraphicsDevice graphicsDevice)
        {
            if (graphicsDevice == null)
                throw new ArgumentNullException("graphicsDevice");

            _device = graphicsDevice;

            _spriteEffect = new LocalSpriteEffect(graphicsDevice);
            _matrixTransform = _spriteEffect.Parameters["MatrixTransform"];
            _spritePass = _spriteEffect.CurrentTechnique.Passes[0];

            _transformMatrix = Matrix.Identity;
            //_projectionMatrix = Matrix.CreateOrthographicOffCenter(0, graphicsDevice.Viewport.Width, graphicsDevice.Viewport.Height, 0, 0, 1);
            _projectionMatrix = XnaExt.Matrix.CreateOrthographic2D(0, 0, graphicsDevice.Viewport.Width, graphicsDevice.Viewport.Height, -1, 0);

            Color = Color.White;

            CalculateIndexBuffer();

            _rasterizerScissorState = new RasterizerState() {
                CullMode = CullMode.None,
                ScissorTestEnable = true,
            };

            // projection uses CreateOrthographicOffCenter to create 2d projection
            // matrix with 0,0 in the upper left.
            /*_basicEffect.Projection = Matrix.CreateOrthographicOffCenter
                (0, graphicsDevice.Viewport.Width,
                graphicsDevice.Viewport.Height, 0,
                0, 1);
            this._basicEffect.World = Matrix.Identity;
            this._basicEffect.View = Matrix.CreateLookAt(Vector3.Zero, Vector3.Forward,
                Vector3.Up);*/
        }