private static void DrawImageLayer(SpriteBatch spriteBatch, float z, Layer layer)
{
ImageLayer imageLayer = layer as ImageLayer;
Rectangle worldRect = new Rectangle((int)imageLayer.HorizontalOffset, (int)imageLayer.VerticalOffset, imageLayer.Width(), imageLayer.Height());
Rectangle screenRect = Camera.WorldToScreen(worldRect);
Rectangle sourceRect = new Rectangle(0, 0, imageLayer.Width(), imageLayer.Height());
spriteBatch.Draw(imageLayer.Image,
screenRect,
sourceRect,
Color.White, 0.0f,
Vector2.Zero,
SpriteEffects.None,
z);
}