A renderer draws a control when the Render(UIControl, UIRenderContext) method is called. Controls are usually rendered by copying images from a texture atlas to the screen - but different renderers can use different methods. The renderer has a SpriteBatch that is used to render the images. BeginBatch can be called to start a batch with the default settings of the renderer. BeginBatch is normally automatically called when a UIScreen is rendered and the batch is finished with EndBatch when the whole screen was rendered. This way all controls are rendered as a single batch. If a control must be rendered with different render states or a different sprite batch, EndBatch must be called to flush the current batch.

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