Example code for "OnRenderTextureGUI" blog post on AngryAnt.com

OnRenderTextureGUI.cs

void OnGUI ()
{
	BeginRenderTextureGUI (m_TargetTexture);

	GUILayout.Box ("This box goes on a render texture!");

	EndRenderTextureGUI ();
}


RenderTexture m_PreviousActiveTexture = null;


protected void BeginRenderTextureGUI (RenderTexture targetTexture)
{
	if (Event.current.type == EventType.Repaint)
	{
		m_PreviousActiveTexture = RenderTexture.active;
		if (targetTexture != null)
		{
			RenderTexture.active = targetTexture;
			GL.Clear (false, true, new Color (0.0f, 0.0f, 0.0f, 0.0f));
		}
	}
}


protected void EndRenderTextureGUI ()
{
	if (Event.current.type == EventType.Repaint)
	{
		RenderTexture.active = m_PreviousActiveTexture;
	}
}