/// <summary>
/// This is called when the game should draw itself.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Draw(GameTime gameTime)
{
tick += (float)gameTime.ElapsedGameTime.TotalSeconds;
graphics.GraphicsDevice.SetRenderTarget(0, mainSurface);
GraphicsDevice.Clear(Color.Black);
// componets draw here
//=================================
base.Draw(gameTime);
Texture2D shipTexture = spriteManager.GetSprite("ship0");
spriteBatch.Begin(SpriteBlendMode.AlphaBlend);
spriteBatch.Draw(shipTexture, new Rectangle(512, 100, 32, 32), Color.White);
spriteBatch.End();
graphics.GraphicsDevice.SetRenderTarget(0, null);
//=================================
// post drawing
postEffectManager.Draw(gameTime);
spriteBatch.Begin(SpriteBlendMode.None);
PostProcessManager.DrawScreenRect(spriteBatch, postEffectManager.OutPutTexture);
spriteBatch.End();
}