Shadows are delayed by one frame

[Philip Taylor]

Shadows seem to be rendered on the screen one frame later than they should be: click on the minimap to jump somewhere (preferably while having a low framerate), and the screen is momentarily bright before all the shadows pop back in.

[Nicolai Hähnle]

(In [4330]) #Bugfix: Shadows appeared to be rendered one frame too late close #141

The problem was that the shadow matrices were setup in BeginFrame, but GraphicsView calls SetCamera after BeginFrame. The solution was to move the shadow matrix setup into CRenderer::SetCamera.

This caused a second problem because RenderReflections/RenderRefractions used SetCamera to change the OpenGL matrices. Solved this problem by distinguishing explicitly between the camera used for the scene as a whole and the camera used to configure OpenGL. The latter can be a virtual camera for shadow or reflection rendering and similar render-to-texture effects.