Dynamically drawing on a texture

How can I dynamically draw on texture(in code).

Like draw text on the texture, and then apply it to an object, and the text by what goes in game.

I don’t need solution like gui text or something like that, I need generic draw from code, that can also draw shapes(or at least set pixels) and not just text.

You already said it :-)

Texture2D.SetPixel or Texture2D.SetPixels for a block of pixels.

http://unity3d.com/support/documentation/ScriptReference/Texture2D.SetPixel.html