title: OpenGL how to create, and render to, a framebuffer that's larger than the window?
body: <p>I gather that I can create a Framebuffer with Renderbuffer and Texture attachments in whatever size I want (that's supported by the card). However, how can I actually draw to the whole thing when <code>glViewport</code> is limited by the <code>GL_MAX_VIEWPORT_DIMS</code>, which needs to be <em>at least</em> as large as the window, and in my case, is no larger. <a href="https://www.khronos.org/opengles/sdk/docs/man/xhtml/glGet.xml" rel="nofollow">https://www.khronos.org/opengles/sdk/docs/man/xhtml/glGet.xml</a></p>
  
  <p>In my use case I'm looking to create a shadow cubemap for a point light that's a nice big sexy size. My window is 1600x900. Due to some post-processing affects that render to quads, which are downsampled, I have previous calls to <code>glViewport</code> that's setting the size to various things. </p>
  
  <p>But I can't make it any larger than the window, so I can't ever draw to the outside areas of my Framebuffer?</p>
  
  <p>Or do games never exceed the size of the window when creating framebuffers?</p>