quite ugly but it works ```cs var a = Vector4.Transform(new Vector4(mappedData.VertexPtr[0].

        var a = Vector4.Transform(new Vector4(mappedData.VertexPtr[0].Position, 0, 0), rotMat);
        var b = Vector4.Transform(new Vector4(mappedData.VertexPtr[1].Position, 0, 0), rotMat);
        var c = Vector4.Transform(new Vector4(mappedData.VertexPtr[2].Position, 0, 0), rotMat);
        var d = Vector4.Transform(new Vector4(mappedData.VertexPtr[3].Position, 0, 0), rotMat);
        
        mappedData.VertexPtr[0].Position = new Vector2(a.X, a.Y);
        mappedData.VertexPtr[1].Position = new Vector2(b.X, b.Y);
        mappedData.VertexPtr[2].Position = new Vector2(c.X, c.Y);
        mappedData.VertexPtr[3].Position = new Vector2(d.X, d.Y);