This document describes how efficient drawing of a 2D GUI can be achieved using
modern 3D graphics accelerator features


Textures

  Any bitmaps used for the GUI should be arranged onto a single large texture.
  The design can either request this as a precondition from the artist or use
  a rectangle packing algorithm.

  The special challenge in XNA is that often, text and dialogs are mixed.
  Remember that polygons have to be drawn in the right order, we can't just
  draw all geometry first and all texts afterwards

  Option 1: Rely entirely on the SpriteBatch for the drawing of the GUI and
            accept that a texture switch (= 2 additional draw calls) may be
            introduced each time a control renders text.

  Option 2: Completely discard the XNA text rendering system and use my own.
            Nuclex.Fonts is way faster and gives more control over font
            positioning (eg. an important feature is to be able to align text
            on its baseline, which ends up in guesswork with the SpriteFont
            class). However, Nuclex.Fonts would mean one more dependency.
            
            Update: The Nuclex Font Importer now uses the SpriteFont format,
            it is no longer possible to take advantage of the Nuclex.Fonts
            text rendering system for this purpose (though fonts imported with
            the Nuclex Font Importer are still centered on their baseline)

  For total freedom of choice, the complete rendering API used by controls has been
  moved into a neutral interface that enables you 
  Option 1

Visual Manager (or how it's called in the end)




Control
  GuiPainter
    DrawString(SpriteFont font, Vector2 location, string text);



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